[Theora-dev] Re: derf README

[Timothy B. Terriberry]

Adam D. Moss wrote:
> The encoder sort-of works, but the resulting video has
> various bold artifacts (or, perhaps, the derf player just
> isn't playing derf-encoded video quite correctly).

I'm interested in specific test cases (original source material and 
encoding settings, if any) that produce these artifacts.

> However, the derf-encoder produces video streams which only
> the derf-decoder can play, which is currently a little worrying
> for backward-compatability.

This is known and expected. One of the hold-ups for beta1 is getting 
mainline decoder support for all of the bitstream features we added to 
VP3. Currently only the experimental decoder supports 4:2:2 and 4:4:4 
pixel formats, block-level quantizer selection, and full quantization 
matrix specification. All of these have been thoroughly documented in 
the specification, however, as well as clearly demarked as not 
compatible with the original VP3. At some point a "VP3-compatible" mode 
is planned for the experimental encoder, which will create streams that 
can be losslessly transcoded back to VP3 for people that care about such 
things.