[FFmpeg-devel] Default color range encoding in Avid ACLR tags embeedded in QuickTime .movs

[Kevin Wheatley]

Hi,

Just looking through the FATE tests and the changes I wanted to make
on reading ACLR atoms and I came across an issue. I wondered what the
expected encoding range is for Y'CbCr during the FATE test runs as
well as more generally.

It would appear that the assumption that the range should be
AVCOL_RANGE_MPEG [16-235] during test runs. Unfortunately the DNxHD
code assumes the opposite unless you specify (libavformat/movenc.c
near line 1038).

I would consider this logic to favor full range in the Avid tags
incorrect and believe it should be reversed to assume [16-235] unless
told full range. FWIW, the default within an Avid is 16-235 for
optimal use of DNxHD.

Thoughts?

Thanks

Kevin