Incorrect ptime with G729

[GoogleCodeExporter]

What steps will reproduce the problem?
1. use G729
2. call and get a tshark trace
3. look at the trace

What is the expected output? What do you see instead?

When using G729, the RTP sent by siphon uses ptime=10ms.
But there is no ptime at all in the SDP, which normally means the voice payload 
will us 20ms.
Ideally, siphon should send 20ms, which uses less bandwidth.

What version of the product are you using? On what operating system?
Siphon 2.2.0 on iPhone OS 2.2.1.

Please provide any additional information below.
iPhone model 1 (Edge)

Original issue reported on code.google.com by david.po...@gmail.com on 2 Mar 2010 at 8:59

[GoogleCodeExporter]

Original comment by samuelv0...@gmail.com on 3 Mar 2010 at 6:04

• Changed state: Accepted

[GoogleCodeExporter]

In g729_default_attr function we should define :
    attr->info.frm_ptime = 20; // I'm not sure
    attr->setting.frm_per_pkt = 2; // I'm sure

Original comment by samuelv0...@gmail.com on 4 Mar 2010 at 5:43

[GoogleCodeExporter]

As far as I know, the G729 use a base frame of 10ms, and then, several frames 
can 
be sent in one packet. The standard is to put 2 frames in one packet, so 20ms.

See:
http://www.cisco.com/en/US/tech/tk652/tk698/technologies_tech_note09186a008
0094ae2.shtml#conv

At the moment, according to the tshark trace I took on the RTP stream coming 
from 
Siphon, the RTP packet is 22 bytes. The header is 12, so the payload is 10 
bytes, 
which is 10ms.

Sending 20ms packets instead of 10ms should bring a dramatic improvement in the 
bandwidth used by G729 calls.

Original comment by david.po...@gmail.com on 4 Mar 2010 at 10:24

[GoogleCodeExporter]

I uploaded a new version of Siphon 
(http://code.google.com/p/siphon/downloads/list ).
This issue should be fixed, could you confirm this ?

Original comment by samuelv0...@gmail.com on 27 Mar 2010 at 4:46

• Changed state: Fixed

[GoogleCodeExporter]

New features and bugs fixed are described here :
http://code.google.com/p/siphon/wiki/Feedback

Original comment by samuelv0...@gmail.com on 27 Mar 2010 at 4:47

[GoogleCodeExporter]

I never cross-compiled Siphon, so I must admit I am not very familiar with the 
procedure and the requirements.
I'll try to check this out, but not sure when I'll have the time.

Original comment by david.po...@gmail.com on 28 Mar 2010 at 9:28

[GoogleCodeExporter]

Hello,
You don't need to compile, you just need to install the last version I 
uploaded, and
try it.
And look the trace like you did it.

Original comment by samuelv0...@gmail.com on 28 Mar 2010 at 1:57

[GoogleCodeExporter]

Oops sorry, I just found out the .deb package was an iPhone package.
I installed the update, and it seems perfect.
Just to check; what I see is that you now send packets with a ptime of 20ms, 
but the SDP does not announce it as 
it is the default ptime.
My switch (FreeSWITCH) does not give me any warnings anymore).

Thank for the patch.

Original comment by david.po...@gmail.com on 28 Mar 2010 at 6:02

[GoogleCodeExporter]

Great!!

Original comment by samuelv0...@gmail.com on 28 Mar 2010 at 7:09

• Changed state: Verified