[mythtv-users] cheap ($250) HD component video capture..

[Cory Papenfuss]

> On Oct 26, 2007, at 2:02 PM, Chris Ribe wrote:
>> I used to encode SD MJPEGs with my PIII back home, doing the same
>> with HD and a core 2 duo shouldn't be any harder.
>
> Is your core 2 duo six times faster than your PIII?  There are
> anywhere from six to nine times the pixels to deal with, depending on
> what resolution you were recording SDTV at..  And it seems like video
> encoding processes generally only run in a single thread, so you're
> going to have to do it with one core.  Maybe when 4.8 GHz chips come
> out? ;)
>
> Considering that modern CPUs are hard pressed to play back HDTV
> streams without hardware acceleration, encoding them on the fly seems
> like a tall order.

 	That's a good way to look at it.  What lots of folks don't realize 
is that 720p requires pretty much the same bandwidth and processing as 
1080i because of the 2x framerate of 720p.

1.92 * 1.08 * 30 = 62 Mp/s (1080i @ 30fps)
1.28 * 0.72 * 60 = 55 Mp/s (720p @ 60fps)
0.72 * 0.48 * 30 = 10 Mp/s (480i)

-Cory

  --

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* Cory Papenfuss, Ph.D., PPSEL-IA                                       *
* Electrical Engineering                                                *
* Virginia Polytechnic Institute and State University                   *
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