Still using analog cable, need advice for quality image

[Flow]

Hi everyone,

I am new to the PVR side of things running XBMC for years and decided it would be nice to get into PVR stuff!

Well well, it has been a few days now, lots of searching for hardware, forums reading... I bought an Hauppauge 2250, right away I saw the image quality was much worse than just having the cable plugged in my tv.

So searching for more I understand that MPEG2 compression is probably a reason for a significant lower quality. I then bought an ATI TV Wonder 750 USB! It fails as a it is USB and will just lose signal...


So what I'm looking to know is that ATI seems to have better analog cable support and Pcie versions TV Wonder 650 does have compression, 750 does not, wouldn't it be better that it does not have such compression so the image quality is better? I can't really find info on the subject since I guess almost everyone now uses digital but here with Videotron analog is still available and suits me.

Btw, my htpc hardware sports an AMD E-350 and I wonder if it will be enough to support a software encoder and if my 6310 onboard graphics be useful in that regard?

I'm open to suggestion, I do realize analog tv tuners will never look as good as the tuner in my tv but looking for the best quality possible. Also, is there much difference in using softencode in NPVR vs a hw encoder?

[Zeb]

Hi Flow. MPEG2 compression isn't the problem. DVDs use MPEG2. Practically every tuner will encode output as MPEG2, either by hardware or software. Hardware encoding reduces the load on your CPU. Too many splitters can ruin picture quality, but there is very likely a software explanation. What version of Windows are you running? On NextPVR's Settings -> Decoders page, what decoder is selected for MPEG2 Video, and what is selected for Video Renderer? When you first open Settings, do you see a warning about DirectX runtimes? Is WinTV fully installed or just the SoftPVR components?

[mvallevand]

If image quality in XBMC is an issue, for analog SD, the first thing I'd check is to make sure de-interlacing is turned on. The SD bitrates that NextPVR uses are also pretty low, so you can probably boost them in config.xml a little bit. Analog cable splitter could also be a confirm, and the 2250 is already split, so try reducing the splits or maybe add a signal booster.

Martin

[johnsonx42]

The default analog quality settings in NPVR are very low; I get great quality from my 2250 using these settings in config.xml:

Code:

<Analog>
    <Bitrate>6000000</Bitrate>
    <BitratePeak>9000000</BitratePeak>
    <BitrateMode>VBR</BitrateMode>
    <FieldOrder>top</FieldOrder>
  </Analog>

You definitely should go back to the 2250 with hardware encoding and two tuners; I have one soft-encoded analog tuner as well, and I can easily tell by the lower quality when a recording was made by the KWorld tuner vs. the 2250.

[Zeb]

True, the decoders you select for NPVR won't have any bearing in XBMC. Config is typically in Users\Public\NPVR unless you're running XP. You can edit it with Notepad, just be careful to save as .xml rather than defaulting to .txt.

[Edit] The ATI TV Wonder HD 750 was troublesome for another user: http://forums.nextpvr.com/showthread.php...post457782

[johnsonx42]

btw, I missed the part in your post where you said you have an E-350. I'd definitely not want to burden such a low-power CPU with software encoding (software encoding uses a fair percentage of one of my 3Ghz Athlon II cores, which are MUCH more powerful than the E-350 cores). Stick with hardware encoding.

[Flow]

Thanks for the answers!

I do have an E-350 and that's why I was wondering if the 6310 graphics was helping at all in conversion, another reason for me to use an Ati tuner vs Hauppauge. In my test running this usb tv wonder 750 i see the picture is much clearer than the hauppauge 2250 and then I wonder if it's because it's Ati or because there is no conversion done. I've tried all the combination of deinterlace and what not possible in XBMC and also in the catalyst and it doesn't make much difference.

What I'd like to try is an Ati 650 to compare it with the Hauppauge 2250. Also I was trying to see if Hauppauge cards could be tweaked and notice that those tweaks worked until the 500 series... is there any newer tweaks that can be applied? What about Graphedit? This is all for live tv though, not doing much of capture...

I'm opened to other brand as well... does anyone know of a device that can potentially bring as clear a picture as cable straight in my tv? I've read lots of threads saying there is no such thing but is it really? Otherwise maybe tweaks?

[Zeb]

If these are used tuners you're trying, it might be that the 2250 was beginning to fail. Nothing lasts forever. Analog cable won't be around much longer, so don't spend too much money on analog tuners. Here's an old thread you might have missed: http://forums.nextpvr.com/showthread.php...post252937

[Flow]

You guys know about graphedit, unless I have misunderstood it, it modifies the hardware path from the encoders / decoders to apply different filters of compression?

By the way the 2250 and USB 750 are both new and I have 30 days to return them so I'm testing what I can with those... The USB 750 being brand new and not reliable makes me wonder how it ever got released! I read the pcie version of the 750 or any device actually is far better, all USB's tend to fail, heat or just not performing as you would expect them to.

So back on the subject... Anyone knows if the AMD 6310 helps in conversion of the video? I searched for Avivo stuff but no info is clear.

Even though the Hauppauge seems to last longer or be more reliable, I really liked the analog quality better on the USB 750, but then again this was using softencode. If the quality is similar on the 650 I would love to try one, if it's the same quality as a 2250 then I might keep it(the 2250). I guess no new hardware will be coming out either to help with analog since it's pretty much out the door. To me the quality is fair on the 2250 but I didn't like the jittery especially when stripes of black and white you could see colors forming in those stripes or when text had jitter or edges seemed more pixelated. For the 750 I noticed there was much less noise or jitter but a bit more blur, also the colors seemed a bit washed, but even then it's less annoying than a jittery image. So you guys thinks that's due to the card chipset or the encode taking place?

I read my posts again and I guess I was thinking softencode meant 'no encode' as in raw video and possibly encode it later? I guess then that encoding is necessary/always happen? Tweaks would be nice to play with, change the bitrate, etc...
Thought softencode could less impair the video as less processing was done to it. Then I started to think about H.264 hw encoders and how those performs.

The whole point of me doing this is that like many, this will need the wife approval! And so far she noticed right away the quality difference on the 2250 vs actual tv tuner, add to this the time for channel change and having to learn something new (XBMC now becoming the tv)... The funniest is I don't even watch tv! The amount of time I've put into this is crazy when you think of it, but I refuse to accept that something like this to me should be easy, well I thought after so many years tv tuners have been around that it would be seemless!

Well, sorry for the long post, at least you know a bit more of where I come from.

[mvallevand]

The analog tuner era is almost over so you are kind of late to the party. In Canada my provider Rogers is not even obliged to provide analog and can pull it anytime. The keep reducing the channels an moving users to the DTA.

Problems on tuning speed are primarily XBMC related, in NextPVR itself tuning is faster, faster in fact then my digital STB.

Martin