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On 01/15/12 19:35, Matt Garman wrote:
<blockquote
cite="mid:mailman.9.1326715204.21401.mythtv-users@mythtv.org"
type="cite">
<pre wrap="">
On Sun, Jan 15, 2012 at 04:49:12PM -0600, Keith Pyle wrote:
</pre>
<blockquote type="cite" style="color: rgb(0, 0, 0);">
<pre wrap=""><span class="moz-txt-citetags">> </span>There has been frequent discussion about the state of Intel graphics
<span class="moz-txt-citetags">> </span>and their Sandy Bridge chip capabilities, so I wanted to share our
<span class="moz-txt-citetags">> </span>recent experiences. Here's the hardware and software being used for
<span class="moz-txt-citetags">> </span>the MythTV front-end system.
</pre>
</blockquote>
<pre wrap="">I am working on a similar system. Here are my specs:
...</pre>
<pre wrap="">I have very slight horizontal tearing across the top 1/10th of my
screen. It's not constant; exists in some scenes, and not in
others. I can <b class="moz-txt-star"><span class="moz-txt-tag">*</span>almost<span class="moz-txt-tag">*</span></b> ignore it.
I tried enabling the XvPreferOverlay setting in xorg.conf that was
suggested here; that had no effect. Same goes for the
i915.powersave=0 module param that I read about somewhere else.
</pre>
<blockquote type="cite" style="color: rgb(0, 0, 0);">
<pre wrap=""><span class="moz-txt-citetags">> </span>We tried switching to ffmpeg & opengl, but Myth would crash on
<span class="moz-txt-citetags">> </span>starting any playback. A bit of debugging identified a
<span class="moz-txt-citetags">> </span>null-pointer dereference in the mesa video driver, which we
<span class="moz-txt-citetags">> </span>reported to freedesktop.org. They fairly quickly posted a
<span class="moz-txt-citetags">> </span>proposed (simple) patch which we have now incorporated. With the
<span class="moz-txt-citetags">> </span>patch, playback works <b class="moz-txt-star"><span class="moz-txt-tag">*</span>very<span class="moz-txt-tag">*</span></b> well with ffmpeg & opengl. While I'm
</pre>
</blockquote>
<pre wrap="">Do you happen to have a link to that patch? Or if it's small enough
can you post it? I too have the "crash when using opengl" issue.
</pre>
</blockquote>
They haven't committed the fix yet, but we picked up the proposed
patch by following the bug report updates and the mesa-dev mailing
list. The patch can be seen here <a
href="http://lists.freedesktop.org/archives/mesa-dev/2012-January/017412.html">http://lists.freedesktop.org/archives/mesa-dev/2012-January/017412.html</a><br>
(Because of indenting changes, it looks like more than it really
is. The effective change is one line to exit the function if the
pointer "intel" is null.) Until the patch is released for your
distribution, you'll need to manually patch
mesa/drivers/dri/intel/intel_screen.c as shown at the above link.<br>
<br>
If you need the mesa source, it can be obtained at <a
href="git://anongit.freedesktop.org/git/mesa/mesa">git://anongit.freedesktop.org/git/mesa/mesa</a><br>
<br>
Keith<br>
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