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

Mats Peterson matsp888 at yahoo.com
Sat Mar 5 04:19:51 CET 2016

On 03/05/2016 01:08 AM, Michael Niedermayer wrote:
> 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 ?

Thought you had it already?

>> 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

And what do you suggest in order to detect this? 1 kb more per frame 
isn't that much. Nut uses it all the time.

You were the one who proposed to use a shared function, and the option 
for a calling program to deliver the palette as side data. That's why I 
wrote the function, to be shared by avienc, movenc and possibly more 
muxers. It would be nice if you could apply these remaining patches now, 
thank you.


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