omx: Add support for broadcom OMX on raspberry pi

The raspberry pi uses the alternative API/ABI for OMX; this makes
such builds incompatible with all the normal OpenMAX implementations.
Since this can't easily be detected at configure time (one can
build for raspberry pi's OMX just fine using the generic, pristine
Khronos OpenMAX IL headers, no need for their own extensions),
require a separate configure switch for it instead.

The broadcom host library can't be unloaded once loaded and started;
the deinit function that it provides is a no-op, and after started,
it has got background threads running, so dlclosing it makes it
crash.

Signed-off-by: Martin Storsjö <martin@martin.st>

Changelog

@@ -54,7 +54,7 @@ version <next>:
 - VAAPI-accelerated format conversion and scaling
 - libnpp/CUDA-accelerated format conversion and scaling
 - VAAPI-accelerate H.264/HEVC/MJPEG encoding
-- Generic OpenMAX IL encoder
+- Generic OpenMAX IL encoder with support for Raspberry Pi
 
 
 version 11:

configure

@@ -145,6 +145,7 @@ Hardware-accelerated decoding/encoding:
   --enable-mmal            enable decoding via MMAL [no]
   --enable-nvenc           enable encoding via NVENC [no]
   --enable-omx             enable encoding via OpenMAX IL [no]
+  --enable-omx-rpi         enable encoding via OpenMAX IL for Raspberry Pi [no]
 
 Individual component options:
   --disable-everything     disable all components listed below
@@ -1259,6 +1260,7 @@ EXTERNAL_LIBRARY_LIST="
 FEATURE_LIST="
     gray
     hardcoded_tables
+    omx_rpi
     runtime_cpudetect
     safe_bitstream_reader
     shared
@@ -4621,7 +4623,12 @@ enabled mmal              && { check_lib interface/mmal/mmal.h mmal_port_connect
                                     check_lib interface/mmal/mmal.h mmal_port_connect ; }
                                 check_lib interface/mmal/mmal.h mmal_port_connect ; } ||
                                die "ERROR: mmal not found"; }
-enabled omx               && { check_header OMX_Core.h || die "ERROR: OpenMAX IL headers not found"; }
+enabled omx_rpi && enable omx
+enabled omx               && { check_header OMX_Core.h ||
+                                { ! enabled cross_compile && enabled omx_rpi && {
+                                    add_cflags -isystem/opt/vc/include/IL ; }
+                                check_header OMX_Core.h ; } ||
+                               die "ERROR: OpenMAX IL headers not found"; }
 enabled openssl           && { check_pkg_config openssl openssl/ssl.h SSL_library_init && {
                                add_cflags $openssl_cflags && add_extralibs $openssl_libs; }||
                                check_lib openssl/ssl.h SSL_library_init -lssl -lcrypto ||

libavcodec/omx.c

@@ -19,6 +19,12 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include "config.h"
+
+#if CONFIG_OMX_RPI
+#define OMX_SKIP64BIT
+#endif
+
 #include <dlfcn.h>
 #include <OMX_Core.h>
 #include <OMX_Component.h>
@@ -69,6 +75,7 @@ static int64_t from_omx_ticks(OMX_TICKS value)
 
 typedef struct OMXContext {
     void *lib;
+    void *lib2;
     OMX_ERRORTYPE (*ptr_Init)(void);
     OMX_ERRORTYPE (*ptr_Deinit)(void);
     OMX_ERRORTYPE (*ptr_ComponentNameEnum)(OMX_STRING, OMX_U32, OMX_U32);
@@ -76,6 +83,7 @@ typedef struct OMXContext {
     OMX_ERRORTYPE (*ptr_FreeHandle)(OMX_HANDLETYPE);
     OMX_ERRORTYPE (*ptr_GetComponentsOfRole)(OMX_STRING, OMX_U32*, OMX_U8**);
     OMX_ERRORTYPE (*ptr_GetRolesOfComponent)(OMX_STRING, OMX_U32*, OMX_U8**);
+    void (*host_init)(void);
 } OMXContext;
 
 static av_cold void *dlsym_prefixed(void *handle, const char *symbol, const char *prefix)
@@ -86,8 +94,23 @@ static av_cold void *dlsym_prefixed(void *handle, const char *symbol, const char
 }
 
