hello, i have a simple question about speex frame size. i work with jspeex - but i think it's speex generic, the question i have. can i use any frame size i want? or does the size have be in a certain ratio to other numbers? and what does the frame size in the decoder mean? encoded or decoded packet frame size? how much data can i hand to the encoder to encode? if i hand i.e. 400 bytes to the encoder, what will i have in return? 180 bytes of encoded data? in gsm it was all so simple... i have 320 bytes and get 133 in return .... (i think those were the numbers). thanks for an answer, ulrich -- Ulrich B. Staudinger http://www.die-horde.de email: us@die-horde.de jid: uls@jabber.org current project: REDHORN http://redhorn.sourceforge.net Blog: uls@jabber.org">http://jabber.linux.it/jogger/user.php?jid=uls@jabber.org</a> <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 '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.
Sorry, there is only one frame size possible, (which you can get with
SPEEX_GET_FRAME_SIZE in the C version). Basically, it's 20ms for
"nominal rates":
narrowband: 160 samples
wideband: 320 samples
ultra-wideband: 640 samples
Jean-Marc
Le jeu 23/10/2003 à 09:29, Ulrich B. Staudinger a écrit
:> hello,
> i have a simple question about speex frame size.
> i work with jspeex - but i think it's speex generic, the question i
have.
> can i use any frame size i want? or does the size have be in a certain
> ratio to other numbers? and what does the frame size in the decoder
> mean? encoded or decoded packet frame size?
>
> how much data can i hand to the encoder to encode?
> if i hand i.e. 400 bytes to the encoder, what will i have in return? 180
> bytes of encoded data?
>
> in gsm it was all so simple... i have 320 bytes and get 133 in return
> .... (i think those were the numbers).
>
> thanks for an answer,
> ulrich
--
Jean-Marc Valin, M.Sc.A., ing. jr.
LABORIUS (http://www.gel.usherb.ca/laborius)
Université de Sherbrooke, Québec, Canada
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Hi
Framesize always refers to the decoded data frame size in samples.
Framesize is dependent on the encoding mode
Narrowband (8kHz): framesize = 160 samples = 320 bytes of PCM
Wideband (16kHz): framesize = 320 samples = 640 bytes of PCM
Ultra Wideband (32kHz): framesize = 640 samples = 1280 bytes of PCM
The size of the encoded data depends on the quality setting, so if you
know for instance that you are using quality 3 on narrowband, that is
119 bits of encoded data per frame which is rounded to 15 bytes per
frame (without counting the ogg headers). If you are using VBR then the
number of bytes used to encode each frame (which says fixed in size)
will vary.
If you have any other questions, don't hesitate to ask
Good luck
Marc Gimpel
Head of research
Wimba
Ulrich B. Staudinger wrote:
> hello,
> i have a simple question about speex frame size.
> i work with jspeex - but i think it's speex generic, the question i
have.
> can i use any frame size i want? or does the size have be in a certain
> ratio to other numbers? and what does the frame size in the decoder
> mean? encoded or decoded packet frame size?
>
> how much data can i hand to the encoder to encode?
> if i hand i.e. 400 bytes to the encoder, what will i have in return?
> 180 bytes of encoded data?
>
> in gsm it was all so simple... i have 320 bytes and get 133 in return
> .... (i think those were the numbers).
>
> thanks for an answer,
> ulrich
>
--- >8 ----
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