[FFmpeg-devel] [PATCH] avformat/apngenc: use the stream parameters extradata if no updated one is made available

Andreas Cadhalpun andreas.cadhalpun at googlemail.com
Wed Nov 2 21:13:41 EET 2016

On 01.11.2016 23:10, Hendrik Leppkes wrote:
> Am 01.11.2016 17:17 schrieb "Andreas Cadhalpun" <
> andreas.cadhalpun at googlemail.com>:
>> Not again, but instead, as the extradata is then only transferred as side data.
>> That way it is again consistent between demuxer/decoder and encoder/muxer.
> I don't think thats a good idea. Demuxers should fill the extradata field
> if any is present and required for decoding - some other decoder might want
> extradata for init or something, and that way you can accommodate it
> without having to wait for the first packet.

Is this documented somewhere?

> That's basically how all demuxers work, will extradata and if it can and
> does change just send an update notice.

Requiring to use codecpar->extradata for passing this from demuxer to decoder,
while at the same time requiring to use AV_PKT_DATA_NEW_EXTRADATA side data
to pass this from muxer to encoder seems quite strange to me.

Best regards,

More information about the ffmpeg-devel mailing list