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RE: [AVT] transmitting g729 bitstream in RTP
Hi
A 10 ms G.729 frame = 10 bytes.
You can have a look at RFC 3551, section 4.5.6.
Aurelien
> -----Message d'origine-----
> De : Murat Artun [mailto:artunmurat at gmail.com]
> Envoyé : jeudi 7 juin 2007 15:56
> À : avt at ietf.org
> Objet : [AVT] transmitting g729 bitstream in RTP
>
> Hello,
>
> I want to ask how the 80-bits long (assume G729B is disabled
> for experimental purposes) G729 coded voice data is
> transmitted using RTP.
>
> ITU test code encoder outputs 11 short integers (parameter
> vector) where these 80-bits are packed following the below scheme:
>
> /*------------------------------------------------------------
> ----------------
> * prm2bits_ld8k -converts encoder parameter vector into
> vector of serial bits
> * bits2prm_ld8k - converts serial received bits to encoder
> parameter vector
> *
> * The transmitted parameters are:
> *
> * LPC: 1st codebook 7+1 bit
> * 2nd codebook 5+5 bit
> *
> * 1st subframe:
> * pitch period 8 bit
> * parity check on 1st period 1 bit
> * codebook index1 (positions) 13 bit
> * codebook index2 (signs) 4 bit
> * pitch and codebook gains 4+3 bit
> *
> * 2nd subframe:
> * pitch period (relative) 5 bit
> * codebook index1 (positions) 13 bit
> * codebook index2 (signs) 4 bit
> * pitch and codebook gains 4+3 bit
>
> *-------------------------------------------------------------
> ---------------
> */ (from BITS.C of ITU test code)
>
> However, as I have followed the ethereal trace of a G729
> voice exchange, I see that only 8-bytes are transmitted for
> each G729 coded 10 ms voice data.
>
> Considering the above parameter scheme that was specified to
> be transmitted in the ITU test code, what is the true packing
> scheme for each 10 ms G729 coded coice data?
>
> Thanks in advice...
>
> --
> M u r at A r t u n, MSc.
> Software Engineer
>
> _______________________________________________
> Audio/Video Transport Working Group
> avt at ietf.org
> https://www1.ietf.org/mailman/listinfo/avt
>
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