lavfi/af_hdcd: Implement high definition audio cd filtering.

Fixes ticket #4441.

Changelog

@@ -24,6 +24,7 @@ version <next>:
 - remap filter
 - hash and framehash muxers
 - colorspace filter
+- hdcd filter
 
 version 3.0:
 - Common Encryption (CENC) MP4 encoding and decoding support

doc/filters.texi

@@ -8255,6 +8255,11 @@ Then, the effect of this Hald CLUT can be visualized with:
 ffplay input.mkv -vf "movie=clut.png, [in] haldclut"
 @end example
 
+@section hdcd
+
+Decodes high definition audio cd data. 16-Bit PCM stream containing hdcd flags
+is converted to 20-bit PCM stream.
+
 @section hflip
 
 Flip the input video horizontally.

libavfilter/Makefile

@@ -103,6 +103,7 @@ OBJS-$(CONFIG_TREMOLO_FILTER)                += af_tremolo.o
 OBJS-$(CONFIG_VIBRATO_FILTER)                += af_vibrato.o generate_wave_table.o
 OBJS-$(CONFIG_VOLUME_FILTER)                 += af_volume.o
 OBJS-$(CONFIG_VOLUMEDETECT_FILTER)           += af_volumedetect.o
+OBJS-$(CONFIG_HDCD_FILTER)                   += af_hdcd.o
 
 OBJS-$(CONFIG_AEVALSRC_FILTER)               += aeval.o
 OBJS-$(CONFIG_ANOISESRC_FILTER)              += asrc_anoisesrc.o

libavfilter/allfilters.c

@@ -104,6 +104,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(EXTRASTEREO,    extrastereo,    af);
     REGISTER_FILTER(FIREQUALIZER,   firequalizer,   af);
     REGISTER_FILTER(FLANGER,        flanger,        af);
+    REGISTER_FILTER(HDCD,           hdcd,           af);
     REGISTER_FILTER(HIGHPASS,       highpass,       af);
     REGISTER_FILTER(JOIN,           join,           af);
     REGISTER_FILTER(LADSPA,         ladspa,         af);

tests/fate/filter-audio.mak

@@ -102,6 +102,12 @@ fate-filter-volume: CMD = md5 -i $(SRC) -af aperms=random,volume=precision=fixed
 fate-filter-volume: CMP = oneline
 fate-filter-volume: REF = 4d6ba75ef3e32d305d066b9bc771d6f4
 
+FATE_AFILTER_SAMPLES-$(call FILTERDEMDECENCMUX, HDCD, FLAC, FLAC, PCM_S24LE, PCM_S24LE) += fate-filter-hdcd
+fate-filter-hdcd: SRC = $(TARGET_SAMPLES)/filter/hdcd.flac
+fate-filter-hdcd: CMD = md5 -i $(SRC) -af hdcd -f s24le
+fate-filter-hdcd: CMP = oneline
+fate-filter-hdcd: REF = 5db465a58d2fd0d06ca944b883b33476
+
 FATE_AFILTER-yes += fate-filter-formats
 fate-filter-formats: libavfilter/formats-test$(EXESUF)
 fate-filter-formats: CMD = run libavfilter/formats-test