[FFmpeg-devel] [PATCH v2 2/2] avformat/mvdec: handle audio sample size

[Peter Ross]

On Wed, Dec 01, 2021 at 04:18:42PM +1100, Peter Ross wrote:
> On Sat, Nov 27, 2021 at 04:45:51PM -0500, John-Paul Stewart wrote:
> > Adds support for reading audio sample size from the data instead of
> > assuming all audio is 16 bits per sample.
> > ---
> >  libavformat/mvdec.c | 18 +++++++++++++++---
> >  1 file changed, 15 insertions(+), 3 deletions(-)
> > 
> > diff --git a/libavformat/mvdec.c b/libavformat/mvdec.c
> > index 8492928820..8b54a9ab04 100644
> > --- a/libavformat/mvdec.c
> > +++ b/libavformat/mvdec.c
> > @@ -299,6 +299,8 @@ static int mv_read_header(AVFormatContext *avctx)
> >      if (version == 2) {
> >          uint64_t timestamp;
> >          int v;
> > +        uint32_t bytes_per_sample;
> > +
> >          avio_skip(pb, 22);
> >  
> >          /* allocate audio track first to prevent unnecessary seeking
> > @@ -341,11 +343,21 @@ static int mv_read_header(AVFormatContext *avctx)
> >          }
> >          avpriv_set_pts_info(ast, 33, 1, ast->codecpar->sample_rate);
> >  
> > -        avio_skip(pb, 4);
> > +        bytes_per_sample = avio_rb32(pb);
> >  
> >          v = avio_rb32(pb);
> >          if (v == AUDIO_FORMAT_SIGNED) {
> > -            ast->codecpar->codec_id = AV_CODEC_ID_PCM_S16BE;
> > +            switch (bytes_per_sample) {
> > +            case 1:
> > +                ast->codecpar->codec_id = AV_CODEC_ID_PCM_S8;
> > +                break;
> > +            case 2:
> > +                ast->codecpar->codec_id = AV_CODEC_ID_PCM_S16BE;
> > +                break;
> > +            default:
> > +                avpriv_request_sample(avctx, "Audio sample size %i bytes", bytes_per_sample);
> > +                break;
> > +            }
> >          } else {
> >              avpriv_request_sample(avctx, "Audio compression (format %i)", v);
> >          }
> > @@ -369,7 +381,7 @@ static int mv_read_header(AVFormatContext *avctx)
> >              avio_skip(pb, 8);
> >              av_add_index_entry(ast, pos, timestamp, asize, 0, AVINDEX_KEYFRAME);
> >              av_add_index_entry(vst, pos + asize, i, vsize, 0, AVINDEX_KEYFRAME);
> > -            timestamp += asize / (ast->codecpar->channels * 2LL);
> > +            timestamp += asize / (ast->codecpar->channels * bytes_per_sample);
> >          }
> >      } else if (!version && avio_rb16(pb) == 3) {
> >          avio_skip(pb, 4);
> > -- 
> > 2.33.0
> 
> thanks for doing this.
> both patches look good. i will apply in a few days.

applied.

-- Peter
(A907 E02F A6E5 0CD2 34CD 20D2 6760 79C5 AC40 DD6B)
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