[mythtv-users] "VDPAU Error: Failed to create output surface"...is this a sign that I need more memory?

[Scott Alfter]

I have an Acer Aspire Revo 1600 set up as a MythTV frontend in a bedroom.  It
had been feeding an old 37" CRT through a VGA-to-composite converter, but we
decided to take advantage of a Black Friday special to upgrade to a 42" LCD (an
LG 42LD400, more specifically).  At first, I connected it over VGA just to get
it working as I had no HDMI cables on hand, but the image was shifted to the
left.  I planned on switching to HDMI anyway, and did that a day or two later
once I had a chance to buy some cables.

The TV doesn't overscan if you set the label for the HDMI input you're using to
"PC" (instead of leaving it blank or selecting one of the other options).
After a little bit of fiddling, I got sound working for both analog and digital
recordings.  Playback of 480i, 480p, and 720p sources works great.  However,
1080i and 1080p videos that previously worked don't work now.

After a bit more troubleshooting, I found that they will work if I set up the
frontend to use the Qt theme painter (had to do that as I'm currently
troubleshooting over VNC).  It fails with the OpenGL theme painter, which is
what I normally use.  The computer still has the 1 GB of RAM that came with it;
I've not cracked open the case.

The VGA-to-composite converter returned EDID information that set it to feed
1024x768.  When I first set up this computer, I had it connected to a 30" LCD
TV that ran at 1280x768 (over both VGA and DVI).  With the new TV, it's now
running at 1920x1080.  /var/log/Xorg.0.log reports that the GPU is taking 512
MB, but since that's half of the system memory, I kinda doubt that it's
actually doing that.  Is the error message in the title coming from a memory
shortage when viewing 1080i/1080p content?  Does the OpenGL renderer use that
much more video memory than the Qt renderer that it's triggered a shortage?
I'm guessing that this is why I've seen others suggest bumping the RAM up in
these boxes; I'd just like to confirm that it's the case before I crack open
the box for an upgrade.  I can probably make do with the Qt renderer in the
meantime.

Scott Alfter
scott at alfter.us