[FFmpeg-user] ProRes conversion to yuv sequence creates visual blocks

[loeffler at eyetrap.net]

Hello All,

I am having trouble converting ProRes clips into a yuv sequence and  
back. Here are my commands

ffmpeg -i input.mov -c:v rawvideo -pix_fmt yuv422p10le -f image2 -s  
1920x1080 %05d.yuv

ffmpeg -f image2 -c:v rawvideo -pix_fmt yuv422p10le -s 1920x1080 -i  
%05d.yuv -r 23.976 -c:v prores out.mov

Any suggestion on why this is creating visual gray shaded blocks on  
top of the video?

Thanks
Markus