Re[4]: [linux-cirrus] Re: Cirrus Logic MaverickCrunch support

Re[4]: [linux-cirrus] Re: Cirrus Logic MaverickCrunch support

[Bora Þahin]

Hi,

Torben> I'm fairly sure that decoding of
Torben> mpeg2 video in most cases would be too slow to consider without the help  
Torben> of some kind of graphical decoder chip.

Unless you use some powered CPU. As it would require to give an example, MPC8540(667-800 MHz) from
PPC family seems ideal for it as a SoC solution...

Thanks...


-- 
Bora SAHIN

Re: [linux-cirrus] Re: Cirrus Logic MaverickCrunch support

[Matt Porter]

On Tue, Feb 01, 2005 at 04:09:57PM +0200, Bora ?ahin wrote:
> Hi,
> 
> Torben> I'm fairly sure that decoding of
> Torben> mpeg2 video in most cases would be too slow to consider without the help  
> Torben> of some kind of graphical decoder chip.
> 
> Unless you use some powered CPU. As it would require to give an example, MPC8540(667-800 MHz) from
> PPC family seems ideal for it as a SoC solution...

Even then, this depends completely on what else the platform has to
do as well as what profile/level of MPEG-2 you are decoding. Something
like a ~800Mhz e500 core has no chance of handling a main profile high
level MPEG-2 stream for playback (typically 720p/1080i video). A high-end
(1.45Ghzish) 7457 with an optimized altivec mpeg2 software decode library
and a video card with iDCT assist is about the minimum PPC for these
applications.

This is why most consumer products are using something with a decoder,
like the integrated one in the IBM STBxxxx chips or the Sigma Designs
decoders.

-Matt

Re: [linux-cirrus] Re: Cirrus Logic MaverickCrunch support

[Stefan Nickl]

On Tue, 2005-02-01 at 09:33 -0700, Matt Porter wrote:
> On Tue, Feb 01, 2005 at 04:09:57PM +0200, Bora ?ahin wrote:
> > Hi,
> > 
> > Torben> I'm fairly sure that decoding of
> > Torben> mpeg2 video in most cases would be too slow to consider without the help  
> > Torben> of some kind of graphical decoder chip.
> > 
> > Unless you use some powered CPU. As it would require to give an example, MPC8540(667-800 MHz) from
> > PPC family seems ideal for it as a SoC solution...
> 
> Even then, this depends completely on what else the platform has to
> do as well as what profile/level of MPEG-2 you are decoding. Something
> like a ~800Mhz e500 core has no chance of handling a main profile high
> level MPEG-2 stream for playback (typically 720p/1080i video). A high-end
> (1.45Ghzish) 7457 with an optimized altivec mpeg2 software decode library
> and a video card with iDCT assist is about the minimum PPC for these
> applications.

Maybe you want to hook up some hardware MPEG decoder to the
Siliconmotion SM501's Zoom Video port.

I'm currently hacking on the XOrg driver for that graphics chip
and could well use a partner in crime ;-)

In any case, if you use a e500 core you want to make sure you get away
with single-precision floating point arithmetics.

-- 
Stefan Nickl
Kontron Modular Computers

Re[2]: [linux-cirrus] Re: Cirrus Logic MaverickCrunch support

[Bora Þahin]

Hi,

Matt> Even then, this depends completely on what else the platform has to
Matt> do as well as what profile/level of MPEG-2 you are decoding. Something
Matt> like a ~800Mhz e500 core has no chance of handling a main profile high
Matt> level MPEG-2 stream for playback (typically 720p/1080i video). A high-end
Matt> (1.45Ghzish) 7457 with an optimized altivec mpeg2 software decode library
Matt> and a video card with iDCT assist is about the minimum PPC for these
Matt> applications.

It is not that quality. I dont know decoding algoritms. But I have a film encoded bu Xvid.
Video Codec
     Aspect ratio: 592 x 320  (1.850 : 1)
     Frame/Sec   : 25
     Avg Bitrate : 1175 kb/s

I think quality is sufficiently enough. My Celeron 466/440 BX buddy does a good job.
     
Matt> This is why most consumer products are using something with a decoder,
Matt> like the integrated one in the IBM STBxxxx chips or

I am looking for probable and reasonable powerful cpu based solutions without going in that
direction...

Matt> the Sigma Designs decoders.

AFAIK, it does not support PPC platform...

-- 
Bora SAHIN