[FFmpeg-user] Numerical histogram output for checking typical broadcast ranges (16-235)

[Phil Rhodes]

> I cannot explain the relevant specifications (and I 
> don't even know where to find them) 


http://www.itu.int/dms_pubrec/itu-r/rec/bt/R-REC-BT.601-7-201103-I!!PDF-E.pdf

"220 (8-bit) or 877 (10-bit) quantization levels with the black level 
corresponding to level 16.00d and the peak white level corresponding 
to level 235.00d. The signal level may occasionally excurse beyond 
level 235.00d or below level 16.00d"

Similarly for 709.
P