[mythtv-users] Compile options for Atom/ION?

[Jim Stichnoth]

On Wed, Oct 7, 2009 at 10:26 AM, Tom Lichti <redpepperracing at gmail.com> wrote:
> On Wed, Oct 7, 2009 at 1:54 PM, Jim Stichnoth <stichnot at gmail.com> wrote:
>> On Wed, Oct 7, 2009 at 3:16 AM, Chris Stevens <chris at mindblow.co.uk> wrote:
>>> I have an Acer Revo using the Atom with ION graphics and have installed
>>> Mandriva 2009.1 Powerpack which comes with the nVidia driver
>>> (dkms-nvidia-current-185.18.36-3mdv2009.1).
>>>
>>> I compiled Mythtv 0.21-fixes with:
>>> ./configure --prefix=/usr --enable-proc-opt --enable-opengl-vsync
>>> --enable-opengl-video --enable-xvmc-opengl
>>>
>>> and everything is fine. You don't need Atom-specific compilation but you
>>> do want the nVidia proprietary driver and OpenGL. Don't forget to enable
>>> the OpenGL in mythfrontend.
>>>
>>> Chris
>>
>> I have all the opengl support compiled in, and I'm using nVidia
>> 185.18.36 and VDPAU.  There's no performance problem during playback,
>> but when I exit a recording, it may take around 10 seconds to return
>> to the recordings page, during which "top" reports mythfrontend using
>> ~100% CPU.  So I was wondering if anyone, especially the gentoo folks,
>> could recommend Atom-specific options that shorten these delays.  I
>> can try --enable-proc-opt, but I was hoping that someone could report
>> their experience on this kind of tuning.
>>
>> I think I'm using the Qt painter.  I'll try switching it to OpenGL and
>> see if that makes a difference.
>
> I see the same thing with the OpenGL painter, but it's more like 30
> seconds...WAF is affected...

I tracked down this 10+ second delay to deallocation of VDPAU buffers.
 For some recordings (especially 1080i it seems), it takes a long
time, like 0.6 seconds, to deallocate each buffer.  There are 17
buffers used by default, leading to 10+ seconds.  I was able to reduce
the number of buffers to the minimum of 6, which seems to work fine
with ATSC and 720p HD-PVR recordings, and the delay is much better.
This is done by adding vdpaubuffersize=6 to the filters section of the
playback profile.

Jim