FFmpeg/configure

#!/bin/sh
#
# Libav configure script
#
# Copyright (c) 2000-2002 Fabrice Bellard
# Copyright (c) 2005-2008 Diego Biurrun
# Copyright (c) 2005-2008 Mans Rullgard
#

# Prevent locale nonsense from breaking basic text processing.
LC_ALL=C
export LC_ALL

# make sure we are running under a compatible shell
# try to make this part work with most shells

try_exec(){
    echo "Trying shell $1"
    type "$1" > /dev/null 2>&1 && exec "$@"
}

unset foo
(: ${foo%%bar}) 2> /dev/null
E1="$?"

(: ${foo?}) 2> /dev/null
E2="$?"

if test "$E1" != 0 || test "$E2" = 0; then
    echo "Broken shell detected.  Trying alternatives."
    export FF_CONF_EXEC
    if test "0$FF_CONF_EXEC" -lt 1; then
        FF_CONF_EXEC=1
        try_exec bash "$0" "$@"
    fi
    if test "0$FF_CONF_EXEC" -lt 2; then
        FF_CONF_EXEC=2
        try_exec ksh "$0" "$@"
    fi
    if test "0$FF_CONF_EXEC" -lt 3; then
        FF_CONF_EXEC=3
        try_exec /usr/xpg4/bin/sh "$0" "$@"
    fi
    echo "No compatible shell script interpreter found."
    echo "This configure script requires a POSIX-compatible shell"
    echo "such as bash or ksh."
    echo "THIS IS NOT A BUG IN LIBAV, DO NOT REPORT IT AS SUCH."
    echo "Instead, install a working POSIX-compatible shell."
    echo "Disabling this configure test will create a broken Libav."
    if test "$BASH_VERSION" = '2.04.0(1)-release'; then
        echo "This bash version ($BASH_VERSION) is broken on your platform."
        echo "Upgrade to a later version if available."
    fi
    exit 1
fi

test -d /usr/xpg4/bin && PATH=/usr/xpg4/bin:$PATH

show_help(){
    cat <<EOF
Usage: configure [options]
Options: [defaults in brackets after descriptions]

Help options:
  --help                   print this message
  --list-decoders          show all available decoders
  --list-encoders          show all available encoders
  --list-hwaccels          show all available hardware accelerators
  --list-demuxers          show all available demuxers
  --list-muxers            show all available muxers
  --list-parsers           show all available parsers
  --list-protocols         show all available protocols
  --list-bsfs              show all available bitstream filters
  --list-indevs            show all available input devices
  --list-outdevs           show all available output devices
  --list-filters           show all available filters

Standard options:
  --logfile=FILE           log tests and output to FILE [config.log]
  --disable-logging        do not log configure debug information
  --prefix=PREFIX          install in PREFIX [$prefix]
  --bindir=DIR             install binaries in DIR [PREFIX/bin]
  --datadir=DIR            install data files in DIR [PREFIX/share/avconv]
  --docdir=DIR             install documentation in DIR [PREFIX/share/doc/libav]
  --libdir=DIR             install libs in DIR [PREFIX/lib]
  --shlibdir=DIR           install shared libs in DIR [PREFIX/lib]
  --incdir=DIR             install includes in DIR [PREFIX/include]
  --mandir=DIR             install man page in DIR [PREFIX/share/man]

Licensing options:
  --enable-gpl             allow use of GPL code, the resulting libs
                           and binaries will be under GPL [no]
  --enable-version3        upgrade (L)GPL to version 3 [no]
  --enable-nonfree         allow use of nonfree code, the resulting libs
                           and binaries will be unredistributable [no]

Configuration options:
  --disable-static         do not build static libraries [no]
  --enable-shared          build shared libraries [no]
  --enable-small           optimize for size instead of speed
  --enable-runtime-cpudetect detect cpu capabilities at runtime (bigger binary)
  --enable-gray            enable full grayscale support (slower color)
  --disable-swscale-alpha  disable alpha channel support in swscale
  --disable-all            disable building components, libraries and programs

Program options:
  --disable-programs       do not build command line programs
  --disable-avconv         disable avconv build
  --disable-avplay         disable avplay build
  --disable-avprobe        disable avprobe build
  --disable-avserver       disable avserver build

Component options:
  --disable-doc            do not build documentation
  --disable-avdevice       disable libavdevice build
  --disable-avcodec        disable libavcodec build
  --disable-avformat       disable libavformat build
  --disable-avutil         disable libavutil build
  --disable-swscale        disable libswscale build
  --disable-avfilter       disable video filter support [no]
  --disable-avresample     disable libavresample build [no]
  --disable-pthreads       disable pthreads [auto]
  --disable-w32threads     disable Win32 threads [auto]
  --disable-network        disable network support [no]
  --disable-dct            disable DCT code
  --disable-error-resilience disable error resilience code
  --disable-lsp            disable LSP code
  --disable-lzo            disable LZO decoder code
  --disable-mdct           disable MDCT code
  --disable-rdft           disable RDFT code
  --disable-fft            disable FFT code

Hardware accelerators:
  --enable-dxva2           enable DXVA2 code
  --enable-vaapi           enable VAAPI code
  --enable-vda             enable VDA code
  --enable-vdpau           enable VDPAU code

Individual component options:
  --disable-everything     disable all components listed below
  --disable-encoder=NAME   disable encoder NAME
  --enable-encoder=NAME    enable encoder NAME
  --disable-encoders       disable all encoders
  --disable-decoder=NAME   disable decoder NAME
  --enable-decoder=NAME    enable decoder NAME
  --disable-decoders       disable all decoders
  --disable-hwaccel=NAME   disable hwaccel NAME
  --enable-hwaccel=NAME    enable hwaccel NAME
  --disable-hwaccels       disable all hwaccels
  --disable-muxer=NAME     disable muxer NAME
  --enable-muxer=NAME      enable muxer NAME
  --disable-muxers         disable all muxers
  --disable-demuxer=NAME   disable demuxer NAME
  --enable-demuxer=NAME    enable demuxer NAME
  --disable-demuxers       disable all demuxers
  --enable-parser=NAME     enable parser NAME
  --disable-parser=NAME    disable parser NAME
  --disable-parsers        disable all parsers
  --enable-bsf=NAME        enable bitstream filter NAME
  --disable-bsf=NAME       disable bitstream filter NAME
  --disable-bsfs           disable all bitstream filters
  --enable-protocol=NAME   enable protocol NAME
  --disable-protocol=NAME  disable protocol NAME
  --disable-protocols      disable all protocols
  --enable-indev=NAME      enable input device NAME
  --disable-indev=NAME     disable input device NAME
  --disable-indevs         disable input devices
  --enable-outdev=NAME     enable output device NAME
  --disable-outdev=NAME    disable output device NAME
  --disable-outdevs        disable output devices
  --disable-devices        disable all devices
  --enable-filter=NAME     enable filter NAME
  --disable-filter=NAME    disable filter NAME
  --disable-filters        disable all filters

External library support:
  --enable-avisynth        enable reading of AviSynth script files [no]
  --enable-bzlib           enable bzlib [autodetect]
  --enable-frei0r          enable frei0r video filtering
  --enable-gnutls          enable gnutls [no]
  --enable-libcdio         enable audio CD grabbing with libcdio
  --enable-libdc1394       enable IIDC-1394 grabbing using libdc1394
                           and libraw1394 [no]
  --enable-libfaac         enable AAC encoding via libfaac [no]
  --enable-libfdk-aac      enable AAC de/encoding via libfdk-aac [no]
  --enable-libfreetype     enable libfreetype [no]
  --enable-libgsm          enable GSM de/encoding via libgsm [no]
  --enable-libilbc         enable iLBC de/encoding via libilbc [no]
  --enable-libmp3lame      enable MP3 encoding via libmp3lame [no]
  --enable-libopencore-amrnb enable AMR-NB de/encoding via libopencore-amrnb [no]
  --enable-libopencore-amrwb enable AMR-WB decoding via libopencore-amrwb [no]
  --enable-libopencv       enable video filtering via libopencv [no]
  --enable-libopenjpeg     enable JPEG 2000 de/encoding via OpenJPEG [no]
  --enable-libopus         enable Opus decoding via libopus [no]
  --enable-libpulse        enable Pulseaudio input via libpulse [no]
  --enable-librtmp         enable RTMP[E] support via librtmp [no]
  --enable-libschroedinger enable Dirac de/encoding via libschroedinger [no]
  --enable-libspeex        enable Speex de/encoding via libspeex [no]
  --enable-libtheora       enable Theora encoding via libtheora [no]
  --enable-libvo-aacenc    enable AAC encoding via libvo-aacenc [no]
  --enable-libvo-amrwbenc  enable AMR-WB encoding via libvo-amrwbenc [no]
  --enable-libvorbis       enable Vorbis encoding via libvorbis [no]
  --enable-libvpx          enable VP8 and VP9 de/encoding via libvpx [no]
  --enable-libwavpack      enable wavpack encoding via libwavpack [no]
  --enable-libwebp         enable WebP encoding via libwebp [no]
  --enable-libx264         enable H.264 encoding via x264 [no]
  --enable-libx265         enable HEVC encoding via x265 [no]
  --enable-libxavs         enable AVS encoding via xavs [no]
  --enable-libxvid         enable Xvid encoding via xvidcore,
                           native MPEG-4/Xvid encoder exists [no]
  --enable-openssl         enable openssl [no]
  --enable-x11grab         enable X11 grabbing [no]
  --enable-zlib            enable zlib [autodetect]

Advanced options (experts only):
  --cross-prefix=PREFIX    use PREFIX for compilation tools [$cross_prefix]
  --enable-cross-compile   assume a cross-compiler is used
  --sysroot=PATH           root of cross-build tree
  --sysinclude=PATH        location of cross-build system headers
  --target-os=OS           compiler targets OS [$target_os]
  --target-exec=CMD        command to run executables on target
  --target-path=DIR        path to view of build directory on target
  --target-samples=DIR     path to samples directory on target
  --toolchain=NAME         set tool defaults according to NAME
  --pkg-config=PKGCONFIG   use pkg-config tool PKGCONFIG [$pkg_config_default]
  --nm=NM                  use nm tool
  --ar=AR                  use archive tool AR [$ar_default]
  --as=AS                  use assembler AS [$as_default]
  --cc=CC                  use C compiler CC [$cc_default]
  --dep-cc=DEPCC           use dependency generator DEPCC [$cc_default]
  --ld=LD                  use linker LD
  --host-cc=HOSTCC         use host C compiler HOSTCC
  --host-cflags=HCFLAGS    use HCFLAGS when compiling for host
  --host-cppflags=HCPPFLAGS use HCPPFLAGS when compiling for host
  --host-ld=HOSTLD         use host linker HOSTLD
  --host-ldflags=HLDFLAGS  use HLDFLAGS when linking for host
  --host-libs=HLIBS        use libs HLIBS when linking for host
  --host-os=OS             compiler host OS [$target_os]
  --extra-cflags=ECFLAGS   add ECFLAGS to CFLAGS [$CFLAGS]
  --extra-ldflags=ELDFLAGS add ELDFLAGS to LDFLAGS [$LDFLAGS]
  --extra-libs=ELIBS       add ELIBS [$ELIBS]
  --extra-version=STRING   version string suffix []
  --optflags=OPTFLAGS      override optimization-related compiler flags
  --build-suffix=SUFFIX    library name suffix []
  --malloc-prefix=PREFIX   prefix malloc and related names with PREFIX
  --arch=ARCH              select architecture [$arch]
  --cpu=CPU                select the minimum required CPU (affects
                           instruction selection, may crash on older CPUs)
  --enable-pic             build position-independent code
  --enable-sram            allow use of on-chip SRAM
  --enable-thumb           compile for Thumb instruction set
  --disable-symver         disable symbol versioning
  --enable-hardcoded-tables use hardcoded tables instead of runtime generation
  --disable-safe-bitstream-reader
                           disable buffer boundary checking in bitreaders
                           (faster, but may crash)
  --enable-memalign-hack   emulate memalign, interferes with memory debuggers
  --enable-lto             use link-time optimization

Optimization options (experts only):
  --disable-asm            disable all assembler optimizations
  --disable-altivec        disable AltiVec optimizations
  --disable-amd3dnow       disable 3DNow! optimizations
  --disable-amd3dnowext    disable 3DNow! extended optimizations
  --disable-mmx            disable MMX optimizations
  --disable-mmxext         disable MMXEXT optimizations
  --disable-sse            disable SSE optimizations
  --disable-sse2           disable SSE2 optimizations
  --disable-sse3           disable SSE3 optimizations
  --disable-ssse3          disable SSSE3 optimizations
  --disable-sse4           disable SSE4 optimizations
  --disable-sse42          disable SSE4.2 optimizations
  --disable-avx            disable AVX optimizations
  --disable-xop            disable XOP optimizations
  --disable-fma3           disable FMA3 optimizations
  --disable-fma4           disable FMA4 optimizations
  --disable-avx2           disable AVX2 optimizations
  --disable-armv5te        disable armv5te optimizations
  --disable-armv6          disable armv6 optimizations
  --disable-armv6t2        disable armv6t2 optimizations
  --disable-vfp            disable VFP optimizations
  --disable-neon           disable NEON optimizations
  --disable-vis            disable VIS optimizations
  --disable-inline-asm     disable use of inline assembler
  --disable-yasm           disable use of yasm assembler

Developer options (useful when working on Libav itself):
  --disable-debug          disable debugging symbols
  --enable-debug=LEVEL     set the debug level [$debuglevel]
  --disable-optimizations  disable compiler optimizations
  --enable-extra-warnings  enable more compiler warnings
  --samples=PATH           location of test samples for FATE, if not set use
                           \$LIBAV_SAMPLES at make invocation time.
  --enable-neon-clobber-test check NEON registers for clobbering (should be
                           used only for debugging purposes)
  --enable-xmm-clobber-test check XMM registers for clobbering (Win64-only;
                           should be used only for debugging purposes)
  --enable-random          randomly enable/disable components
  --disable-random
  --enable-random=LIST     randomly enable/disable specific components or
  --disable-random=LIST    component groups. LIST is a comma-separated list
                           of NAME[:PROB] entries where NAME is a component
                           (group) and PROB the probability associated with
                           NAME (default 0.5).
  --random-seed=VALUE      seed value for --enable/disable-random

NOTE: Object files are built at the place where configure is launched.
EOF
  exit 0
}

quotes='""'

log(){
    echo "$@" >> $logfile
}

log_file(){
    log BEGIN $1
    pr -n -t $1 >> $logfile
    log END $1
}

echolog(){
    log "$@"
    echo "$@"
}

warn(){
    log "WARNING: $*"
    WARNINGS="${WARNINGS}WARNING: $*\n"
}

die(){
    echolog "$@"
    cat <<EOF

If you think configure made a mistake, make sure you are using the latest
version from Git.  If the latest version fails, report the problem to the
libav-tools@libav.org mailing list or IRC #libav on irc.freenode.net.
EOF
    if disabled logging; then
        cat <<EOF
Rerun configure with logging enabled (do not use --disable-logging), and
include the log this produces with your report.
EOF
    else
        cat <<EOF
Include the log file "$logfile" produced by configure as this will help
solving the problem.
EOF
    fi
    exit 1
}

# Avoid locale weirdness, besides we really just want to translate ASCII.
toupper(){
    echo "$@" | tr abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ
}

tolower(){
    echo "$@" | tr ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz
}

c_escape(){
    echo "$*" | sed 's/["\\]/\\\0/g'
}

sh_quote(){
    v=$(echo "$1" | sed "s/'/'\\\\''/g")
    test "x$v" = "x${v#*[!A-Za-z0-9_/.+-]}" || v="'$v'"
    echo "$v"
}

cleanws(){
    echo "$@" | sed 's/^ *//;s/  */ /g;s/ *$//'
}

filter(){
    pat=$1
    shift
    for v; do
        eval "case $v in $pat) echo $v ;; esac"
    done
}

filter_out(){
    pat=$1
    shift
    for v; do
        eval "case $v in $pat) ;; *) echo $v ;; esac"
    done
}

map(){
    m=$1
    shift
    for v; do eval $m; done
}

add_suffix(){
    suffix=$1
    shift
    for v; do echo ${v}${suffix}; done
}

set_all(){
    value=$1
    shift
    for var in $*; do
        eval $var=$value
    done
}

set_weak(){
    value=$1
    shift
    for var; do
        eval : \${$var:=$value}
    done
}

sanitize_var_name(){
    echo $@ | sed 's/[^A-Za-z0-9_]/_/g'
}

set_safe(){
    var=$1
    shift
    eval $(sanitize_var_name "$var")='$*'
}

get_safe(){
    eval echo \$$(sanitize_var_name "$1")
}

pushvar(){
    for pvar in $*; do
        eval level=\${${pvar}_level:=0}
        eval ${pvar}_${level}="\$$pvar"
        eval ${pvar}_level=$(($level+1))
    done
}

popvar(){
    for pvar in $*; do
        eval level=\${${pvar}_level:-0}
        test $level = 0 && continue
        eval level=$(($level-1))
        eval $pvar="\${${pvar}_${level}}"
        eval ${pvar}_level=$level
        eval unset ${pvar}_${level}
    done
}

enable(){
    set_all yes $*
}

disable(){
    set_all no $*
}

enable_weak(){
    set_weak yes $*
}

disable_weak(){
    set_weak no $*
}

enable_safe(){
    for var; do
        enable $(echo "$var" | sed 's/[^A-Za-z0-9_]/_/g')
    done
}

disable_safe(){
    for var; do
        disable $(echo "$var" | sed 's/[^A-Za-z0-9_]/_/g')
    done
}

do_enable_deep(){
    for var; do
        enabled $var && continue
        eval sel="\$${var}_select"
        eval sgs="\$${var}_suggest"
        pushvar var sgs
        enable_deep $sel
        popvar sgs
        enable_deep_weak $sgs
        popvar var
    done
}

enable_deep(){
    do_enable_deep $*
    enable $*
}

enable_deep_weak(){
    for var; do
        disabled $var && continue
        pushvar var
        do_enable_deep $var
        popvar var
        enable_weak $var
    done
}

enabled(){
    test "${1#!}" = "$1" && op== || op=!=
    eval test "x\$${1#!}" $op "xyes"
}

disabled(){
    test "${1#!}" = "$1" && op== || op=!=
    eval test "x\$${1#!}" $op "xno"
}

enabled_all(){
    for opt; do
        enabled $opt || return 1
    done
}

disabled_all(){
    for opt; do
        disabled $opt || return 1
    done
}

enabled_any(){
    for opt; do
        enabled $opt && return 0
    done
}

disabled_any(){
    for opt; do
        disabled $opt && return 0
    done
    return 1
}

set_default(){
    for opt; do
        eval : \${$opt:=\$${opt}_default}
    done
}

is_in(){
    value=$1
    shift
    for var in $*; do
        [ $var = $value ] && return 0
    done
    return 1
}

do_check_deps(){
    for cfg; do
        cfg="${cfg#!}"
        enabled ${cfg}_checking && die "Circular dependency for $cfg."
        disabled ${cfg}_checking && continue
        enable ${cfg}_checking
        append allopts $cfg

        eval dep_all="\$${cfg}_deps"
        eval dep_any="\$${cfg}_deps_any"
        eval dep_sel="\$${cfg}_select"
        eval dep_sgs="\$${cfg}_suggest"
        eval dep_ifa="\$${cfg}_if"
        eval dep_ifn="\$${cfg}_if_any"

        pushvar cfg dep_all dep_any dep_sel dep_sgs dep_ifa dep_ifn
        do_check_deps $dep_all $dep_any $dep_sel $dep_sgs $dep_ifa $dep_ifn
        popvar cfg dep_all dep_any dep_sel dep_sgs dep_ifa dep_ifn

