Mauro,
It's agood plan, except that is is BAD idea to remove
"ph_astream_decoded_framesize_get" calls....
Please keep them....
Thanks
Vadim
Mauro Sergio Ferreira Brasil wrote:
Hi Guys!
Let me explain why have I made that question so maybe we can get to a
conclusion here.
The point is quite simple: I want to remove all those "reformatation"
blocks on "ph_media_retrieve_decoded_frame" method because I think they
won't be necessary any more.
And they won't be necessary because of the solution I'll propose here
to the "device with same framesize" issue.
Having some thought about this problem I realized that the simplest and
easier solution is to get all "phapi" core to the way it was before,
blocking all device initialization, buffer allocation, and code/decode
stuff to operate always considering a framesize correspondent to 20ms
packetization.
Methods that use "ph_astream_decoded_framesize_get" today will use
"codec->decoded_framesize" directly.
The changes to codec initialization will be removed too, because we
will use code/decode routines only with buffers which their encoded and
decoded sizes correspond to 20ms packetization.
The rest of the magic will happen with adaption buffers that will be
used on incoming and outcoming edges of "phapi" with "ortp".
For example: for incoming (RX) path, the adaption buffer code will be
placed on "ph_media_retrieve_decoded_frame" method so it process and
return only a buffer with the correspondent size of 20ms packetization,
keeping the rest of the current RTP packet to be processed on next call.
I have already validated that point and it seems it will work pretty
fine, but I still have to validate the outcoming (TX) point.
Any of you have any disagreements or questions about this approach ?
Can you point some problems that maybe I couldn't see yet ?
Thanks and best regards,
Mauro.
jerome wagner escreveu:
Hi
I maybe wrong but I remember this happening sometimes during codec
renegociation (early media like ring tone negociated by a server, and
then media is negociated with the endpoint using another codec).
Jerome
2009/7/30 Vadim Lebedev <[email protected]>
Hi Mauro
Le 29 juil. 09 à 20:01, Mauro Sergio Ferreira Brasil a écrit
:
Hello there!
I was checking method "ph_media_retrieve_decoded_frame" in order to
make this final adjustment, and I've got stuck on some considerable
blocks of code intended to handle a condition where the size of RTP
packet received from the other part is bigger than expected.
This is indicated by variable "needreformat".
Is this intended to handle situations where the other part of
conversation don't respect the negotiated packetization ?
For example, we indicated preferable packetization through "ptime:20"
attribute, but the other part keeps sending RTP packets with a bigger
frame size than expected.
Is for this only reason that these code are used, or am I missing some
other situation that will demand such "reformatation" ?
Yes, it is the only reason...
Thanks and best regards,
Mauro.
jerome wagner escreveu:
Mauro,
I would follow Vadim on this one.
There are 2 cases that should be checked :
- 1/ really be careful about Linux and MacOSX sound
drivers. I agree windows drivers always give you the "standard"
framesizes you ask but this is not the case for Linux or MacOSX
- 2/ pay attention to the far-end media mixing during
3-way conference. Payloads may arrive on different end points with
different framesizes. mixing must occur at a shared framesize.
The current phapi approach is optimized in many cases I
think (less intermediary buffers = less memory usage) and I think that
a dynamic graph construction 'a la gstreamer' would be a + :
* no buffers when they are not needed (and for embedded
targets they are more than often are not needed)
* buffers for some scenarios
So a step by step approach could be to add an entity
with
a meta-description of the graph inside phapi to known which graph
elements are activated and which are not, with what parameters. I don't
know about the mediastreamer (ortp side project) integration that Vadim
was talking about recently so I can't really give you more help on this
one.
Hope this helps,
Jerome
Jerome
2009/7/28 Vadim Lebedev <[email protected]>
IMO this is the
correct way...
Thanks
Vadim
Mauro Sergio Ferreira Brasil wrote:
Hi Jerome!
I've asked information about how common is that condition because I had
no problem here initializing the audio devices of the same soundcard
with different framesizes.
I've made lots of test calls using my onboard soundcard on Windows with
some variety of framesize scenarios, like: 40ms on TX and 20ms on RX;
30ms on both paths (iLBC's "mode" parameter config), etc.
Now, considering that I can't rely on anything, I suppose the best
choice is to get back the audio devices initialization blocked (i.e.
hardcoded) to work with the framesize resulting of 20ms packetization
for both paths.
This will avoid lots of changes and the inevitable demanded tests.
We initialize incoming and outcoming audio paths to work always with
framesize of 160 shorts (or 320 if we work at 16 KHz) - that is the way
it used to work before the patch I've sent, and create buffer adaption
routines to both paths oh "phmedia-audio.c" in order to process the
incoming and outgoing data accordingly.
What do you think ?
Thanks and best regards,
Mauro.
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| Technology
and Quality on Information |
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TQI - Technology and Quality on Information
| At.,
|
 |
| Technology
and Quality
on Information |
| Mauro Sérgio
Ferreira Brasil |
| Coordenador
de Projetos e
Analista de Sistemas |
| + [email protected] |
| : www.tqi.com.br |
| ( + 55 (34)3291-1700 |
| ( + 55 (34)9971-2572 |
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