[FFmpeg-user] Levels and Primaries

Rio Kierkels riokierkels at gmail.com
Wed Feb 12 09:59:05 CET 2014

Just to update this thread. My conjecture is that ffmpeg does the correct
scaling of the Luma values during the R'G'B' to Y'CbCr matrix transform.
It can be a bit confusing because the pix_fmt options are defined as the
defunct format notation yuv implying a luma (Y') component with any type of
chroma component.
This makes it uncertain what format conversion will be done from a color
science point of view. A more accurate representation would be ycbcr (just
a side note).

According to a link given by Rens Dijkshoorn
http://www.fourcc.org/fccyvrgb.php and my new and shiny book Digital Video
and HD by Charles Poynton
The scaling is a standard thing in the conversion. The only difference
being the way Y' is weighted according to BT.601 or BT.709 standards.

I am learning a lot here so I hope people keep giving different views on
the matter!


More information about the ffmpeg-user mailing list