[FFmpeg-user] Calculate file size for lossless encoding

[Ulf Zibis]

Hi,

I used the following command on a 155 minute grabbing:

ffmpeg -video_size 1680x888 -framerate 25 -f x11grab -i :0.0+0,81 -c:v libx264rgb -crf 0 -preset ultrafast output.mkv

Assuming, the RGB range is 8 + 8 + 8 bit or 3 byte, I calculate:

3 x 25 x 60 x 155 x 1680 x 888 = 1040.6 GByte

But the file is only 93.7 GByte.

How can that be ?

-Ulf