        [ -n "$dep_ifa" ] && { enabled_all $dep_ifa && enable_weak $cfg; }
        [ -n "$dep_ifn" ] && { enabled_any $dep_ifn && enable_weak $cfg; }
        enabled_all  $dep_all || disable $cfg
        enabled_any  $dep_any || disable $cfg
        disabled_any $dep_sel && disable $cfg

        if enabled $cfg; then
            enable_deep $dep_sel
            enable_deep_weak $dep_sgs
        fi

        disable ${cfg}_checking
    done
}

check_deps(){
    unset allopts

    do_check_deps "$@"

    for cfg in $allopts; do
        enabled $cfg || continue
        eval dep_extralibs="\$${cfg}_extralibs"
        test -n "$dep_extralibs" && add_extralibs $dep_extralibs
    done
}

print_config(){
    pfx=$1
    files=$2
    shift 2
    map 'eval echo "$v \${$v:-no}"' "$@" |
    awk "BEGIN { split(\"$files\", files) }
        {
            c = \"$pfx\" toupper(\$1);
            v = \$2;
            sub(/yes/, 1, v);
            sub(/no/,  0, v);
            for (f in files) {
                file = files[f];
                if (file ~ /\\.h\$/) {
                    printf(\"#define %s %d\\n\", c, v) >>file;
                } else if (file ~ /\\.asm\$/) {
                    printf(\"%%define %s %d\\n\", c, v) >>file;
                } else if (file ~ /\\.mak\$/) {
                    n = -v ? \"\" : \"!\";
                    printf(\"%s%s=yes\\n\", n, c) >>file;
                }
            }
        }"
}

print_enabled(){
    suf=$1
    shift
    for v; do
        enabled $v && printf "%s\n" ${v%$suf};
    done
}

append(){
    var=$1
    shift
    eval "$var=\"\$$var $*\""
}

prepend(){
    var=$1
    shift
    eval "$var=\"$* \$$var\""
}

add_cppflags(){
    append CPPFLAGS "$@"
}

add_cflags(){
    append CFLAGS $($cflags_filter "$@")
}

add_asflags(){
    append ASFLAGS $($asflags_filter "$@")
}

add_ldflags(){
    append LDFLAGS $($ldflags_filter "$@")
}

add_stripflags(){
    append STRIPFLAGS "$@"
}

add_extralibs(){
    prepend extralibs $($ldflags_filter "$@")
}

add_host_cppflags(){
    append host_cppflags "$@"
}

add_host_cflags(){
    append host_cflags $($host_cflags_filter "$@")
}

add_host_ldflags(){
    append host_ldflags $($host_ldflags_filter "$@")
}

add_compat(){
    append compat_objs $1
    shift
    map 'add_cppflags -D$v' "$@"
}

check_cmd(){
    log "$@"
    "$@" >> $logfile 2>&1
}

cc_o(){
    eval printf '%s\\n' $CC_O
}

cc_e(){
    eval printf '%s\\n' $CC_E
}

check_cc(){
    log check_cc "$@"
    cat > $TMPC
    log_file $TMPC
    check_cmd $cc $CPPFLAGS $CFLAGS "$@" $CC_C $(cc_o $TMPO) $TMPC
}

check_cpp(){
    log check_cpp "$@"
    cat > $TMPC
    log_file $TMPC
    check_cmd $cc $CPPFLAGS $CFLAGS "$@" $(cc_e $TMPO) $TMPC
}

as_o(){
    eval printf '%s\\n' $AS_O
}

check_as(){
    log check_as "$@"
    cat > $TMPS
    log_file $TMPS
    check_cmd $as $CPPFLAGS $ASFLAGS "$@" $AS_C $(as_o $TMPO) $TMPS
}

check_inline_asm(){
    log check_inline_asm "$@"
    name="$1"
    code="$2"
    shift 2
    disable $name
    check_cc "$@" <<EOF && enable $name
void foo(void){ __asm__ volatile($code); }
EOF
}

check_insn(){
    log check_insn "$@"
    check_inline_asm ${1}_inline "\"$2\""
    echo "$2" | check_as && enable ${1}_external || disable ${1}_external
}

check_yasm(){
    log check_yasm "$@"
    echo "$1" > $TMPS
    log_file $TMPS
    shift 1
    check_cmd $yasmexe $YASMFLAGS "$@" -o $TMPO $TMPS
}

ld_o(){
    eval printf '%s\\n' $LD_O
}

check_ld(){
    log check_ld "$@"
    flags=$(filter_out '-l*' "$@")
    libs=$(filter '-l*' "$@")
    check_cc $($cflags_filter $flags) || return
    flags=$($ldflags_filter $flags)
    libs=$($ldflags_filter $libs)
    check_cmd $ld $LDFLAGS $flags $(ld_o $TMPE) $TMPO $libs $extralibs
}

print_include(){
    hdr=$1
    test "${hdr%.h}" = "${hdr}" &&
        echo "#include $hdr"    ||
        echo "#include <$hdr>"
}

check_code(){
    log check_code "$@"
    check=$1
    headers=$2
    code=$3
    shift 3
    {
        for hdr in $headers; do
            print_include $hdr
        done
        echo "int main(void) { $code; return 0; }"
    } | check_$check "$@"
}

check_cppflags(){
    log check_cppflags "$@"
    check_cc "$@" <<EOF && append CPPFLAGS "$@"
int x;
EOF
}

test_cflags(){
    log test_cflags "$@"
    set -- $($cflags_filter "$@")
    check_cc "$@" <<EOF
int x;
EOF
}

check_cflags(){
    log check_cflags "$@"
    test_cflags "$@" && add_cflags "$@"
}

test_ldflags(){
    log test_ldflags "$@"
    check_ld "$@" <<EOF
int main(void){ return 0; }
EOF
}

check_ldflags(){
    log check_ldflags "$@"
    test_ldflags "$@" && add_ldflags "$@"
}

test_stripflags(){
    log test_stripflags "$@"
    # call check_cc to get a fresh TMPO
    check_cc <<EOF
int main(void) { return 0; }
EOF
    check_cmd $strip $STRIPFLAGS "$@" $TMPO
}

check_stripflags(){
    log check_stripflags "$@"
    test_stripflags "$@" && add_stripflags "$@"
}

check_header(){
    log check_header "$@"
    header=$1
    shift
    disable_safe $header
    check_cpp "$@" <<EOF && enable_safe $header
#include <$header>
int x;
EOF
}

check_func(){
    log check_func "$@"
    func=$1
    shift
    disable $func
    check_ld "$@" <<EOF && enable $func
extern int $func();
int main(void){ $func(); }
EOF
}

check_mathfunc(){
    log check_mathfunc "$@"
    func=$1
    narg=$2
    shift 2
    test $narg = 2 && args="f, g" || args="f"
    disable $func
    check_ld "$@" <<EOF && enable $func
#include <math.h>
float foo(float f, float g) { return $func($args); }
int main(void){ return 0; }
EOF
}

check_func_headers(){
    log check_func_headers "$@"
    headers=$1
    funcs=$2
    shift 2
    {
        for hdr in $headers; do
            print_include $hdr
        done
        for func in $funcs; do
            echo "long check_$func(void) { return (long) $func; }"
        done
        echo "int main(void) { return 0; }"
    } | check_ld "$@" && enable $funcs && enable_safe $headers
}

check_cpp_condition(){
    log check_cpp_condition "$@"
    header=$1
    condition=$2
    shift 2
    check_cpp "$@" <<EOF
#include <$header>
#if !($condition)
#error "unsatisfied condition: $condition"
#endif
EOF
}

check_lib(){
    log check_lib "$@"
    header="$1"
    func="$2"
    shift 2
    check_header $header && check_func $func "$@" && add_extralibs "$@"
}

check_lib2(){
    log check_lib2 "$@"
    headers="$1"
    funcs="$2"
    shift 2
    check_func_headers "$headers" "$funcs" "$@" && add_extralibs "$@"
}

check_pkg_config(){
    log check_pkg_config "$@"
    pkg="$1"
    headers="$2"
    funcs="$3"
    shift 3
    check_cmd $pkg_config --exists --print-errors $pkg || return
    pkg_cflags=$($pkg_config --cflags $pkg)
    pkg_libs=$($pkg_config --libs $pkg)
    check_func_headers "$headers" "$funcs" $pkg_cflags $pkg_libs "$@" &&
        set_safe ${pkg}_cflags $pkg_cflags   &&
        set_safe ${pkg}_libs   $pkg_libs
}

check_exec(){
    check_ld "$@" && { enabled cross_compile || $TMPE >> $logfile 2>&1; }
}

check_exec_crash(){
    code=$(cat)

    # exit() is not async signal safe.  _Exit (C99) and _exit (POSIX)
    # are safe but may not be available everywhere.  Thus we use
    # raise(SIGTERM) instead.  The check is run in a subshell so we
    # can redirect the "Terminated" message from the shell.  SIGBUS
    # is not defined by standard C so it is used conditionally.

    (check_exec "$@") >> $logfile 2>&1 <<EOF
#include <signal.h>
static void sighandler(int sig){
    raise(SIGTERM);
}
int foo(void){
    $code
}
int (*func_ptr)(void) = foo;
int main(void){
    signal(SIGILL, sighandler);
    signal(SIGFPE, sighandler);
    signal(SIGSEGV, sighandler);
#ifdef SIGBUS
    signal(SIGBUS, sighandler);
#endif
    return func_ptr();
}
EOF
}

check_type(){
    log check_type "$@"
    headers=$1
    type=$2
    shift 2
    disable_safe "$type"
    check_code cc "$headers" "$type v" "$@" && enable_safe "$type"
}

check_struct(){
    log check_struct "$@"
    headers=$1
    struct=$2
    member=$3
    shift 3
    disable_safe "${struct}_${member}"
    check_code cc "$headers" "const void *p = &(($struct *)0)->$member" "$@" &&
        enable_safe "${struct}_${member}"
}

check_builtin(){
    log check_builtin "$@"
    name=$1
    headers=$2
    builtin=$3
    shift 3
    disable "$name"
    check_code ld "$headers" "$builtin" "$@" && enable "$name"
}

check_compile_assert(){
    log check_compile_assert "$@"
    name=$1
    headers=$2
    condition=$3
    shift 3
    disable "$name"
    check_code cc "$headers" "char c[2 * !!($condition) - 1]" "$@" && enable "$name"
}

require(){
    name="$1"
    header="$2"
    func="$3"
    shift 3
    check_lib $header $func "$@" || die "ERROR: $name not found"
}

require2(){
    name="$1"
    headers="$2"
    func="$3"
    shift 3
    check_lib2 "$headers" $func "$@" || die "ERROR: $name not found"
}

require_pkg_config(){
    pkg="$1"
    check_pkg_config "$@" || die "ERROR: $pkg not found"
    add_cflags    $(get_safe ${pkg}_cflags)
    add_extralibs $(get_safe ${pkg}_libs)
}

hostcc_e(){
    eval printf '%s\\n' $HOSTCC_E
}

hostcc_o(){
    eval printf '%s\\n' $HOSTCC_O
}

check_host_cc(){
    log check_host_cc "$@"
    cat > $TMPC
    log_file $TMPC
    check_cmd $host_cc $host_cflags "$@" $HOSTCC_C $(hostcc_o $TMPO) $TMPC
}

check_host_cpp(){
    log check_host_cpp "$@"
    cat > $TMPC
    log_file $TMPC
    check_cmd $host_cc $HOSTCPPFLAGS $HOSTCFLAGS "$@" $(hostcc_e $TMPO) $TMPC
}

check_host_cppflags(){
    log check_host_cppflags "$@"
    check_host_cc "$@" <<EOF && append host_cppflags "$@"
int x;
EOF
}

check_host_cflags(){
    log check_host_cflags "$@"
    set -- $($host_cflags_filter "$@")
    check_host_cc "$@" <<EOF && append host_cflags "$@"
int x;
EOF
}

check_host_cpp_condition(){
    log check_host_cpp_condition "$@"
    header=$1
    condition=$2
    shift 2
    check_host_cpp "$@" <<EOF
#include <$header>
#if !($condition)
#error "unsatisfied condition: $condition"
#endif
EOF
}

apply(){
    file=$1
    shift
    "$@" < "$file" > "$file.tmp" && mv "$file.tmp" "$file" || rm "$file.tmp"
}

cp_if_changed(){
    cmp -s "$1" "$2" && echo "$2 is unchanged" && return
    mkdir -p "$(dirname $2)"
    $cp_f "$1" "$2"
}

# CONFIG_LIST contains configurable options, while HAVE_LIST is for
# system-dependent things.

COMPONENT_LIST="
    bsfs
    decoders
    demuxers
    encoders
    filters
    hwaccels
    indevs
    muxers
    outdevs
    parsers
    protocols
"

EXAMPLE_LIST="
    avcodec_example
    filter_audio_example
    metadata_example
    output_example
    transcode_aac_example
"

EXTERNAL_LIBRARY_LIST="
    avisynth
    bzlib
    frei0r
    gnutls
    libcdio
    libdc1394
    libfaac
    libfdk_aac
    libfreetype
    libgsm
    libilbc
    libmp3lame
    libopencore_amrnb
    libopencore_amrwb
    libopencv
    libopenjpeg
    libopus
    libpulse
    librtmp
    libschroedinger
    libspeex
    libtheora
    libvo_aacenc
    libvo_amrwbenc
    libvorbis
    libvpx
    libwavpack
    libwebp
    libx264
    libx265
    libxavs
    libxvid
    openssl
    x11grab
    zlib
"

HWACCEL_LIST="
    dxva2
    vaapi
    vda
    vdpau
"

LIBRARY_LIST="
    avcodec
    avdevice
    avfilter
    avformat
    avresample
    avutil
    swscale
"

PROGRAM_LIST="
    avconv
    avplay
    avprobe
    avserver
"

CONFIG_LIST="
    $COMPONENT_LIST
    $EXAMPLE_LIST
    $EXTERNAL_LIBRARY_LIST
    $HWACCEL_LIST
    $LIBRARY_LIST
    $PROGRAM_LIST
    dct
    doc
    error_resilience
    fft
    gpl
    gray
    hardcoded_tables
    lsp
    lzo
    mdct
    memalign_hack
    neon_clobber_test
    network
    nonfree
    pic
    pod2man
    rdft
    runtime_cpudetect
    safe_bitstream_reader
    shared
    small
    sram
    static
    swscale_alpha
    texi2html
    thumb
    version3
    xmm_clobber_test
"

THREADS_LIST="
    pthreads
    w32threads
"

ATOMICS_LIST="
    atomics_gcc
    atomics_suncc
    atomics_win32
"

ARCH_LIST="
    aarch64
    alpha
    arm
    avr32
    avr32_ap
    avr32_uc
    bfin
    ia64
    m68k
    mips
    mips64
    parisc
    ppc
    ppc64
    s390
    sh4
    sparc
    sparc64
    tilegx
    tilepro
    tomi
    x86
    x86_32
    x86_64
"

ARCH_EXT_LIST_ARM="
    armv5te
    armv6
    armv6t2
    neon
    vfp
    vfpv3
"

ARCH_EXT_LIST_X86_SIMD="
    amd3dnow
    amd3dnowext
    avx
    avx2
    fma3
    fma4
    mmx
    mmxext
    sse
    sse2
    sse3
    sse4
    sse42
    ssse3
    xop
"

ARCH_EXT_LIST_X86="
    $ARCH_EXT_LIST_X86_SIMD
    cpunop
    i686
"

ARCH_EXT_LIST="
    $ARCH_EXT_LIST_ARM
    $ARCH_EXT_LIST_X86
    altivec
    ppc4xx
    vis
"

HAVE_LIST_CMDLINE="
    inline_asm
    symver
    yasm
"

HAVE_LIST_PUB="
    bigendian
    fast_unaligned
"

MATH_FUNCS="
    atanf
    atan2f
    cbrtf
    cosf
    exp2
    exp2f
    expf
    isinf
    isnan
    ldexpf
    llrint
    llrintf
    log2
    log2f
    log10f
    lrint
    lrintf
    powf
    rint
    round
    roundf
    sinf
    trunc
    truncf
"

HAVE_LIST="
    $ARCH_EXT_LIST
    $(add_suffix _external $ARCH_EXT_LIST)
    $(add_suffix _inline   $ARCH_EXT_LIST)
    $ATOMICS_LIST
    $HAVE_LIST_CMDLINE
    $HAVE_LIST_PUB
    $MATH_FUNCS
    $THREADS_LIST
    aligned_malloc
    aligned_stack
    alsa_asoundlib_h
    altivec_h
    arpa_inet_h
    asm_mod_q
    atomic_cas_ptr
    atomics_native
    attribute_may_alias
    attribute_packed
    cdio_paranoia_h
    cdio_paranoia_paranoia_h
    closesocket
    CommandLineToArgvW
    CryptGenRandom
    dcbzl
    dev_bktr_ioctl_bt848_h
    dev_bktr_ioctl_meteor_h
    dev_ic_bt8xx_h
    dev_video_bktr_ioctl_bt848_h
    dev_video_meteor_ioctl_meteor_h
    direct_h
    dlfcn_h
    dlopen
    dos_paths
    dxva_h
    ebp_available
    ebx_available
    fast_64bit
    fast_clz
    fast_cmov
    fcntl
    flt_lim
    fork
    getaddrinfo
    gethrtime
    getopt
    GetProcessAffinityMask
    GetProcessMemoryInfo
    GetProcessTimes
    getrusage
    getservbyport
    GetSystemTimeAsFileTime
    gettimeofday
    gnu_as
    gsm_h
    ibm_asm
    inet_aton
    inline_asm_labels
    io_h
    isatty
    jack_port_get_latency_range
    ldbrx
    libc_msvcrt
    libdc1394_1
    libdc1394_2
    local_aligned_16
    local_aligned_8
    localtime_r
    loongson
    mach_absolute_time
    mach_mach_time_h
    machine_ioctl_bt848_h
    machine_ioctl_meteor_h
    machine_rw_barrier
    malloc_h
    MapViewOfFile
    memalign
    MemoryBarrier
    mkstemp
    mm_empty
    mmap
    mprotect
    nanosleep
    poll_h
    posix_memalign
    pragma_deprecated
    rdtsc
    sched_getaffinity
    sdl
    SetConsoleTextAttribute
    setmode
    setrlimit
    Sleep
    sndio_h
    socklen_t
    soundcard_h
    strerror_r
    strptime
    struct_addrinfo
    struct_group_source_req
    struct_ip_mreq_source
    struct_ipv6_mreq
    struct_pollfd
    struct_rusage_ru_maxrss
    struct_sockaddr_in6
    struct_sockaddr_sa_len
    struct_sockaddr_storage
    struct_v4l2_frmivalenum_discrete
    symver_asm_label
    symver_gnu_asm
    sync_val_compare_and_swap
    sys_mman_h
    sys_param_h
    sys_resource_h
    sys_select_h
    sys_soundcard_h
    sys_time_h
    sys_un_h
    sys_videoio_h
    sysconf
    sysctl
    threads
    unistd_h
    usleep
    vdpau_x11
    vfp_args
    VirtualAlloc
    windows_h
    winsock2_h
    xform_asm
    xlib
    xmm_clobbers
"

# options emitted with CONFIG_ prefix but not available on the command line
CONFIG_EXTRA="
    aandcttables
    ac3dsp
    audio_frame_queue
    dsputil
    gcrypt
    golomb
    gplv3
    h263dsp
    h264chroma
    h264dsp
    h264pred
    h264qpel
    hpeldsp
    huffman
    intrax8
    lgplv3
    lpc
    mpegaudio
    mpegaudiodsp
    mpegvideo
    mpegvideoenc
    nettle
    rangecoder
    riffdec
    riffenc
    rtpdec
    rtpenc_chain
    sinewin
    videodsp
    vp3dsp
"

CMDLINE_SELECT="
    $ARCH_EXT_LIST
    $CONFIG_LIST
    $HAVE_LIST_CMDLINE
    $THREADS_LIST
    asm
    cross_compile
    debug
    extra_warnings
    logging
    lto
    optimizations
"

PATHS_LIST="
    bindir
    datadir
    docdir
    incdir
    libdir
    mandir
    prefix
    shlibdir
"

CMDLINE_SET="
    $PATHS_LIST
    ar
    arch
    as
    build_suffix
    cc
    cpu
    cross_prefix
    dep_cc
    extra_version
    host_cc
    host_cflags
    host_ld
    host_ldflags
    host_libs
    host_os
    ld
    logfile
    malloc_prefix
    nm
    optflags
    pkg_config
    random_seed
    samples
    sysinclude
    sysroot
    target_exec
    target_os
    target_path
    target_samples
    toolchain
"

CMDLINE_APPEND="
    extra_cflags
    host_cppflags
"

# code dependency declarations

# architecture extensions

armv5te_deps="arm"
armv6_deps="arm"
armv6t2_deps="arm"
neon_deps_any="aarch64 arm"
vfp_deps_any="aarch64 arm"
vfpv3_deps="vfp"

map 'eval ${v}_inline_deps=inline_asm' $ARCH_EXT_LIST_ARM

altivec_deps="ppc"
ppc4xx_deps="ppc"

vis_deps="sparc"

cpunop_deps="i686"
x86_64_select="i686"
x86_64_suggest="fast_cmov"

amd3dnow_deps="mmx"
amd3dnowext_deps="amd3dnow"
i686_deps="x86"
mmx_deps="x86"
mmxext_deps="mmx"
sse_deps="mmxext"
sse2_deps="sse"
sse3_deps="sse2"
ssse3_deps="sse3"
sse4_deps="ssse3"
sse42_deps="sse4"
avx_deps="sse42"
xop_deps="avx"
fma3_deps="avx"
fma4_deps="avx"
avx2_deps="avx"

mmx_external_deps="yasm"
mmx_inline_deps="inline_asm"
mmx_suggest="mmx_external mmx_inline"

for ext in $(filter_out mmx $ARCH_EXT_LIST_X86_SIMD); do
    eval dep=\$${ext}_deps
    eval ${ext}_external_deps='"${dep}_external"'
    eval ${ext}_inline_deps='"${dep}_inline"'
    eval ${ext}_suggest='"${ext}_external ${ext}_inline"'
done

aligned_stack_if_any="aarch64 ppc x86"
fast_64bit_if_any="aarch64 alpha ia64 mips64 parisc64 ppc64 sparc64 x86_64"
fast_clz_if_any="aarch64 alpha avr32 mips ppc x86"
fast_unaligned_if_any="aarch64 ppc x86"

need_memalign="altivec neon sse"

