Record with Alpha Channel

Does anyone had success to use the FFMPEG Consumer to record a video including the alpha channel?

I tried the following:

  • libx265 with yuva420p, the video is then simply recorded without alpha channel
  • prores_* uses so much CPU, that is can barely handle more than 10 frames per second. I wanted to tune the speed settings but all passed private options are ignored (e.g. -bits_per_mb:v 8000)
  • I tried to use libvpx but again I fail because I can’t set the private options from the coded (would need to set -auto-alt-ref 0 to support aloha channel)

Does anyone knows a successful combination of codec/options or someone knows how to pass private options to the FFmpeg consumer?

I’m using CasparCG 2.2

Thanks for the help,


Yannis Güdel, Co-Founder livemotion gmbh

Try this in server 2.1

ADD 1 FILE "" -b:v 50000000 -codec:v prores_ks -pix_fmt yuva444p10le

@vimlesh1975 tried it out but without success. When recording for 10 seconds, I get a video which is around 2s because of so many dropped frames.