[FFmpeg-user] maintaining full swing when encoding in 10 bit (want to preserve all values from 0-1023)

[Andy Furniss]

Marwan Daar wrote:
> I tried the scale command with the 10 bit build, but no luck.
> Resulting video was one uniform color rather than 8 distinct bars.

Possibly because it did work but every video player by default will
assume limited range for yuv so stretch and not display anything
above/below the video levels. It will also be pot luck whether by
default you will get to see 10 bit 444 or whether the player ends up
converting it to 8 bit 420.

FWIW using your 1.png I can convert to full range yuv44410le and back to
png and the result is very similar to the master (=+1 on the values as
shown by imagemagic display).

Squashing to video then expanding back to png48 there was more of a
difference = +12.

I didn't test zscale yet and am just "clicking around" to see numbers
rather than judging ramp smoothness (not that 1.png is a ramp anyway).