Hi,<br>I chose speex initially because i had some work in VQ on speex i.e. modifying split VQ to GMM based parametric VQ and I thought If I train the GMM based VQ codebooks with audio signal and then do audio coding with speex, I probably get a better(smaller) residual signal even with speex. But I couldnt get that.<br>I was trying to get a lossless bitstream by MUXing the speex-bitstream and the entropy encoded error signal from speex. <br><br>I still have 2 months time but I need to do some useful and fundamentally strong work(even if its a small improvement). I can work day and night, But want to come up with some results. Results could be anything which make sense.<br>If you could suggest me some work in order to improve even a small part in lossless coding, I would be grateful.<br><br>I am sorry for any act of not respecting you in the past. I consider you at the top in guiding me.<br><br>Thanking you,<br><br>Regards,<br>Devilal<br><br><br><br><b><i>Jean-Marc Valin
<Jean-Marc.Valin@USherbrooke.ca></i></b> wrote:<blockquote class="replbq" style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;"> > I have one doubt again, that is Vorbis use DCT/MDCT based algorithm<br>> and also use psychoacoustic model so this is lossy codec. <br><br>Speex is also a lossy codec.<br><br>> And I dont think it ca regenerate a better matching waveform than<br>> speex. <br><br>At bit-rates above 32 kbps, Vorbis tends to produce better results than<br>Speex, even for speech. The only advantages of Speex over Vorbis at<br>these high rates is the lower latency and lower encoding complexity.<br><br>> Then there comes FLAC which is the perfect answer to my question, I<br>> suppose. But my concern is this that FLAC use simple prediction<br>> algorithm and doesnt use any CELP based algo which could have model<br>> the waveform coding by having a large codebook and comparing the<br>> residual signal and selecting
the codebook index.<br><br>FLAC is entirely different. You need to choose between perfect quality<br>and low bit-rate. FLAC isn't better or worse than Speex. If you can't<br>decide between the two, then you've obviously have no idea what your<br>after in the first place.<br><br>> For this, shall I start understanding and modifying FLAC itself in<br>> case I need to do something for lossless coding or I can try on Speex<br>> and than apply entropy coding.<br>> I am getting quite good(comparable) results for audio signal(44.1KHz)<br>> if use speex and separate entropy coding.<br><br>You apply entropy coding to the Speex bit-stream or you encode the Speex<br>error to make a lossless codec (which I already mentioned is a stupid<br>idea)?<br><br>> Please suggest me clearly as I have very small time left to wrap up my<br>> work to submit.<br><br>To be honest, that's the least of my problem. If you were clear in the<br>first place and listened to advice I already gave,
you might have been<br>better off already.<br><br> Jean-Marc<br></blockquote><br><BR><BR>***************************************************************************<br>Devi Lal Sharma<br>Final Yr. Dual Degree(Communications)<br>IIT MADRAS<br><br>Mobile: +91-9986423985(I am currently in bangalore)<br>email: devilal_sharma@yahoo.com, devilal@gmail.com<br>***************************************************************************<p>
<hr size=1><a href="http://us.rd.yahoo.com/mail_us/taglines/postman3/*http://us.rd.yahoo.com/evt=39666/*http://beta.messenger.yahoo.com ">Yahoo! Messenger with Voice.</a> PC-to-Phone calls for ridiculously low rates.