[mythtvnz] Freeview|HD - anyone tried a Mac?

[Steven Ellis]

On 25/08/2008, at 12:18 PM, Nick Rout wrote:

>
>
> On Mon, Aug 25, 2008 at 12:13 PM, Wade Maxfield <mythtvnz at hotblack.co.nz 
> > wrote:
> Nick Rout wrote:
> > Occurs to me that at least some Mac models have hardware h.264  
> acceleration.
> > Can Myth on Mac OSX use this acceleration? Has anyone tried this?  
> Can other
> > software on Mac OSX or Linux on a Mac access this feature?
> >
> > Nick.
> >
>
> The Apple supplied DVD player and other Apple apps use the graphic
> processor for hardware acceleration. I don't know of many other apps
> that can use it. I don't know if this is because Apple is using  
> private
> APIs or not. There are some apps that use the GPU for video  
> processing,
> but they're mainly effects like Blur, Sepia Tone, Inverting colours,  
> etc
> (all effects provided by Core Image processing). I haven't seen much
> info floating round on using the GPU for video decoding (but I'm not a
> developer - so that doesn't count for much)
>
> There was work a while ago on some code to try and use the DVD/MPEG2
> methods for playback. I think it stalled.
>
> 0.21 has some options under the playback profiles to use quartz-accel.
> This will try to use the graphics processor for MPEG2 playback.  This
> didn't work reliably on the machines I've tried (G5 Tower, G4 Tower,  
> Mac
> Mini G4, Mac Mini Intel, MacBook Pro). Some crashed, and others didn't
> look that good when it did work.  I haven't tried this since 0.21 was
> first released.
>
> As far as other apps on Linux using this, it's the same old story with
> ATI/Nvidia drivers not using hardware acceleration.  Once you're in
> Linux, it's just a PC with Nvidia or ATI graphics hardware (or even
> Intel embedded graphics on the Mini)
>
>  - Wade
>
> Yeah I figured that would be the case with linux, but I had hoped  
> Apple might allow some sort of open api to the hardware decoding  
> through a OSX API. Pipe dream I guess, knowing apple!
>

Still can't get quicktime to play the original DVB-T streams, but I  
did use Handbrake to trancode some at around the same bitrate to  
Quicktime compatible H.264 based MP4 files. Interestingly the CPU load  
under Quicktime for these is close to the CPU load under EyeTV. VLC on  
the same stream is about 5-6% higher. Hence it doesn't look like Apple  
has HW acceleration for H.264 in Quicktime just yet.

Steve

Steven Ellis - Technical Director
OpenMedia Limited
email   - steven at openmedia.co.nz
website - http://www.openmedia.co.nz

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