[FFmpeg-devel] What is the correct way to read Avid ACLR atom?

Kevin Wheatley kevin.j.wheatley at gmail.com
Wed Feb 4 12:51:02 CET 2015


Hi,

I've been looking at what the appropriate place and method to read in
the ACLR atom placed in the Avid codecs so that we can automatically
set the color_range.

>From my reading of the code the mov.c code the parse table shunts the
reading of the atom to mov_read_avid(), which in turn calls
mov_read_extradata() which leaves the data in the codec extradata
buffer.

The issue would be at which point is the preferred point to look into
that buffer and set the colour_range, should it be done in the
specific codec's file in libavcodec (I'm only interested in DNxHD but
I assume the other Avid codecs might need it), or because of this
duplication should the change be made in libavformat/mov.c somewhere
like mov_read_avid() in a similar way to the mov_read_ares()
functions?

Thanks

Kevin


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