From: Gabriel Bouvigne <[EMAIL PROTECTED]> Subject: Re: [mp3encoder] psychoacoustic model based on MDCT Date: Wed, 18 Jun 2003 11:01:57 +0200
> > i would like to know if there is any possibility to improve encoding speed > > by combining the 2 transfomations (MDCT + FFT) by exchanging the > > psychoacoustic model transformation (FFT) with an MDCT and then reducing the > > two MDCTs to one. is there already an implementation? and where can i find > > more information concerning this topic? > > This should be possible as some AAC encoders are working this way > (Psytel and Nero). Yes, that's so called "CMDCT". > However, the fft transform is not that slow compared to the overall > speed (at least in Lame) You're right. FFT is not slow at least in LAME. This is why the FFT with 3DNow!/SSE does not make significant result. By profiling the LAME, FFTs (for long and short) takes only about 4.5%. -- Takehiro TOMINAGA // may the source be with you! _______________________________________________ mp3encoder mailing list [EMAIL PROTECTED] http://minnie.tuhs.org/mailman/listinfo/mp3encoder
