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

[James Almer]

On 5/11/2020 8:59 AM, Andreas Rheinhardt wrote:
> 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?)

It's possible, but i don't know if that's expected behavior or not.
Editing the codecpar is done by some muxers, true, but the doxy stats
it's "filled by the caller before avformat_write_header()".
An option could be to have a copy of the AVCodecParameters that can be
edited in st->internal instead, and leave the caller one in st alone.

Will apply, thanks.