[Asterisk-Dev] video in iax2 spec

[Steve Kann]

Derek Smithies wrote:

>Hi,
> Openh323 has windows video grab routines. They are used in myphone, a 
>windows openh323 client. The latest myphone is on sf, dated june 2004
>
>===============================================
>
>
>  
>
>>> I do not understand why you wrote your own SDL display code.
>>>
>>>      
>>>
>>Were you going to write it for me?
>>    
>>
>I already have. They are inside pwlib - ready for you to use.
>
>  
>
You're talking about two different things here; "SDL display code", and 
capture code.

For capture, I need code which works on Win32, Linux, and Mac OS X. I 
don't yet see Mac OS X capture code in pwlib. I did find this library 
called "PortVideoSDL", which, although quite sparse and incomplete (and 
also, as it stood, not able to provide YUV 4:2:0 planar pixelformats), 
but easy to get going with. I don't expect that this is the final 
solution, because the code doesn't provide device enumeration, and a 
bunch of things I need, and also because it's licensed GPL; being GPL 
licensed presents restrictions, the most important of which is that it 
will prevent me from using any kind of patented codec.

I would consider using parts of pwlib for capture, but it is licensed 
MPL, and therefore, cannot be used in a GPL application (like iaxComm).

Ahh the vagaries of licensing. I'd need to find out if it's possible for 
the authors to make exceptions for MPL-licensed code, or just for 
pwlib-derived capture..

Anyway, as far as "SDL display code", I wrote about 10 lines of SDL code 
(ok, maybe 50), in a test application (vtestcall); I plan to keep video 
display out of the library, because I expect that different applications 
are each going to want to handle it differently. I'll probably just pass 
pointers to decompressed video up to the application (perhaps with 
timestamps, and perhaps with the applications choice of pixel format, 
etc) in some way, and let applications deal with display.

Also, I've got a question for you: Are you finding that most modern 
windows video devices are still available for use with VFW? I've read in 
some places that it seems that newer capture devices are supporting 
DirectShow only?

-SteveK