[mythtv-users] myth front end on new mac mini core 2 duo?

[Todd Ignasiak]

2009/3/18 Adam Stylinski <kungfujesus06 at gmail.com>:
> On Tue, Mar 17, 2009 at 10:26:57PM -0700, Jason wrote:
>> Hi Damian,
>>
>> > Does anyone have an direct experience (or know someone/URL) of getting one
>> > of the new Mac Mini (upper model - the one with the NVIDIA GeForce 9400M
>> > with 256MB of shared DDR3 SDRAM) working with the OS X mythfrontend ?
>> >
>> > If so... can you answer... does it play HD (1080i) content without trouble?
>>
>> I just got a new mini yesterday.  It's the base model.
>>
>> I downloaded the latest -fixes branch release of the frontend and played with that for a short while.  I didn't do any scientific testing, but it didn't appear that any acceleration was in use.  The video played back fine, but it seemed a bit sluggish in fast moving scenes and after jumps forward.  I don't see any evidence that GPU acceleration is being used.  (I didn't see any evidence that it wasn't being used either.)
>>
>> I've installed mythbuntu on a bootcamp partition using the instructions here:  http://blog.costan.us/2009/03/ubuntu-810-or-904-on-mac-mini.html   The video playback performance in that installation "feels" a bit better.  My goal is to get VDPAU working on it in the next few days.
>>
>> Jason
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>
> Wait doesn't the "Quartz" acceleration option automatically use OS X's built in GPU acceleration?  The latest Leopard I thought integrated that functionality right into the video API.

OSX doesn't provide video decode acceleration.  Well, it sort-of
does.. there is a closed API used by the DVD Player.app for MPEG2
offload from back in the days when DVD decode stressed the CPU.
There is experimental support for that in MythFrontend, but my
experience has been that it is not stable enough to use.

My understanding of the Quartz support is that it does basic video
overlay and scaling processing.  Those are very important baseline
video display functions, but not what people think about when
discussing "GPU Acceleration".

There are murmurs about Apple providing better GPU offload support in
their next version.  But, I don't think it's known how open that will
be and whether MythTV will be able to take advantage of it.


But,  the Mac Mini has plenty of horsepower for 1080i MPEG2 decoding
without any GPU offload.   I used an old Core Duo 1.66GHz Mac Mini
with 1GB RAM for my HD frontend for a long time, and while it took a
big chunk of the CPU it did decode 1080i just fine.  In fact, I ran
both my Myth backend and frontend on that Mini with HDHomeRun tuners,
and it worked well.

I recently picked up the new 2GHz Mini, and as expected it has quite a
bit more CPU headroom when doing MPEG2 HD decoding.   I plan on
upgrading my Mini to 4GB of RAM, but I'm not in a hurry to do so.
MythFrontend (and Boxee) work fine in 1GB, and I don't think more
video memory will be used at all.   Once OSX 10.6 is out, maybe more
video memory will be useful, but in the current software decoding
mode, it doesn't seem to be a factor.


Also, someone reported earlier in the thread that de-interlacing was
not supported.  This is not what I have found.  I use the CPU++
decoder settings, and I deleted the first option, leaving the one set
for "Standard" MPEG decoder with the "Quartz" video mode, and in the
next menu I set "Kernel" de-int and it works fine.