[gst-devel] Re: [patch] gstreamer v4l2 source frame rate detection

Martin_Rubli at logitech.com Martin_Rubli at logitech.com
Fri May 5 01:24:05 CEST 2006

Hi Edgard,

> Yes, framerate could change, for example if you change the current input
> (Television, Composite1, S-Video) it may change the norm (PALM, NTSC,
> ...) or else you change the norm by hand.

Ok, granted, but that is not something the device would do without the
application requesting it (which is what I meant with "dynamically"). And
it's easy to fix, too. Just call get_fps to update the v4l2src->fps_x
variables when the video mode is changed in set_norm. Do you want to write
this? Like I mentioned, I couldn't test it with a TV card anyway.

> > BTW: in the meantime, to use your webcam with v4l2src use
> > use-fixed-fps=false, I hope it works.

I had tried that, it didn't work but I don't exactly remember why. If you
need me to reproduce it with the pre-patch version, let me know.

Anytime you need some webcam testing (V4L2-capable prefered :-), just let
me know.

Different topic: I was wondering why the v4l2src plugin restricts the
maximum image height to 576 when it queries a device's size limit
(gst_v4l2src_get_size_limits). Does anyone have an explanation for this? If
I remove the limit I'm able to source webcam streams at resolutions like
1280x960 without problems.


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