looks like webcam lye about framerate

[Alexey Fisher <bug-track fisher-privat net>]

Hallo
after i started to hack on performance problem by cheese i found other
problem with my webcams. Looks like they all lye about real frame rate.
You can set it to use 30 fps or 10 fps but there will be no changes in
image quality. The problem for cheese - with 30 fps we use more cpu and
make bigger files, even there is only actual 10fps stream.

Please test your cam with this command:

$(sleep 10 && killall mplayer)& mplayer -tv
driver=v4l2:width=960:height=720:device=/dev/video0 tv://

change resolution according your cam. make 3 tests, first one is not
always good. Find this line:
v4l2: 96 frames successfully processed, 4 frames dropped.
it mean i have about 10fps at resolution 960x720.

My cam should actually do  30 fps starting with resolution 640x480, max
what it get 10-13 fps.

Please make some test, send your feedbacks.

Regards,
	Alexey