[mythtv-users] Choppy HDTV playback

Jarod Wilson lists at wilsonet.com
Fri Feb 9 03:42:34 UTC 2007

On Feb 08, 2007, at 18:21, Steven Adeff wrote:

> On 2/8/07, Jarod Wilson <lists at wilsonet.com> wrote:
>> Steven Adeff wrote:
>>> On 2/6/07, Yan Seiner <yan at seiner.com> wrote:
>>>> OK, I have recording happening!
>>>> Thank you everyone!
>>>> I am running 0.20-fixes, and it all seems to be working.
>>>> I can record on both tuners, and play back - almost.  (Aside: the
>>>> backend has 4-400GB Seagate SATA drives, and those things are  
>>>> *NOISY*!!!
>>>> Definitely not recommended for a frontend; with both tuners  
>>>> recording,
>>>> it sounds like someone is rolling a tin can full of steel balls  
>>>> inside.)
>>>> Typically I transcode the HDTV recordings down to 720x480 so my  
>>>> other
>>>> frontends can handle them, but I have two front ends that should  
>>>> be able
>>>> to handle the full resolution stream.
>>>> When I try to play them, though, I get very choppy playback - two
>>>> seconds of play, pause, two seconds of playback, pause....
>> [...]
>>>> Is that right?  Where do I look?  Backend should be adequate -  
>>>> it barely
>>>> breaks a sweat.  Poseidon (the frontend) is an Athlon 2800+ with an
>>>> Nvidia 6200 and DVI out to a 1366x720 LCD panel.  Not enough  
>>>> horsepower
>>>> there?
>>> not without XvMC enabled, no. You'll want at least a 3200+ on  
>>> Poseidon.
>> Note to self: figure out exactly *why* you can play back both  
>> 1080i and
>> 720p material just fine on a 2600+ w/o xvmc...
> 1080i streams have a much higher resolution than 720p, 2073600 vs
> 921600 per frame. So you may be able to handle 720p with that
> processor, 1080i is just too much.

Only it isn't. My 2600 plays back 1080i material just fine as well.  
Roughly 2 years ago, I had an Athlon XP 1800+ that could *almost* cut  
it for 1080i material as well.

Jarod Wilson
jarod at wilsonet.com

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