[Asterisk-Dev] Re: video in iax2 spec

[Steve Kann]

There's quite a few things you're talking about here -- much of this 
might be more appropriate for the iaxclient-devel list though:

First, the status of video in iaxclient right now:  What I have in there 
is really just some test code.  At best, what it will do is make an IAX2 
audio call, while at the same time, capturing, encoding, and perhaps 
decoding local video.  (I.e. it will display either the raw captured 
video, or the captured video after encoding and decoding).  It doesn't 
yet have any provision for sending video over the network, or receiving 
video from the network.

There's a few network things that need to be worked out before that's 
going to work well -- defining specifically what the packetization of 
video frames look like, how to send some out-of-band information that's 
necessary (like Theora codebooks, etc).

Also, in iaxclient itself, there's a bunch of things that need work.  
The present "PortVideo-SDL" stuff in there is rather inflexible, and 
doesn't have the functionality we need.   It's also GPL, and I'd much 
prefer to have something with a less restrictive license, because the 
GPL conflicts with the license for iLBC, for example, and precludes 
using other kinds of encumbered codecs, like H.264, etc.  So, we need to 
work on that whole issue.

Below, some responses to particular points:

Stefano Falsetto wrote:

>Hi List!
>
>I'm interested in developing audio/video transport in iaxclient. 
>I'm reading vtestcall code from iaxclient CVS, and I've some question about 
>it.
>First of all: the output file. I've still not understand what data format is 
>using. It's very sparse, with some data and many 0-padding data... What is 
>it?
>Second: the video output is broken. I can see only green/purple blobs...
>
>Third: the call terminate unexplectely.
>I'm using testcall with following command line:
>
>./testcall -F 23 15 90000 352 288 -V -f iax_output.raw 127.0.0.1
>  
>
Yeah, the H264 stuff in there right now doesn't seem to work properly;  
I think all the other formats work though.

I'm not sure what happens if you try to use "-f" with vtestcall -- at 
best it would only do something for audio.  If you don't use "-f", then 
the normal audio layer will be used, and you'll get an audio call that 
works, along with the local video stuff as described above.

>At this moment asterisk is responding calls originated from testcall, and it
>say that it is playing the audio files from default extension (I'm using a 
>"default" configuration, with dialplan taken from examples). I dont hear 
>nothing. I suppose that audio will go to iax_output.raw file, but I don't 
>understand where all audio data can be stored in an almost completely 
>0-filled file.
>After a random time, asterisk hangup with the error reported in following 
>output (begining from answer call):
>
>   -- Accepting unauthenticated call from 127.0.0.1, requested format = 4, 
>actual format = 2
>    -- Executing Wait("IAX2/guest at 127.0.0.1:32834/1", "1") in new stack
>    -- Executing Answer("IAX2/guest at 127.0.0.1:32834/1", "") in new stack
>    -- Executing DigitTimeout("IAX2/guest at 127.0.0.1:32834/1", "5") in new 
>stack
>    -- Set Digit Timeout to 5
>    -- Executing ResponseTimeout("IAX2/guest at 127.0.0.1:32834/1", "10") in new 
>stack
>    -- Set Response Timeout to 10
>    -- Executing BackGround("IAX2/guest at 127.0.0.1:32834/1", "demo-congrats") 
>in new stack
>    -- Playing 'demo-congrats' (language 'en')
>    -- Executing BackGround("IAX2/guest at 127.0.0.1:32834/1", "demo-instruct") 
>in new stack
>    -- Playing 'demo-instruct' (language 'en')
>Jul  7 16:03:10 WARNING[17205]: chan_iax2.c:1477 attempt_transmit: Max retries 
>exceeded to host 127.0.0.1 on IAX2/guest at 127.0.0.1:32834/1 (type = 6, 
>subclass = 11, ts=10021, seqno=4)
>Jul  7 16:03:10 WARNING[20427]: file.c:550 ast_readaudio_callback: Failed to 
>write frame
>  == Spawn extension (default, s, 6) exited non-zero on 
>'IAX2/guest at 127.0.0.1:32834/1'
>    -- Hungup 'IAX2/guest at 127.0.0.1:32834/1'
>
>
>There is someone that can help me? 
>Steve, are you still working to this project?
>  
>
I haven't done much work on it recently, but I plan to get back to it 
sometime soon, and would definitely make time to work with people who 
are interested in helping to move it forward..

>There is someone that is interested to make this "proof of concept" somethig 
>useful?
>  
>