[mythtv-users] PVR-500 picture quality

[Larry Finger]

On 02/01/2010 09:37 AM, Devin Heitmueller wrote:
> 
> One thing that I try to help debug these issues is I keep a small
> Windows XP partition on all of the boxes I have capture hardware
> installed in (which I am legally allowed to do since all the PCs came
> with XP anyway).  When I see a problem, I can reboot into Windows and
> see if it occurs as well with the default software that comes with the
> tuner.  This will help narrow down whether the issue is hardware or
> driver specific.
> 
> This thread has talked about variability in signal conditions as well
> as the capabilities of the hardware in general.  However, you should
> also consider that many of these problems *could* be driver issues.
> For example, I debugged a quality issue last week in the saa7113
> driver where the end result was flipping one register bit to enable
> one of the filters that should have been enabled by default (and was
> under Windows).  And that problem had been there for *years* since
> nobody with the appropriate experience had taken the time to notice
> and then debug the problem (and it was "good enough" for most users).
> 
> In other words, don't discount the possibility that the performance is
> crappy because the driver is not properly programming the hardware.
> The reality is that in many cases the developer does just enough work
> to get the capture card "working", and misses things that an trained
> eye is likely to notice.  And not to disparage any of the driver
> developers (I am one in fact), most of us would not fall into the
> category of "a trained eye".

On my PVR-500 running under kernel 2.6.29.6, I see no artifacts introduced by
the ivtv driver. Because of the analog signal from the cable, I get a little
speckle, but not worse than is seen on a 36" TV connected directly to the cable.