#37 Odd CPU usage

[James Green]

OK, so I installed btt2-v4l2 (from the sourceforge
project) on to my kernel 2.4.4 machine.

I fired xawtv up, and it, as usual, uses practically no
cpu, normal high frame rate.

I fired up zapping, and I got a normal frame rate, but
50% cpu uage (higher or lower depending on window size).

Switching between modes in zapping revealed:

* in Preview mode: normal frame rate, high cpu usage
* in Capture mode: reduced frame rate, 12-14% cpu usage.

This seems very odd. I believe the Preview mode should
be much less than the Capture mode (nearly 0% cpu)?
Reporting as a bug because I know garettex says there
should be nearly 0% cpu usage.

I'm running XF4.0.3, nvidia drivers running a GeForece
IIMX with a 2X AGP mobo. FWIW, XF4 is _not_ loading the
"v4l" driver.

One day I'll reach my dream of having high frame rate
and 0% cpu in both windowed mode and fullscreen. Sigh.

[James Green]

Logged In: YES
user_id=1174

I forgot to mention, the following popped up in a console:

Error: v4linterface.c (616) [z_switch_input]:
Couldn't find input with hash 7852c6d9

If that's any help...

[Ińaki García Etxebarria]

Logged In: YES
user_id=7928

I don't know which can be the source of the cpu usage in
preview mode. Perhaps this sheds some light (you'll have to
do some profiling...):
check the latest cvs
run './autogen.sh --enable-profiling && make clean && make'
That will create a profilable executable. Run it in preview
mode for some seconds (>20). Then get the profiling info
'gprof src/zapping > profile'. Please send the profile to
garetxe@users.sourceforge.net.

> One day I'll reach my dream of having high frame rate
> and 0% cpu in both windowed mode and fullscreen. Sigh.
It's nice, i can see it every day :-) unfortunately, I
cannot make it work for all people :-(

PD: Please run any tests with the --no-vbi flag to zapping.

> Error: v4linterface.c (616) [z_switch_input]:
> Couldn't find input with hash 7852c6d9
Not inportant. Appears because you switched controllers
(V4L1<->V4L2)