[FFmpeg-devel] [RFC] AAC Encoder, now more optimal

Robert Swain robert.swain
Fri Sep 5 15:27:05 CEST 2008

2008/9/5 Kostya <kostya.shishkov at gmail.com>:
> After some time (I'd like to have more free time to spend on it though),
> I want to expose my new AAC encoder.
> It is slower than realtime since it uses search for optimal quantizers
> for given quality.
> Known weak points:
> * no bitrate management (it uses fixed quality for now)
> * no M/S detection
> * quantization is not optimal yet
> I haven't implemented those because it will slow encoder even more, so
> debug session will include an hour rest (and in case of M/S detection
> I don't know how to implement it) - 16sec sample coding takes 42 secs
> on my PPC G4-1.42GHz and 39 secs on Core2 1.8MHz.
> Any comments, suggestions, speedup tricks are extremely welcomed
> (especially the latter).

Obviously this is in the process of being improved. I'm not sure what
a reasonable target for encoding speed is for AAC but I'm fairly sure
something around 10-20x realtime is achievable with Nero's encoder.
Less than realtime audio encoding is... unusual. :) Still, if it was
the best quality AAC encoder around, that would bring it some


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