[mythtv-users] MacOS Hardware Acceleration

[Todd Ignasiak]

On 2/17/06, Jarod Wilson <jarod at wilsonet.com> wrote:
>
> On Friday 17 February 2006 09:49, Todd Ignasiak wrote:
> > Does anyone here have more information, or pointers to more information
> on
> > the MacOS X MPEG2 hardware acceleration code recently submitted to the
> svn?
> >
> >
> > I am very interested in this, but I have been unable to find any
> > information beyond the couple mails on the dev mailing list.
> >
> > Apparently, it's based on the "Accellent" project for reverse
> engineering
> > the API used by the apple DVD player (
> > http://www.defyne.org/dvb/accellent.html ).
> >
> > I'm not sure how far along the project/code is.
>
> Still not quite there yet, Nigel is still working on merging it all in,
> getting it to build properly, etc. Watch the -dev list and -commits for
> details.



Thanks,  I'll do that.

> But, once stable, this
> > would make the Mac Mini into an excellent HDTV MythTV frontend.
>
> I *highly* doubt that. Accellent appears to be more akin to Xv or XvMC
> acceleration provided by an nVidia card, where you still need a fair
> amount
> of cpu horsepower to watch HDTV. To use such a slow machine, you need a
> full-out hardware mpeg2 decoder, capable of handling HDTV-sized frames,
> more
> akin to the UniChrome Pro. But I could be wrong.


Yes, Accellent is reverse engineering MacOS APIs to the same hardware
functions used in XvMC and Windows DxVA (i.e. offloading the motion
compensation and iDCT portions of MPEG2 decoding to the GPU).

Prior to moving to MythTV, I used some Windows HD software.  On my old P3
933, using a Radeon 7000 and DxVA, I could do HDTV.   My 1.42GHz PowerPC G4
is quite a bit faster than that old P3.   Unless the ffmpeg and/or display
code in Unix is much less efficient, I'm thinking the Mini will have enough
horsepower.

-- I just checked the Accellent developer's site, and he said he tested
playback of 720p content on a 1.25GHz G4, and it took only 25% of the CPU.
That's even lower than I would expect,  I'm anxious to see it in action in
MythTV.
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