# system capabilities
log2_deps="!libc_msvcrt"

symver_if_any="symver_asm_label symver_gnu_asm"

# threading support
atomics_gcc_if="sync_val_compare_and_swap"
atomics_suncc_if="atomic_cas_ptr machine_rw_barrier"
atomics_win32_if="MemoryBarrier"
atomics_native_if_any="$ATOMICS_LIST"
w32threads_deps="atomics_native"
threads_if_any="$THREADS_LIST"

# subsystems
dct_select="rdft"
error_resilience_select="dsputil"
lpc_select="dsputil"
mdct_select="fft"
rdft_select="fft"
mpegaudio_select="mpegaudiodsp"
mpegaudiodsp_select="dct"
mpegvideo_select="dsputil hpeldsp videodsp"
mpegvideoenc_select="mpegvideo"

# decoders / encoders
aac_decoder_select="mdct sinewin"
aac_encoder_select="audio_frame_queue mdct sinewin"
aac_latm_decoder_select="aac_decoder aac_latm_parser"
ac3_decoder_select="mdct ac3dsp ac3_parser dsputil"
ac3_encoder_select="mdct ac3dsp dsputil"
ac3_fixed_encoder_select="mdct ac3dsp dsputil"
aic_decoder_select="dsputil golomb"
alac_encoder_select="lpc"
als_decoder_select="dsputil"
amrnb_decoder_select="lsp"
amrwb_decoder_select="lsp"
amv_decoder_select="sp5x_decoder"
ape_decoder_select="dsputil"
asv1_decoder_select="dsputil"
asv1_encoder_select="dsputil"
asv2_decoder_select="dsputil"
asv2_encoder_select="dsputil"
atrac1_decoder_select="mdct sinewin"
atrac3_decoder_select="mdct"
atrac3p_decoder_select="mdct sinewin"
bink_decoder_select="dsputil hpeldsp"
binkaudio_dct_decoder_select="mdct rdft dct sinewin"
binkaudio_rdft_decoder_select="mdct rdft sinewin"
cavs_decoder_select="dsputil golomb h264chroma videodsp"
cllc_decoder_select="dsputil"
comfortnoise_encoder_select="lpc"
cook_decoder_select="dsputil mdct sinewin"
cscd_decoder_select="lzo"
cscd_decoder_suggest="zlib"
dca_decoder_select="mdct"
dnxhd_decoder_select="dsputil"
dnxhd_encoder_select="aandcttables dsputil mpegvideoenc"
dvvideo_decoder_select="dsputil"
dvvideo_encoder_select="dsputil"
dxa_decoder_deps="zlib"
eac3_decoder_select="ac3_decoder"
eac3_encoder_select="ac3_encoder"
eamad_decoder_select="aandcttables dsputil mpegvideo"
eatgq_decoder_select="aandcttables dsputil"
eatqi_decoder_select="aandcttables error_resilience mpegvideo"
ffv1_decoder_select="dsputil golomb rangecoder"
ffv1_encoder_select="dsputil rangecoder"
ffvhuff_decoder_select="huffyuv_decoder"
ffvhuff_encoder_select="huffyuv_encoder"
fic_decoder_select="dsputil golomb"
flac_decoder_select="golomb"
flac_encoder_select="dsputil golomb lpc"
flashsv_decoder_deps="zlib"
flashsv_encoder_deps="zlib"
flashsv2_decoder_deps="zlib"
flv_decoder_select="h263_decoder"
flv_encoder_select="h263_encoder"
fourxm_decoder_select="dsputil"
fraps_decoder_select="dsputil huffman"
g2m_decoder_deps="zlib"
g2m_decoder_select="dsputil"
h261_decoder_select="error_resilience mpegvideo"
h261_encoder_select="aandcttables mpegvideoenc"
h263_decoder_select="error_resilience h263_parser h263dsp mpegvideo"
h263_encoder_select="aandcttables h263dsp mpegvideoenc"
h263i_decoder_select="h263_decoder"
h263p_encoder_select="h263_encoder"
h264_decoder_select="golomb h264chroma h264dsp h264pred h264qpel videodsp"
h264_decoder_suggest="error_resilience"
hevc_decoder_select="dsputil golomb videodsp"
huffyuv_decoder_select="dsputil"
huffyuv_encoder_select="dsputil huffman"
iac_decoder_select="imc_decoder"
imc_decoder_select="dsputil fft mdct sinewin"
indeo3_decoder_select="hpeldsp"
interplay_video_decoder_select="hpeldsp"
jpegls_decoder_select="golomb mjpeg_decoder"
jpegls_encoder_select="golomb"
jv_decoder_select="dsputil"
lagarith_decoder_select="dsputil"
ljpeg_encoder_select="aandcttables mpegvideoenc"
loco_decoder_select="golomb"
mdec_decoder_select="dsputil error_resilience mpegvideo"
metasound_decoder_select="lsp mdct sinewin"
mimic_decoder_select="dsputil hpeldsp"
mjpeg_decoder_select="dsputil hpeldsp"
mjpeg_encoder_select="aandcttables dsputil mpegvideoenc"
mjpegb_decoder_select="mjpeg_decoder"
mlp_decoder_select="dsputil mlp_parser"
motionpixels_decoder_select="dsputil"
mp1_decoder_select="mpegaudio"
mp1float_decoder_select="mpegaudio"
mp2_decoder_select="mpegaudio"
mp2float_decoder_select="mpegaudio"
mp3_decoder_select="mpegaudio"
mp3adu_decoder_select="mpegaudio"
mp3adufloat_decoder_select="mpegaudio"
mp3float_decoder_select="mpegaudio"
mp3on4_decoder_select="mpegaudio"
mp3on4float_decoder_select="mpegaudio"
mpc7_decoder_select="dsputil mpegaudiodsp"
mpc8_decoder_select="dsputil mpegaudiodsp"
mpeg_xvmc_decoder_deps="X11_extensions_XvMClib_h"
mpeg_xvmc_decoder_select="mpeg2video_decoder"
mpeg1video_decoder_select="error_resilience mpegvideo"
mpeg1video_encoder_select="aandcttables mpegvideoenc"
mpeg2video_decoder_select="error_resilience mpegvideo"
mpeg2video_encoder_select="aandcttables mpegvideoenc"
mpeg4_decoder_select="h263_decoder mpeg4video_parser"
mpeg4_encoder_select="h263_encoder"
msmpeg4v1_decoder_select="h263_decoder"
msmpeg4v2_decoder_select="h263_decoder"
msmpeg4v2_encoder_select="h263_encoder"
msmpeg4v3_decoder_select="h263_decoder"
msmpeg4v3_encoder_select="h263_encoder"
mss2_decoder_select="error_resilience vc1_decoder"
mxpeg_decoder_select="mjpeg_decoder"
nellymoser_decoder_select="mdct sinewin"
nellymoser_encoder_select="audio_frame_queue mdct sinewin"
nuv_decoder_select="dsputil lzo"
png_decoder_deps="zlib"
png_decoder_select="dsputil"
png_encoder_deps="zlib"
png_encoder_select="dsputil"
prores_decoder_select="dsputil"
prores_encoder_select="dsputil"
qcelp_decoder_select="lsp"
qdm2_decoder_select="mdct rdft mpegaudiodsp"
ra_144_encoder_select="audio_frame_queue lpc"
ralf_decoder_select="golomb"
rv10_decoder_select="error_resilience h263_decoder h263dsp"
rv10_encoder_select="h263_encoder"
rv20_decoder_select="error_resilience h263_decoder h263dsp"
rv20_encoder_select="h263_encoder"
rv30_decoder_select="error_resilience golomb h264chroma h264pred h264qpel mpegvideo videodsp"
rv40_decoder_select="error_resilience golomb h264chroma h264pred h264qpel mpegvideo videodsp"
shorten_decoder_select="golomb"
sipr_decoder_select="lsp"
sp5x_decoder_select="mjpeg_decoder"
svq1_decoder_select="hpeldsp"
svq1_encoder_select="aandcttables dsputil hpeldsp mpegvideoenc"
svq3_decoder_select="h264_decoder hpeldsp mpegvideo"
svq3_decoder_suggest="zlib"
tak_decoder_select="dsputil"
theora_decoder_select="vp3_decoder"
thp_decoder_select="mjpeg_decoder"
tiff_decoder_suggest="zlib"
tiff_encoder_suggest="zlib"
truehd_decoder_select="mlp_decoder"
truemotion2_decoder_select="dsputil"
truespeech_decoder_select="dsputil"
tscc_decoder_deps="zlib"
twinvq_decoder_select="mdct lsp sinewin"
utvideo_decoder_select="dsputil"
utvideo_encoder_select="dsputil huffman"
vble_decoder_select="dsputil"
vc1_decoder_select="error_resilience h263_decoder h264chroma h264qpel intrax8"
vc1image_decoder_select="vc1_decoder"
vorbis_decoder_select="mdct"
vorbis_encoder_select="mdct"
vp3_decoder_select="hpeldsp vp3dsp videodsp"
vp5_decoder_select="h264chroma hpeldsp videodsp vp3dsp"
vp6_decoder_select="h264chroma hpeldsp huffman videodsp vp3dsp"
vp6a_decoder_select="vp6_decoder"
vp6f_decoder_select="vp6_decoder"
vp8_decoder_select="h264pred videodsp"
vp9_decoder_select="videodsp"
webp_decoder_select="vp8_decoder"
wmapro_decoder_select="mdct sinewin"
wmav1_decoder_select="mdct sinewin"
wmav1_encoder_select="mdct sinewin"
wmav2_decoder_select="mdct sinewin"
wmav2_encoder_select="mdct sinewin"
wmavoice_decoder_select="lsp rdft dct mdct sinewin"
wmv1_decoder_select="h263_decoder"
wmv1_encoder_select="h263_encoder"
wmv2_decoder_select="h263_decoder intrax8 videodsp"
wmv2_encoder_select="h263_encoder"
wmv3_decoder_select="vc1_decoder"
wmv3image_decoder_select="wmv3_decoder"
zerocodec_decoder_deps="zlib"
zlib_decoder_deps="zlib"
zlib_encoder_deps="zlib"
zmbv_decoder_deps="zlib"
zmbv_encoder_deps="zlib"

# hardware accelerators
dxva2_deps="dxva2api_h"
vaapi_deps="va_va_h"
vda_deps="VideoDecodeAcceleration_VDADecoder_h pthreads"
vda_extralibs="-framework CoreFoundation -framework VideoDecodeAcceleration -framework QuartzCore"
vdpau_deps="vdpau_vdpau_h vdpau_vdpau_x11_h"

h263_vaapi_hwaccel_deps="vaapi"
h263_vaapi_hwaccel_select="h263_decoder"
h263_vdpau_hwaccel_deps="vdpau"
h263_vdpau_hwaccel_select="h263_decoder"
h264_dxva2_hwaccel_deps="dxva2"
h264_dxva2_hwaccel_select="h264_decoder"
h264_vaapi_hwaccel_deps="vaapi"
h264_vaapi_hwaccel_select="h264_decoder"
h264_vda_hwaccel_deps="vda"
h264_vda_hwaccel_select="h264_decoder"
h264_vdpau_hwaccel_deps="vdpau"
h264_vdpau_hwaccel_select="h264_decoder"
mpeg1_vdpau_hwaccel_deps="vdpau"
mpeg1_vdpau_hwaccel_select="mpeg1video_decoder"
mpeg2_dxva2_hwaccel_deps="dxva2"
mpeg2_dxva2_hwaccel_select="mpeg2video_decoder"
mpeg2_vaapi_hwaccel_deps="vaapi"
mpeg2_vaapi_hwaccel_select="mpeg2video_decoder"
mpeg2_vdpau_hwaccel_deps="vdpau"
mpeg2_vdpau_hwaccel_select="mpeg2video_decoder"
mpeg4_vaapi_hwaccel_deps="vaapi"
mpeg4_vaapi_hwaccel_select="mpeg4_decoder"
mpeg4_vdpau_hwaccel_deps="vdpau"
mpeg4_vdpau_hwaccel_select="mpeg4_decoder"
vc1_dxva2_hwaccel_deps="dxva2"
vc1_dxva2_hwaccel_select="vc1_decoder"
vc1_vaapi_hwaccel_deps="vaapi"
vc1_vaapi_hwaccel_select="vc1_decoder"
vc1_vdpau_hwaccel_deps="vdpau"
vc1_vdpau_hwaccel_select="vc1_decoder"
wmv3_dxva2_hwaccel_select="vc1_dxva2_hwaccel"
wmv3_vaapi_hwaccel_select="vc1_vaapi_hwaccel"
wmv3_vdpau_hwaccel_select="vc1_vdpau_hwaccel"

# parsers
h264_parser_select="golomb h264chroma h264dsp h264pred h264qpel videodsp"
mpeg4video_parser_select="error_resilience h263dsp mpegvideo"
mpegvideo_parser_select="error_resilience mpegvideo"
vc1_parser_select="mpegvideo"

# external libraries
libfaac_encoder_deps="libfaac"
libfaac_encoder_select="audio_frame_queue"
libfdk_aac_decoder_deps="libfdk_aac"
libfdk_aac_encoder_deps="libfdk_aac"
libfdk_aac_encoder_select="audio_frame_queue"
libgsm_decoder_deps="libgsm"
libgsm_encoder_deps="libgsm"
libgsm_ms_decoder_deps="libgsm"
libgsm_ms_encoder_deps="libgsm"
libilbc_decoder_deps="libilbc"
libilbc_encoder_deps="libilbc"
libmp3lame_encoder_deps="libmp3lame"
libmp3lame_encoder_select="audio_frame_queue"
libopencore_amrnb_decoder_deps="libopencore_amrnb"
libopencore_amrnb_encoder_deps="libopencore_amrnb"
libopencore_amrnb_encoder_select="audio_frame_queue"
libopencore_amrwb_decoder_deps="libopencore_amrwb"
libopenjpeg_decoder_deps="libopenjpeg"
libopenjpeg_encoder_deps="libopenjpeg"
libopus_decoder_deps="libopus"
libopus_encoder_deps="libopus"
libopus_encoder_select="audio_frame_queue"
libschroedinger_decoder_deps="libschroedinger"
libschroedinger_encoder_deps="libschroedinger"
libspeex_decoder_deps="libspeex"
libspeex_encoder_deps="libspeex"
libspeex_encoder_select="audio_frame_queue"
libtheora_encoder_deps="libtheora"
libvo_aacenc_encoder_deps="libvo_aacenc"
libvo_aacenc_encoder_select="audio_frame_queue"
libvo_amrwbenc_encoder_deps="libvo_amrwbenc"
libvorbis_encoder_deps="libvorbis"
libvorbis_encoder_select="audio_frame_queue"
libvpx_vp8_decoder_deps="libvpx"
libvpx_vp8_encoder_deps="libvpx"
libvpx_vp9_decoder_deps="libvpx"
libvpx_vp9_encoder_deps="libvpx"
libwavpack_encoder_deps="libwavpack"
libwebp_encoder_deps="libwebp"
libx264_encoder_deps="libx264"
libx265_encoder_deps="libx265"
libxavs_encoder_deps="libxavs"
libxvid_encoder_deps="libxvid"

# demuxers / muxers
ac3_demuxer_select="ac3_parser"
asf_demuxer_select="riffdec"
asf_muxer_select="riffenc"
asf_stream_muxer_select="asf_muxer"
avi_demuxer_select="riffdec"
avi_muxer_select="riffenc"
avisynth_demuxer_deps="avisynth"
avisynth_demuxer_select="riffdec"
caf_demuxer_select="riffdec"
dirac_demuxer_select="dirac_parser"
dxa_demuxer_select="riffdec"
eac3_demuxer_select="ac3_parser"
f4v_muxer_select="mov_muxer"
flac_demuxer_select="flac_parser"
hds_muxer_select="flv_muxer"
hls_muxer_select="mpegts_muxer"
ipod_muxer_select="mov_muxer"
ismv_muxer_select="mov_muxer"
matroska_audio_muxer_select="matroska_muxer"
matroska_demuxer_select="riffdec"
matroska_demuxer_suggest="bzlib lzo zlib"
matroska_muxer_select="riffenc"
mmf_muxer_select="riffenc"
mov_demuxer_select="riffdec"
mov_demuxer_suggest="zlib"
mov_muxer_select="riffenc rtpenc_chain"
mp3_demuxer_select="mpegaudio_parser"
mp4_muxer_select="mov_muxer"
mpegts_muxer_select="adts_muxer latm_muxer"
mpegtsraw_demuxer_select="mpegts_demuxer"
mxf_d10_muxer_select="mxf_muxer"
nut_muxer_select="riffenc"
nuv_demuxer_select="riffdec"
ogg_demuxer_select="golomb"
psp_muxer_select="mov_muxer"
rtp_demuxer_select="sdp_demuxer"
rtpdec_select="asf_demuxer rm_demuxer rtp_protocol mpegts_demuxer mov_demuxer"
rtsp_demuxer_select="http_protocol rtpdec"
rtsp_muxer_select="rtp_muxer http_protocol rtp_protocol rtpenc_chain"
sap_demuxer_select="sdp_demuxer"
sap_muxer_select="rtp_muxer rtp_protocol rtpenc_chain"
sdp_demuxer_select="rtpdec"
smoothstreaming_muxer_select="ismv_muxer"
spdif_muxer_select="aac_parser"
tak_demuxer_select="tak_parser"
tg2_muxer_select="mov_muxer"
tgp_muxer_select="mov_muxer"
w64_demuxer_select="wav_demuxer"
wav_demuxer_select="riffdec"
wav_muxer_select="riffenc"
webm_muxer_select="riffenc"
wtv_demuxer_select="riffdec"
xmv_demuxer_select="riffdec"
xwma_demuxer_select="riffdec"

# indevs / outdevs
alsa_indev_deps="alsa_asoundlib_h snd_pcm_htimestamp"
alsa_outdev_deps="alsa_asoundlib_h"
bktr_indev_deps_any="dev_bktr_ioctl_bt848_h machine_ioctl_bt848_h dev_video_bktr_ioctl_bt848_h dev_ic_bt8xx_h"
dv1394_indev_deps="dv1394"
dv1394_indev_select="dv_demuxer"
fbdev_indev_deps="linux_fb_h"
jack_indev_deps="jack_jack_h pthreads"
libcdio_indev_deps="libcdio"
libdc1394_indev_deps="libdc1394"
oss_indev_deps_any="soundcard_h sys_soundcard_h"
oss_outdev_deps_any="soundcard_h sys_soundcard_h"
pulse_indev_deps="libpulse"
sndio_indev_deps="sndio_h"
sndio_outdev_deps="sndio_h"
v4l2_indev_deps_any="linux_videodev2_h sys_videoio_h"
vfwcap_indev_deps="capCreateCaptureWindow vfwcap_defines"
vfwcap_indev_extralibs="-lavicap32"
x11grab_indev_deps="x11grab XShmCreateImage"

# protocols
ffrtmpcrypt_protocol_deps="!librtmp_protocol"
ffrtmpcrypt_protocol_deps_any="gcrypt nettle openssl"
ffrtmpcrypt_protocol_select="tcp_protocol"
ffrtmphttp_protocol_deps="!librtmp_protocol"
ffrtmphttp_protocol_select="http_protocol"
gopher_protocol_select="network"
http_protocol_select="tcp_protocol"
httpproxy_protocol_select="tcp_protocol"
https_protocol_select="tls_protocol"
librtmp_protocol_deps="librtmp"
librtmpe_protocol_deps="librtmp"
librtmps_protocol_deps="librtmp"
librtmpt_protocol_deps="librtmp"
librtmpte_protocol_deps="librtmp"
mmsh_protocol_select="http_protocol"
mmst_protocol_select="network"
rtmp_protocol_deps="!librtmp_protocol"
rtmp_protocol_select="tcp_protocol"
rtmpe_protocol_select="ffrtmpcrypt_protocol"
rtmps_protocol_deps="!librtmp_protocol"
rtmps_protocol_select="tls_protocol"
rtmpt_protocol_select="ffrtmphttp_protocol"
rtmpte_protocol_select="ffrtmpcrypt_protocol ffrtmphttp_protocol"
rtmpts_protocol_select="ffrtmphttp_protocol https_protocol"
rtp_protocol_select="udp_protocol"
sctp_protocol_deps="struct_sctp_event_subscribe"
sctp_protocol_select="network"
srtp_protocol_select="rtp_protocol"
tcp_protocol_select="network"
tls_protocol_deps_any="openssl gnutls"
tls_protocol_select="tcp_protocol"
udp_protocol_select="network"
unix_protocol_deps="sys_un_h"
unix_protocol_select="network"

