Set default pixel format for ffmpeg to YUV420P?

[TobiX]

Currently, the default settings for ffmpeg are:

docker-selenium/Dockerfile

Line 934 in cb7d4e2

FFMPEG_CODEC_ARGS="-crf 0 -preset ultrafast -qp 0" \

Since x11grab creates frames with full color depth, this generates H.264 streams with the YUV444P pixel format. This is unfortunate, since the OpenH264 decoder used in Firefox doesn't support that pixel format (AFAICS). Would it be possible to add -pix_fmt yuv420p to the default options?

[elgalu]

Sure @TobiX , just send us a PR