Quality Issues - Interesting Observation

[mike1961]

Hello - Ever since I got my NVidia Dual TV tuner card, the quality is certainly better than my old PVR 500. But, some channels still sometimes come in a little blurred. For the longest time I figured it had to be due to the signal. After all, it's not a high definitiion signal. Then, I noticed something very interesting; the quality appears to be the same regardless of whether I record in Fair quality at .9 gb hour, dvd extra long 1.4, dvd long 2.4 gb/hr, or even dvd standard at 3.2 gb/hour. I tried getting a separate graphics card for the workstations since mine is built on the motherboard with my AOpen shuttle workstations. That made no difference.

My workstations are AOpen, AMD 3200 with 512 RAM ATI built on the motherboard.

I'm stumped as to why it doesn't seem to matter what quality I record in. The quality looks better on our 27 TV tube but on the 40" LCD it looks okay on some channels and just so/so on others (almost as if it is a "soft focus" and not sharp or crisp). But, I can't see why Fair quality would look the same as DVD standard. I have checked the file sizes and they are definitely recording at approx the setting I select.

Any ideas?

Thanks,
Mike

[stevech]

I speculate that the reason my Sage display from the S-video out jack is soft is that the video card's choices near NTSC formats is only 800 x 600. That requires resampling that reduces resolution. Again, this is speculation.

A hardware mpeg decoder wouldn't have this problem, I suppose. Maybe some newer video card chipsets have special support for video-out that's not tied to the PC display format choice.

[AngelofDeth]

You should be able to set your resolution to 640x480 or 720x480. Display settings/Advanced/Adapter/List all Modes should give you all the resolution options.

[stevech]

Originally Posted by AngelofDeth

You should be able to set your resolution to 640x480 or 720x480. Display settings/Advanced/Adapter/List all Modes should give you all the resolution options.

I could choose 640x480 instead of 800 x 600. Seems kinda small...see screen grab...not shown in the screen grab are 3 other modes, also 800x600 and larger

[stanger89]

Originally Posted by mike1961

the quality appears to be the same regardless of whether I record in Fair quality at .9 gb hour, dvd extra long 1.4, dvd long 2.4 gb/hr, or even dvd standard at 3.2 gb/hour.

I'm stumped as to why it doesn't seem to matter what quality I record in.

Recording quality and final picture quality are not directly/linearly related. There is very much, a point of deminishing returns with increasing the recording quality. Where that point is depends on a lot of variables, like how "clean" your source is, how good your encoder is, etc.

If you've got a very clean source, it doesn't surprise me at all that you see no improvement above 2.4GB/hr or even 1.4GB/hr. It may be a simple case that you've got a clean source, and a good encoder, and that there's nothing to be gained by going above .9GB/hr.

The quality looks better on our 27 TV tube but on the 40" LCD it looks okay on some channels and just so/so on others (almost as if it is a "soft focus" and not sharp or crisp).

That sounds about right for SD TV on a relatively large HD display. SD was meant to be used on small displays, smaller than 27" IIRC, it was never meant for use on large screens.

But, I can't see why Fair quality would look the same as DVD standard.

See above, once you reach the "threshold", you won't see much of an improvement increasing bitrate. My question to you is this. Do you see macroblocking at 0.9GB/hr? Macroblocking is the callsign of using too few bits (too low a recording quality).

Ever since I went from analog cable to Dish Network, my assumptions about required recording quality have changed significantly. With a noisy source (analog cable) I had to use about 3GB/hr to avoid macroblocking. With Dish Network, I've been able to drop that quite a bit, actually haven't taken the time to see just how low I can go.

[mike1961]

Will changing the resolution make "that big of a difference if any at all?" I'm currently at 1366x768 (wide screen). I find that when I change the brightness on the screen it does not have any affect in media players. So, I was thinking that perhaps the media players (including Sage) have their own separate graphics modes. In fact, I have found when I hook up a projector to my laptop, it displays everything out of the projector except the media player mpg file (like when I display a slideshow) and the only way to get the projector to display this is to not split the signal between projector and LCD. The point of all this is that I'm just wondering if the resolution has anything to do with the resolution of the media player.

Thanks,
Mike