# filters
blackframe_filter_deps="gpl"
boxblur_filter_deps="gpl"
cropdetect_filter_deps="gpl"
delogo_filter_deps="gpl"
drawtext_filter_deps="libfreetype"
frei0r_filter_deps="frei0r dlopen"
frei0r_filter_extralibs='$ldl'
frei0r_src_filter_deps="frei0r dlopen"
frei0r_src_filter_extralibs='$ldl'
hqdn3d_filter_deps="gpl"
interlace_filter_deps="gpl"
ocv_filter_deps="libopencv"
resample_filter_deps="avresample"
scale_filter_deps="swscale"

# examples
avcodec_example_deps="avcodec avutil"
filter_audio_example_deps="avfilter avutil"
metadata_example_deps="avformat avutil"
output_example_deps="avcodec avformat avutil swscale"
transcode_aac_example_deps="avcodec avformat avresample"

# libraries
avcodec_deps="avutil"
avdevice_deps="avutil avcodec avformat"
avfilter_deps="avutil"
avformat_deps="avutil avcodec"
avresample_deps="avutil"
swscale_deps="avutil"

# programs
avconv_deps="avcodec avfilter avformat avresample swscale"
avconv_select="aformat_filter anull_filter asyncts_filter atrim_filter format_filter
               fps_filter null_filter resample_filter scale_filter
               setpts_filter trim_filter"
avplay_deps="avcodec avformat avresample swscale sdl"
avplay_libs='$sdl_libs'
avplay_select="rdft"
avprobe_deps="avcodec avformat"
avserver_deps="avformat fork !shared"
avserver_select="ffm_muxer rtp_protocol rtsp_demuxer"

# documentation
pod2man_deps="doc"
texi2html_deps="doc"

# default parameters

logfile="config.log"

# installation paths
prefix_default="/usr/local"
bindir_default='${prefix}/bin'
datadir_default='${prefix}/share/avconv'
docdir_default='${prefix}/share/doc/libav'
incdir_default='${prefix}/include'
libdir_default='${prefix}/lib'
mandir_default='${prefix}/share/man'
shlibdir_default="$libdir_default"

# toolchain
ar_default="ar"
cc_default="gcc"
host_cc_default="gcc"
cp_f="cp -f"
ln_s="ln -s -f"
nm_default="nm -g"
objformat="elf"
pkg_config_default=pkg-config
ranlib="ranlib"
strip="strip"
yasmexe="yasm"

nogas=":"

# machine
arch_default=$(uname -m)
cpu="generic"

# OS
target_os_default=$(tolower $(uname -s))
host_os=$target_os_default

# configurable options
enable $EXAMPLE_LIST $LIBRARY_LIST $PROGRAM_LIST

enable asm
enable debug
enable doc
enable optimizations
enable safe_bitstream_reader
enable static
enable swscale_alpha

# By default, enable only those hwaccels that have no external dependencies.
enable dxva2 vdpau

# build settings
SHFLAGS='-shared -Wl,-soname,$$(@F)'
LIBPREF="lib"
LIBSUF=".a"
FULLNAME='$(NAME)$(BUILDSUF)'
LIBNAME='$(LIBPREF)$(FULLNAME)$(LIBSUF)'
SLIBPREF="lib"
SLIBSUF=".so"
SLIBNAME='$(SLIBPREF)$(FULLNAME)$(SLIBSUF)'
SLIBNAME_WITH_VERSION='$(SLIBNAME).$(LIBVERSION)'
SLIBNAME_WITH_MAJOR='$(SLIBNAME).$(LIBMAJOR)'
LIB_INSTALL_EXTRA_CMD='$$(RANLIB) "$(LIBDIR)/$(LIBNAME)"'
SLIB_INSTALL_NAME='$(SLIBNAME_WITH_VERSION)'
SLIB_INSTALL_LINKS='$(SLIBNAME_WITH_MAJOR) $(SLIBNAME)'

asflags_filter=echo
cflags_filter=echo
ldflags_filter=echo

AS_C='-c'
AS_O='-o $@'
CC_C='-c'
CC_E='-E -o $@'
CC_O='-o $@'
LD_O='-o $@'
LD_LIB='-l%'
LD_PATH='-L'
HOSTCC_C='-c'
HOSTCC_E='-E -o $@'
HOSTCC_O='-o $@'
HOSTLD_O='-o $@'

host_libs='-lm'
host_cflags_filter=echo
host_ldflags_filter=echo

target_path='$(CURDIR)'

# since the object filename is not given with the -MM flag, the compiler
# is only able to print the basename, and we must add the path ourselves
DEPCMD='$(DEP$(1)) $(DEP$(1)FLAGS) $($(1)DEP_FLAGS) $< | sed -e "/^\#.*/d" -e "s,^[[:space:]]*$(*F)\\.o,$(@D)/$(*F).o," > $(@:.o=.d)'
DEPFLAGS='-MM'

# find source path
if test -f configure; then
    source_path=.
else
    source_path=$(cd $(dirname "$0"); pwd)
    echo "$source_path" | grep -q '[[:blank:]]' &&
        die "Out of tree builds are impossible with whitespace in source path."
    test -e "$source_path/config.h" &&
        die "Out of tree builds are impossible with config.h in source dir."
fi

for v in "$@"; do
    r=${v#*=}
    l=${v%"$r"}
    r=$(sh_quote "$r")
    LIBAV_CONFIGURATION="${LIBAV_CONFIGURATION# } ${l}${r}"
done

find_things(){
    thing=$1
    pattern=$2
    file=$source_path/$3
    sed -n "s/^[^#]*$pattern.*([^,]*, *\([^,]*\)\(,.*\)*).*/\1_$thing/p" "$file"
}

ENCODER_LIST=$(find_things  encoder  ENC      libavcodec/allcodecs.c)
DECODER_LIST=$(find_things  decoder  DEC      libavcodec/allcodecs.c)
HWACCEL_LIST=$(find_things  hwaccel  HWACCEL  libavcodec/allcodecs.c)
PARSER_LIST=$(find_things   parser   PARSER   libavcodec/allcodecs.c)
BSF_LIST=$(find_things      bsf      BSF      libavcodec/allcodecs.c)
MUXER_LIST=$(find_things    muxer    _MUX     libavformat/allformats.c)
DEMUXER_LIST=$(find_things  demuxer  DEMUX    libavformat/allformats.c)
OUTDEV_LIST=$(find_things   outdev   OUTDEV   libavdevice/alldevices.c)
INDEV_LIST=$(find_things    indev    _IN      libavdevice/alldevices.c)
PROTOCOL_LIST=$(find_things protocol PROTOCOL libavformat/allformats.c)
FILTER_LIST=$(find_things   filter   FILTER   libavfilter/allfilters.c)

ALL_COMPONENTS="
    $BSF_LIST
    $DECODER_LIST
    $DEMUXER_LIST
    $ENCODER_LIST
    $FILTER_LIST
    $HWACCEL_LIST
    $INDEV_LIST
    $MUXER_LIST
    $OUTDEV_LIST
    $PARSER_LIST
    $PROTOCOL_LIST
"

for n in $COMPONENT_LIST; do
    v=$(toupper ${n%s})_LIST
    eval enable \$$v
    eval ${n}_if_any="\$$v"
done

enable $ARCH_EXT_LIST

die_unknown(){
    echo "Unknown option \"$1\"."
    echo "See $0 --help for available options."
    exit 1
}

print_3_columns() {
    cat | tr ' ' '\n' | sort | pr -r -3 -t
}

show_list() {
    suffix=_$1
    shift
    echo $* | sed s/$suffix//g | print_3_columns
    exit 0
}

rand_list(){
    IFS=', '
    set -- $*
    unset IFS
    for thing; do
        comp=${thing%:*}
        prob=${thing#$comp}
        prob=${prob#:}
        is_in ${comp} $COMPONENT_LIST && eval comp=\$$(toupper ${comp%s})_LIST
        echo "prob ${prob:-0.5}"
        printf '%s\n' $comp
    done
}

do_random(){
    action=$1
    shift
    random_seed=$(awk "BEGIN { srand($random_seed); print srand() }")
    $action $(rand_list "$@" | awk "BEGIN { srand($random_seed) } \$1 == \"prob\" { prob = \$2; next } rand() < prob { print }")
}

for opt do
    optval="${opt#*=}"
    case "$opt" in
        --extra-ldflags=*)
            add_ldflags $optval
        ;;
        --extra-libs=*)
            add_extralibs $optval
        ;;
        --disable-devices)
            disable $INDEV_LIST $OUTDEV_LIST
        ;;
        --enable-debug=*)
            debuglevel="$optval"
        ;;
        --disable-programs)
            disable $PROGRAM_LIST
        ;;
        --disable-everything)
            map 'eval unset \${$(toupper ${v%s})_LIST}' $COMPONENT_LIST
        ;;
        --disable-all)
            map 'eval unset \${$(toupper ${v%s})_LIST}' $COMPONENT_LIST
            disable $LIBRARY_LIST $PROGRAM_LIST doc
        ;;
        --enable-random|--disable-random)
            action=${opt%%-random}
            do_random ${action#--} $COMPONENT_LIST
        ;;
        --enable-random=*|--disable-random=*)
            action=${opt%%-random=*}
            do_random ${action#--} $optval
        ;;
        --enable-*=*|--disable-*=*)
            eval $(echo "${opt%%=*}" | sed 's/--/action=/;s/-/ thing=/')
            is_in "${thing}s" $COMPONENT_LIST || die_unknown "$opt"
            eval list=\$$(toupper $thing)_LIST
            name=$(echo "${optval}" | sed "s/,/_${thing}|/g")_${thing}
            $action $(filter "$name" $list)
        ;;
        --enable-?*|--disable-?*)
            eval $(echo "$opt" | sed 's/--/action=/;s/-/ option=/;s/-/_/g')
            if is_in $option $COMPONENT_LIST; then
                test $action = disable && action=unset
                eval $action \$$(toupper ${option%s})_LIST
            elif is_in $option $CMDLINE_SELECT; then
                $action $option
            else
                die_unknown $opt
            fi
        ;;
        --list-*)
            NAME="${opt#--list-}"
            is_in $NAME $COMPONENT_LIST || die_unknown $opt
            NAME=${NAME%s}
            eval show_list $NAME \$$(toupper $NAME)_LIST
        ;;
        --help|-h) show_help
        ;;
        *)
            optname="${opt%%=*}"
            optname="${optname#--}"
            optname=$(echo "$optname" | sed 's/-/_/g')
            if is_in $optname $CMDLINE_SET; then
                eval $optname='$optval'
            elif is_in $optname $CMDLINE_APPEND; then
                append $optname "$optval"
            else
                die_unknown $opt
            fi
        ;;
    esac
done

disabled logging && logfile=/dev/null

echo "# $0 $LIBAV_CONFIGURATION" > $logfile
set >> $logfile

test -n "$cross_prefix" && enable cross_compile

if enabled cross_compile; then
    test -n "$arch" && test -n "$target_os" ||
        die "Must specify target arch and OS when cross-compiling"
fi

ar_default="${cross_prefix}${ar_default}"
cc_default="${cross_prefix}${cc_default}"
nm_default="${cross_prefix}${nm_default}"
pkg_config_default="${cross_prefix}${pkg_config_default}"
ranlib="${cross_prefix}${ranlib}"
strip="${cross_prefix}${strip}"

sysinclude_default="${sysroot}/usr/include"

case "$toolchain" in
    clang-asan)
        cc_default="clang"
        add_cflags  -fsanitize=address
        add_ldflags -fsanitize=address
    ;;
    clang-tsan)
        cc_default="clang"
        add_cflags  -fsanitize=thread -pie
        add_ldflags -fsanitize=thread -pie
    ;;
    clang-usan)
        cc_default="clang"
        add_cflags  -fsanitize=undefined
        add_ldflags -fsanitize=undefined
    ;;
    gcc-asan)
        cc_default="gcc"
        add_cflags  -fsanitize=address
        add_ldflags -fsanitize=address
    ;;
    gcc-tsan)
        cc_default="gcc"
        add_cflags  -fsanitize=thread -pie -fPIC
        add_ldflags -fsanitize=thread -pie -fPIC
    ;;
    gcc-usan)
        cc_default="gcc"
        add_cflags  -fsanitize=undefined
        add_ldflags -fsanitize=undefined
    ;;
    valgrind-massif)
        target_exec_default="valgrind"
        target_exec_args="--alloc-fn=av_malloc --alloc-fn=av_mallocz"
    ;;
    valgrind-memcheck)
        target_exec_default="valgrind"
        target_exec_args="--track-origins=yes --leak-check=full"
    ;;
    msvc)
        # Check whether the current MSVC version needs the C99 converter.
        # From MSVC 2013 (compiler major version 18) onwards, it does actually
        # support enough of C99 to build libav. Default to the new
        # behaviour if the regexp was unable to match anything, since this
        # successfully parses the version number of existing supported
        # versions that require the converter (MSVC 2010 and 2012).
        cl_major_ver=$(cl 2>&1 | sed -n 's/.*Version \([[:digit:]]\{1,\}\)\..*/\1/p')
        if [ -z "$cl_major_ver" ] || [ $cl_major_ver -ge 18 ]; then
            cc_default="cl"
        else
            cc_default="c99wrap cl"
        fi
        ld_default="link"
        nm_default="dumpbin -symbols"
        ar_default="lib"
        target_os_default="win32"
        # Use a relative path for TMPDIR. This makes sure all the
        # ffconf temp files are written with a relative path, avoiding
        # issues with msys/win32 path conversion for MSVC parameters
        # such as -Fo<file> or -out:<file>.
        TMPDIR=.
    ;;
    icl)
        cc_default="icl"
        ld_default="xilink"
        nm_default="dumpbin -symbols"
        ar_default="xilib"
        target_os_default="win32"
        TMPDIR=.
    ;;
    gcov)
        add_cflags  -fprofile-arcs -ftest-coverage
        add_ldflags -fprofile-arcs -ftest-coverage
    ;;
    hardened)
        add_cflags  -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -fno-strict-overflow -fstack-protector-all
        add_ldflags -Wl,-z,relro -Wl,-z,now
    ;;
    ?*)
        die "Unknown toolchain $toolchain"
    ;;
esac

set_default arch cc pkg_config sysinclude target_exec target_os
enabled cross_compile || host_cc_default=$cc
set_default host_cc

if ! $pkg_config --version >/dev/null 2>&1; then
    warn "$pkg_config not found, library detection may fail."
    pkg_config=false
fi

exesuf() {
    case $1 in
        mingw32*|win32|win64|cygwin*|*-dos|freedos|opendos|os/2*|symbian) echo .exe ;;
    esac
}

EXESUF=$(exesuf $target_os)
HOSTEXESUF=$(exesuf $host_os)

# set temporary file name
: ${TMPDIR:=$TEMPDIR}
: ${TMPDIR:=$TMP}
: ${TMPDIR:=/tmp}

if ! check_cmd mktemp -u XXXXXX; then
    # simple replacement for missing mktemp
    # NOT SAFE FOR GENERAL USE
    mktemp(){
        echo "${2%%XXX*}.${HOSTNAME}.${UID}.$$"
    }
fi

tmpfile(){
    tmp=$(mktemp -u "${TMPDIR}/ffconf.XXXXXXXX")$2 &&
        (set -C; exec > $tmp) 2>/dev/null ||
        die "Unable to create temporary file in $TMPDIR."
    append TMPFILES $tmp
    eval $1=$tmp
}

trap 'rm -f -- $TMPFILES' EXIT

tmpfile TMPASM .asm
tmpfile TMPC   .c
tmpfile TMPE   $EXESUF
tmpfile TMPH   .h
tmpfile TMPO   .o
tmpfile TMPS   .S
tmpfile TMPSH  .sh
tmpfile TMPV   .ver

unset -f mktemp

chmod +x $TMPE

# make sure we can execute files in $TMPDIR
cat > $TMPSH 2>> $logfile <<EOF
#! /bin/sh
EOF
chmod +x $TMPSH >> $logfile 2>&1
if ! $TMPSH >> $logfile 2>&1; then
    cat <<EOF
Unable to create and execute files in $TMPDIR.  Set the TMPDIR environment
variable to another directory and make sure that it is not mounted noexec.
EOF
    die "Sanity test failed."
fi

ccc_flags(){
    for flag; do
        case $flag in
            -std=c99)           echo -c99                       ;;
            -mcpu=*)            echo -arch ${flag#*=}           ;;
            -mieee)             echo -ieee                      ;;
            -O*|-fast)          echo $flag                      ;;
            -fno-math-errno)    echo -assume nomath_errno       ;;
            -g)                 echo -g3                        ;;
            -Wall)              echo -msg_enable level2         ;;
            -Wno-pointer-sign)  echo -msg_disable ptrmismatch1  ;;
            -Wl,*)              echo $flag                      ;;
            -f*|-W*)                                            ;;
            *)                  echo $flag                      ;;
        esac
   done
}

cparser_flags(){
    for flag; do
        case $flag in
            -Wno-switch)             echo -Wno-switch-enum ;;
            -Wno-format-zero-length) ;;
            -Wdisabled-optimization) ;;
            -Wno-pointer-sign)       echo -Wno-other ;;
            *)                       echo $flag ;;
        esac
    done
}

msvc_common_flags(){
    for flag; do
        case $flag in
            # In addition to specifying certain flags under the compiler
            # specific filters, they must be specified here as well or else the
            # generic catch all at the bottom will print the original flag.
            -Wall)                ;;
            -std=c99)             ;;
            # Common flags
            -fomit-frame-pointer) ;;
            -g)                   echo -Z7 ;;
            -fno-math-errno)      ;;
            -fno-common)          ;;
            -fno-signed-zeros)    ;;
            -fPIC)                ;;
            -mthumb)              ;;
            -march=*)             ;;
            -lz)                  echo zlib.lib ;;
            -lavifil32)           echo vfw32.lib ;;
            -lavicap32)           echo vfw32.lib user32.lib ;;
            -l*)                  echo ${flag#-l}.lib ;;
            *)                    echo $flag ;;
        esac
    done
}

msvc_flags(){
    msvc_common_flags "$@"
    for flag; do
        case $flag in
            -Wall)                echo -W4 -wd4244 -wd4127 -wd4018 -wd4389     \
                                       -wd4146 -wd4057 -wd4204 -wd4706 -wd4305 \
                                       -wd4152 -wd4324 -we4013 -wd4100 -wd4214 \
                                       -wd4273 ;;
        esac
    done
}

icl_flags(){
    msvc_common_flags "$@"
    for flag; do
        case $flag in
            # Despite what Intel's documentation says -Wall, which is supported
            # on Windows, does enable remarks so disable them here.
            -Wall)                echo $flag -Qdiag-disable:remark ;;
            -std=c99)             echo -Qstd=c99 ;;
        esac
    done
}

pgi_flags(){
    for flag; do
        case $flag in
            -flto)                echo -Mipa=fast,libopt,libinline,vestigial ;;
            -fomit-frame-pointer) echo -Mnoframe ;;
            -g)                   echo -gopt ;;
            *)                    echo $flag ;;
        esac
    done
}

suncc_flags(){
    for flag; do
        case $flag in
            -march=*|-mcpu=*)
                case "${flag#*=}" in
                    native)                   echo -xtarget=native       ;;
                    v9|niagara)               echo -xarch=sparc          ;;
                    ultrasparc)               echo -xarch=sparcvis       ;;
                    ultrasparc3|niagara2)     echo -xarch=sparcvis2      ;;
                    i586|pentium)             echo -xchip=pentium        ;;
                    i686|pentiumpro|pentium2) echo -xtarget=pentium_pro  ;;
                    pentium3*|c3-2)           echo -xtarget=pentium3     ;;
                    pentium-m)          echo -xarch=sse2 -xchip=pentium3 ;;
                    pentium4*)          echo -xtarget=pentium4           ;;
                    prescott|nocona)    echo -xarch=sse3 -xchip=pentium4 ;;
                    *-sse3)             echo -xarch=sse3                 ;;
                    core2)              echo -xarch=ssse3 -xchip=core2   ;;
                    corei7)           echo -xarch=sse4_2 -xchip=nehalem  ;;
                    corei7-avx)       echo -xarch=avx -xchip=sandybridge ;;
                    amdfam10|barcelona|bdver*) echo -xarch=sse4_1        ;;
                    athlon-4|athlon-[mx]p)     echo -xarch=ssea          ;;
                    k8|opteron|athlon64|athlon-fx)
                                               echo -xarch=sse2a         ;;
                    athlon*)                   echo -xarch=pentium_proa  ;;
                esac
                ;;
            -std=c99)             echo -xc99              ;;
            -fomit-frame-pointer) echo -xregs=frameptr    ;;
            -fPIC)                echo -KPIC -xcode=pic32 ;;
            -W*,*)                echo $flag              ;;
            -f*-*|-W*|-mimpure-text)                      ;;
            -shared)              echo -G                 ;;
            *)                    echo $flag              ;;
        esac
    done
}

