[Asterisk-video] about h324m codec negotiate

[Borja SIXTO]

Hi,

Sergio use h263p (RFC2429) to pack the video stream, but the video is in 
h263 (not with h263+ codec).
H263+ adds some annexes to improve the video quality, and cannoy be 
supported by some 3G video phones.

If you want to use h263p (RFC2429) to establish SIP video calls, you 
need to disable the annexes and configure the SIP phone to use h263 
standard (not all the phone will allow to configure that).

In the other cases, you should use the video transcoder to conciliate 
the 2 video codecs (h263p for 3G/h324m side and h263, h263p(real, not 
limited as for 3G) or h264 for the SIP phone).

Regards,


Borja from i6net




Le 17/05/2010 05:06, Ethan Liu a écrit :
>
> Hi Sergio,
>
> I'm sorry to trouble you, but I have some question about h324m protocol.
>
> The SIP phone cannot get video when I use h.263 codec bridged SIP and 
> 3G calls.
>
> And I checked the problem that it seems “create_ast_frame” function 
> only use h.263plus codec by default.
>
> “send->subclass = AST_FORMAT_H263_PLUS | mark;”
>
> I try modify that codec to h.263 only, but it’s failed. There are two 
> question:
>
> 1. Can I use libh324m negotiate codec with 3G phone use h.263 only?
>
> I saw that it seems can negotiate h.263 or h.263 version 
> 3(h.263++/h.263 2000), but how to negotiate h.263 1996 or h.263 
> plus(h.263 1998)?
>
> 2. How can I translate from h.263 plus to h.263 ? it seems only has 
> different heard, right?
>
> Wait for your suggestion. Thank you.
>
> Ethan
>

-- 
Borja Sixto, Research&  Innovation - http://www.i6net.com
Office: +34 911877477 | Gtalk: bsixto | Skype: borja.sixto

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