HydrogenAudio

Lossy Audio Compression => Ogg Vorbis => Ogg Vorbis - Tech => Topic started by: rc55 on 2001-10-15 22:36:55

Title: Low Bitrate OGG Encoding (8,16,32...)
Post by: rc55 on 2001-10-15 22:36:55
Hi There,

I'm very keen on embracing OGG as my streaming audio format of choice but one thing I'd love to see supported is modem bitrate encoding support.

No doubt this will be supported in the future... but is there any ETA on this? (I do hope I'm not lumbered with the "It's done when its done!!!!" response, perhaps a rough guess or its priority in development would be more useful)

Or, can you do this already with an encoder hack?

Ideally, I'd be interested in
- 32kbps Stereo (44.1khz ideally; 22.05khz hack would be ok)
- 20kbps Mono (Not sure how mono lies in Vorbis though...

I cant claim to understand the format completely from an encoding perspective... and I've read about and chatted in various rooms but hopefully someone around here can help.

I am new to this forum so have a little patience while I adjust to the etiquette 

Cheers

Ruairi
Title: Low Bitrate OGG Encoding (8,16,32...)
Post by: Jon Ingram on 2001-10-15 23:05:35
You're going to have to resample to get bitrates that low at the moment, and probably in the future.

Vorbis handles mono input fine, but obviously can't do the channel coupling tricks that it can do with stereo... so you won't get half the bitrate by making the input mono.

Vorbis also handles sample rates other than 44.1/48, but isn't currently fully tuned for them.
Title: Low Bitrate OGG Encoding (8,16,32...)
Post by: Garf on 2001-10-15 23:35:15
Quote
Originally posted by rc55


Or, can you do this already with an encoder hack?

Ideally, I'd be interested in
- 32kbps Stereo (44.1khz ideally; 22.05khz hack would be ok)
- 20kbps Mono (Not sure how mono lies in Vorbis though...


The RC2 encoder has code for a 32kbps 22khz stereo mode, and a 48kbps 32khz stereo mode. I'm not sure about the mono modes.

I made a 32kbps 32kHz stereo mode once, but the results weren't very enjoyable.

--
GCP
Title: Low Bitrate OGG Encoding (8,16,32...)
Post by: rc55 on 2001-10-16 01:12:58
How excellent to have someone who actually writes Vorbis here!

Regarding the 32kbit/s 22khz stereo mode... could you tell me the requirements of the source file?

I.e. Does it need to be saved as a 22.050 or can oggenc resample?

Does having a Windows .WAV header affect this?

Would the encoded bitstream be compatible with the Winamp plugin (if not any suggestions)?

And finally, what would the command line be?

Thanks for your help. If it does become useful I'll probably make a web page about it.

Cheers

Ruairi
Title: Low Bitrate OGG Encoding (8,16,32...)
Post by: Garf on 2001-10-16 01:40:52
Quote
Originally posted by rc55

I.e. Does it need to be saved as a 22.050 or can oggenc resample?


Oggenc cannot resample, so you'll have to do it in advance with another program.

Quote
Does having a Windows .WAV header affect this?


If there is no WAV header, you need to specify the format the file is in yourself (use oggenc -h to see how).

Quote
Would the encoded bitstream be compatible with the Winamp plugin (if not any suggestions)?


Yes. Anything that has an RC1 or later decoder can decode _any_ Vorbis 1.0 file.


Quote
And finally, what would the command line be?


oggenc -b 32 file.wav

--
GCP
Title: Low Bitrate OGG Encoding (8,16,32...)
Post by: PatchWorKs on 2001-10-16 10:02:18
"Command line" sounds a bit old.

Try thoose utils instead:

http://www.blorp.com/~peter/ (http://www.blorp.com/~peter/) (winamp plugs, rc2 encoder too)

http://www.dbpoweramp.com (http://www.dbpoweramp.com) (format converter, OGG rc2)
Title: Low Bitrate OGG Encoding (8,16,32...)
Post by: rc55 on 2001-10-16 10:57:39
Garf: Many thanks for your help!

Patchworks: I'll try them now, thanks!

Ruairi