[FFmpeg-devel] Help needed with muxing issues pertaining to raw AVI and QuickTime video

Mats Peterson matsp888 at yahoo.com
Mon Feb 15 12:40:05 CET 2016


On 02/15/2016 12:38 PM, Michael Niedermayer wrote:
> On Mon, Feb 15, 2016 at 05:38:03AM +0100, Mats Peterson wrote:
>> I'm not very confident on the muxing side, therefore I would be
>> grateful if anyone able to look outside of his own agenda could look
>> into possible solutions in order to solve the following issues
>> pertaining to writing AVI and QuickTime files created with "-vcodec
>> rawvideo":
>>
>> 1. Incorrect stride. It should be 4-byte aligned for AVI, and 2-byte
>> aligned for QuickTime. Currently it's the same as for nut, i.e. the
>> minimum possible. This will logically only work for files with even
>> widths.
>>
>> 2. Palette being included in the frames. This is OK for nut, but
>> it's clearly non-standard behaviour for AVI and QuickTime, and it
>> makes the files unplayable with anything else than FFplay.
>
> as the rawvideo encoder doesnt "know" into which container it will be
> stored, the muxer has to "adjust" the data before writing
> the .write_packet functions for avi & mov/mp4 should check if their
> input is a affected rawvieo case, and if so allocate a new packet
> and copy the data into the rcorrectly strided image, then continue
> with the new packet as if it was the old
>

Yes, that is decently understood.

> The code doing this should be factored out so its not duplicated
> between the 2 muxers
>

Yes. There is quite some work to do, alright. Don't look at me, though. 
As I said, I don't feel confident enough to implement this.

Mats



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