tms470_flags(){
    for flag; do
        case $flag in
            -march=*|-mcpu=*)
                case "${flag#*=}" in
                    armv7-a|cortex-a*)      echo -mv=7a8 ;;
                    armv7-r|cortex-r*)      echo -mv=7r4 ;;
                    armv7-m|cortex-m*)      echo -mv=7m3 ;;
                    armv6*|arm11*)          echo -mv=6   ;;
                    armv5*e|arm[79]*e*|arm9[24]6*|arm96*|arm102[26])
                                            echo -mv=5e  ;;
                    armv4*|arm7*|arm9[24]*) echo -mv=4   ;;
                esac
                ;;
            -mfpu=neon)     echo --float_support=vfpv3 --neon ;;
            -mfpu=vfp)      echo --float_support=vfpv2        ;;
            -mfpu=vfpv3)    echo --float_support=vfpv3        ;;
            -mfpu=vfpv3-d16) echo --float_support=vfpv3d16    ;;
            -msoft-float)   echo --float_support=vfplib       ;;
            -O[0-3]|-mf=*)  echo $flag                        ;;
            -g)             echo -g -mn                       ;;
            -pds=*)         echo $flag                        ;;
            -D*|-I*)        echo $flag                        ;;
            --gcc|--abi=*)  echo $flag                        ;;
            -me)            echo $flag                        ;;
        esac
    done
}

probe_cc(){
    pfx=$1
    _cc=$2

    unset _type _ident _cc_c _cc_e _cc_o _flags _cflags
    unset _ld_o _ldflags _ld_lib _ld_path
    unset _depflags _DEPCMD _DEPFLAGS
    _flags_filter=echo

    if $_cc -v 2>&1 | grep -q '^gcc.*LLVM'; then
        _type=llvm_gcc
        gcc_extra_ver=$(expr "$($_cc --version | head -n1)" : '.*\((.*)\)')
        _ident="llvm-gcc $($_cc -dumpversion) $gcc_extra_ver"
        _depflags='-MMD -MF $(@:.o=.d) -MT $@'
        _cflags_speed='-O3'
        _cflags_size='-Os'
    elif $_cc -v 2>&1 | grep -qi ^gcc; then
        _type=gcc
        gcc_version=$($_cc --version | head -n1)
        gcc_basever=$($_cc -dumpversion)
        gcc_pkg_ver=$(expr "$gcc_version" : '[^ ]* \(([^)]*)\)')
        gcc_ext_ver=$(expr "$gcc_version" : ".*$gcc_pkg_ver $gcc_basever \\(.*\\)")
        _ident=$(cleanws "gcc $gcc_basever $gcc_pkg_ver $gcc_ext_ver")
        if ! $_cc -dumpversion | grep -q '^2\.'; then
            _depflags='-MMD -MF $(@:.o=.d) -MT $@'
        fi
        _cflags_speed='-O3'
        _cflags_size='-Os'
    elif $_cc --version 2>/dev/null | grep -q ^icc; then
        _type=icc
        _ident=$($_cc --version | head -n1)
        _depflags='-MMD'
        _cflags_speed='-O3'
        _cflags_size='-Os'
        _cflags_noopt='-O1'
    elif $_cc -v 2>&1 | grep -q xlc; then
        _type=xlc
        _ident=$($_cc -qversion 2>/dev/null | head -n1)
        _cflags_speed='-O5'
        _cflags_size='-O5 -qcompact'
    elif $_cc -V 2>/dev/null | grep -q Compaq; then
        _type=ccc
        _ident=$($_cc -V | head -n1 | cut -d' ' -f1-3)
        _DEPFLAGS='-M'
        _cflags_speed='-fast'
        _cflags_size='-O1'
        _flags_filter=ccc_flags
    elif $_cc --vsn 2>/dev/null | grep -q "ARM C/C++ Compiler"; then
        test -d "$sysroot" || die "No valid sysroot specified."
        _type=armcc
        _ident=$($_cc --vsn | head -n1)
        armcc_conf="$PWD/armcc.conf"
        $_cc --arm_linux_configure                 \
             --arm_linux_config_file="$armcc_conf" \
             --configure_sysroot="$sysroot"        \
             --configure_cpp_headers="$sysinclude" >>$logfile 2>&1 ||
             die "Error creating armcc configuration file."
        $_cc --vsn | grep -q RVCT && armcc_opt=rvct || armcc_opt=armcc
        _flags="--arm_linux_config_file=$armcc_conf --translate_gcc"
        as_default="${cross_prefix}gcc"
        _depflags='-MMD'
        _cflags_speed='-O3'
        _cflags_size='-Os'
    elif $_cc -version 2>/dev/null | grep -Eq 'TMS470|TI ARM'; then
        _type=tms470
        _ident=$($_cc -version | head -n1 | tr -s ' ')
        _flags='--gcc --abi=eabi -me'
        _cc_e='-ppl -fe=$@'
        _cc_o='-fe=$@'
        _depflags='-ppa -ppd=$(@:.o=.d)'
        _cflags_speed='-O3 -mf=5'
        _cflags_size='-O3 -mf=2'
        _flags_filter=tms470_flags
    elif $_cc -v 2>&1 | grep -q clang; then
        _type=clang
        _ident=$($_cc --version | head -n1)
        _depflags='-MMD -MF $(@:.o=.d) -MT $@'
        _cflags_speed='-O3'
        _cflags_size='-Os'
    elif $_cc -V 2>&1 | grep -q Sun; then
        _type=suncc
        _ident=$($_cc -V 2>&1 | head -n1 | cut -d' ' -f 2-)
        _DEPCMD='$(DEP$(1)) $(DEP$(1)FLAGS) $($(1)DEP_FLAGS) $< | sed -e "1s,^.*: ,$@: ," -e "\$$!s,\$$, \\\," -e "1!s,^.*: , ," > $(@:.o=.d)'
        _DEPFLAGS='-xM1 -xc99'
        _ldflags='-std=c99'
        _cflags_speed='-O5'
        _cflags_size='-O5 -xspace'
        _flags_filter=suncc_flags
    elif $_cc -v 2>&1 | grep -q 'PathScale\|Path64'; then
        _type=pathscale
        _ident=$($_cc -v 2>&1 | head -n1 | tr -d :)
        _depflags='-MMD -MF $(@:.o=.d) -MT $@'
        _cflags_speed='-O2'
        _cflags_size='-Os'
        _flags_filter='filter_out -Wdisabled-optimization'
    elif $_cc -v 2>&1 | grep -q Open64; then
        _type=open64
        _ident=$($_cc -v 2>&1 | head -n1 | tr -d :)
        _depflags='-MMD -MF $(@:.o=.d) -MT $@'
        _cflags_speed='-O2'
        _cflags_size='-Os'
        _flags_filter='filter_out -Wdisabled-optimization|-Wtype-limits|-fno-signed-zeros'
    elif $_cc -V 2>&1 | grep -q Portland; then
        _type=pgi
        _ident="PGI $($_cc -V 2>&1 | awk '/^pgcc/ { print $2; exit }')"
        opt_common='-alias=ansi -Mdse -Mlre -Mpre'
        _cflags_speed="-O3 -Mautoinline -Munroll=c:4 $opt_common"
        _cflags_size="-O2 -Munroll=c:1 $opt_common"
        _cflags_noopt="-O1"
        _flags_filter=pgi_flags
    elif $_cc 2>&1 | grep -q Microsoft; then
        _type=msvc
        _ident=$($cc 2>&1 | head -n1)
        _DEPCMD='$(DEP$(1)) $(DEP$(1)FLAGS) $($(1)DEP_FLAGS) $< 2>&1 | awk '\''/including/ { sub(/^.*file: */, ""); gsub(/\\/, "/"); if (!match($$0, / /)) print "$@:", $$0 }'\'' > $(@:.o=.d)'
        _DEPFLAGS='$(CPPFLAGS) $(CFLAGS) -showIncludes -Zs'
        _cflags_speed="-O2"
        _cflags_size="-O1"
        if $_cc 2>&1 | grep -q Linker; then
            _ld_o='-out:$@'
        else
            _ld_o='-Fe$@'
        fi
        _cc_o='-Fo$@'
        _cc_e='-P -Fi$@'
        _flags_filter=msvc_flags
        _ld_lib='lib%.a'
        _ld_path='-libpath:'
        _flags='-nologo'
        _cflags='-D_USE_MATH_DEFINES -D_CRT_SECURE_NO_WARNINGS -Dinline=__inline -FIstdlib.h -Dstrtoll=_strtoi64'
        if [ $pfx = hostcc ]; then
            append _cflags -Dsnprintf=_snprintf
        fi
    elif $_cc 2>&1 | grep -q Intel; then
        _type=icl
        _ident=$($cc 2>&1 | head -n1)
        _depflags='-QMMD -QMF$(@:.o=.d) -QMT$@'
        # Not only is O3 broken on 13.x+ but it is slower on all previous
        # versions (tested) as well.
        _cflags_speed="-O2"
        _cflags_size="-O1 -Oi" # -O1 without -Oi miscompiles stuff
        if $_cc 2>&1 | grep -q Linker; then
            _ld_o='-out:$@'
        else
            _ld_o='-Fe$@'
        fi
        _cc_o='-Fo$@'
        _cc_e='-P'
        _flags_filter=icl_flags
        _ld_lib='lib%.a'
        _ld_path='-libpath:'
        # -Qdiag-error to make icl error when seeing certain unknown arguments
        _flags='-nologo -Qdiag-error:4044,10157'
        # -Qvec- -Qsimd- to prevent miscompilation, -GS for consistency
        # with MSVC which enables it by default.
        _cflags='-D_USE_MATH_DEFINES -FIstdlib.h -Dstrtoll=_strtoi64 -Qms0 -Qvec- -Qsimd- -GS'
        if [ $pfx = hostcc ]; then
            append _cflags -Dsnprintf=_snprintf
        fi
    elif $_cc --version 2>/dev/null | grep -q ^cparser; then
        _type=cparser
        _ident=$($_cc --version | head -n1)
        _depflags='-MMD'
        _cflags_speed='-O4'
        _cflags_size='-O2'
        _flags_filter=cparser_flags
    fi

    eval ${pfx}_type=\$_type
    eval ${pfx}_ident=\$_ident
}

set_ccvars(){
    eval ${1}_C=\${_cc_c-\${${1}_C}}
    eval ${1}_E=\${_cc_e-\${${1}_E}}
    eval ${1}_O=\${_cc_o-\${${1}_O}}

    if [ -n "$_depflags" ]; then
        eval ${1}_DEPFLAGS=\$_depflags
    else
        eval ${1}DEP=\${_DEPCMD:-\$DEPCMD}
        eval ${1}DEP_FLAGS=\${_DEPFLAGS:-\$DEPFLAGS}
        eval DEP${1}FLAGS=\$_flags
    fi
}

probe_cc cc "$cc"
cflags_filter=$_flags_filter
cflags_speed=$_cflags_speed
cflags_size=$_cflags_size
cflags_noopt=$_cflags_noopt
add_cflags $_flags $_cflags
cc_ldflags=$_ldflags
set_ccvars CC

probe_cc hostcc "$host_cc"
host_cflags_filter=$_flags_filter
add_host_cflags  $_flags $_cflags
set_ccvars HOSTCC

test -n "$cc_type" && enable $cc_type ||
    warn "Unknown C compiler $cc, unable to select optimal CFLAGS"

: ${as_default:=$cc}
: ${dep_cc_default:=$cc}
: ${ld_default:=$cc}
: ${host_ld_default:=$host_cc}
set_default ar as dep_cc ld host_ld

probe_cc as "$as"
asflags_filter=$_flags_filter
add_asflags $_flags $_cflags
set_ccvars AS

probe_cc ld "$ld"
ldflags_filter=$_flags_filter
add_ldflags $_flags $_ldflags
test "$cc_type" != "$ld_type" && add_ldflags $cc_ldflags
LD_O=${_ld_o-$LD_O}
LD_LIB=${_ld_lib-$LD_LIB}
LD_PATH=${_ld_path-$LD_PATH}

probe_cc hostld "$host_ld"
host_ldflags_filter=$_flags_filter
add_host_ldflags $_flags $_ldflags
HOSTLD_O=${_ld_o-$HOSTLD_O}

if [ -z "$CC_DEPFLAGS" ] && [ "$dep_cc" != "$cc" ]; then
    probe_cc depcc "$dep_cc"
    CCDEP=${_DEPCMD:-$DEPCMD}
    CCDEP_FLAGS=${_DEPFLAGS:=$DEPFLAGS}
    DEPCCFLAGS=$_flags
fi

if $ar 2>&1 | grep -q Microsoft; then
    arflags="-nologo"
    ar_o='-out:$@'
elif $ar 2>&1 | grep -q 'Texas Instruments'; then
    arflags="rq"
    ar_o='$@'
elif $ar 2>&1 | grep -q 'Usage: ar.*-X.*any'; then
    arflags='-Xany -r -c'
    ar_o='$@'
else
    arflags="rc"
    ar_o='$@'
fi

add_cflags $extra_cflags
add_asflags $extra_cflags

if test -n "$sysroot"; then
    case "$cc_type" in
        gcc|llvm_gcc|clang)
            add_cppflags --sysroot="$sysroot"
            add_ldflags --sysroot="$sysroot"
        ;;
        tms470)
            add_cppflags -I"$sysinclude"
            add_ldflags  --sysroot="$sysroot"
        ;;
    esac
fi

if test "$cpu" = host; then
    enabled cross_compile &&
        die "--cpu=host makes no sense when cross-compiling."

    case "$cc_type" in
        gcc|llvm_gcc)
            check_native(){
                $cc $1=native -v -c -o $TMPO $TMPC >$TMPE 2>&1 || return
                sed -n "/cc1.*$1=/{
                            s/.*$1=\\([^ ]*\\).*/\\1/
                            p
                            q
                        }" $TMPE
            }
            cpu=$(check_native -march || check_native -mcpu)
        ;;
    esac

    test "${cpu:-host}" = host &&
        die "--cpu=host not supported with compiler $cc"
fi

# Deal with common $arch aliases
case "$arch" in
    aarch64|arm64)
        arch="aarch64"
    ;;
    arm*)
        arch="arm"
    ;;
    mips*|IP*)
        arch="mips"
    ;;
    parisc*|hppa*)
        arch="parisc"
    ;;
    "Power Macintosh"|ppc*|powerpc*)
        arch="ppc"
    ;;
    s390|s390x)
        arch="s390"
    ;;
    sh4|sh)
        arch="sh4"
    ;;
    sun4u|sparc*)
        arch="sparc"
    ;;
    tilegx|tile-gx)
        arch="tilegx"
    ;;
    i[3-6]86|i86pc|BePC|x86pc|x86_64|amd64)
        arch="x86"
    ;;
esac

is_in $arch $ARCH_LIST || warn "unknown architecture $arch"
enable $arch

# Add processor-specific flags
if enabled aarch64; then

    case $cpu in
        armv*)
            cpuflags="-march=$cpu"
        ;;
        *)
            cpuflags="-mcpu=$cpu"
        ;;
    esac

elif enabled alpha; then

    cpuflags="-mcpu=$cpu"

elif enabled arm; then

    check_arm_arch() {
        check_cpp_condition stddef.h \
            "defined __ARM_ARCH_${1}__ || defined __TARGET_ARCH_${2:-$1}" \
            $cpuflags
    }

    probe_arm_arch() {
        if   check_arm_arch 4;        then echo armv4;
        elif check_arm_arch 4T;       then echo armv4t;
        elif check_arm_arch 5;        then echo armv5;
        elif check_arm_arch 5E;       then echo armv5e;
        elif check_arm_arch 5T;       then echo armv5t;
        elif check_arm_arch 5TE;      then echo armv5te;
        elif check_arm_arch 5TEJ;     then echo armv5te;
        elif check_arm_arch 6;        then echo armv6;
        elif check_arm_arch 6J;       then echo armv6j;
        elif check_arm_arch 6K;       then echo armv6k;
        elif check_arm_arch 6Z;       then echo armv6z;
        elif check_arm_arch 6ZK;      then echo armv6zk;
        elif check_arm_arch 6T2;      then echo armv6t2;
        elif check_arm_arch 7;        then echo armv7;
        elif check_arm_arch 7A  7_A;  then echo armv7-a;
        elif check_arm_arch 7R  7_R;  then echo armv7-r;
        elif check_arm_arch 7M  7_M;  then echo armv7-m;
        elif check_arm_arch 7EM 7E_M; then echo armv7-m;
        elif check_arm_arch 8A  8_A;  then echo armv8-a;
        fi
    }

    [ "$cpu" = generic ] && cpu=$(probe_arm_arch)

    case $cpu in
        armv*)
            cpuflags="-march=$cpu"
            subarch=$(echo $cpu | sed 's/[^a-z0-9]//g')
        ;;
        *)
            cpuflags="-mcpu=$cpu"
            case $cpu in
                cortex-a*)                               subarch=armv7a  ;;
                cortex-r*)                               subarch=armv7r  ;;
                cortex-m*)                 enable thumb; subarch=armv7m  ;;
                arm11*)                                  subarch=armv6   ;;
                arm[79]*e*|arm9[24]6*|arm96*|arm102[26]) subarch=armv5te ;;
                armv4*|arm7*|arm9[24]*)                  subarch=armv4   ;;
                *)                             subarch=$(probe_arm_arch) ;;
            esac
        ;;
    esac

    case "$subarch" in
        armv5t*)    enable fast_clz                ;;
        armv[6-8]*) enable fast_clz fast_unaligned ;;
    esac

elif enabled avr32; then

    case $cpu in
        ap7[02]0[0-2])
            subarch="avr32_ap"
            cpuflags="-mpart=$cpu"
        ;;
        ap)
            subarch="avr32_ap"
            cpuflags="-march=$cpu"
        ;;
        uc3[ab]*)
            subarch="avr32_uc"
            cpuflags="-mcpu=$cpu"
        ;;
        uc)
            subarch="avr32_uc"
            cpuflags="-march=$cpu"
        ;;
    esac

elif enabled bfin; then

    cpuflags="-mcpu=$cpu"

elif enabled mips; then

    cpuflags="-march=$cpu"

elif enabled ppc; then

    case $(tolower $cpu) in
        601|ppc601|powerpc601)
            cpuflags="-mcpu=601"
            disable altivec
        ;;
        603*|ppc603*|powerpc603*)
            cpuflags="-mcpu=603"
            disable altivec
        ;;
        604*|ppc604*|powerpc604*)
            cpuflags="-mcpu=604"
            disable altivec
        ;;
        g3|75*|ppc75*|powerpc75*)
            cpuflags="-mcpu=750"
            disable altivec
        ;;
        g4|745*|ppc745*|powerpc745*)
            cpuflags="-mcpu=7450"
        ;;
        74*|ppc74*|powerpc74*)
            cpuflags="-mcpu=7400"
        ;;
        g5|970|ppc970|powerpc970)
            cpuflags="-mcpu=970"
        ;;
        power[3-7]*)
            cpuflags="-mcpu=$cpu"
        ;;
        cell)
            cpuflags="-mcpu=cell"
            enable ldbrx
        ;;
        e500mc)
            cpuflags="-mcpu=e500mc"
            disable altivec
        ;;
        e500v2)
            cpuflags="-mcpu=8548 -mhard-float -mfloat-gprs=double"
            disable altivec
        ;;
        e500)
            cpuflags="-mcpu=8540 -mhard-float"
            disable altivec
        ;;
    esac

elif enabled sparc; then

    case $cpu in
        cypress|f93[04]|tsc701|sparcl*|supersparc|hypersparc|niagara|v[789])
            cpuflags="-mcpu=$cpu"
            disable vis
        ;;
        ultrasparc*|niagara[234])
            cpuflags="-mcpu=$cpu"
        ;;
    esac

elif enabled x86; then

    case $cpu in
        i[345]86|pentium)
            cpuflags="-march=$cpu"
            disable mmx
        ;;
        # targets that do NOT support nopl and conditional mov (cmov)
        pentium-mmx|k6|k6-[23]|winchip-c6|winchip2|c3)
            cpuflags="-march=$cpu"
            disable i686
        ;;
        # targets that do support nopl and conditional mov (cmov)
        i686|pentiumpro|pentium[23]|pentium-m|athlon|athlon-tbird|athlon-4|athlon-[mx]p|athlon64*|k8*|opteron*|athlon-fx|core2|corei7*|amdfam10|barcelona|atom|bdver*)
            cpuflags="-march=$cpu"
            enable i686
            enable fast_cmov
        ;;
        # targets that do support conditional mov but on which it's slow
        pentium4|pentium4m|prescott|nocona)
            cpuflags="-march=$cpu"
            enable i686
            disable fast_cmov
        ;;
    esac

fi

if [ "$cpu" != generic ]; then
    add_cflags  $cpuflags
    add_asflags $cpuflags
fi

