[Fwd: Re: [mythtv-users] PVR-250 480x480 jitter in hardware encode]

john lawler maillist at tgice.com
Wed Apr 14 09:52:35 EDT 2004

In normal operations (i.e., *not* 480x480 mode), I've had no problems.
This is when I set the dimensions to 352x240 in mythtv.  I've been
running for around 1 month like that with few issues.  That doesn't give
you a very good sample, but it's my impression that the PVR-250 card is
one of the best for Mythtv.  If you don't believe me, ask Jarod.

I'd also like to note to everyone that suggested going to 720x480, this 
seems to work fine for me.  I have watched several minutes of a program 
I recorded like this and haven't yet seen any of those annoying flashes. 
  This'll work fine for making SVCDs too, of course.

Thanks for the suggestions, guys.


Rob Comstock wrote:

> I am considering switching from BT848 card to pvr-250 at some point.
> all this talk of unstable systems, flickering frames, 2x playback make me
> think I should stay put. So I put forth the following questions:
> 1) Has anyone run a pvr-250 flawlessly at 480x480 capture? At other
> "high res" settings? With high system stability (longer than 3 months
> between reboots)?
> 2) Does PVR-250 work flawlessly at VCD resolution all the time?
> Thanks!
> Rob
> ----- Original Message ----- 
> From: "Mikhail D'Vane" <mikhaildvane at hotmail.com>
> To: <mythtv-users at mythtv.org>
> Sent: Tuesday, April 13, 2004 10:50 AM
> Subject: RE: [mythtv-users] PVR-250 480x480 jitter in hardware encode
>>The only comfort I can offer you is the assurance that you're not alone in 
>>this problem.  I have the exact same issue and I have come across at least 
>>other post by someone who had the problem and did the same experiment you
>>did with the same results.
>>I have not done as much experimenting, but what I do know is that the 
>>of ivtv driver makes a difference.  Currently, I'm running 0.1.9 and I see 
>>the out-of-
>>place frame at about the same rate you do.  If I downgrade ivtv to 0.1.7, 
>>out-of-place frame is gone, but my system stability suffers (daily 
>>required).  If I upgrade to ivtv 0.1.10pre2, the video plays at about 2x the
>>normal speed, but the audio is fine (so... it's unwatchable).
>>I'm just holding out for the next release of the ivtv driver.  It seems like 
>>speed problem is being addressed (some posts to thie effect on the ivtv 
>>I'll have to try capture in something other than 480x480, since I transcode 
>>mpegs I want to burn to DVD, anyway (not enough CPU to play 720x480,
>>stutter-free in my frontend).
>>>From: john lawler <maillist at tgice.com>
>>>Reply-To: Discussion about mythtv <mythtv-users at mythtv.org>
>>>To: Discussion about mythtv <mythtv-users at mythtv.org>
>>>Subject: [mythtv-users] PVR-250 480x480 jitter in hardware encode
>>>Date: Tue, 13 Apr 2004 11:34:48 -0500
>>>Hi guys,
>>>This has been a nagging problem for me ever since I got my box setup a 
>>>couple of months ago, but I'd forgotten about it ever since I switched most 
>>>of my recordings to VCD (MPEG-1 352x240) mode.  However, now I want to 
>>>record some shows and transfer them to SVCD, so I need to capture at the 
>>>default 480x480 resolution and use nuvexport for it.
>>>However, here's the problem.  I followed Jarod's guide almost verbatim (a 
>>>few unimportant divergences), which means I have all the ivtv versions 
>>>(including firmware) that he suggested and all of that, though I haven't 
>>>done any special tweaking of that driver or anything.
>>>Whenever I record something in 480x480, at various points during playback, 
>>>I get this annoying tearing or jitter in the video, where a couple of 
>>>frames tend to slide out of the picture, or something, and then it'll go 
>>>back fine for several seconds or even a few minutes and then come back.
>>>I've exported the shows using nuvexport to SVCD and played them in Winamp 
>>>on a windows machine and I get the exact same jitter in the exact same 
>>>points--this conclusively proves that the problem is not in playback on the 
>>>myth box.  Thus, it must be entirely in the capture, which narrows things a 
>>>I've already googled and searched the mailing list, of course, and I hear 
>>>murmurs about somewhat similar issues, but nothing that sounds exactly the 
>>>I also don't have any problem with the sound sync or anything else, it's 
>>>just those frames flickering from time to time.
>>>So... anyone else have a similar experience?  Preferably with a rock-solid 
>>>resolution?  I figure it probably has something to do with either ivtv 
>>>having a slight bug in it or my configuration of ivtv.
>>>Thanks a bunch guys,  mythtv rocks!
>>>  hardware specs (for reference and posting)
>>>    Chaintech 7NIF2 mobo (get the exact BIOS date, think it's 9/xx/2003)
>>>    on board nvidia nforce2 video (w/ shared system memory) + TVout
>>>        + audio + net (all on board)
>>>    Athlon-XP 2400+
>>>    512MB PC2700 Crucial RAM
>>>    Hauppauge PVR 250
>>>    Western Digital 60GB hd 7200rpm
>>>  software specs
>>>    essentially identical to Jarod's guide as of about mid-March 2004.
>>>mythtv-users mailing list
>>>mythtv-users at mythtv.org
>>FREE pop-up blocking with the new MSN Toolbar - get it now! 
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