GSM compression

[yawnmoth]

it seems like GSM compression is usually used on cell phones, at pretty low bitrates... so, i'm currious... how does GSM compression compare to ogg vorbis at bit rates like 16kbps (i think this is average for cell phones)? Also, how does high bitrates GSM compression sound, compared to stuff like ogg vorbis, and MP3?

[rjamorim]

Those formats have different purposes.

Vorbis is targeted at general music. GSM is targeted at human voice.

What means, if you try to encode a music at the same bitrate in both formats, Vorbis will probably sound better. If you try to encode voice, GSM will probably sound better.

And there aren't "high bitrates" in GSM, since it's targeted at voice only. Max bitrate is 13kbps - "full rate"

More info on GSM:
http://rice.ecs.soton.ac.uk/jason/speech_codecs/standards/gsm.html

Regards;

Roberto.

[ChristianHJW]

http://news.gmane.org/thread.php?group=gmane.comp.audio.compression.speex.devel

GSM compression could be better compared to Speex than Vorbis i guess ...

[DSPguru]

it should be extremly easy to write a G.729 DSF (8kbps), if using VoiceAge's x86 floating-point implementation (va_g729a.lib).

i find g729's quality very impressive (relatively!!), but you should know that it's heavily patented.

[rjamorim]

Originally posted by DSPguru
i find g729's quality very impressive (relatively!!), but you should know that it's heavily patented.

Where can I find an encoder? I would like to take a look at it.

[DSPguru]

http://www.voiceage.net/

[yawnmoth]

Max bitrate is 13kbps - "full rate"

I don't entirely understand this... why do lossy compression schemes have max bitrates?

[DaveQB]

so would GSM make more sense and return better size/quality then OGG in TV shows that have nothing but voice in them ???

going to try this out tonight, encoding the same show in
Xvid/OGG
Xvid/GSM
Xvid/TrueSpeech

[Sigmatador]

what about GSM versus Speex ???? :D

[DaveQB]

how do u implement Speex in an A/V stream ??

i use a batch file to play back Speex encoded files
and i cant seek

[Tommy Carrot]

I think you can find speex winamp plugin somewhere (probably on Rarewares), which can seek, and i believe i've heard about speex DSF somewhere, but i may be wrong.

[Animaniac]

Originally posted by Tommy Carrot
I think you can find speex winamp plugin somewhere (probably on Rarewares), which can seek, and i believe i've heard about speex DSF somewhere, but i may be wrong.

There's a Speex ACM.

[Tommy Carrot]

Originally posted by Animaniac
There's a Speex ACM.

You're right. I wanted to say (write) that. :)

[DaveQB]

cool
i found some info here (http://www.everwicked.com/forums/printthread.php?threadid=1999)

the winamp plugin didnt allow playback of a speex file

the direct show install failed complaining of missing msvcrtd.dll
i downloaded a copy and placed it in the C:\%windir%\system folder
but then it complained of a missing entry point in that file.
so i dunno :rolleyes:

PS the Front End is good,
writes the bat file for you, better then the ones i write :D

edit: Ps and fix URL

[DaveQB]

Speex ACM ?? :confused:

[celtic_druid]

http://www.openacm.org/