# compiler sanity check
check_exec <<EOF
int main(void){ return 0; }
EOF
if test "$?" != 0; then
    echo "$cc is unable to create an executable file."
    if test -z "$cross_prefix" && ! enabled cross_compile ; then
        echo "If $cc is a cross-compiler, use the --enable-cross-compile option."
        echo "Only do this if you know what cross compiling means."
    fi
    die "C compiler test failed."
fi

add_cppflags -D_ISOC99_SOURCE
check_cflags -std=c99
check_cc -D_FILE_OFFSET_BITS=64 <<EOF && add_cppflags -D_FILE_OFFSET_BITS=64
#include <stdlib.h>
EOF
check_cc -D_LARGEFILE_SOURCE <<EOF && add_cppflags -D_LARGEFILE_SOURCE
#include <stdlib.h>
EOF

add_host_cppflags -D_ISOC99_SOURCE
check_host_cflags -std=c99
check_host_cflags -Wall
check_host_cflags -O3

check_64bit(){
    arch32=$1
    arch64=$2
    expr=$3
    check_code cc "" "int test[2*($expr) - 1]" &&
        subarch=$arch64 || subarch=$arch32
}

case "$arch" in
    aarch64|alpha|ia64)
        spic=$shared
    ;;
    mips)
        check_64bit mips mips64 '_MIPS_SIM > 1'
        spic=$shared
    ;;
    parisc)
        check_64bit parisc parisc64 'sizeof(void *) > 4'
        spic=$shared
    ;;
    ppc)
        check_64bit ppc ppc64 'sizeof(void *) > 4'
        spic=$shared
    ;;
    s390)
        check_64bit s390 s390x 'sizeof(void *) > 4'
        spic=$shared
    ;;
    sparc)
        check_64bit sparc sparc64 'sizeof(void *) > 4'
        spic=$shared
    ;;
    x86)
        check_64bit x86_32 x86_64 'sizeof(void *) > 4'
        if test "$subarch" = "x86_64"; then
            spic=$shared
        fi
    ;;
esac

enable $subarch
enabled spic && enable_weak pic

# OS specific
case $target_os in
    aix)
        SHFLAGS=-shared
        add_cppflags '-I\$(SRC_PATH)/compat/aix'
        enabled shared && add_ldflags -Wl,-brtl
        ;;
    haiku)
        prefix_default="/boot/common"
        network_extralibs="-lnetwork"
        host_libs=
        ;;
    sunos)
        SHFLAGS='-shared -Wl,-h,$$(@F)'
        enabled x86 && SHFLAGS="-mimpure-text $SHFLAGS"
        network_extralibs="-lsocket -lnsl"
        # When using suncc to build, the Solaris linker will mark
        # an executable with each instruction set encountered by
        # the Solaris assembler.  As our libraries contain their own
        # guards for processor-specific code, instead suppress
        # generation of the HWCAPS ELF section on Solaris x86 only.
        enabled_all suncc x86 &&
            echo "hwcap_1 = OVERRIDE;" > mapfile &&
            add_ldflags -Wl,-M,mapfile
        nm_default='nm -P -g'
        ;;
    netbsd)
        disable symver
        oss_indev_extralibs="-lossaudio"
        oss_outdev_extralibs="-lossaudio"
        ;;
    openbsd|bitrig)
        disable symver
        SHFLAGS='-shared'
        SLIB_INSTALL_NAME='$(SLIBNAME).$(LIBMAJOR).$(LIBMINOR)'
        SLIB_INSTALL_LINKS=
        oss_indev_extralibs="-lossaudio"
        oss_outdev_extralibs="-lossaudio"
        ;;
    dragonfly)
        disable symver
        ;;
    freebsd)
        ;;
    bsd/os)
        add_extralibs -lpoll -lgnugetopt
        ;;
    darwin)
        gas="gas-preprocessor.pl $cc"
        enabled ppc && add_asflags -force_cpusubtype_ALL
        SHFLAGS='-dynamiclib -Wl,-single_module -Wl,-install_name,$(SHLIBDIR)/$(SLIBNAME_WITH_MAJOR),-current_version,$(LIBVERSION),-compatibility_version,$(LIBMAJOR)'
        enabled x86_32 && append SHFLAGS -Wl,-read_only_relocs,suppress
        add_ldflags -Wl,-dynamic,-search_paths_first
        SLIBSUF=".dylib"
        SLIBNAME_WITH_VERSION='$(SLIBPREF)$(FULLNAME).$(LIBVERSION)$(SLIBSUF)'
        SLIBNAME_WITH_MAJOR='$(SLIBPREF)$(FULLNAME).$(LIBMAJOR)$(SLIBSUF)'
        objformat="macho"
        enabled x86_64 && objformat="macho64"
        enabled_any pic shared ||
            { check_cflags -mdynamic-no-pic && add_asflags -mdynamic-no-pic; }
        ;;
    mingw32*)
        if test $target_os = "mingw32ce"; then
            disable network
        else
            target_os=mingw32
        fi
        LIBTARGET=i386
        if enabled x86_64; then
            LIBTARGET="i386:x86-64"
        elif enabled arm; then
            LIBTARGET=arm-wince
        fi
        check_ldflags -Wl,--nxcompat
        check_ldflags -Wl,--dynamicbase
        shlibdir_default="$bindir_default"
        SLIBPREF=""
        SLIBSUF=".dll"
        SLIBNAME_WITH_VERSION='$(SLIBPREF)$(FULLNAME)-$(LIBVERSION)$(SLIBSUF)'
        SLIBNAME_WITH_MAJOR='$(SLIBPREF)$(FULLNAME)-$(LIBMAJOR)$(SLIBSUF)'
        SLIB_EXTRA_CMD=-'sed -e "s/ @[^ ]*//" $$(@:$(SLIBSUF)=.orig.def) > $$(@:$(SLIBSUF)=.def); $(DLLTOOL) -m $(LIBTARGET) -d $$(@:$(SLIBSUF)=.def) -l $(SUBDIR)$(SLIBNAME:$(SLIBSUF)=.lib) -D $(SLIBNAME_WITH_MAJOR)'
        SLIB_INSTALL_NAME='$(SLIBNAME_WITH_MAJOR)'
        SLIB_INSTALL_LINKS=
        SLIB_INSTALL_EXTRA_SHLIB='$(SLIBNAME:$(SLIBSUF)=.lib)'
        SLIB_INSTALL_EXTRA_LIB='lib$(SLIBNAME:$(SLIBSUF)=.dll.a) $(SLIBNAME_WITH_MAJOR:$(SLIBSUF)=.def)'
        SHFLAGS='-shared -Wl,--output-def,$$(@:$(SLIBSUF)=.orig.def) -Wl,--out-implib,$(SUBDIR)lib$(SLIBNAME:$(SLIBSUF)=.dll.a) -Wl,--enable-runtime-pseudo-reloc -Wl,--enable-auto-image-base'
        objformat="win32"
        dlltool="${cross_prefix}dlltool"
        ranlib=:
        enable dos_paths
        ;;
    win32|win64)
        disable symver
        if enabled shared; then
            # Link to the import library instead of the normal static library
            # for shared libs.
            LD_LIB='%.lib'
            # Cannot build both shared and static libs with MSVC or icl.
            disable static
        fi
        shlibdir_default="$bindir_default"
        SLIBPREF=""
        SLIBSUF=".dll"
        SLIBNAME_WITH_VERSION='$(SLIBPREF)$(FULLNAME)-$(LIBVERSION)$(SLIBSUF)'
        SLIBNAME_WITH_MAJOR='$(SLIBPREF)$(FULLNAME)-$(LIBMAJOR)$(SLIBSUF)'
        SLIB_CREATE_DEF_CMD='$(SRC_PATH)/compat/windows/makedef $(SUBDIR)lib$(NAME).ver $(OBJS) > $$(@:$(SLIBSUF)=.def)'
        SLIB_INSTALL_NAME='$(SLIBNAME_WITH_MAJOR)'
        SLIB_INSTALL_LINKS=
        SLIB_INSTALL_EXTRA_SHLIB='$(SLIBNAME:$(SLIBSUF)=.lib)'
        SLIB_INSTALL_EXTRA_LIB='$(SLIBNAME_WITH_MAJOR:$(SLIBSUF)=.def)'
        SHFLAGS='-dll -def:$$(@:$(SLIBSUF)=.def) -implib:$(SUBDIR)$(SLIBNAME:$(SLIBSUF)=.lib)'
        objformat="win32"
        ranlib=:
        enable dos_paths
        ;;
    cygwin*)
        target_os=cygwin
        shlibdir_default="$bindir_default"
        SLIBPREF="cyg"
        SLIBSUF=".dll"
        SLIBNAME_WITH_VERSION='$(SLIBPREF)$(FULLNAME)-$(LIBVERSION)$(SLIBSUF)'
        SLIBNAME_WITH_MAJOR='$(SLIBPREF)$(FULLNAME)-$(LIBMAJOR)$(SLIBSUF)'
        SLIB_INSTALL_NAME='$(SLIBNAME_WITH_MAJOR)'
        SLIB_INSTALL_LINKS=
        SLIB_INSTALL_EXTRA_LIB='lib$(FULLNAME).dll.a'
        SHFLAGS='-shared -Wl,--out-implib,$(SUBDIR)lib$(FULLNAME).dll.a'
        objformat="win32"
        enable dos_paths
        ;;
    *-dos|freedos|opendos)
        network_extralibs="-lsocket"
        objformat="coff"
        enable dos_paths
        add_cppflags -U__STRICT_ANSI__
        ;;
    linux)
        enable dv1394
        ;;
    irix*)
        target_os=irix
        ranlib="echo ignoring ranlib"
        ;;
    os/2*)
        ln_s="cp -f"
        objformat="aout"
        add_cppflags -D_GNU_SOURCE
        add_ldflags -Zomf -Zbin-files -Zargs-wild -Zmap
        SHFLAGS='$(SUBDIR)$(NAME).def -Zdll -Zomf'
        LIBSUF="_s.a"
        SLIBPREF=""
        SLIBSUF=".dll"
        SLIBNAME_WITH_VERSION='$(SLIBPREF)$(NAME)-$(LIBVERSION)$(SLIBSUF)'
        SLIBNAME_WITH_MAJOR='$(SLIBPREF)$(shell echo $(NAME) | cut -c1-6)$(LIBMAJOR)$(SLIBSUF)'
        SLIB_CREATE_DEF_CMD='echo LIBRARY $(SLIBNAME_WITH_MAJOR) INITINSTANCE TERMINSTANCE > $(SUBDIR)$(NAME).def; \
            echo PROTMODE >> $(SUBDIR)$(NAME).def; \
            echo CODE PRELOAD MOVEABLE DISCARDABLE >> $(SUBDIR)$(NAME).def; \
            echo DATA PRELOAD MOVEABLE MULTIPLE NONSHARED >> $(SUBDIR)$(NAME).def; \
            echo EXPORTS >> $(SUBDIR)$(NAME).def; \
            emxexp -o $(OBJS) >> $(SUBDIR)$(NAME).def'
        SLIB_EXTRA_CMD='emximp -o $(SUBDIR)$(LIBPREF)$(NAME)_dll.a $(SUBDIR)$(NAME).def; \
            emximp -o $(SUBDIR)$(LIBPREF)$(NAME)_dll.lib $(SUBDIR)$(NAME).def;'
        SLIB_INSTALL_EXTRA_LIB='$(LIBPREF)$(NAME)_dll.a $(LIBPREF)$(NAME)_dll.lib'
        enable dos_paths
        ;;
    gnu/kfreebsd)
        add_cppflags -D_BSD_SOURCE
        ;;
    gnu)
        ;;
    qnx)
        add_cppflags -D_QNX_SOURCE
        network_extralibs="-lsocket"
        ;;
    symbian)
        SLIBSUF=".dll"
        enable dos_paths
        add_cflags --include=$sysinclude/gcce/gcce.h -fvisibility=default
        add_cppflags -D__GCCE__ -D__SYMBIAN32__ -DSYMBIAN_OE_POSIX_SIGNALS
        add_ldflags -Wl,--target1-abs,--no-undefined \
                    -Wl,-Ttext,0x80000,-Tdata,0x1000000 -shared \
                    -Wl,--entry=_E32Startup -Wl,-u,_E32Startup
        add_extralibs -l:eexe.lib -l:usrt2_2.lib -l:dfpaeabi.dso \
                      -l:drtaeabi.dso -l:scppnwdl.dso -lsupc++ -lgcc \
                      -l:libc.dso -l:libm.dso -l:euser.dso -l:libcrt0.lib
        ;;
    osf1)
        add_cppflags -D_OSF_SOURCE -D_POSIX_PII -D_REENTRANT
        ;;
    minix)
        ;;
    plan9)
        add_cppflags -D_C99_SNPRINTF_EXTENSION  \
                     -D_REENTRANT_SOURCE        \
                     -D_RESEARCH_SOURCE         \
                     -DFD_SETSIZE=96            \
                     -DHAVE_SOCK_OPTS
        add_compat strtod.o strtod=avpriv_strtod
        network_extralibs='-lbsd'
        exeobjs=compat/plan9/main.o
        disable avserver
        cp_f='cp'
        ;;
    none)
        ;;
    *)
        die "Unknown OS '$target_os'."
        ;;
esac

# determine libc flavour

probe_libc(){
    pfx=$1
    pfx_no_=${pfx%_}
    # uclibc defines __GLIBC__, so it needs to be checked before glibc.
    if check_${pfx}cpp_condition features.h "defined __UCLIBC__"; then
        eval ${pfx}libc_type=uclibc
        add_${pfx}cppflags -D_POSIX_C_SOURCE=200112 -D_XOPEN_SOURCE=600
    elif check_${pfx}cpp_condition features.h "defined __GLIBC__"; then
        eval ${pfx}libc_type=glibc
        add_${pfx}cppflags -D_POSIX_C_SOURCE=200112 -D_XOPEN_SOURCE=600
    # MinGW headers can be installed on Cygwin, so check for newlib first.
    elif check_${pfx}cpp_condition newlib.h "defined _NEWLIB_VERSION"; then
        eval ${pfx}libc_type=newlib
        add_${pfx}cppflags -U__STRICT_ANSI__
    # MinGW64 is backwards compatible with MinGW32, so check for it first.
    elif check_${pfx}cpp_condition _mingw.h "defined __MINGW64_VERSION_MAJOR"; then
        eval ${pfx}libc_type=mingw64
        add_${pfx}cppflags -U__STRICT_ANSI__ -D__USE_MINGW_ANSI_STDIO=1
        eval test \$${pfx_no_}cc_type = "gcc" &&
            add_${pfx}cppflags -D__printf__=__gnu_printf__
    elif check_${pfx}cpp_condition _mingw.h "defined __MINGW_VERSION"  ||
         check_${pfx}cpp_condition _mingw.h "defined __MINGW32_VERSION"; then
        eval ${pfx}libc_type=mingw32
        check_${pfx}cpp_condition _mingw.h "__MINGW32_MAJOR_VERSION > 3 || \
            (__MINGW32_MAJOR_VERSION == 3 && __MINGW32_MINOR_VERSION >= 15)" ||
            die "ERROR: MinGW32 runtime version must be >= 3.15."
        add_${pfx}cppflags -U__STRICT_ANSI__ -D__USE_MINGW_ANSI_STDIO=1
        eval test \$${pfx_no_}cc_type = "gcc" &&
            add_${pfx}cppflags -D__printf__=__gnu_printf__
    elif check_${pfx}cpp_condition crtversion.h "defined _VC_CRT_MAJOR_VERSION"; then
        eval ${pfx}libc_type=msvcrt
        # The MSVC 2010 headers (Win 7.0 SDK) set _WIN32_WINNT to
        # 0x601 by default unless something else is set by the user.
        # This can easily lead to us detecting functions only present
        # in such new versions and producing binaries requiring windows 7.0.
        # Therefore explicitly set the default to XP unless the user has
        # set something else on the command line.
        check_${pfx}cpp_condition stdlib.h "defined(_WIN32_WINNT)" ||
            add_${pfx}cppflags -D_WIN32_WINNT=0x0502
    elif check_${pfx}cpp_condition stddef.h "defined __KLIBC__"; then
        eval ${pfx}libc_type=klibc
    elif check_${pfx}cpp_condition sys/cdefs.h "defined __BIONIC__"; then
        eval ${pfx}libc_type=bionic
    elif check_${pfx}cpp_condition sys/brand.h "defined LABELED_BRAND_NAME"; then
        eval ${pfx}libc_type=solaris
        add_${pfx}cppflags -D__EXTENSIONS__ -D_XOPEN_SOURCE=600
    fi
}

probe_libc
test -n "$libc_type" && enable libc_$libc_type
probe_libc host_
test -n "$host_libc_type" && enable host_libc_$host_libc_type

case $libc_type in
    bionic)
        add_compat strtod.o strtod=avpriv_strtod
        ;;
    msvcrt)
        add_compat strtod.o strtod=avpriv_strtod
        add_compat msvcrt/snprintf.o snprintf=avpriv_snprintf   \
                                     _snprintf=avpriv_snprintf  \
                                     vsnprintf=avpriv_vsnprintf
        ;;
esac

# hacks for compiler/libc/os combinations

if enabled_all tms470 libc_glibc; then
    CPPFLAGS="-I${source_path}/compat/tms470 ${CPPFLAGS}"
    add_cppflags -D__USER_LABEL_PREFIX__=
    add_cppflags -D__builtin_memset=memset
    add_cppflags -D__gnuc_va_list=va_list -D_VA_LIST_DEFINED
    add_cflags   -pds=48    # incompatible redefinition of macro
fi

if enabled_all ccc libc_glibc; then
    add_ldflags -Wl,-z,now  # calls to libots crash without this
fi

check_compile_assert flt_lim "float.h limits.h" "DBL_MAX == (double)DBL_MAX" ||
    add_cppflags '-I\$(SRC_PATH)/compat/float'

esc(){
    echo "$*" | sed 's/%/%25/g;s/:/%3a/g'
}

echo "config:$arch:$subarch:$cpu:$target_os:$(esc $cc_ident):$(esc $LIBAV_CONFIGURATION)" >config.fate

check_cpp_condition stdlib.h "defined(__PIC__) || defined(__pic__) || defined(PIC)" && enable_weak pic

set_default $PATHS_LIST
set_default nm

# we need to build at least one lib type
if ! enabled_any static shared; then
    cat <<EOF
At least one library type must be built.
Specify --enable-static to build the static libraries or --enable-shared to
build the shared libraries as well. To only build the shared libraries specify
--disable-static in addition to --enable-shared.
EOF
    exit 1;
fi

die_license_disabled() {
    enabled $1 || { enabled $2 && die "$2 is $1 and --enable-$1 is not specified."; }
}

die_license_disabled gpl libcdio
die_license_disabled gpl libx264
die_license_disabled gpl libx265
die_license_disabled gpl libxavs
die_license_disabled gpl libxvid
die_license_disabled gpl x11grab

die_license_disabled nonfree libfaac
die_license_disabled nonfree libfdk_aac
die_license_disabled nonfree openssl

die_license_disabled version3 libopencore_amrnb
die_license_disabled version3 libopencore_amrwb
die_license_disabled version3 libvo_aacenc
die_license_disabled version3 libvo_amrwbenc

enabled version3 && { enabled gpl && enable gplv3 || enable lgplv3; }

disabled optimizations || check_cflags -fomit-frame-pointer

enable_weak_pic() {
    disabled pic && return
    enable pic
    add_cppflags -DPIC
    case "$target_os" in
    mingw*|cygwin*)
        ;;
    *)
        add_cflags -fPIC
        ;;
    esac
    add_asflags  -fPIC
}

enabled pic && enable_weak_pic

check_cc <<EOF || die "Symbol mangling check failed."
int ff_extern;
EOF
sym=$($nm $TMPO | awk '/ff_extern/{ print substr($0, match($0, /[^ \t]*ff_extern/)) }')
extern_prefix=${sym%%ff_extern*}

check_cc <<EOF && enable_weak inline_asm
void foo(void) { __asm__ volatile ("" ::); }
EOF

_restrict=
for restrict_keyword in restrict __restrict__ __restrict; do
    check_cc <<EOF && _restrict=$restrict_keyword && break
void foo(char * $restrict_keyword p);
EOF
done

check_cc <<EOF && enable pragma_deprecated
void foo(void) { _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"") }
EOF

check_cc <<EOF && enable attribute_packed
struct { int x; } __attribute__((packed)) x;
EOF

check_cc <<EOF && enable attribute_may_alias
union { int x; } __attribute__((may_alias)) x;
EOF

check_cc <<EOF || die "endian test failed"
unsigned int endian = 'B' << 24 | 'I' << 16 | 'G' << 8 | 'E';
EOF
od -t x1 $TMPO | grep -q '42 *49 *47 *45' && enable bigendian

check_inline_asm inline_asm_labels '"1:\n"'

if enabled aarch64; then
    # internal assembler in clang 3.3 does not support this instruction
    enabled neon && check_insn neon 'ext   v0.8B, v0.8B, v1.8B, #1'
    enabled vfp  && check_insn vfp  'fmadd d0,    d0,    d1,    d2'

    map 'enabled_any ${v}_external ${v}_inline || disable $v' $ARCH_EXT_LIST_ARM

elif enabled alpha; then

    check_cflags -mieee

elif enabled arm; then

    check_cpp_condition stddef.h "defined __thumb__" && enable_weak thumb
    enabled thumb && check_cflags -mthumb || check_cflags -marm
    nogas=die

    if     check_cpp_condition stddef.h "defined __ARM_PCS_VFP"; then
        enable vfp_args
    elif ! check_cpp_condition stddef.h "defined __ARM_PCS || defined __SOFTFP__"; then
        case "${cross_prefix:-$cc}" in
            *hardfloat*)         enable vfp_args;   fpabi=vfp ;;
            *) check_ld <<EOF && enable vfp_args && fpabi=vfp || fpabi=soft ;;
__asm__ (".eabi_attribute 28, 1");
int main(void) { return 0; }
EOF
        esac
        warn "Compiler does not indicate floating-point ABI, guessing $fpabi."
    fi

    enabled armv5te && check_insn armv5te 'qadd r0, r0, r0'
    enabled armv6   && check_insn armv6   'sadd16 r0, r0, r0'
    enabled armv6t2 && check_insn armv6t2 'movt r0, #0'
    enabled neon    && check_insn neon    'vadd.i16 q0, q0, q0'
    enabled vfp     && check_insn vfp     'fadds s0, s0, s0'
    enabled vfpv3   && check_insn vfpv3   'vmov.f32 s0, #1.0'

