thanks for your reply, could you explain why 44.1kHz is *not* recommended with SPEEX ? Vincent ----- Original Message ----- From: "Jean-Marc Valin" <jean-marc.valin at usherbrooke.ca> To: "Vincent Burel" <vincent.burel at vb-audio.com> Cc: "Ashhar Farhan" <farhan at phonestack.com>; <speex-dev at xiph.org> Sent: Wednesday, November 12, 2008 1:27 PM Subject: Re: [Speex-dev] SPEEX on iPhone ?> Vincent Burel a ?crit : > > ok, interesting ! > > Do you know how much CPU it takes for a real time encoding/decoding ?it's> > more around 20% or 80% instead ? > > Do you know if it works for 44100 Hz / 32kbps / Quality =8 ? > > Did I ever mention that 44.1kHz is *not* recommended. Usually, 16 kHz is > best, although 32 kHz can be good in *some* cases. In any case, you'll > need to listen to the result before deciding. I just want to make it > clear that higher is not necessarily better. > > Jean-Marc
2008/11/13 Vincent Burel <vincent.burel at vb-audio.com>:> could you explain why 44.1kHz is *not* recommended with SPEEX ?my understanding is that the speex modes are tuned for particular sample rates, so using the 32kHz mode with 44.1kHz data will not yield as good quality as using the 32kHz mode with 32kHz data. Conrad.
----- Original Message ----- From: "Conrad Parker" <conrad at metadecks.org> To: "Vincent Burel" <vincent.burel at vb-audio.com> Cc: "Jean-Marc Valin" <jean-marc.valin at usherbrooke.ca>; <speex-dev at xiph.org> Sent: Thursday, November 13, 2008 1:18 AM Subject: Re: [Speex-dev] SPEEX on iPhone ?> 2008/11/13 Vincent Burel <vincent.burel at vb-audio.com>: > > could you explain why 44.1kHz is *not* recommended with SPEEX ? > > my understanding is that the speex modes are tuned for particular > sample rates, so using the 32kHz mode with 44.1kHz data will not yield > as good quality as using the 32kHz mode with 32kHz data.ok, it's strange, by nature, such compression algorithm are able to make down or upsampling very well... Do there is an impact on CPU load ? Vincent