[FFmpeg-devel] [RFC] QP table API

[Anton Khirnov]

Hi,
sending a proposed new API for exporting QP tables (and possibly other
things in the future). It is based on a patch from Juan De León
(cf. <20190819233655.171637-1-juandl at google.com>).

The set is intended for dicussion, not merging at this point. It does
not adapt the filters and thus breaks FATE.

Some points to discuss:
- should the per-block structure store the final per-block quantizer or
  the delta from the per-frame value (each can be easily computed from
  the other, so it's more of a convenience question)? deltas are used in
  the current set as suggested by Lynne
- do we want per-plane quantizers in each block? The original patch
  didn't have them. Do we want separate AC/DC quantizers? Anything else?
- what to do with (M)JPEG? AFAIU it doesn't have a quantizer scale like
  later codecs, just full quantization matrices. Our decoder currently
  exports some number calculated from those in a non-obvious way. Is
  that useful or should that be dropped?

Please comment.

-- 
Anton Khirnov