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Picture Quality
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Author:  ALF [ Fri Oct 13, 2006 3:08 am ]
Post subject:  Picture Quality
I have a AMD Athlon 1600+, 512MB DDR, and a Maxtor Ultra16 ATA/133 300GB (L01R300) hard drive.

My question here is I'm after max picture quality. I want the playback on recorded TV shows to look just like I was watching them for the first time on TV.

I have basic cable service and plan on using the composite (RCA-yellow) video output back to my TV.

I've been thinking about the Hauppauge WinTV-PVR-250 with Remote or the AVerTV PVR 150 Plus (white box) (MTVPVR15P).

A new AVerTV PVR is about half the price of a new Hauppauge WinTV-PVR-250 with Remote.


What do you guys think? Any suggestions?
Author:  alien [ Fri Oct 13, 2006 8:08 am ]
Post subject: 
I don't think it is possible to go analog->digital->analog without some loss of quality due to deinterlacing and resolution conversions.

However, with the new overscan options in mythTV 0.20, I have come a lot closer than I ever expected even though I am limited to composite. Only by watching very closely can I see some mpeg artifacts. These might be cured with a higher sample rate, but the difference is so small, it isn't worth it. I'm also running SD DVB and it is noticably better then watching analog first time on the TV. I can't receive DVB direct on the TV, so I can't compare that.

What I did to "tune" the picture:

[Edit: I should add a "0. Pick the best connection method" first. I only have SCART (Composite) on my TV, so I don't have much option here. Search the forums as there is already a lot of discussion on this.]

1. Added 1024x768 at the start of the MODES line in XF86Config-4. I have heard it said that 800x600 (the default) is "good enough". However, it is close enough to the PAL resolution that I was getting very slight "jags" in stationary straight edges that I think was due to the resolution conversions. Increasing the resolution solved this. I didn't use the native PAL resolution because the new MythTV overscan truncates lines and it would no longer fit exactly (the drivers would correct that, but I expect I would get the jags back).

2. Go into the program guide, alt-x to bring up and xterm then start nvidia-settings (I have a nvidia card). Increase the overscan until the guide just fits on the screen. You can use other menues, but I find the guide the best one for showing the edges of the used menu space. I did not use livetv to set the overscan here because I then ended up clipped mythtv menus.

3. In the playback settings, enable "kernal" deinterlacing with no filter. "Bobx2" is another good deinterlacer, but it doesn't work well with the overscan percentage in the next step on my card. I found "linear" didn't look as good.

4. Check playback. You will probably find that there are still black bars around the picture. Go into the Playback Settings and increase the Overscan percentage. This may take a bit of trial an error, but I ended up at 5%.

5. Start playback. Open up nvidia-settings again. Set the flicker filter to the lowest setting that has no flicker. Then fix the other settings (particularly vibrance which is the only one I had to change from default). I changed back and forth between liveTV and direct cable verify I had a good picture.

6. "Add nvidia-settings --load-config-only" to ~mythtv/.fluxbox/apps so the tuned config is loaded whenever mythtv starts.

I'm sure others may have other ways of doing it, but I have tried many things in the last couple of years and this resulted in the best picture for me.

Allen
Author:  tjc [ Fri Oct 13, 2006 6:29 pm ]
Post subject: 
http://www.knoppmythwiki.org/index.php? ... lityIssues
Author:  ALF [ Fri Oct 13, 2006 10:08 pm ]
Post subject: 
I don't actually have a running MythTV box yet. I'm just trying to figure out if the picture quaility is even worth spending the money to build one.
Author:  tjc [ Fri Oct 13, 2006 10:40 pm ]
Post subject: 
With the proper hardware and drivers the picture quality can be very good indeed. Because the compression used for storage is lossy (you're squeezing it about 100:1 after all), the results may not be quite as good as watching live with a best of breed TV tuner, but it's certainly better than a VCR, and probably about 95% of the way to that best possible live picture. We've even had a number of folks report that the picture they got from their MythTV setup was actually better than what their TV tuner was capable of.

