[Asterisk-video] My AMR experience with app_h324m

[Reza Fatahillah]

Thanks for the reply.
I'm composing the rtp packet for amr like this:
1. Add CMR which is F0
2. Add TOC which for my case is 3C => 0 111 0 00 (Fbit
FTbits Qbit PBits)
3. Add AMR Frame(AMR Header+AMR Core Speech) comes
from the encoder(3gpp's AMR library). Which for my
case start from 3C too.
So the final bytestream will be like this F0 3C
3C02...05.

Then the trouble comes :). To make it work now i have
to remove manually the first byte(AMR Header) from
encoder result.


Reza.
--- Klaus Darilion <klaus.mailinglists at pernau.at>
wrote:

> Hi!
> 
> I think it would be best if Asterisk internally uses
> the RTP format of 
> AMR octed-aligned. This way, Asterisk can relay AMR
> frames from/to RTP 
> without any need to analyze and manipulate the AMR
> frame.
> 
> The RTP format is (RFC 4867, section 4.4):
> 
> 1 byte CMR (codec mode request)
> x bytes ToC (table of contents, indicate the AMR
> mode of each AMR frame)
> x AMR frames
> 
> Thus, if you have 1 frame encoded in mode 7 you will
> have 33 bytes:
> 1 byte CMR
> 1 byte TOC
> 31 bytes AMR frame in mode 7


       
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