Libavcodec mpeg2 4:2:2 and non-linear encoding support like, especially, something, received, support

andy

I just received something very interesting from the ffmpeg dev mailing list. Its the first post from Baptiste COUDURIER  on that topic:Originally Posted by Baptiste COUDURIERHi

Im trying to mod the mpeg2 encoder to use 4:2:2 profile.

Here is a preliminary work, and results are correct for intra only
streams. I will work on Long GOP encoding after.

I would like your comments, especially from someone who really know
mpeg2 specs, and knowing if Im really out or if im going into the right
direction.

Weighting is not yet taken into account (422 and 444 requires different
coeffs).

Next step for me would be to enable intra_vlc_format encoding. I just
digged into the code and found that some support was envisaged (code is
disabled in mpeg1_encode_block, but is here).
Any hints to achieve that ?

And finally supporting non linear q_scale_type.
All this work is to support D10 encoding, widely used in editing systems:
smpte_store/sta.../pdf/s356m.pdf

I attached the patch.

I hope it will also work soon on other than intra-only streams
Would be very interesting also for FFdshow developing as it would make capturing in 4:2:2 mpeg2 via ffdshow encoder possible.

that's an interesting development indeed.

would nonlinear scale improve things at all?  i think it may require some big rewrites in ratecontrol (which is a very good thing IMO...).