coefficients tag in mpeg2

[jmac698]

I'm looking for a tool that can process an mpeg2 to set or change the coefficients. I'd like to put a color test pattern into an mpeg2 and it's pretty difficult if you have no control over the coefficients.

It would also be useful to avoid pre-converting to account for wrong coefficients, that's just making useless numerical errors for the sake of a few bytes we need to change in the mpeg2!

[jmac698]

bbmpeg can set the coefficients in advanced options. Finally, you can encode direct from avs and match coefficients! If your source is cap, set Rec601 in bbmpeg, if it's dvb/hdtv/most dvd, set rec709. No need for colormatrix, which loses precision in multiple conversions.
Only problem, bbmpeg is an older encoder. I tried freeenc (libavcodec based), there are no options for color coefficients. I assume this applies to all libavcodec encoders

We need this as an option in restream :)