[FFmpeg-devel] [PATCH v5 1/4 v7] lavf/avienc: Add support for palette side data

Mats Peterson matsp888 at yahoo.com
Sat Mar 5 14:32:56 CET 2016

On 03/05/2016 02:24 PM, Mats Peterson wrote:
> On 03/05/2016 12:21 PM, Mats Peterson wrote:
>> I've noticed that avienc.c is close to useless for use with stdout. It
>> only checks pb->seekable in a few places, and for example the
>> ff_end_tag() function uses avio_seek(), but that one is used in several
>> places where there is no check for a seekable stream.
>> Anyway, this version adds the AVISF_VIDEO_PALCHANGES flag properly to
>> the 'strh' chunk, per the Microsoft documentation.
>> Mats
> The original toon.avi doesn't contain xxpc chunks at keyframes either,
> if that can be of any comfort. It only contains two xxpc chunks, at
> that. If you're able to invent something nice regarding palette changes
> on keyframes, please go ahead. But please add what's available in the
> meantime.
> Mats

In my book it should be up to the demuxer/decoder to keep track of 
previous palettes. You said yourself that no xxpc chunks should be 
included if they are identical to the first palette.


Mats Peterson

More information about the ffmpeg-devel mailing list