[mythtv-users] Recording problems with PVR-350 and MythTV 0.24.3

Michael T. Dean mtdean at thirdcontact.com
Wed Sep 26 05:19:36 UTC 2012


On 09/25/2012 09:07 PM, David Parker wrote:
> On Tue, Sep 25, 2012 at 9:29 AM, Michael T. Dean wrote:
>> On 09/25/2012 04:27 AM, David Watkins wrote:
>>
>>> On 24 September 2012 19:09, David Parker wrote:
>>>> I recently decided to upgrade from my old MythTV box running 0.21 to a
>>>> new box running 0.24.3.  I chose version 0.24.3 because I have a
>>>> PVR-350 and PVR-150, and I read in the release notes that support for
>>>> these cards was dropped in 0.25.
>>> AFAIK it was only the video output support for the PVR350 that was
>>> dropped.
>>>
>> Yes--though, technically, it's only support for the PVR-350 decoder that was
>> dropped.  You can still use PVR-350 TV out, but will have to use the CPU to
>> decode and Xv for display.
>>
>> Use of the cards for encoding is still fine.  And, if you want, you can
>> still use the TV out (though you'll probably get much better quality from a
>> good nvidia video card).
>>
> Thanks for the responses, David and Mike.  That's good to know.  What
> would the quality loss be if I upgraded to 0.25 and switched from
> hardware decoding to CPU decoding?  The CPU a 2.8 GHz Pentium D.

You're likely to get better quality output using an nvidia video card 
with CPU decoding than you'd get with PVR-350 decoder output or PVR-350 
Xv output.

Since the PVR-350 would still be encoding, there's no loss there.  So, 
you'd likely do better.

And a 2.8GHz Pentium D has plenty of power to decode 720x480 at 30 MPEG-2 
output from your PVR-350 without even breaking a sweat--probably at less 
than 10% CPU.

The biggest problem you'll have, though, is if you still need TV out 
(i.e. Composite/S-Video/SCART or whatever) versus a "real" output (VGA, 
DVI, HDMI, ...), you may find it hard to come by an nvidia card these 
days that supports it.

> For the immediate problem, is there anything I can try?  It appears
> that my ability to record programs is completely broken, and in
> addition to only recording 15 minutes of the first program, each of my
> test recordings has only had sound for the first 10 seconds and then
> it cuts out.  Would a downgrade to 0.23 be worth a try?  Also, could
> this be a symptom of overheating the capture card?  Just curious,
> because this PC is a BTX design with mostly passive cooling, so it
> probably has poor airflow.

I'd think you'd be better off going to newer than older versions.  
Again, there's /no/ reason you can't go to newer versions with your 
hardware.  All you lose is the 
always-had-more-disadvantages-than-advantages PVR-350 decoder

> I was really hoping to avoid buying a new tuner card, but if it comes
> down to that, do you have any recommendations for Nvidia cards?  I'd
> love to get one with hardware encoding and decoding like the PVR-350
> if possible.

nvidia card would be a graphics (output) card.  The tuner card is a TV 
input card.  You'll need a capture card (but you have one--in the 
PVR-350) as well as a graphics card.  You can use the PVR-350 as a 
"dumb" graphics card with its Xv support, but I was trying to say that 
using an nvidia graphics card would give you better output quality than 
the PVR-350 (i.e. you can, but don't need to, upgrade and improve 
quality if you like).

Mike


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