Hi, Was wondering if any gurus could tell me if it is possible to stream Ogg on very low bandwidth links (for example satellite phone) where the expected bandwidth would almost certainly be less than 19Kbps, and probably more like 10Kbps. I am not after great audio at this bitrate, mono with an audio bandwidth less than 5KHz. I have done some testing (not streaming though) listening to 8Kbps MP3 - it's pretty bad, but sufferable. Is this possible? Can anyone direct me to some tools that I can test this with? (ie: a server app & a client) I am running Wintel. PS: I can't use speech codecs (such as speex) because of the content, it's not speech (obviously - otherwise I would go that way!) Thanks, Owen. --- >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 'vorbis-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.
On Thu, Aug 14, 2003 at 03:50:46PM +1000, engdev wrote:> > I am not after great audio at this bitrate, mono with an audio > bandwidth less than 5KHz. I have done some testing (not streaming > though) listening to 8Kbps MP3 - it's pretty bad, but sufferable.The same is true for ogg. Drop it down to a low samplerate (11 or 8), mono, and you can get really really low bitrate Ogg. 8kbps, I think I've managed as low as 4kbps, but it sounded horrible.> Can anyone direct me to some tools that I can test this with? (ie: a > server app & a client)www.icecast.org (server) www.oddsock.org (client and windows icecast2)> I am running Wintel.Recommend running GNU/Linux for this. More flexibility.> PS: I can't use speech codecs (such as speex) because of the content, > it's not speech (obviously - otherwise I would go that way!)If you're streaming music, may I suggest that low bitrate is not what you're looking for. Instead try to go Wifi, or get a better phone, or grab one of those high bitrate satellite modem things that cost more but provide good coverage and bandwidth in remote parts of africa, middle east, etc. I know someone that did a live video feed from Iraq during the war using one of these things, was quicktime vp3 but it worked good. <p> -------------- next part -------------- A non-text attachment was scrubbed... Name: part Type: application/pgp-signature Size: 188 bytes Desc: not available Url : http://lists.xiph.org/pipermail/vorbis/attachments/20030814/a6c02e1e/part-0001.pgp
On Thu, 2003-08-14 at 00:50, engdev wrote:> Was wondering if any gurus could tell me if it is possible to stream > Ogg on very low bandwidth links (for example satellite phone) where > the expected bandwidth would almost certainly be less than 19Kbps, and > probably more like 10Kbps.For testing how low Vorbis can go, you don't need a full client/server setup at first. I did some fiddling using sox and oggenc (command line tools often found on Linux systems, but available for windows as well). You could also use an audio editor that lets you resample audio and mix down a stereo file to mono along with OggdropXP to do the Vorbis encoding. I took a track I had ripped from CD and used sox to resample and mix it down to 8 kHz mono: ox test.wav -r 8000 -c 1 test8kHz.wav resample I then encoded it using quality -1, the lowest VBR quality setting the current encoder allows: oggenc -q -1 test8khz.wav The resulting file was 10.9 kbps, but without any bitrate management, so there were bitrate spikes that might not be good for your application. The result was bad but livable, though I've never heard MP3 at this low of a bitrate, so I have no point of reference. Harder limits can be achieved with managed bitrates. With: oggenc --managed -M 10 test8khz.wav I got a file with the bitrate capped at 10 kbps (but no explicit minimum or average requested). Not surprisingly, the encoder used every bit possible under these constraints, resulting in a file with an average bitrate of 10 kbps. In comparing the VBR with the managed bitrate version, you can definitely hear the points where the encoder jumped the bitrate up in the quality -1 encoding to prevent a particularly bad artifact, but the managed bitrate version had to let through. Incidentally, I found that an average bitrate of 8.3 kbps was the lowest I was able to push the encoder to: oggenc --managed -b 8 test8khz.wav (That sets the average bitrate but not the min or max) Anything lower and oggenc informed me that the bitrate parameters were invalid. --- Stan Seibert <p>--- >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 'vorbis-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.
Holy (cow?) I had a look at Garfs samples. That is very impressive at such a low bitrate! @Jonathon You say that "floggy" is part of GT3b1. On Garfs page he says that his GT3 beta 1 is tuned for quality levels of 5 to 10, the opposite end I would have expected. Is this the one that he created his low bitrate samples with? (Perhaps Garf himself can answer this). Thanks for all the replies guys. --- >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 'vorbis-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.
Oh yeah, I forgot the disclaimer... Before Garf kills me, floggy is completely in development, and its use is not recommended under any circumstances... I just thought I should point out its existence and impressive performance even after such little development. But again, the highpass at 70Hz is a good recommendation for improving quality at very low bitrates. -Jonathan <p>--- >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 'vorbis-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.