[Libav-user] muxing.c with RGBA

[Alex Cohn]

On Sat, Sep 8, 2012 at 4:39 PM, Gonzalo Garramuno <ggarra13 at gmail.com> wrote:
>
> 2012/9/7 Arash Cordi <arash.cordi at gmail.com>
>>
>> most video formats only support yuv. there's nothing you can do about it.
>> why would you want to do that anyway?
>>
> I have my movie data in RGBA and would like to avoid translation to encode
> faster and to keep the data the same.
>
> Gonzalo Garramuño
> ggarra13 at gmail.com

If your main concern is "keep the data the same", you probably need a
lossless encoder. There exist a few, see for example the summary:
http://www.media-matters.net/docs/resources/Digital%20Files/General/lossless_codecs_test_en.pdf

Regarding performance, typically the resources required for RGB to YUV
conversion are negligible compared to encoding, so you should be
careful to choose the encoder that delivers best speed for your
compression requirements, and let ffmpeg take care of color space.

The tricky part is if you want to send reliably the transparency
information (the A of RGBA). Very few players respect the alpha
channel.

BR,
Alex Cohn