 static av_cold int omx_try_load(OMXContext *s, void *logctx,
-                                const char *libname, const char *prefix)
+                                const char *libname, const char *prefix,
+                                const char *libname2)
 {
+    if (libname2) {
+        s->lib2 = dlopen(libname2, RTLD_NOW | RTLD_GLOBAL);
+        if (!s->lib2) {
+            av_log(logctx, AV_LOG_WARNING, "%s not found\n", libname);
+            return AVERROR_ENCODER_NOT_FOUND;
+        }
+        s->host_init = dlsym(s->lib2, "bcm_host_init");
+        if (!s->host_init) {
+            av_log(logctx, AV_LOG_WARNING, "bcm_host_init not found\n");
+            dlclose(s->lib2);
+            s->lib2 = NULL;
+            return AVERROR_ENCODER_NOT_FOUND;
+        }
+    }
     s->lib = dlopen(libname, RTLD_NOW | RTLD_GLOBAL);
     if (!s->lib) {
         av_log(logctx, AV_LOG_WARNING, "%s not found\n", libname);
@@ -106,6 +129,9 @@ static av_cold int omx_try_load(OMXContext *s, void *logctx,
         av_log(logctx, AV_LOG_WARNING, "Not all functions found in %s\n", libname);
         dlclose(s->lib);
         s->lib = NULL;
+        if (s->lib2)
+            dlclose(s->lib2);
+        s->lib2 = NULL;
         return AVERROR_ENCODER_NOT_FOUND;
     }
     return 0;
@@ -114,8 +140,12 @@ static av_cold int omx_try_load(OMXContext *s, void *logctx,
 static av_cold OMXContext *omx_init(void *logctx, const char *libname, const char *prefix)
 {
     static const char * const libnames[] = {
-        "libOMX_Core.so",
-        "libOmxCore.so",
+#if CONFIG_OMX_RPI
+        "/opt/vc/lib/libopenmaxil.so", "/opt/vc/lib/libbcm_host.so",
+#else
+        "libOMX_Core.so", NULL,
+        "libOmxCore.so", NULL,
+#endif
         NULL
     };
     const char* const* nameptr;
@@ -126,14 +156,14 @@ static av_cold OMXContext *omx_init(void *logctx, const char *libname, const cha
     if (!omx_context)
         return NULL;
     if (libname) {
-        ret = omx_try_load(omx_context, logctx, libname, prefix);
+        ret = omx_try_load(omx_context, logctx, libname, prefix, NULL);
         if (ret < 0) {
             av_free(omx_context);
             return NULL;
         }
     } else {
-        for (nameptr = libnames; *nameptr; nameptr++)
-            if (!(ret = omx_try_load(omx_context, logctx, *nameptr, prefix)))
+        for (nameptr = libnames; *nameptr; nameptr += 2)
+            if (!(ret = omx_try_load(omx_context, logctx, nameptr[0], prefix, nameptr[1])))
                 break;
         if (!*nameptr) {
             av_free(omx_context);
@@ -141,6 +171,8 @@ static av_cold OMXContext *omx_init(void *logctx, const char *libname, const cha
         }
     }
 
+    if (omx_context->host_init)
+        omx_context->host_init();
     omx_context->ptr_Init();
     return omx_context;
 }
@@ -298,6 +330,12 @@ static av_cold int find_component(OMXContext *omx_context, void *logctx,
     char **components;
     int ret = 0;
 
+#if CONFIG_OMX_RPI
+    if (av_strstart(role, "video_encoder.", NULL)) {
+        av_strlcpy(str, "OMX.broadcom.video_encode", str_size);
+        return 0;
+    }
+#endif
     omx_context->ptr_GetComponentsOfRole((OMX_STRING) role, &num, NULL);
     if (!num) {
         av_log(logctx, AV_LOG_WARNING, "No component for role %s found\n", role);

libavcodec/version.h

@@ -29,7 +29,7 @@
 
 #define LIBAVCODEC_VERSION_MAJOR 57
 #define LIBAVCODEC_VERSION_MINOR 18
-#define LIBAVCODEC_VERSION_MICRO  0
+#define LIBAVCODEC_VERSION_MICRO  1
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
                                                LIBAVCODEC_VERSION_MINOR, \