On Mon, Jul 06, 2009 at 09:14:00PM -0400, Alex Converse wrote: > I'd like to take a minute to discuss the status of the AAC encoder and > where it is going. > > In SoC svn: > --Applies cleanly to SVN HEAD > --The most egregious of the artifacting is gone (sections being > replaced by silence or having the wrong volume, etc.) > --Lacks TNS
> --Lacks multichannel support Ahem, I've added it long time ago. > --Lacks rate control > --Lacks SBR > --Produces illegal bitstreams by violating the maximum frame size This one could be fixed. > --Below faac quality > --Well below the quality of competitive encoders > > In my tree: > --Ruggles' PARCOR > --Rudimentary TNS support based on ISO 13818-7 Annex C > --TNS coefficient compressor > --Various performance opts > --Different value for CLIPPED_ESCAPE (165113.5f * IQ) > --Substantial rate control related re-factoring > --Pseudo ABR rate control > --Maximum frame size enforcement > --VBR rate control that forces comically high bitrate output. Heh, do you mean it's always maximum frame size? > TNS is not helpful at the moment. Sharp attacks are losing most of > their power before we get to the TNS stage. I believe this is may be > psy model related. > > To be frank, at this point it seems like it might be prudent for me to > stop working on this and move to either replacing the > non-redistributable parts of faac (to get something legal and faac > quality) or improving the 3GPP code (to get something awesome but not > distributable). At this point both code bases offer better quality and > more features (including SBR support from 3GPP). Dsputil is awesome > but developing this encoder inside ffmpeg is constricting to say the > least. I'm stronly against it. It seems to me that it's easier to backport FAAC psy model and codebook selection to our encoder to get comparative output - IIRC non-LGPL parts of libfaac are exactly the basic stuff I implemented. > So I'm wondering what other people have in mind (or completed but > tucked out of sight) for this code base? > > Regards, > > Alex Converse _______________________________________________ FFmpeg-soc mailing list [email protected] https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-soc
