xf86-video-intel: XV using the wrong pipe

JM Ibanez jm at orangeandbronze.com
Fri Apr 13 09:45:02 PDT 2007

Alan Hourihane <alanh at fairlite.demon.co.uk> writes:

> On Fri, 2007-04-13 at 22:31 +0800, JM Ibanez wrote:
>> Alan Hourihane <alanh at fairlite.demon.co.uk> writes:
>> > On Fri, 2007-04-13 at 22:02 +0800, JM Ibanez wrote:
>> >> Hi,
>> >> 
>> >> Since bugs.freedesktop.org seems to be down, I might as well report this
>> >> here. Has anyone encountered this?
>> >> 
>> >> On my laptop, XVideo using xf86-video-intel git seems to be using the
>> >> wrong pipe (or at least, it is "hardcoded" to just one pipe). When I
>> >> have another display plugged in but cloned to the laptop's display
>> >> (i.e. they're displaying the same image at the same resolution), running
>> >> 'mplayer -vo xv /some/mpg/file' will show output on the external display
>> >> and a blue screen on the laptop display. However, when I configure
>> >> dual-head (mergefb), there's output when mplayer's window is in the
>> >> external display, but blue screen on the local display.
>> >> 
>> >> Anyone experience this aside from me?
>> >
>> > That's actually a feature of the chip. It can't display the overlay to
>> > both pipes at the same time. 
>> >
>> > If you run cloned on the same pipe, then it works, but there's the
>> > restriction that the same resolution & refresh rate must be compatible
>> > with both output devices.
>> It's the *same* resolution and *same* refresh rate.
>> And, it gets even more interesting.
>> Without any external display plugged in, nothing comes out when playing
>> movies on the local display; *however*, when the external display is
>> plugged in and is made a clone, output shows on the external display.
>> It's a bug, I tell you. :)
> I bet you've got the option "Clone" in your xorg.conf ??

Nope. See my xorg.conf, attached.

> If so, it's not a bug, it's the feature I describe. You need to do
> this..
> Option "MonitorLayout" "NONE,CRT+LFP"
> to get true cloned on a single pipe. And make sure you remove the Clone
> option.

I'm using XRandR 1.2 to achieve cloning, so I can't say whether or not
it's doing what 'Option "Clone"' did in the pre-modesetting driver.


> That may well be a bug, it should be flipping the output pipe for Xv
> when the video window moves.

Exactly. In my case, it seems that Git HEAD is driving Xv only on one
pipe, regardless of where the overlay is really.

>> > The alternative is to use textured overlay which will work either way.
>> How do you enable that on the i855GM? (considering also that I have DRI
>> disabled due to my virtual screen size being larger than 2048)
> You need to use the latest 1.9.94 driver.

I'm on Git HEAD, as mentioned in my first post.

JM Ibanez
Software Architect
Orange & Bronze Software Labs, Ltd. Co.

jm at orangeandbronze.com

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