[Asterisk-video] [rizzo at icir.org: call for testers for team/rizzo/video_v2]

[Matteo Brancaleoni]

Hi,

Il Thursday 27 September 2007 10:46:13 Luigi Rizzo ha scritto:
> currently i don't have plans to do it but it is not terribly difficult,
> you only need to touch two functions - video_open() in the part that deals
> with webcam (the ioctl() to set the format etc. are different in V4L2),
> and video_read() in the part that reads from the camera (as far as i
> know V4L2 does not support the read() interface so you have to mmap
> a buffer).

I've digged into v4l2 specs and the read() is present but depends
on the cam driver. The cam I'm using now (using uvcvideo drivers)
does not have it, only mmap'ed buffer.

> > about resolution...
> > H263+ can handle formats up to 1408x1152
> > (should be 128x96, 176x144, 352x288, 704x576, and 1408x1152) and
> > ffmpeg supports all of them, is possible to raise the limit of 352x288 ?
>
> there are no restrictions on the resolution other than
> memory and CPU power.
> A side problem might be that at the moment the transmission is still
> bursty - especially in I frames, we pass the entire list of ast_frames
> to the channel driver at once, and at high resolution the list might
> be very long. Ideally we should implement some form of shaping to
> release the ast_frames at a fixed maximum rate.
> This is something that we plan to do.
Ok, good to know.

Matteo.

-- 
Matteo Brancaleoni
R&D Director
Tel  :+39.02.70633354
Voip :sip:matteo at sip.voismart.it