    [ $target_os = linux ] ||
        map 'enabled_any ${v}_external ${v}_inline || disable $v' \
            $ARCH_EXT_LIST_ARM

    check_inline_asm asm_mod_q '"add r0, %Q0, %R0" :: "r"((long long)0)'

    [ $target_os != win32 ] && enabled_all armv6t2 shared !pic && enable_weak_pic

elif enabled mips; then

    check_inline_asm loongson '"dmult.g $1, $2, $3"'

elif enabled parisc; then

    if enabled gcc; then
        case $($cc -dumpversion) in
            4.[3-8].*) check_cflags -fno-optimize-sibling-calls ;;
        esac
    fi

elif enabled ppc; then

    enable local_aligned_8 local_aligned_16

    check_inline_asm dcbzl     '"dcbzl 0, %0" :: "r"(0)'
    check_inline_asm ibm_asm   '"add 0, 0, 0"'
    check_inline_asm ppc4xx    '"maclhw r10, r11, r12"'
    check_inline_asm xform_asm '"lwzx %1, %y0" :: "Z"(*(int*)0), "r"(0)'

    # AltiVec flags: The FSF version of GCC differs from the Apple version
    if enabled altivec; then
        nogas=warn
        check_cflags -maltivec -mabi=altivec &&
        { check_header altivec.h && inc_altivec_h="#include <altivec.h>" ; } ||
        check_cflags -faltivec

        # check if our compiler supports Motorola AltiVec C API
        check_cc <<EOF || disable altivec
$inc_altivec_h
int main(void) {
    vector signed int v1 = (vector signed int) { 0 };
    vector signed int v2 = (vector signed int) { 1 };
    v1 = vec_add(v1, v2);
    return 0;
}
EOF

        enabled altivec || warn "Altivec disabled, possibly missing --cpu flag"
    fi

elif enabled sparc; then

    enabled vis && check_inline_asm vis '"pdist %f0, %f0, %f0"'

elif enabled x86; then

    check_builtin rdtsc    intrin.h   "__rdtsc()"
    check_builtin mm_empty mmintrin.h "_mm_empty()"

    enable local_aligned_8 local_aligned_16

    # check whether EBP is available on x86
    # As 'i' is stored on the stack, this program will crash
    # if the base pointer is used to access it because the
    # base pointer is cleared in the inline assembly code.
    check_exec_crash <<EOF && enable ebp_available
volatile int i=0;
__asm__ volatile ("xorl %%ebp, %%ebp" ::: "%ebp");
return i;
EOF

    # check whether EBX is available on x86
    check_inline_asm ebx_available '""::"b"(0)' &&
        check_inline_asm ebx_available '"":::"%ebx"'

    # check whether xmm clobbers are supported
    check_inline_asm xmm_clobbers '"":::"%xmm0"'

    # check whether binutils is new enough to compile SSSE3/MMXEXT
    enabled ssse3  && check_inline_asm ssse3_inline  '"pabsw %xmm0, %xmm0"'
    enabled mmxext && check_inline_asm mmxext_inline '"pmaxub %mm0, %mm1"'

    if ! disabled_any asm mmx yasm; then
        if check_cmd $yasmexe --version; then
            enabled x86_64 && yasm_extra="-m amd64"
            yasm_debug="-g dwarf2"
        elif check_cmd nasm -v; then
            yasmexe=nasm
            yasm_debug="-g -F dwarf"
            enabled x86_64 && test "$objformat" = elf && objformat=elf64
        fi

        YASMFLAGS="-f $objformat $yasm_extra"
        enabled pic               && append YASMFLAGS "-DPIC"
        test -n "$extern_prefix"  && append YASMFLAGS "-DPREFIX"
        case "$objformat" in
            elf*) enabled debug && append YASMFLAGS $yasm_debug ;;
        esac

        check_yasm "movbe ecx, [5]" && enable yasm ||
            die "yasm/nasm not found or too old. Use --disable-yasm for a crippled build."
        check_yasm "vpmacsdd xmm0, xmm1, xmm2, xmm3" || disable xop_external
        check_yasm "vfmadd132ps ymm0, ymm1, ymm2"    || disable fma3_external
        check_yasm "vfmaddps ymm0, ymm1, ymm2, ymm3" || disable fma4_external
        check_yasm "CPU amdnop" || disable cpunop
    fi

    case "$cpu" in
        athlon*|opteron*|k8*|pentium|pentium-mmx|prescott|nocona|atom|geode)
            disable fast_clz
        ;;
    esac

fi

if enabled asm; then
    as=${gas:=$as}
    check_as <<EOF && enable gnu_as || \
        $nogas "GNU assembler not found, install gas-preprocessor"
.macro m n
\n: .int 0
.endm
m x
EOF
fi

check_ldflags -Wl,--as-needed

if check_func dlopen; then
    ldl=
elif check_func dlopen -ldl; then
    ldl=-ldl
fi

if ! disabled network; then
    check_type "sys/types.h sys/socket.h" socklen_t
    check_type netdb.h "struct addrinfo"
    check_type netinet/in.h "struct group_source_req" -D_BSD_SOURCE
    check_type netinet/in.h "struct ip_mreq_source" -D_BSD_SOURCE
    check_type netinet/in.h "struct ipv6_mreq" -D_DARWIN_C_SOURCE
    check_type netinet/in.h "struct sockaddr_in6"
    check_type poll.h "struct pollfd"
    check_type "sys/types.h sys/socket.h" "struct sockaddr_storage"
    check_struct "sys/types.h sys/socket.h" "struct sockaddr" sa_len
    check_type netinet/sctp.h "struct sctp_event_subscribe"
    check_func getaddrinfo $network_extralibs
    check_func getservbyport $network_extralibs
    check_func inet_aton $network_extralibs
    # Prefer arpa/inet.h over winsock2
    if check_header arpa/inet.h ; then
        check_func closesocket
    elif check_header winsock2.h ; then
        check_func_headers winsock2.h closesocket -lws2 &&
            network_extralibs="-lws2" ||
        { check_func_headers winsock2.h closesocket -lws2_32 &&
            network_extralibs="-lws2_32"; } || disable winsock2_h network
        check_func_headers ws2tcpip.h getaddrinfo $network_extralibs
        check_type ws2tcpip.h socklen_t
        check_type ws2tcpip.h "struct addrinfo"
        check_type ws2tcpip.h "struct group_source_req"
        check_type ws2tcpip.h "struct ip_mreq_source"
        check_type ws2tcpip.h "struct ipv6_mreq"
        check_type winsock2.h "struct pollfd"
        check_type ws2tcpip.h "struct sockaddr_in6"
        check_type ws2tcpip.h "struct sockaddr_storage"
        check_struct winsock2.h "struct sockaddr" sa_len
    else
        disable network
    fi
fi

# Solaris has nanosleep in -lrt, OpenSolaris no longer needs that
check_func nanosleep || { check_func nanosleep -lrt && add_extralibs -lrt; }

check_func  fcntl
check_func  fork
check_func_headers stdlib.h getenv
check_func  gethrtime
check_func  getopt
check_func  getrusage
check_struct "sys/time.h sys/resource.h" "struct rusage" ru_maxrss
check_func  gettimeofday
check_func  isatty
check_func  localtime_r
check_func  mach_absolute_time
check_func  ${malloc_prefix}memalign            && enable memalign
check_func  mkstemp
check_func  mmap
check_func  mprotect
check_func  ${malloc_prefix}posix_memalign      && enable posix_memalign
check_func_headers malloc.h _aligned_malloc     && enable aligned_malloc
check_func  setrlimit
check_func  strerror_r
check_func  strptime
check_func  sched_getaffinity
check_builtin sync_val_compare_and_swap "" "int *ptr; int oldval, newval; __sync_val_compare_and_swap(ptr, oldval, newval)"
check_builtin machine_rw_barrier mbarrier.h "__machine_rw_barrier()"
check_builtin atomic_cas_ptr atomic.h "void **ptr; void *oldval, *newval; atomic_cas_ptr(ptr, oldval, newval)"
check_builtin MemoryBarrier windows.h "MemoryBarrier()"
check_func  sysconf
check_func  sysctl
check_func  usleep
check_func_headers io.h setmode
check_lib2 "windows.h shellapi.h" CommandLineToArgvW -lshell32
check_lib2 "windows.h wincrypt.h" CryptGenRandom -ladvapi32
check_lib2 "windows.h psapi.h" GetProcessMemoryInfo -lpsapi
check_func_headers windows.h GetProcessAffinityMask
check_func_headers windows.h GetProcessTimes
check_func_headers windows.h GetSystemTimeAsFileTime
check_func_headers windows.h MapViewOfFile
check_func_headers windows.h SetConsoleTextAttribute
check_func_headers windows.h Sleep
check_func_headers windows.h VirtualAlloc

check_header direct.h
check_header dlfcn.h
check_header dxva.h
check_header dxva2api.h
check_header io.h
check_header mach/mach_time.h
check_header malloc.h
check_header poll.h
check_header sys/mman.h
check_header sys/param.h
check_header sys/resource.h
check_header sys/select.h
check_header sys/time.h
check_header sys/un.h
check_header unistd.h
check_header vdpau/vdpau.h
check_header vdpau/vdpau_x11.h
check_header VideoDecodeAcceleration/VDADecoder.h
check_header windows.h
check_header X11/extensions/XvMClib.h

if ! disabled w32threads && ! enabled pthreads; then
    check_func_headers "windows.h process.h" _beginthreadex &&
        enable w32threads || disable w32threads
fi

# check for some common methods of building with pthread support
# do this before the optional library checks as some of them require pthreads
if ! disabled pthreads && ! enabled w32threads; then
    enable pthreads
    if check_func pthread_join -pthread; then
        add_cflags -pthread
        add_extralibs -pthread
    elif check_func pthread_join -pthreads; then
        add_cflags -pthreads
        add_extralibs -pthreads
    elif check_func pthread_join -lpthreadGC2; then
        add_extralibs -lpthreadGC2
    elif check_lib pthread.h pthread_join -lpthread; then
        :
    elif ! check_func pthread_join; then
        disable pthreads
    fi
fi

disabled  zlib || check_lib   zlib.h      zlibVersion -lz   || disable  zlib
disabled bzlib || check_lib2 bzlib.h BZ2_bzlibVersion -lbz2 || disable bzlib

check_lib math.h sin -lm && LIBM="-lm"
enabled vaapi && require vaapi va/va.h vaInitialize -lva

atan2f_args=2
ldexpf_args=2
powf_args=2

for func in $MATH_FUNCS; do
    eval check_mathfunc $func \${${func}_args:-1}
done

# these are off by default, so fail if requested and not available
enabled avisynth          && { { check_header "avisynth/avisynth_c.h" && check_lib2 "windows.h" LoadLibrary; } ||
                               { check_header "avxsynth/avxsynth_c.h" && check_lib2 "dlfcn.h" dlopen -ldl; } ||
                               die "ERROR: LoadLibrary/dlopen not found, or avisynth header not found"; }
enabled frei0r            && { check_header frei0r.h || die "ERROR: frei0r.h header not found"; }
enabled gnutls            && require_pkg_config gnutls gnutls/gnutls.h gnutls_global_init
enabled libfaac           && require2 libfaac "stdint.h faac.h" faacEncGetVersion -lfaac
enabled libfdk_aac        && require libfdk_aac fdk-aac/aacenc_lib.h aacEncOpen -lfdk-aac
enabled libfreetype       && require_pkg_config freetype2 "ft2build.h FT_FREETYPE_H" FT_Init_FreeType
enabled libgsm            && { for gsm_hdr in "gsm.h" "gsm/gsm.h"; do
                                   check_lib "${gsm_hdr}" gsm_create -lgsm && break;
                               done || die "ERROR: libgsm not found"; }
enabled libilbc           && require libilbc ilbc.h WebRtcIlbcfix_InitDecode -lilbc
enabled libmp3lame        && require "libmp3lame >= 3.98.3" lame/lame.h lame_set_VBR_quality -lmp3lame
enabled libopencore_amrnb && require libopencore_amrnb opencore-amrnb/interf_dec.h Decoder_Interface_init -lopencore-amrnb
enabled libopencore_amrwb && require libopencore_amrwb opencore-amrwb/dec_if.h D_IF_init -lopencore-amrwb
enabled libopencv         && require_pkg_config opencv opencv/cv.h cvCreateImageHeader
enabled libopenjpeg       && require_pkg_config libopenjpeg1 openjpeg.h opj_version
enabled libopus           && require_pkg_config opus opus_multistream.h opus_multistream_decoder_create
enabled libpulse          && require_pkg_config libpulse-simple pulse/simple.h pa_simple_new
enabled librtmp           && require_pkg_config librtmp librtmp/rtmp.h RTMP_Socket
enabled libschroedinger   && require_pkg_config schroedinger-1.0 schroedinger/schro.h schro_init
enabled libspeex          && require libspeex speex/speex.h speex_decoder_init -lspeex
enabled libtheora         && require libtheora theora/theoraenc.h th_info_init -ltheoraenc -ltheoradec -logg
enabled libvo_aacenc      && require libvo_aacenc vo-aacenc/voAAC.h voGetAACEncAPI -lvo-aacenc
enabled libvo_amrwbenc    && require libvo_amrwbenc vo-amrwbenc/enc_if.h E_IF_init -lvo-amrwbenc
enabled libvorbis         && require libvorbis vorbis/vorbisenc.h vorbis_info_init -lvorbisenc -lvorbis -logg
enabled libvpx            && {
    enabled libvpx_vp8_decoder && { check_lib2 "vpx/vpx_decoder.h vpx/vp8dx.h" vpx_codec_dec_init_ver -lvpx ||
                                    die "ERROR: libvpx decoder version must be >=0.9.1"; }
    enabled libvpx_vp8_encoder && { check_lib2 "vpx/vpx_encoder.h vpx/vp8cx.h" "vpx_codec_enc_init_ver VPX_CQ" -lvpx ||
                                    die "ERROR: libvpx encoder version must be >=0.9.6"; }
    enabled libvpx_vp9_decoder && { check_lib2 "vpx/vpx_decoder.h vpx/vp8dx.h" "vpx_codec_vp9_dx" -lvpx || disable libvpx_vp9_decoder; }
    enabled libvpx_vp9_encoder && { check_lib2 "vpx/vpx_encoder.h vpx/vp8cx.h" "vpx_codec_vp9_cx" -lvpx || disable libvpx_vp9_encoder; } }
enabled libwavpack        && require libwavpack wavpack/wavpack.h WavpackOpenFileOutput  -lwavpack
enabled libwebp           && require_pkg_config libwebp webp/encode.h WebPGetEncoderVersion
enabled libx264           && require libx264 x264.h x264_encoder_encode -lx264 &&
                             { check_cpp_condition x264.h "X264_BUILD >= 118" ||
                               die "ERROR: libx264 version must be >= 0.118."; }
enabled libx265           && require_pkg_config x265 x265.h x265_encoder_encode &&
                             { check_cpp_condition x265.h "X265_BUILD >= 9" ||
                               die "ERROR: libx265 version must be >= 9."; }
enabled libxavs           && require libxavs xavs.h xavs_encoder_encode -lxavs
enabled libxvid           && require libxvid xvid.h xvid_global -lxvidcore
enabled openssl           && { check_lib openssl/ssl.h SSL_library_init -lssl -lcrypto ||
                               check_lib openssl/ssl.h SSL_library_init -lssl32 -leay32 ||
                               check_lib openssl/ssl.h SSL_library_init -lssl -lcrypto -lws2_32 -lgdi32 ||
                               die "ERROR: openssl not found"; }

if enabled gnutls; then
    { check_lib nettle/bignum.h nettle_mpz_get_str_256 -lnettle -lhogweed -lgmp && enable nettle; } ||
    { check_lib gcrypt.h gcry_mpi_new -lgcrypt && enable gcrypt; }
fi

# libdc1394 check
if enabled libdc1394; then
    { check_lib dc1394/dc1394.h dc1394_new -ldc1394 -lraw1394 &&
        enable libdc1394_2; } ||
    { check_lib libdc1394/dc1394_control.h dc1394_create_handle -ldc1394_control -lraw1394 &&
        enable libdc1394_1; } ||
    die "ERROR: No version of libdc1394 found "
fi

if check_pkg_config sdl SDL_events.h SDL_PollEvent; then
    check_cpp_condition SDL.h "(SDL_MAJOR_VERSION<<16 | SDL_MINOR_VERSION<<8 | SDL_PATCHLEVEL) >= 0x010201" $sdl_cflags &&
    check_cpp_condition SDL.h "(SDL_MAJOR_VERSION<<16 | SDL_MINOR_VERSION<<8 | SDL_PATCHLEVEL) < 0x010300" $sdl_cflags &&
    enable sdl
fi

pod2man --help     > /dev/null 2>&1 && enable pod2man   || disable pod2man
texi2html -version > /dev/null 2>&1 && enable texi2html || disable texi2html

check_header linux/fb.h
check_header linux/videodev2.h
check_struct linux/videodev2.h "struct v4l2_frmivalenum" discrete

check_header sys/videoio.h

check_func_headers "windows.h vfw.h" capCreateCaptureWindow "$vfwcap_indev_extralibs"
# check that WM_CAP_DRIVER_CONNECT is defined to the proper value
# w32api 3.12 had it defined wrong
check_cpp_condition vfw.h "WM_CAP_DRIVER_CONNECT > WM_USER" && enable vfwcap_defines

# check for ioctl_meteor.h, ioctl_bt848.h and alternatives
{ check_header dev/bktr/ioctl_meteor.h &&
  check_header dev/bktr/ioctl_bt848.h; } ||
{ check_header machine/ioctl_meteor.h &&
  check_header machine/ioctl_bt848.h; } ||
{ check_header dev/video/meteor/ioctl_meteor.h &&
  check_header dev/video/bktr/ioctl_bt848.h; } ||
check_header dev/ic/bt8xx.h

check_header sndio.h
check_header sys/soundcard.h
check_header soundcard.h

enabled_any alsa_indev alsa_outdev &&
    check_lib2 alsa/asoundlib.h snd_pcm_htimestamp -lasound

enabled jack_indev && check_lib2 jack/jack.h jack_client_open -ljack &&
    check_func jack_port_get_latency_range -ljack

enabled_any sndio_indev sndio_outdev && check_lib2 sndio.h sio_open -lsndio

if enabled libcdio; then
    check_lib2 "cdio/cdda.h cdio/paranoia.h" cdio_cddap_open -lcdio_paranoia -lcdio_cdda -lcdio ||
    check_lib2 "cdio/paranoia/cdda.h cdio/paranoia/paranoia.h" cdio_cddap_open -lcdio_paranoia -lcdio_cdda -lcdio
fi

check_lib X11/Xlib.h XOpenDisplay -lX11 && enable xlib

enabled x11grab                                           &&
require Xext X11/extensions/XShm.h XShmCreateImage -lXext &&
require Xfixes X11/extensions/Xfixes.h XFixesGetCursorImage -lXfixes &&
{ enabled xlib || die "ERROR: Xlib not found"; }

enabled vdpau &&
    check_cpp_condition vdpau/vdpau.h "defined VDP_DECODER_PROFILE_MPEG4_PART2_ASP" ||
    disable vdpau

enabled vdpau && enabled xlib &&
    check_func_headers "vdpau/vdpau.h vdpau/vdpau_x11.h" vdp_device_create_x11 -lvdpau &&
    prepend avconv_libs $($ldflags_filter "-lvdpau") &&
    enable vdpau_x11

enabled debug && add_cflags -g"$debuglevel" && add_asflags -g"$debuglevel"

# add some useful compiler flags if supported
check_cflags -Wdeclaration-after-statement
check_cflags -Wall
check_cflags -Wdisabled-optimization
check_cflags -Wpointer-arith
check_cflags -Wredundant-decls
check_cflags -Wcast-qual
check_cflags -Wwrite-strings
check_cflags -Wtype-limits
check_cflags -Wundef
check_cflags -Wmissing-prototypes
check_cflags -Wstrict-prototypes
enabled extra_warnings && check_cflags -Winline

check_disable_warning(){
    warning_flag=-W${1#-Wno-}
    test_cflags $warning_flag && add_cflags $1
}

check_disable_warning -Wno-parentheses
check_disable_warning -Wno-switch
check_disable_warning -Wno-format-zero-length
check_disable_warning -Wno-pointer-sign

