Why does video look so lousy on computer monitors?

Discussion in 'Archived Threads 2001-2004' started by Tom Koegel, Jan 3, 2002.

  1. Tom Koegel

    Tom Koegel Stunt Coordinator

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    I've been playing around a bit with some quasi home theater PC applications. I have a Sony PC with a TV tuner an on-board MPEG2 encoder such that it emulates, sort of, a DVR like a Tivo or a Replay. (This is just a toy/test bed; this is not currently set up as part of my home theater system.) And I've often thought about the possibility of setting up some sort of large LCD monitor with a small PC as a bedroom home theater. What stops me in my tracks, though, is the extremely poor quality video presentation on computer monitors. To my eye, at least, this is not solely an LCD issue; I notice the same effect on conventional CRT monitors (although it is lessened). Colors looked washed out; resolution generally looks far weaker than on a standard TV set. Is this a brightness/contrast issue? Color temperature? Something else? I just got back from a CompUSA where they were running Jurassic Park III on one of those 24" Apple Cinema LCD monitors, and the picture looked "softer" than what I would expect on my 40" 16:9 non-HDTV RPTV. (Although I will say that it did not have the washed out look of my 18" Sony LCD or CRT monitors.)

    Tom Koegel
     
  2. Hugh M

    Hugh M Second Unit

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    The HTPC can provide the highest quality DVD playback. It takes effort, which is something that may not have been put into the Comp USA setup. I run my DVDs on a 27" 800x600 (at 960x540)monitor, and I couldn't imagine a better picture than what I am currently seeing. If I were using a larger screen I am sure I would be able to spot some problems, but once I found them I wouldn't be able to do much about them because the HTPC can basically provide the best PQ there is.
    as far as captured video, the best results are with the free dscaler software. ( www.dscaler.org ) there are hardware requirements that you need to check at that site.
    one of these is a certain type of capture card. If you are really interested in this, then pick up an IO Magic PC PVR the next time you can find one at CompUSA. They go for $40, sometimes with a $20 rebate as well!. This capture card has a very clean svideo input, which is currently the only thing you should focus on when trying to use the HTPC for external video sources. Using the dscaler software the results are amazing. Its a science really, the people involved in the project have put alot of effort into deinterlacing methods and so forth. One of them, Mark Rejhon, even went on to help design the Rock (expensive video processor).
    Couple things to consider. On a big big screen certain sources (like digital cable, or satelite) which are compressed carelessly will be hard to watch when they are blown up. Dscaler can't improve much on these because of compression artifacts, and if you find yourself watching one of these sources on a projector you may start to become a bit edgy.[​IMG]
    But a cheap capture card like the IO Magic, and the dscaler software will make a huge difference over using standard software/capture solutions. I have been able to make this comparison with my VIVO feature on my Radeon card. I'm disappointed that I spent money on it, now that I have found a better solution.
    Right now I am limited to lousy analog cable with poor signal quality, so I don't use the HTPC for viewing TV. The dscaler/capture card combo on a monitor with my crappy signal would probably drive me so mad about the $40/month cable bill. It just exposes the poor quality more than I can handle.[​IMG] But for VHS, and for the PS2 the picture quality on my 800x600 monitor is great. Dscaler makes PS One games look like PS2 games. I have a Sony Trinitron 27" TV next to the 27" monitor and when doing a direct comparison of svideo sources on the monitor, and then on the TV, there is no comparison at all.
    Also to benfit from any video output of the HTPC it is essential to use a progressive or hidef capable display. The only thing I can think of that the HTPC/Standard display combo is good for is music visualizations and stuff like that. Otherwise you are better off going with one or the other. Either a progressive/hidef display with an HTPC, or a standard siplay without. No use mixing them up.
     
  3. Hugh M

    Hugh M Second Unit

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    to give you an example if you use an iomagic card, run svideo from a vcr and use the dscaler software, the VHS tapes look alot better than they used to.

    I can dig up some screenshots I have seen from digital ota tv (non-HDTV) sources run through dscaler if you like. They are pretty.
     
  4. Ken Chan

    Ken Chan Producer

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    A couple of differences: monitors have a different gamma response than TVs, so the brightness -- or less ambiguously, the black level -- is generally off. This is often aggravated because monitors aren't set to the right brightness to begin with. Have you tried using something like Avia, Video Essentials, or THX Optimode to calibrate the monitor?

    Monitors are progressive, while TV and DVDs are interlaced, so they have to do some kind of deinterlacing. Simple bob deinterlacing will soften the picture.

    Monitors are also high-resolution displays; TVs hide flaws (and you expect it to look kinda mushy anyway). Scaling up can make the picture either soft (anti-aliasing) or chunky. And you're probably sitting closer to the monitor in proportion to its screen size.

    I've seen HDTV on a monitor and it looks better than it does on big-screen sets. Part of this is of course that tubes still look better than rear projection, but the point is that TV can look good on a monitor. (HDTV is a better match for a monitor's resolution than DVD and much better than low-res TV.)

    //Ken
     
  5. Tom Koegel

    Tom Koegel Stunt Coordinator

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    Thanks, Hugh and Ken. I guess I'll play with VE and see what I come up with. I suppose it is just a trick of the eye, or of expectations, that a large conventional monitor looks "sharper" than a computer monitor.

    Tom
     

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