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avformat/iamf_writer: fix coded audio_roll_distance values

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'seek_preroll' corresponds to 'audio_roll_distance' in IAMF[1]

[1]https://aomediacodec.github.io/iamf/v1.0.0-errata.html#audio_roll_distance

Signed-off-by: James Almer <jamrial@gmail.com>
(cherry picked from commit 2094f4029563d8fe5e62663bc04fc1f109448182)
This commit is contained in:
Felicia Lim 2024-07-09 15:27:16 -07:00 committed by James Almer
parent df2d21a47b
commit 5e43483206
2 changed files with 30 additions and 2 deletions
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2
libavformat/iamf_parse.c
View File

@ -683,7 +683,7 @@ static int audio_element_obu(void *s, IAMFContext *c, AVIOContext *pb, int len)
substream->codecpar->codec_id = codec_config->codec_id;
substream->codecpar->frame_size = codec_config->nb_samples;
substream->codecpar->sample_rate = codec_config->sample_rate;
substream->codecpar->seek_preroll = codec_config->seek_preroll;
substream->codecpar->seek_preroll = -codec_config->seek_preroll * codec_config->nb_samples;
switch(substream->codecpar->codec_id) {
case AV_CODEC_ID_AAC:

30
libavformat/iamf_writer.c
View File

@ -72,6 +72,34 @@ static int update_extradata(IAMFCodecConfig *codec_config)
return 0;
}
static int populate_audio_roll_distance(IAMFCodecConfig *codec_config)
{
switch (codec_config->codec_id) {
case AV_CODEC_ID_OPUS:
if (!codec_config->nb_samples)
return AVERROR(EINVAL);
// ceil(3840 / nb_samples)
codec_config->seek_preroll = -(1 + ((3840 - 1) / codec_config->nb_samples));
break;
case AV_CODEC_ID_AAC:
codec_config->seek_preroll = -1;
break;
case AV_CODEC_ID_FLAC:
case AV_CODEC_ID_PCM_S16BE:
case AV_CODEC_ID_PCM_S24BE:
case AV_CODEC_ID_PCM_S32BE:
case AV_CODEC_ID_PCM_S16LE:
case AV_CODEC_ID_PCM_S24LE:
case AV_CODEC_ID_PCM_S32LE:
codec_config->seek_preroll = 0;
break;
default:
return AVERROR(EINVAL);
}
return 0;
}
static int fill_codec_config(IAMFContext *iamf, const AVStreamGroup *stg,
IAMFCodecConfig *codec_config)
{
@ -83,7 +111,7 @@ static int fill_codec_config(IAMFContext *iamf, const AVStreamGroup *stg,
codec_config->sample_rate = st->codecpar->sample_rate;
codec_config->codec_tag = st->codecpar->codec_tag;
codec_config->nb_samples = st->codecpar->frame_size;
codec_config->seek_preroll = st->codecpar->seek_preroll;
populate_audio_roll_distance(codec_config);
if (st->codecpar->extradata_size) {
codec_config->extradata = av_memdup(st->codecpar->extradata, st->codecpar->extradata_size);
if (!codec_config->extradata)