search for: 28kbps

...als when encoded at 20ms > framesize, versus quality at 10ms. This effect is mode=AUDIO only. > Using mode==VOIP shows no sig. difference between 10 and 20ms framing > at this bitrate. Pesq totally overreacts, as it is wont to do :) > However, I do hear a slight drop. Admittedly, 28kbps is a low bitrate > to be running in mode=AUDIO. Is this effect known? Is there a > difference in processing with audio mode between 10ms and (other > framesizes)? I reckon it will go away if I throw some more bitrate > at it, but wanted to understand it a bit better. > >...

Hi Opus list, Please forgive me if this has been asked before. I find that Opus encoder created in mode OPUS_APPLICATION_AUDIO (as opposed to _VOIP) is using a lot of bits to encode silent periods of speech. This is relevant to a voip application for which good quality music is desirable, and in which I add a minimal comfort noise (order of few bits loud, e.g. MLS signal of amplitude 1 or 2)

...t some software developers have implemented it, and that according to hydrogen audio forums topic on speech compression quality -2 gave 32KBPS stereo on 44.1KHZ files and 16KBPS mono at the same sampling rate. I actually don't think I believe those bitrates to be true, perhaps 40KBPS stereo and 28KBPS mono. I am very curious about this. Any info worth knowing? -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.xiph.org/pipermail/vorbis/attachments/20071027/c306c365/attachment.htm

...y for voice signals when encoded at 20ms framesize, versus quality at 10ms. This effect is mode=AUDIO only. Using mode==VOIP shows no sig. difference between 10 and 20ms framing at this bitrate. Pesq totally overreacts, as it is wont to do :) However, I do hear a slight drop. Admittedly, 28kbps is a low bitrate to be running in mode=AUDIO. Is this effect known? Is there a difference in processing with audio mode between 10ms and (other framesizes)? I reckon it will go away if I throw some more bitrate at it, but wanted to understand it a bit better. Thanks very much, KevinC

...ood for 10ms/audio, poorer for 20ms/audio. Quality equivalent for 10,20ms for mode=voip. PESQ was the tool that alerted me to something of interest, but I don't trust PESQ to almost any degree! It's good for hearing relative differences, of course, but not absolutes. Bitrate here was 28kbps, but I hear same thing at 32kbps. Please find attached a zip file with the audio files, converted to .wavs for simpler listening. https://www.dropbox.com/s/bzu4i3dmg5f91tv/20msAudioModeQuestion.zip?dl=0 <https://www.dropbox.com/s/bzu4i3dmg5f91tv/20msAudioModeQuestion.zip?dl=0> If the...

...s the sample rate on the output, but I'm not sure if you guys would know how Lame calls the Vorbis encoder... Anyway, I've been resampling to 16k & applying a 6.4k lowpass filter using ResampAudio (Thanks heaps, Jelle, for the link!), then using Lame to compress the output file to about 28kbps average bitrate with Vorbis' Mode A, & I think it should be possible to compress music to 20kbps, but that can't be done currently without doing some vicious filtering beforehand, & also using 12/11/8 kHz sampling. I think that if one of Ogg's aims is to completely replace the R...