@@ -272,6 +272,9 @@ static int update_extradata(AVCodecParameters *codecpar)
switch(codecpar->codec_id) {
case AV_CODEC_ID_OPUS:
AV_WB8(codecpar->extradata + 9, codecpar->ch_layout.nb_channels);
+ AV_WL16(codecpar->extradata + 10, AV_RB16(codecpar->extradata + 10)); // Byte swap pre-skip
+ AV_WL32(codecpar->extradata + 12, AV_RB32(codecpar->extradata + 12)); // Byte swap sample rate
+ AV_WL16(codecpar->extradata + 16, AV_RB16(codecpar->extradata + 16)); // Byte swap Output Gain
break;
case AV_CODEC_ID_AAC: {
uint8_t buf[5];
@@ -42,8 +42,12 @@ static int update_extradata(IAMFCodecConfig *codec_config)
if (codec_config->extradata_size < 19)
return AVERROR_INVALIDDATA;
codec_config->extradata_size -= 8;
- memmove(codec_config->extradata, codec_config->extradata + 8, codec_config->extradata_size);
- AV_WB8(codec_config->extradata + 1, 2); // set channels to stereo
+ AV_WB8(codec_config->extradata + 0, AV_RL8(codec_config->extradata + 8)); // version
+ AV_WB8(codec_config->extradata + 1, 2); // set channels to stereo
+ AV_WB16(codec_config->extradata + 2, AV_RL16(codec_config->extradata + 10)); // Byte swap pre-skip
+ AV_WB32(codec_config->extradata + 4, AV_RL32(codec_config->extradata + 12)); // Byte swap sample rate
+ AV_WB16(codec_config->extradata + 8, 0); // set Output Gain to 0
+ AV_WB8(codec_config->extradata + 10, AV_RL8(codec_config->extradata + 18)); // Mapping family
break;
case AV_CODEC_ID_FLAC: {
uint8_t buf[13];
@@ -1,7 +1,7 @@
-#extradata 0: 19, 0x379c0490
-#extradata 1: 19, 0x379c0490
-#extradata 2: 19, 0x3792048f
-#extradata 3: 19, 0x3792048f
+#extradata 0: 19, 0x3a0e0490
+#extradata 1: 19, 0x3a0e0490
+#extradata 2: 19, 0x3a04048f
+#extradata 3: 19, 0x3a04048f
#tb 0: 1/48000
#media_type 0: audio
#codec_id 0: opus
@@ -1,7 +1,7 @@
-#extradata 0: 19, 0x379c0490
-#extradata 1: 19, 0x379c0490
-#extradata 2: 19, 0x3792048f
-#extradata 3: 19, 0x3792048f
+#extradata 0: 19, 0x3a0e0490
+#extradata 1: 19, 0x3a0e0490
+#extradata 2: 19, 0x3a04048f
+#extradata 3: 19, 0x3a04048f
#tb 0: 1/48000
#media_type 0: audio
#codec_id 0: opus
Clause 3.11.1 of IAMF[1] states the values are stored in big endian, in contrast to the Ogg Encapsulation for Opus[2] where they are in little endian. [1]https://aomediacodec.github.io/iamf/v1.0.0-errata.html#opus-specific [2]https://datatracker.ietf.org/doc/html/rfc7845#section-5.1 Signed-off-by: James Almer <jamrial@gmail.com> --- libavformat/iamf_parse.c | 3 +++ libavformat/iamf_writer.c | 8 ++++++-- tests/ref/fate/iamf-5_1-copy | 8 ++++---- tests/ref/fate/iamf-5_1-demux | 8 ++++---- 4 files changed, 17 insertions(+), 10 deletions(-)