# add some linker flags
check_ldflags -Wl,--warn-common
check_ldflags -Wl,-rpath-link=libswscale:libavfilter:libavdevice:libavformat:libavcodec:libavutil:libavresample
test_ldflags -Wl,-Bsymbolic && append SHFLAGS -Wl,-Bsymbolic

# add some strip flags
# -wN '..@*' is more selective than -x, but not available everywhere.
check_stripflags -wN \'..@*\' || check_stripflags -x || strip='true'

enabled neon_clobber_test &&
    check_ldflags -Wl,--wrap,avcodec_open2              \
                  -Wl,--wrap,avcodec_decode_audio4      \
                  -Wl,--wrap,avcodec_decode_video2      \
                  -Wl,--wrap,avcodec_decode_subtitle2   \
                  -Wl,--wrap,avcodec_encode_audio2      \
                  -Wl,--wrap,avcodec_encode_video2      \
                  -Wl,--wrap,avcodec_encode_subtitle    \
                  -Wl,--wrap,avresample_convert ||
    disable neon_clobber_test

enabled xmm_clobber_test &&
    check_ldflags -Wl,--wrap,avcodec_open2              \
                  -Wl,--wrap,avcodec_decode_audio4      \
                  -Wl,--wrap,avcodec_decode_video2      \
                  -Wl,--wrap,avcodec_decode_subtitle2   \
                  -Wl,--wrap,avcodec_encode_audio2      \
                  -Wl,--wrap,avcodec_encode_video2      \
                  -Wl,--wrap,avcodec_encode_subtitle    \
                  -Wl,--wrap,avresample_convert         \
                  -Wl,--wrap,sws_scale ||
    disable xmm_clobber_test

echo "X{};" > $TMPV
if test_ldflags -Wl,--version-script,$TMPV; then
    append SHFLAGS '-Wl,--version-script,\$(SUBDIR)lib\$(NAME).ver'
    check_cc <<EOF && enable symver_asm_label
void ff_foo(void) __asm__ ("av_foo@VERSION");
void ff_foo(void) { ${inline_asm+__asm__($quotes);} }
EOF
    check_cc <<EOF && enable symver_gnu_asm
__asm__(".symver ff_foo,av_foo@VERSION");
void ff_foo(void) {}
EOF
fi

if [ -z "$optflags" ]; then
    if enabled small; then
        optflags=$cflags_size
    elif enabled optimizations; then
        optflags=$cflags_speed
    else
        optflags=$cflags_noopt
    fi
fi

check_optflags(){
    check_cflags "$@"
    enabled lto && check_ldflags "$@"
}


if enabled lto; then
    test "$cc_type" != "$ld_type" && die "LTO requires same compiler and linker"
    check_cflags  -flto
    check_ldflags -flto $cpuflags
fi

check_optflags $optflags
check_optflags -fno-math-errno
check_optflags -fno-signed-zeros

if enabled icc; then
    # Just warnings, no remarks
    check_cflags -w1
    # -wd: Disable following warnings
    # 144, 167, 556: -Wno-pointer-sign
    # 1292: attribute "foo" ignored
    # 1419: external declaration in primary source file
    # 10006: ignoring unknown option -fno-signed-zeros
    # 10148: ignoring unknown option -Wno-parentheses
    # 10156: ignoring option '-W'; no argument required
    check_cflags -wd144,167,556,1292,1419,10006,10148,10156
    # 11030: Warning unknown option --as-needed
    # 10156: ignoring option '-export'; no argument required
    check_ldflags -wd10156,11030
    # icc 11.0 and 11.1 work with ebp_available, but don't pass the test
    enable ebp_available
    if enabled x86_32; then
        icc_version=$($cc -dumpversion)
        test ${icc_version%%.*} -ge 11 &&
            check_cflags -falign-stack=maintain-16-byte ||
            disable aligned_stack
    fi
elif enabled ccc; then
    # disable some annoying warnings
    add_cflags -msg_disable bitnotint
    add_cflags -msg_disable mixfuncvoid
    add_cflags -msg_disable nonstandcast
    add_cflags -msg_disable unsupieee
elif enabled gcc; then
    check_optflags -fno-tree-vectorize
    check_cflags -Werror=implicit-function-declaration
    check_cflags -Werror=missing-prototypes
    check_cflags -Werror=return-type
    check_cflags -Werror=declaration-after-statement
    check_cflags -Werror=vla
    enabled extra_warnings || check_disable_warning -Wno-maybe-uninitialized
elif enabled llvm_gcc; then
    check_cflags -mllvm -stack-alignment=16
elif enabled clang; then
    check_cflags -mllvm -stack-alignment=16
    check_cflags -Qunused-arguments
    check_cflags -Werror=implicit-function-declaration
    check_cflags -Werror=missing-prototypes
    check_cflags -Werror=return-type
elif enabled cparser; then
    add_cflags -Wno-missing-variable-declarations
    add_cflags -Wno-empty-statement
elif enabled armcc; then
    # 2523: use of inline assembler is deprecated
    add_cflags -W${armcc_opt},--diag_suppress=2523
    add_cflags -W${armcc_opt},--diag_suppress=1207
    add_cflags -W${armcc_opt},--diag_suppress=1293 # assignment in condition
    add_cflags -W${armcc_opt},--diag_suppress=3343 # hardfp compat
    add_cflags -W${armcc_opt},--diag_suppress=167  # pointer sign
    add_cflags -W${armcc_opt},--diag_suppress=513  # pointer sign
elif enabled tms470; then
    add_cflags -pds=824 -pds=837
    disable inline_asm
elif enabled pathscale; then
    add_cflags -fstrict-overflow -OPT:wrap_around_unsafe_opt=OFF
elif enabled_any msvc icl; then
    enabled x86_32 && disable aligned_stack
    enabled_all x86_32 debug && add_cflags -Oy-
    enabled debug && add_ldflags -debug
    enable pragma_deprecated
    if enabled icl; then
        # -Qansi-alias is basically -fstrict-aliasing, but does not work
        # (correctly) on icl 13.x.
        check_cpp_condition "windows.h" "__ICL < 1300 || __ICL >= 1400" &&
            add_cflags -Qansi-alias
        # icl will pass the inline asm tests but inline asm is currently
        # not supported (build will fail)
        disable inline_asm
    fi
fi

case $as_type in
    clang)
        add_asflags -Qunused-arguments
    ;;
esac

case $ld_type in
    clang)
        check_ldflags -Qunused-arguments
    ;;
esac

case $target_os in
    osf1)
        enabled ccc && add_ldflags '-Wl,-expect_unresolved,*'
    ;;
    plan9)
        add_cppflags -Dmain=plan9_main
    ;;
esac

enabled asm || { arch=c; disable $ARCH_LIST $ARCH_EXT_LIST; }

check_deps $CONFIG_LIST       \
           $CONFIG_EXTRA      \
           $HAVE_LIST         \
           $ALL_COMPONENTS    \

! enabled_any memalign posix_memalign aligned_malloc &&
    enabled_any $need_memalign && enable memalign_hack

for thread in $THREADS_LIST; do
    if enabled $thread; then
        test -n "$thread_type" &&
            die "ERROR: Only one thread type must be selected." ||
            thread_type="$thread"
    fi
done

echo "install prefix            $prefix"
echo "source path               $source_path"
echo "C compiler                $cc"
echo "C library                 $libc_type"
if test "$host_cc" != "$cc"; then
    echo "host C compiler           $host_cc"
    echo "host C library            $host_libc_type"
fi
echo "ARCH                      $arch ($cpu)"
if test "$build_suffix" != ""; then
    echo "build suffix              $build_suffix"
fi
if test "$extra_version" != ""; then
    echo "version string suffix     $extra_version"
fi
echo "big-endian                ${bigendian-no}"
echo "runtime cpu detection     ${runtime_cpudetect-no}"
if enabled x86; then
    echo "${yasmexe}                      ${yasm-no}"
    echo "MMX enabled               ${mmx-no}"
    echo "MMXEXT enabled            ${mmxext-no}"
    echo "3DNow! enabled            ${amd3dnow-no}"
    echo "3DNow! extended enabled   ${amd3dnowext-no}"
    echo "SSE enabled               ${sse-no}"
    echo "SSSE3 enabled             ${ssse3-no}"
    echo "AVX enabled               ${avx-no}"
    echo "XOP enabled               ${xop-no}"
    echo "FMA3 enabled              ${fma3-no}"
    echo "FMA4 enabled              ${fma4-no}"
    echo "i686 features enabled     ${i686-no}"
    echo "CMOV is fast              ${fast_cmov-no}"
    echo "EBX available             ${ebx_available-no}"
    echo "EBP available             ${ebp_available-no}"
fi
if enabled aarch64; then
    echo "NEON enabled              ${neon-no}"
    echo "VFP enabled               ${vfp-no}"
fi
if enabled arm; then
    echo "ARMv5TE enabled           ${armv5te-no}"
    echo "ARMv6 enabled             ${armv6-no}"
    echo "ARMv6T2 enabled           ${armv6t2-no}"
    echo "VFP enabled               ${vfp-no}"
    echo "NEON enabled              ${neon-no}"
fi
if enabled ppc; then
    echo "AltiVec enabled           ${altivec-no}"
    echo "PPC 4xx optimizations     ${ppc4xx-no}"
    echo "dcbzl available           ${dcbzl-no}"
fi
if enabled sparc; then
    echo "VIS enabled               ${vis-no}"
fi
echo "debug symbols             ${debug-no}"
echo "optimize for size         ${small-no}"
echo "optimizations             ${optimizations-no}"
echo "static                    ${static-no}"
echo "shared                    ${shared-no}"
echo "new filter support        ${avfilter-no}"
echo "network support           ${network-no}"
echo "threading support         ${thread_type-no}"
echo "safe bitstream reader     ${safe_bitstream_reader-no}"
echo "SDL support               ${sdl-no}"
test -n "$random_seed" &&
    echo "random seed               ${random_seed}"
echo

echo "External libraries:"
print_enabled '' $EXTERNAL_LIBRARY_LIST | print_3_columns
echo

for type in decoder encoder hwaccel parser demuxer muxer protocol filter bsf indev outdev; do
    echo "Enabled ${type}s:"
    eval list=\$$(toupper $type)_LIST
    print_enabled '_*' $list | print_3_columns
    echo
done

license="LGPL version 2.1 or later"
if enabled nonfree; then
    license="nonfree and unredistributable"
elif enabled gplv3; then
    license="GPL version 3 or later"
elif enabled lgplv3; then
    license="LGPL version 3 or later"
elif enabled gpl; then
    license="GPL version 2 or later"
fi

echo "License: $license"

echo "Creating config.mak and config.h..."

test -e Makefile || echo "include $source_path/Makefile" > Makefile

config_files="$TMPH config.mak"

cat > config.mak <<EOF
# Automatically generated by configure - do not modify!
LIBAV_CONFIGURATION=$LIBAV_CONFIGURATION
prefix=$prefix
LIBDIR=\$(DESTDIR)$libdir
SHLIBDIR=\$(DESTDIR)$shlibdir
INCDIR=\$(DESTDIR)$incdir
BINDIR=\$(DESTDIR)$bindir
DATADIR=\$(DESTDIR)$datadir
DOCDIR=\$(DESTDIR)$docdir
MANDIR=\$(DESTDIR)$mandir
SRC_PATH=$source_path
CC_IDENT=$cc_ident
ARCH=$arch
CC=$cc
AS=$as
LD=$ld
DEPCC=$dep_cc
DEPCCFLAGS=$DEPCCFLAGS \$(CPPFLAGS)
DEPAS=$as
DEPASFLAGS=$DEPASFLAGS \$(CPPFLAGS)
YASM=$yasmexe
DEPYASM=$yasmexe
AR=$ar
ARFLAGS=$arflags
AR_O=$ar_o
RANLIB=$ranlib
STRIP=$strip
LN_S=$ln_s
CPPFLAGS=$CPPFLAGS
CFLAGS=$CFLAGS
ASFLAGS=$ASFLAGS
AS_C=$AS_C
AS_O=$AS_O
CC_C=$CC_C
CC_E=$CC_E
CC_O=$CC_O
LD_O=$LD_O
LD_LIB=$LD_LIB
LD_PATH=$LD_PATH
DLLTOOL=$dlltool
LDFLAGS=$LDFLAGS
SHFLAGS=$(echo $($ldflags_filter $SHFLAGS))
STRIPFLAGS=$STRIPFLAGS
YASMFLAGS=$YASMFLAGS
BUILDSUF=$build_suffix
FULLNAME=$FULLNAME
LIBPREF=$LIBPREF
LIBSUF=$LIBSUF
LIBNAME=$LIBNAME
SLIBPREF=$SLIBPREF
SLIBSUF=$SLIBSUF
EXESUF=$EXESUF
EXTRA_VERSION=$extra_version
CCDEP=$CCDEP
CCDEP_FLAGS=$CCDEP_FLAGS
ASDEP=$ASDEP
ASDEP_FLAGS=$ASDEP_FLAGS
CC_DEPFLAGS=$CC_DEPFLAGS
AS_DEPFLAGS=$AS_DEPFLAGS
HOSTCC=$host_cc
HOSTLD=$host_ld
HOSTCFLAGS=$host_cflags
HOSTCPPFLAGS=$host_cppflags
HOSTEXESUF=$HOSTEXESUF
HOSTLDFLAGS=$host_ldflags
HOSTLIBS=$host_libs
DEPHOSTCC=$host_cc
DEPHOSTCCFLAGS=$DEPHOSTCCFLAGS \$(HOSTCCFLAGS)
HOSTCCDEP=$HOSTCCDEP
HOSTCCDEP_FLAGS=$HOSTCCDEP_FLAGS
HOSTCC_DEPFLAGS=$HOSTCC_DEPFLAGS
HOSTCC_C=$HOSTCC_C
HOSTCC_O=$HOSTCC_O
HOSTLD_O=$HOSTLD_O
TARGET_EXEC=$target_exec $target_exec_args
TARGET_PATH=$target_path
TARGET_SAMPLES=${target_samples:-\$(SAMPLES)}
CFLAGS-avplay=$sdl_cflags
ZLIB=$($ldflags_filter -lz)
LIB_INSTALL_EXTRA_CMD=$LIB_INSTALL_EXTRA_CMD
EXTRALIBS=$extralibs
COMPAT_OBJS=$compat_objs
EXEOBJS=$exeobjs
INSTALL=install
LIBTARGET=${LIBTARGET}
SLIBNAME=${SLIBNAME}
SLIBNAME_WITH_VERSION=${SLIBNAME_WITH_VERSION}
SLIBNAME_WITH_MAJOR=${SLIBNAME_WITH_MAJOR}
SLIB_CREATE_DEF_CMD=${SLIB_CREATE_DEF_CMD}
SLIB_EXTRA_CMD=${SLIB_EXTRA_CMD}
SLIB_INSTALL_NAME=${SLIB_INSTALL_NAME}
SLIB_INSTALL_LINKS=${SLIB_INSTALL_LINKS}
SLIB_INSTALL_EXTRA_LIB=${SLIB_INSTALL_EXTRA_LIB}
SLIB_INSTALL_EXTRA_SHLIB=${SLIB_INSTALL_EXTRA_SHLIB}
SAMPLES:=${samples:-\$(LIBAV_SAMPLES)}
EOF

get_version(){
    lcname=lib${1}
    name=$(toupper $lcname)
    file=$source_path/$lcname/version.h
    eval $(awk "/#define ${name}_VERSION_M/ { print \$2 \"=\" \$3 }" "$file")
    eval ${name}_VERSION=\$${name}_VERSION_MAJOR.\$${name}_VERSION_MINOR.\$${name}_VERSION_MICRO
    eval echo "${lcname}_VERSION=\$${name}_VERSION" >> config.mak
    eval echo "${lcname}_VERSION_MAJOR=\$${name}_VERSION_MAJOR" >> config.mak
    eval echo "${lcname}_VERSION_MINOR=\$${name}_VERSION_MINOR" >> config.mak
}

map 'get_version $v' $LIBRARY_LIST

print_program_libs(){
    eval "program_libs=\$${1}_libs"
    eval echo "LIBS-${1}=${program_libs}" >> config.mak
}

map 'print_program_libs $v' $PROGRAM_LIST

cat > $TMPH <<EOF
/* Automatically generated by configure - do not modify! */
#ifndef LIBAV_CONFIG_H
#define LIBAV_CONFIG_H
#define LIBAV_CONFIGURATION "$(c_escape $LIBAV_CONFIGURATION)"
#define LIBAV_LICENSE "$(c_escape $license)"
#define AVCONV_DATADIR "$(eval c_escape $datadir)"
#define CC_IDENT "$(c_escape ${cc_ident:-Unknown compiler})"
#define restrict $_restrict
#define EXTERN_PREFIX "${extern_prefix}"
#define EXTERN_ASM ${extern_prefix}
#define SLIBSUF "$SLIBSUF"
EOF

test -n "$malloc_prefix" &&
    echo "#define MALLOC_PREFIX $malloc_prefix" >>$TMPH

if enabled yasm; then
    append config_files $TMPASM
    printf '' >$TMPASM
fi

enabled getenv || echo "#define getenv(x) NULL" >> $TMPH

print_config ARCH_   "$config_files" $ARCH_LIST
print_config HAVE_   "$config_files" $HAVE_LIST
print_config CONFIG_ "$config_files" $CONFIG_LIST       \
                                     $CONFIG_EXTRA      \
                                     $ALL_COMPONENTS    \

echo "#endif /* LIBAV_CONFIG_H */" >> $TMPH

# Do not overwrite an unchanged config.h to avoid superfluous rebuilds.
cp_if_changed $TMPH config.h
touch .config

enabled yasm && cp_if_changed $TMPASM config.asm

cat > $TMPH <<EOF
/* Generated by ffconf */
#ifndef AVUTIL_AVCONFIG_H
#define AVUTIL_AVCONFIG_H
EOF

print_config AV_HAVE_ $TMPH $HAVE_LIST_PUB

echo "#endif /* AVUTIL_AVCONFIG_H */" >> $TMPH

cp_if_changed $TMPH libavutil/avconfig.h

test -n "$WARNINGS" && printf "\n$WARNINGS"

# build pkg-config files

pkgconfig_generate(){
    name=$1
    shortname=${name#lib}${build_suffix}
    comment=$2
    version=$3
    libs=$4
    requires=$5
    enabled ${name#lib} || return 0
    mkdir -p $name
    cat <<EOF > $name/$name.pc
prefix=$prefix
exec_prefix=\${prefix}
libdir=$libdir
includedir=$incdir

Name: $name
Description: $comment
Version: $version
Requires: $(enabled shared || echo $requires)
Requires.private: $(enabled shared && echo $requires)
Conflicts:
Libs: -L\${libdir} -l${shortname} $(enabled shared || echo $libs)
Libs.private: $(enabled shared && echo $libs)
Cflags: -I\${includedir}
EOF
    cat <<EOF > $name/$name-uninstalled.pc
prefix=
exec_prefix=
libdir=\${pcfiledir}
includedir=${source_path}

Name: $name
Description: $comment
Version: $version
Requires: $requires
Conflicts:
Libs: \${libdir}/${LIBPREF}${shortname}${LIBSUF} $libs
Cflags: -I\${includedir}
EOF
}

lavfi_libs="libavutil = $LIBAVUTIL_VERSION"
enabled movie_filter    && prepend lavfi_libs "libavformat >= $LIBAVFORMAT_VERSION, libavcodec >= $LIBAVCODEC_VERSION,"
enabled resample_filter && prepend lavfi_libs "libavresample >= $LIBAVRESAMPLE_VERSION,"
enabled scale_filter    && prepend lavfi_libs "libswscale >= $LIBSWSCALE_VERSION,"

pkgconfig_generate libavutil     "Libav utility library"          "$LIBAVUTIL_VERSION"     "$LIBM"
pkgconfig_generate libavcodec    "Libav codec library"            "$LIBAVCODEC_VERSION"    "$extralibs" "libavutil = $LIBAVUTIL_VERSION"
pkgconfig_generate libavformat   "Libav container format library" "$LIBAVFORMAT_VERSION"   "$extralibs" "libavcodec = $LIBAVCODEC_VERSION"
pkgconfig_generate libavdevice   "Libav device handling library"  "$LIBAVDEVICE_VERSION"   "$extralibs" "libavformat = $LIBAVFORMAT_VERSION"
pkgconfig_generate libavfilter   "Libav video filtering library"  "$LIBAVFILTER_VERSION"   "$extralibs" "$lavfi_libs"
pkgconfig_generate libavresample "Libav audio resampling library" "$LIBAVRESAMPLE_VERSION" "$extralibs" "libavutil = $LIBAVUTIL_VERSION"
pkgconfig_generate libswscale    "Libav image rescaling library"  "$LIBSWSCALE_VERSION"    "$LIBM"      "libavutil = $LIBAVUTIL_VERSION"