Improving PVR-150 video quality.

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G4EWJ
Posts: 748
Joined: Wed Feb 17, 2010 10:11 am

Improving PVR-150 video quality.

Post by G4EWJ » Sat Jan 26, 2013 6:54 pm

In his talk at the BGM, G7OCD remarked that the video bandwidth of the PVR-150 was less than that of the PVR-350 and showed a grating transmitted through each to demonstrate this.

It appears that Hauppauge weren't happy with the comb filter in the PVR-150 because of the dot crawl it introduced and turned it off by default. The comb filter separates luma from chroma on the composite input. I found some old tweaks whereby the comb filter may be turned back on. It does introduce some dot crawl, which is particularly noticeable with blocks of colour such as on-screen graphics, but the resolution does improve.

The problem is discussed here:

http://www.shspvr.com/smf/index.php?topic=9618.0
http://forum.videohelp.com/threads/3086 ... omb-Filter

The registry tweaks can be found here:

http://www.shspvr.com/smf/index.php?act ... attach=277

There are various levels of the setting. Higher levels give better quality, but more dot crawl. I would start with 1F. Just double click it and answer YES to the question, then reboot.

Notes in the settings mention that they are only for driver versions >= 23297. Version 25037 has been the latest driver on the Hauppauge site since the DigiLite project started, but you may have an earlier one if you're using the driver off the disk that came with the PVR-150.

If you have an earlier driver than 25037, it may be worth searching in the registry to see if the setting is already there. It isn't there by default for the 25037. If it is there and you're happy with the video quality, then I wouldn't change it. Take care when in the registry that you don't change anything else by accident.

START, RUN, REGEDIT, EDIT, FIND, SrcCombCfg

You can check your driver version with CONTROL PANEL, SYSTEM, HARDWARE, DEVICE MANAGER, SOUND/VIDEO, HAUPPAUGE WINTV, PROPERTIES, DRIVER.

The above relates to PAL - I don't know the implications for NTSC. S-Video input doesn't use the comb filter.

Please report back with your findings.

Brian
Last edited by G4EWJ on Sat Mar 23, 2013 12:30 pm, edited 1 time in total.

OA5ATV
Posts: 14
Joined: Mon Apr 09, 2012 12:03 am

Re: Improving PVR-150 video quality.

Post by OA5ATV » Thu Feb 07, 2013 4:20 am

Hi Brian;
I use PVR-150 NTSC.
I use the settings 1F and got a noticeable improvement in the quality of video
About GraphEdit, You say (DigiLite UDP v2.50 Setup – v20):

"GraphEdit is very good at forgetting its settings (usually only video and audio parameters).
Check them each time the graph is loaded"

I use this tool;
http://web.archive.org/web/200611081052 ... weaker.zip
store the tool in a folder in C, running, settings and GraphEdit remembers the its settings
73
Josue

G4EWJ
Posts: 748
Joined: Wed Feb 17, 2010 10:11 am

Re: Improving PVR-150 video quality.

Post by G4EWJ » Thu Feb 07, 2013 3:19 pm

Good to know the quality improves with NTSC as well.

Thanks for the tip on the Hauppauge utility. I'll mention that in the DigiLite UDP thread.

Brian

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