> Date: Fri, 05 Dec 2003 13:22:53 -0500 > From: Jean-Marc Valin <Jean-Marc.Valin@USherbrooke.ca> > > I think I see what you mean, though I haven't been able to listen to > your wma file (not everyone has a wma decoder). The problem probably > only lies in the VBR tuning for wideband which hasn't received much work > yet. One way to check that is to encode in constant bit-rate and see > what the results are. I'm pretty sure you'll notice the problem appears > only at (CBR) quality 5 or below.=20 > > Jean-Marci have done further testing, and even at constant bitrates, wma is far superior, from an "overall listening experience" point of view. it seems that: speex maintains the crispness/treble of the recording, but with the cost of computer-ish background noise, like turning into russian radio stations on the am band, if you get my drift. ess sounds are particularily fragile to this. wma removes all high-freq/treble of the voice, and makes it "round" and dark, but there is no evidence of the computer-bleep bleep effects made by speex, the human voices sound like human voices, only blunter, in a way. ess sounds do not become embarassing. to accomplish the same file size (or bit rate) with wma and spx, the spx quality turns out so poor it is not usable (quality 2) i tried to downsample my wav files from 44100 to 32000 to meet with spx optimizations, but this did not help the situation really. it would be fantastic if spx could be able to compress voice to the extent wma does, but maintain the crispness and treble of the original voice, as far as this is possible. wma seems also less tolerant to music between voices than spx, which is good. a voice encoder should not accept music at all, it should just make garble of silence of it, to the extent that this is possible to detect. wma seems to do this to a certain extent. i am a programmer, but i do not know sound compression algorithms, so i may be talking on wrong grounds, but i would just like to find the best voice compresion program on earth, and just now i have to choose between large/good spx files and small/blunt wma files. it would be great if this could be improved in coming releases. olav --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'speex-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
> i have done further testing, and even at constant bitrates, wma is far > superior, from an "overall listening experience" point of view.OK, one thing at a time, so will you please leave wma out of that for now?> it seems that: > > speex maintains the crispness/treble of the recording, but with the > cost of computer-ish background noise, like turning into russian > radio stations on the am band, if you get my drift. ess sounds are > particularily fragile to this.Have you tried to identify at what CBR quality the esses start sounding bad?> i tried to downsample my wav files from 44100 to 32000 to meet with > spx optimizations, but this did not help the situation really.Please try at 16 kHz instead. The 32000 Hz mode uses some tricks that probably aren't optimally tuned yet. At least at 16 kHz, it'll be easier to identify the problem. Jean-Marc -- Jean-Marc Valin, M.Sc.A., ing. jr. LABORIUS (http://www.gel.usherb.ca/laborius) Université de Sherbrooke, Québec, Canada -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 190 bytes Desc: Ceci est une partie de message numériquement signée. Url : http://lists.xiph.org/pipermail/speex-dev/attachments/20031210/5bb61828/signature-0001.pgp
> OK, one thing at a time, so will you please leave wma out of that for > now?ok :)> > > it seems that: > >=20 > > speex maintains the crispness/treble of the recording, but with the > > cost of computer-ish background noise, like turning into russian > > radio stations on the am band, if you get my drift. ess sounds are > > particularily fragile to this. > > Have you tried to identify at what CBR quality the esses start sounding > bad?yes. 9 with this particular piece. the ess sounds may not be a problem with other types of streams (like streams from radio that have bad quality from the start), but this piece is from a cd, done by an actor in a studio with cd quality. so hmmm...> > i tried to downsample my wav files from 44100 to 32000 to meet with > > spx optimizations, but this did not help the situation really. > > Please try at 16 kHz instead. The 32000 Hz mode uses some tricks that > probably aren't optimally tuned yet. At least at 16 kHz, it'll be easier > to identify the problem.=20i will try 16khz --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'speex-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
Hi, I have been reading this list for a long time and now I have a question: How does Speex compere with other compression software like AMBE etc, in terms of quality versus file size or processing power needed, specialy in terms of the finished project even if something is not available at this moment ?? thanks, Alain --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'speex-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
> How does Speex compere with other compression software like AMBE etc, in > terms of quality versus file size or processing power needed, specialy > in terms of the finished project even if something is not available at > this moment ??I honestly have no idea. I would expect a recent state of the art codec to beat Speex in normal operations. Depending on the codec, however, Speex may be able to win on extra features (e.g. variable bit-rate, variable complexity, embedded bit-stream for narrow vs. wide). Jean-Marc -- Jean-Marc Valin, M.Sc.A., ing. jr. LABORIUS (http://www.gel.usherb.ca/laborius) Université de Sherbrooke, Québec, Canada -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 190 bytes Desc: Ceci est une partie de message numériquement signée. Url : http://lists.xiph.org/pipermail/speex-dev/attachments/20040206/667536ef/signature-0001.pgp