Playback on TV via GB-PVR fuzzy compared

[BenTO]

My video picture quality seems fuzzy when playing back on GBPVR compared to playing back in Windows Media Player.  I have only a composite out for video to the TV, but it is still sharper in Windows Media Player.

So my question is how can I sharpen the picture when playing back through GB-PVR?  Is this a codec issue?

Thanks for any help you can give.

Ben

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Intel MB, P3-1GHZ, 512MB RAM, 200GB drive, WinTV PVR-250, Radeon 7000 PCI with composite video out, Windows XP Pro.

[Guest]

Just started playing with GBPVR and I must say I'm very impressed !

I too noticed the disparity in playback quality between Media player and WinTV 2000 and GBPVR. I gather this is .NET overhead sucking up CPU cycles, and directshow compensating by decreasing playback quality ?

I reduced my video card (ATI Rage 128 Pro AIW) from 32 bit color to 16 and this helped - less pixelation but a bit more aliasing on the colors. Today I built a new machine and upgraded the CPU from Duron 900/256m to P4 1.7ghz/384m and this picked up the quality and let me go back to 32 bit color. It still looks better in Media player tho.

I tried the Hauppauge codec (I have a PVR150) and an mpeg codec from an older version of PowerDVD - not much difference.

Maybe I have to build a 3ghz machine for GBPVR ; )

Rich

[sub]

Quote[/b] ]I too noticed the disparity in playback quality between Media player and WinTV 2000 and GBPVR. I gather this is .NET overhead sucking up CPU cycles, and directshow compensating by decreasing playback quality ?

No, that wont be the case. If you use the same bitrate and decoder as WinTV2000, then the results will be exactly the same.

[Guest]

Quote[/b] (sub @ Jan. 06 2005,00:32)]

Quote[/b] ]
No, that wont be the case. If you use the same bitrate and decoder as WinTV2000, then the results will be exactly the same.

Hmmm... I'm playing the same files that were recorded in GBPVR (medium quality) and they definitely look better whan played back in WinTV2000 and Media player. They are more pixelated when played in GBPVR. I'm using the Hauppauge codecs. DVD playback looks fine in GBPVR. Could this be an anomoly caused by the video card ?

I have the stock .net 1.1 install, DX9c.
I also have WinLIRC installed as my channel changer but I don't think it uses much CPU until you change channels.

My system
PVR150
384m
P4 1.7ghz
ATI Rage128 Pro

Any suggestions as to what to tweek ?

Sub & team - brilliant job !!! I will be making my donation shortly, just want to be sure this isn't all too good to be true !

Rich

[Guest]

I'll poke around with the sharpness. I have tried changing sharpness in the ATI display dialogs, and it definitely improves the TVout quality. I suspect your registry tweek does the same thing.

The root problem is something about the sw decode/codecs. I can exit GBPVR, play the identical recorded file in media player or winTV2000 and the quality is better. In GBPVR its like the decoder is dropping pixels - the picture looks like its about half the resolution with the same mpeg file.

Its still quite viewable, but I'd love to get a better picture without having to exit GBPVR to watch the recorded files.

Rich

[sub]

If you have FFDShow or dscaler installed, its possible one of these is manipulating the video.

[rheslip]

Thanks for the ideas !

I tried the 900mhz machine with FFDshow and the stills (!!! looked better but it clearly didn't have enough horsepower for FFDshow so I removed it. Theres nothing in there but the Hauppauge codec now. I'll do some more experiments...

Maybe I just need a better video card.

Rich

[rheslip]

Well, I've played with this thing for hours and hours and I still don't know whats going on. Tried the sharpness tweek, a couple of other video codecs and no difference. I guess I'll just have to spring for a new video card. Frustrating though - if I open a recorded file in Graphedit it shows GBPVR parser -> Hauppauge video decoder -> Video renderer. When I play it it in Graphedit it looks great. Play it in GBPVR - blocky video.

Can anybody recommend a relatively cheap, fanless card that works well with GBPVR ? I need composite TV output for my setup. I can get a Radeon 9000 pretty cheap, and I've read the Matrox Millenium has good TVout.

Thanks, Rich

[rheslip]

Just to close this one out - the video quality issue is fixed on my Rage128 pro, but why is a mystery to me.

My setup was working using the CH3 output of the satellite box but I was getting some nasty audio clipping at times with the PVR150's tuner, and I had the blocky video problem. In order to get better video/audio quality I wired the satellite box to the PVR using composite video and the 1/8 stereo input jack (had to run 80ft of audio cable to reach the computer) As soon as I reconfigured GBPVR to use the composite input the blocky video problem dissapeared on live video and recordings.

Even stuff I recorded thru the tuner input plays back perfectly now. It makes no sense to me why changing the input to the PVR 150 would fix the back end video renderer, but it did.

Rich

[BenTO]

Thanks for all the responses to this question that I originally posted.   Just to clarify what I'm seeing, "fuzzy" might not also be the right word for it... the playback is somewhat "soft".   It isn't blocky in the way that I've seen it when I go to 16-bit colour rather than 32-bit colour.  When watching Live TV, for example, it is like watching a film version of live TV rather than a video version of live TV.

I haven't had much time to test different things, but I think my problem is either:

1) a software codec difference between Windows Media Player and GB-PVR.  Playback still looks sharper on WMP.

2) the CPU is underpowered when playing back in GB-PVR compared to Windows Media Player.  Turning off FFDSHOW is a good idea too (which I had turned on).

3) my video card's composite out is not great

4) update drivers for PVR-250


Thanks to Rich (rheslip) for continuing the thread and giving me some more ideas to try.  

At the present time, I'm very happy with the way GB-PVR is - everything works well enough for my wife!  It's not perfect, but that is the fun with this product.  I'm almost afraid to touch anything now.

Cheers,
Ben

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My system: Intel MB, P3-1GHZ, 512MB RAM, 200GB drive, WinTV PVR-250, Radeon 7000 PCI with composite video out, Windows XP Pro.
GB-PVR 2.38.13