TV Tuner question

[Messerschmitt]

Hello, I bought a TV Tuner, TV-PVR V-Stream.

The little problem I have is no matter what settings I use, I don't get the exact same quality that the TV Tuner is giving when I record. The recording is allways a bit lower quality than the live picture. I have MPEG 1 2 4, AVI, VCD (PAL, NTSC), DVD (PAL, NTSC), SVCD (PAL, NTSC). I set the highest resolution for these, Up to 4000 Bitrate (Kbps) and even 8400 (Can't see the difference between these 2 values), set the quality to Highest. Yet, the quality is still lower than the live streaming. Is there any secret I could use so I can get the same max quality I get when I am watching it on live?

[ripken204]

im not exactly sure what the best quality is. so uve tried them all on highest settings and max resolution? do u have any clue what format the stream is coming thru in?

[03GrandAmGT]

If you can spend some money and get the Hauppauge pvr-250. These have a great performance track, not to mention they are hardware based encoders. The KWorld

http://www.newegg.com/Product/Product.asp?...N82E16815116616

I have tried some of the ATI, Kworld, (and others like the Kworld) Pinnicle. The best one I have found was the PVR-250. I have had my HTPC system up and running since 2002 and have had no problems with quality issues.

If you decide to go with a Hauppauge card here's a couple of links for tweaks.

http://www.shspvr.com/

http://www.cask-of-amontillado.com/htpc.html

Good Luck

jd

[ripken204]

someday i want to get that hauppauge with the dual tuner, that would be nice.

[03GrandAmGT]

someday i want to get that hauppauge with the dual tuner, that would be nice.

Ya, but there have been some problems with them watching and recording at the same time. I myself am looking at getting another 250 and put that next to the one I have and I'll have the same thing.

jd

[CoffeeFiend]

Is there any secret I could use so I can get the same max quality I get when I am watching it on live?

Nope. That is analog capturing in a nutshell: poor quality. Even the Hauppauge cards have so-so results (just not as bad as some other cards, but nothing great). If you want the same quality, then you gotta look into DVB cards (100% quality, bit for bit copies, but the feeds are usually encrypted though), or ATSC tuners if there are OTA feeds in your area or such.

Analog capturing will always look bad. There is just too much conversions, recompression, filtering, cabling, interference, noise, distortion, miscalibration, etc.

This is what you're essentially doing with those capture cards:

Digital signal (cable/sat/dvd/whatever) -> mpeg decoder -> DACs -> filters -> plugs and wiring -> more filters -> ADC -> on the fly compression -> dumped to your HD.

Whereas with DVB cards and other ways to capture digitally, it's more like

Digital signal (cable/sat/dvd/whatever) -> dumped to your HD.

Skipping the entire "digital to analog and back to digital and recompressed again" thing. You skip the ugly conversions, the filtering, the noise, etc. And capture cards aren't calibrated perfectly. Their white and black levels are always a bit off (I've seen some recordings that were pretty bad).

To make an analogy with AudioCDs (yes, them old things), analog capturing would be:

Play CD in whatever player you have, plug the line out in your sound card, and record it as a average bitrate CBR mp3 on the fly. (all kinds of noise is added, sound is distorted a bit, etc)

versus

Rip the disc digitally with a PC to WAV files.

Actually, when you think of it, this is EXACTLY what happens when capturing the audio with your capture card, vs when you capture digitally (keeping AC3 5.1 or DTS instead)... Just like for the video.

I think anyone can tell what the difference is going to be like, or at least which will sound better.

So no, don't ever expect the same type of quality you'll get from a DVD rip or such. Never. Gonna. Happen.

[ripken204]

do u know of a good dvr then?

[CoffeeFiend]

Depends... Most PVRs and recorders are also analog solutions (tivo et al). I've only seen 2 types of "real" DVRs before, those for use with digital cable packages (which are proprietary, and vary from a provider to another, and I don't have cable), or the satellite PVRs (which is what I use - the echostar 510 or 5900 specifically). But I can't stay echostar stuff is reliable. They've replaced this receiver 5 times under warranty so far! (HD in the original broke, all replacements were DOA except the last one). But the recording quality is there... (I also used to use a DVB-S card, but with recent changes in nagra2... there's nothing left to watch)

[Messerschmitt]

Kinda puzzeled, does that means that when recording, because you have to convert to mpeg, and whatever more it's doing, the quality of the recorded file will be less than the live streaming through the same TV Tunner card? So because of this, the recording will allways be less quality than the actual live stream I am watching?

As other options I have: Video Input Format - UYVY, YUY2, RGB24.

As a side note, when recording on Mpeg format, I can only have 25 frames, while when recording to .avi or mpeg 4 I get 29.97 frames (I have the option to change it but no matter what I select the output will still be the same). Same for the audio. It's allways 44100 Hertz, even if I select let's say 48000 Hertz. It's this software problem? Practicaly I can't have a Mpeg4 (outputs as .avi) format or Avi because the sound will remain behind the image.

Edited July 30, 2006 by Messerschmitt

[CoffeeFiend]

Kinda puzzeled, does that means that when recording, because you have to convert to mpeg, and whatever more it's doing, the quality of the recorded file will be less than the live streaming through the same TV Tunner card? So because of this, the recording will allways be less quality than the actual live stream I am watching?

Yes. Analog capturing and recompressing in a lossy format will ALWAYS result in a degraded picture (all explained in previous post, even with analogies).

You use 25 or 29.970 frames depending on what system is in use where you live (PAL or NTSC). If it only lets you select one, chances are it's the one in use in your area.

As for audio, 44.1KHz is AudioCD-like sampling frequency, 48KHz is the frequency used by DVDs. But it will not make a difference... You're still doing low-quality analog capture and recompressing anyways...

As for mpeg4, it's not a capture codec but more of an archival one. That's what you'd use to convert your shows post-editing and recording if you want smaller files, losing even more quality in the process...

[Messerschmitt]

Thank you for all the explanations. Really appriciated.

I found a way to preserve as much quality. If anyone is interested: Mpeg-2 Highest res, Highest qual, 8000 bit rate.

After that encoding with DivX (couldn't find Xvid to try it also) 1300 bit rate.

In my opinion the quality is very acceptable giving the circumastances