[FFmpeg-user] ProRes encoding: Question about FFmpeg docs

[Gonzalo Garramuño]

El 11/03/18 a las 08:40, Erik Dobberkau escribió:
> See
> https://video.stackexchange.com/questions/20555/what-are-the-differences-between-the-three-bundled-ffmpeg-prores-encoders
> It's a bit outdated but still good for background info.

Does anyone have any hints on saving the alpha channel?  I have tried 
encoding an exr with alpha channel into a mov file with the following 
command:

$ ffmpeg -i bunny.%04d.exr -c:v prores_ks -profile:v 4444 -pix_fmt 
yuva444p10le bunny.mov

and I get a mov file but without an alpha channel.  ffprobe reports:

Stream #0:0(eng): Video: prores (ap4h / 0x68347061), 
yuva444p10le(progressive), 1280x720, 61876 kb/s, SAR 1:1 DAR 16:9, 25 
fps, 25 tbr, 12800 tbn, 12800 tbc (default)

-- 
Gonzalo Garramuño