[ivtv-users] Perf issues with the ivtvfb driver

[Sander Sweers]

On Fri, Oct 31, 2008 at 21:34, ps1 <ps1 at schirrms.net> wrote:
>> I'm so sorry for the buzz...

Don't worry. These messages are achived and tthese get indexed by
search engines. Someone might have the same question and it will help
that person.

>> In fact, as I read everywhere that "all ivtv drivers are now in the
>> kernel", I didn't understand that the ivtv X11 driver is still needed :-(

The kernel modules have, yes. But the xdriver is like the x11 radeon driver.

>> I think a big warning about the fact that *this* driver is still not
>> part of the distro will not be too much !

I am not sure how many distro's are packaging it nowadays... But the
howto's usually point you to 3rd party repositories.

>>> Ah, yes it changed name. If someone does not beat me to it I will
>>> update the wiki next week
>>>
>> No no !!! Don't update ! Just write that the ivtv X driver is mearly
>> mandatory,even on latest kernel ! (I think that most people installing
>> a TV on a PVR-350 out want to play videos ;-)

Now that I read it again and checked the wiki I noticed the wiki is
already up to date. I also misread this section of your e-mail :-( The
driver should definately need to be ivtv in the device section.
Changing it to fbdev you will not get accelerated xvideo!

>>> *If* you use the mpeg decoder then yes it will also put audio out. The
>>> xdriver will not output audio as it is not using the decoder chip but
>>> uses the framebuffer directly bypassing the decoder.
>>>
>> OK, I had added a spare sound card in the system anyway. I see the
>> next step then !

Just a warning, the decoder chip can only handle mpeg audio. So things
like vorbis, flac or aac will not play through it. In  that case you
will need a soundcard.

>> I'm so happy, running the same video with 30 % cpu usage

If configured properly I think you can get this down with another 10%.

>> (under X,
>> because I suppose that I cannot use the ivtv X driver with a
>> framebuffer mode !)

Xdriver uses the PVR-350's framebuffer but unlike the plain
framebuffer driver it can accelerate xvideo.

Greets
Sander