[FFmpeg-devel] [PATCH 2/2] avformat/ivfenc: move bsf insertion to the init function

[Anton Khirnov]

Quoting Andreas Rheinhardt (2020-05-11 13:59:27)
> James Almer:
> > Signed-off-by: James Almer <jamrial at gmail.com>
> > ---
> >  libavformat/ivfenc.c | 24 ++++++++++--------------
> >  1 file changed, 10 insertions(+), 14 deletions(-)
> > 
> > diff --git a/libavformat/ivfenc.c b/libavformat/ivfenc.c
> > index 0ce4a85171..0951f56c92 100644
> > --- a/libavformat/ivfenc.c
> > +++ b/libavformat/ivfenc.c
> > @@ -43,6 +43,16 @@ static int ivf_init(AVFormatContext *s)
> >          return AVERROR(EINVAL);
> >      }
> >  
> > +    if (par->codec_id == AV_CODEC_ID_VP9) {
> > +        int ret = ff_stream_add_bitstream_filter(s->streams[0], "vp9_superframe", NULL);
> > +        if (ret < 0)
> > +            return ret;
> > +    } else if (par->codec_id == AV_CODEC_ID_AV1) {
> > +        int ret = ff_stream_add_bitstream_filter(s->streams[0], "av1_metadata", "td=insert");
> > +        if (ret < 0)
> > +            return ret;
> > +    }
> > +
> >      return 0;
> >  }
> >  
> > @@ -100,19 +110,6 @@ static int ivf_write_trailer(AVFormatContext *s)
> >      return 0;
> >  }
> >  
> > -static int ivf_check_bitstream(struct AVFormatContext *s, const AVPacket *pkt)
> > -{
> > -    int ret = 1;
> > -    AVStream *st = s->streams[pkt->stream_index];
> > -
> > -    if (st->codecpar->codec_id == AV_CODEC_ID_VP9)
> > -        ret = ff_stream_add_bitstream_filter(st, "vp9_superframe", NULL);
> > -    else if (st->codecpar->codec_id == AV_CODEC_ID_AV1)
> > -        ret = ff_stream_add_bitstream_filter(st, "av1_metadata", "td=insert");
> > -
> > -    return ret;
> > -}
> > -
> >  static const AVCodecTag codec_ivf_tags[] = {
> >      { AV_CODEC_ID_VP8,  MKTAG('V', 'P', '8', '0') },
> >      { AV_CODEC_ID_VP9,  MKTAG('V', 'P', '9', '0') },
> > @@ -131,6 +128,5 @@ AVOutputFormat ff_ivf_muxer = {
> >      .write_header = ivf_write_header,
> >      .write_packet = ivf_write_packet,
> >      .write_trailer = ivf_write_trailer,
> > -    .check_bitstream = ivf_check_bitstream,
> >      .codec_tag    = (const AVCodecTag* const []){ codec_ivf_tags, 0 },
> >  };
> > 
> LGTM. (Would it actually make sense/be possible to replace st->codecpar
> with the output codecparameters of the bsf if the bsf is initialized in
> the init function, so that it is easier for the muxer to locate the
> right codecparameters when writing the header?)

I'd say ideally the muxer internals should be decoupled from the
outwards user-facing AVFormatContext/AVStream and not touch them
directly. Same for the codecs.
It would probably take a lot of work to implement though.

-- 
Anton Khirnov