My experience is that after a bit of fine tuning, the results are more than good enough. Good enough that when flipping back and forth between the TVs tuner and the MYthTV output it's easy to get confused about which is which, and while I can still see a small difference, it's often hard to say which is the better picture.
Author:  ALF [ Fri Oct 13, 2006 10:47 pm ]
Post subject: 
Thanks tjc. That's what I wanted to hear.

Now for the real question: What hardware are you using?

I only have standard cable - not even digital so I'm not worried about something like HD quaility.
Author:  tjc [ Sat Oct 14, 2006 7:51 am ]
Post subject: 
See my signature block for the basics, and my Tier 2 posting for more details.

I'm capturing SDTV from cable and playing it back via S-Video to my 27" Panasonic CT-27SF22T1 which was a medium to high end model when I bought it maybe 10 years ago now.
Author:  marc.aronson [ Sat Oct 14, 2006 8:10 am ]
Post subject: 
I use the Hauppauge PVR-250 and am very pleased with the picture quality captured from basic analog cable and played back on a 50" HDTV. I use a video bit rate of 3300 CBR, 720x480 resolution. When I had a 32" TV I found that a bit rate of 2200 CBR, 352x480 resolution was sufficient.

Hauppauge also has a PVR-150 card that is much less expensive than the the Hauppauge PVR-250 -- you may want to look at that. I don't know how the Avermedia 150 compares to the Hauppauge 150.

Finally, probably worth look at this entry in the wiki: http://www.knoppmythwiki.org/index.php? ... CardYouUse

Marc
Author:  ALF [ Mon Oct 16, 2006 1:04 am ]
Post subject: 
Since I can't get a good deal for a used one on ebay, I think I'm gonna spring for a new one.

Amazon.com's prices:
PVR-350 - $129.94 (new)
PVR-250 - $149.99 (new)

Any idea why the 350 is less than the 250?

Thanks guys. I really hope I enjoy this new MythTV system.
Author:  spideyk21 [ Mon Oct 16, 2006 6:42 am ]
Post subject: 
For those prices why not just pick up the PVR-500 at Newegg for $140.00? Dual tuner for the same prices as the single tuners you have found. It does not have TV out but neither does the PVR-250.

[url]http://www.newegg.com/Product/Product.asp?Item=N82E16815116628[/url]

Newegg also has the PVR-150 for $60.00 if single tuner is what you are after.
[url]http://www.newegg.com/Product/Product.asp?Item=N82E16815116633[/url]

Both work well with MythTV from what I hear.
Author:  ALF [ Mon Oct 16, 2006 6:01 pm ]
Post subject: 
Thanks spideyk21. Wow, $60 for a PVR-150. I'll try one of them and if it doesn't work as well as expected, I guess I can always return it :lol:

Looks like someone even posted a review about it because they also use it with MythTV.

My only problem I see myself running into is that my 'extra' system I plan on using has a Via chipset.

Processor: AMD Athlon™ XP Processor 1600+ (1.40GHz)
Chipset: VIA KM 266
Author:  Big boy stan [ Wed Oct 18, 2006 2:15 pm ]
Post subject: 
tjc, I noticed in your profile that you have both a 150 and a 250. Do you notice any difference in the picture quality between the two. Can you tell which one a particular recording was done on (without checking of course)?
Author:  tjc [ Wed Oct 18, 2006 6:47 pm ]
Post subject: 
Not with modern drivers. There was a while in the 0.4.x series where recordings on the 150 were seriously sub-par, but with any of the current versions (0.4.7, 0.7.1, 0.8.0) I can't really tell.
Author:  ALF [ Wed Oct 18, 2006 7:00 pm ]
Post subject: 
Ok cool- so I should be fine getting the PVR-150 then- woot!
Author:  tjc [ Wed Oct 18, 2006 7:06 pm ]
Post subject: 
Just be aware that you may need to do some simple tweaking due to tuner chip changes. The stuff required is easy enough, if you're expecting it and it's not some mysterious issue. ;-)

My proactive good deed for the day is pointing you to where to find the troiubleshooting page if this comes up: http://www.knoppmythwiki.org/index.php?page=TroubleShooting especially: http://www.knoppmythwiki.org/index.php?page=BlackScreenWatchingTV
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