[FFmpeg-devel] [PATCH 2/2] avformat/mov: read PCM audio configuration box ('pcmC') if available

Marton Balint cus at passwd.hu
Mon Jun 27 21:36:42 EEST 2022



On Sun, 19 Jun 2022, Marton Balint wrote:

> From: Ivan Baykalov <4rusxg at gmail.com>
>
> For ipcm and fpcm streams, big-endian format is the default, but it can be changed
> with additional 'pcmC' sub-atom of audio sample description.
>
> Details can be found in ISO/IEC 23003-5:2020
>
> Fixes ticket #9763.
> Fixes ticket #9790.
>
> Patch simplified by Marton Balint.

Applied the series.

Regards,
Marton

>
> Signed-off-by: Marton Balint <cus at passwd.hu>
> ---
> libavformat/mov.c | 22 ++++++++++++++++++++++
> 1 file changed, 22 insertions(+)
>
> diff --git a/libavformat/mov.c b/libavformat/mov.c
> index 0660a51492..c6fbe511c0 100644
> --- a/libavformat/mov.c
> +++ b/libavformat/mov.c
> @@ -1553,6 +1553,9 @@ static void set_last_stream_little_endian(AVFormatContext *fc)
>     st = fc->streams[fc->nb_streams-1];
>
>     switch (st->codecpar->codec_id) {
> +    case AV_CODEC_ID_PCM_S16BE:
> +        st->codecpar->codec_id = AV_CODEC_ID_PCM_S16LE;
> +        break;
>     case AV_CODEC_ID_PCM_S24BE:
>         st->codecpar->codec_id = AV_CODEC_ID_PCM_S24LE;
>         break;
> @@ -1579,6 +1582,24 @@ static int mov_read_enda(MOVContext *c, AVIOContext *pb, MOVAtom atom)
>     return 0;
> }
>
> +static int mov_read_pcmc(MOVContext *c, AVIOContext *pb, MOVAtom atom)
> +{
> +    int format_flags;
> +
> +    if (atom.size < 6) {
> +        av_log(c->fc, AV_LOG_ERROR, "Empty pcmC box\n");
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    avio_r8(pb);    // version
> +    avio_rb24(pb);  // flags
> +    format_flags = avio_r8(pb);
> +    if (format_flags == 1) // indicates little-endian format. If not present, big-endian format is used
> +        set_last_stream_little_endian(c->fc);
> +
> +    return 0;
> +}
> +
> static int mov_read_colr(MOVContext *c, AVIOContext *pb, MOVAtom atom)
> {
>     AVStream *st;
> @@ -7674,6 +7695,7 @@ static const MOVParseTableEntry mov_default_parse_table[] = {
> { MKTAG('S','A','3','D'), mov_read_SA3D }, /* ambisonic audio box */
> { MKTAG('S','A','N','D'), mov_read_SAND }, /* non diegetic audio box */
> { MKTAG('i','l','o','c'), mov_read_iloc },
> +{ MKTAG('p','c','m','C'), mov_read_pcmc }, /* PCM configuration box */
> { 0, NULL }
> };
>
> -- 
> 2.35.3
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".
>


More information about the ffmpeg-devel mailing list