v4l2-ctl --set-fmt-video=width=1280,height=720 can be skipped

[hessenfarmer]

the command v4l2-ctl --set-fmt-video=width=1280,height=720 can be skipped if we specify the -video_size 1280x720 parameter in ffmpeg command.
Furthermore I got a lot of small snowflakes artifacts without specifying the Gop with -g 2*framerate

[PrawnMan]

Cheers! I didnt realize whilst pouring over the ffmpeg documentation!