Wow, lots of interesting issues here...
HowardC wrote:
Well with that being said, you can't get a true ntsc signal from a pc without a great deal of effort because it is using tv-out scan conversion. While technically tv-out is ntsc the downsampling and overscan "crunching" going on will give you some serious crawl lines.
You can get proper NTSC through the TV out if you use 640x480 with full overscan - no downsampling, no crunching. If there's a 'flicker filter' setting, you'd probably want that off, unless you want a little blurring.
Not all card/OS/driver combinations make this possible, though. I had to use an older nVidia driver for Linux when I set up tv out on a Gf4 -- the newest version broke the overscan option.
If you're using the RGB outputs at 15 KHz, then the rescaling issues go away entirely. You might still want to tweak the custom timing values to get more or less overscan, or adjust the H/V widths on the monitor, but that would be about it.
Matt Ownby wrote:
Well, one thing I am not sure about is although the laserdisc is interlaced, is the video overlay (for non-Dragon's Lair games) interlaced?
Yes and no.
Technically, the overlay is interlaced, as it becomes part of the one video signal going to the monitor. However, most laser games don't change the overlay during a frame, so both interlaced fields of the frame have the same graphics. You can see a small amount of flicker (not much since the graphics are the same in both fields), but no extra resolution.
I think a few games (Astron Belt?) may update the display on every field, though, making it a 'proper' interlaced output. This doesn't add more resolution, it just makes a motion a bit smoother.
(Side note: there are a few non-laser games that use interlace - Spy Hunter and Rampage come to mind. The display is more detailed, but flickers a bit.)
In the case of Daphne, the overlay graphics are updated once per frame, so the interlaced fields will always be the same. I suppose it would be nice to have an option to double the update speed, but this would be a minor difference and cause a big performance hit. Might still be worth a look someday...
lowlight wrote:
While HD is very nice, for me, a game like DL doesn't feel right if it's free of all of the original visual defects that were produced by the hardware; that's what feels authentic to me.
I'm with you on this one -- cleaned up and/or HD versions of these games look really nice, but I also appreciate seeing the artifacts of the original technology. (I know Matt doesn't like the -seekdelay feature either, but I love it.
I find that instant seeks throw off the 'rhythym' of the game.)
lowlight wrote:
If the original source footage hasn't been de-interlaced (a straight extraction of a laserdisc, for instance), would the resulting image be closer to the authenticty that the original game and a normal television set can provide with such a swicth ( -interlaced), or do you feel it would have minimal effect?
If you're using an interlaced display, I'd say use an interlaced mpeg captured from the laserdisc. I'm not 100% sure how libmpeg2 handles 3:2 pulldown for 24fps video streams, so you might not get the exact 3:2 field sequence. I can't say I've ever observed this difference when comparing the two, so it may be a non-issue. Some games have video that doesn't deal with inverse-telecine / deinterlacing well, so you'd definitely want to use an interlaced capture for an interlaced display for them.
While we're talking about
maximum authenticity, I should probably mention that the finer dot pitch on the tri-sync monitor may make the interlace scanlines a bit more apparent than on a plain standard-res monitor or a TV.
On the other hand, a TV will have somewhat different NTSC to RGB decoding than the original game's monitor, so that still looks a bit different. For games with overlay, a TV will be significantly less sharp, or add NTSC decoding artifacts if you use a composite connection.
So what you
really need is a standard-res arcade monitor, with the original NTSC decoder for non-overlay games, and a 15KHz RGB connection for overlay games. Sorry, everyone...
Hehe
-Warren.