[FFmpeg-devel] [PATCH v5 1/4 v3] lavf/avienc: Add support for palette side data

Michael Niedermayer michael at niedermayer.cc
Sat Mar 5 01:08:20 CET 2016

On Fri, Mar 04, 2016 at 10:12:41PM +0100, Mats Peterson wrote:
> On 03/04/2016 10:02 PM, Mats Peterson wrote:
> >On 03/04/2016 09:52 PM, Mats Peterson wrote:
> >>On 03/04/2016 08:44 PM, Michael Niedermayer wrote:
> >>>On Fri, Mar 04, 2016 at 11:59:11AM +0100, Mats Peterson wrote:
> >>>>On 03/04/2016 05:59 AM, Mats Peterson wrote:
> >>>>>Removed some unused variables in AVIStream.
> >>>>>
> >>>>
> >>>>
> >>>>I would like to remind you of the fact that this patch (and the one
> >>>>for riffenc.c) is needed for stream copying of Microsoft Video 1
> >>>>(CRAM) in 8-bit mode, Microsoft RLE4 and Microsoft RLE8. There are
> >>>>possibly more codecs using a palette, but these are the ones I can
> >>>>come up with at the moment.
> >>>
> >>>i tried CRAM and MSRLE, but these already work when streamcopied
> >>>before, do you have a testcase that does not work
> >>>
> >>
> >>It works, but only so much. On stream copy, it will only write the
> >>palette after BITMAPINFOHEADER to the destination file. It won't write
> >>any xxpc palette switching chunks to the file.
> >>
> >>Mats
> >>
> >The xxpc chunks come as palette side data.
> >
> >Mats
> Try ffmpeg -i 8bpp_129.avi -vcodec copy test.avi, with and without

where can i find that file ?

> the avienc.c and riffenc.c patch. The destination file will only
> contain xxpc chunks with my patch applied.

pc chunks are only needed when the palette changes, if its the same
for the whole file and after BITMAPINFOHEADER then theres no need
for pc chunks
a testcase with changing palette would be ideal for fate


Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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