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September 12, 2005

vhs-hell ii: the sequel

i encountered what was easily the worst video signal i've ever seen today - and my expensive equipment rose to the task.

this was the mario 2 all levels run. at first when i saw it i thought there was no way i was going to be able to do it, because the vsync was virtually gone, so the image was rotating vertically every few seconds. it later turned out that it was only doing that in certain spots, but then there was still that the odd field was several lines higher than the even field, for a truly seizure-inducing 60 hz vibration of the picture. i tried dropping every other half-frame (making 29.97 fps, or 'f2' as i call it), and that solved it, but there would be no chance of a high quality version if i went with that solution.

then i tried capturing without the standalone tbc just to see what would happen. the shuddering problem (where the odd field was several lines higher than the even field) was gone, but i couldn't capture anything - without the standalone tbc's help, up to half the frames were being dropped by the capture card. the tbc would be necessary to capture this run.

so i played with the settings on the uber vcr a bit and tried turning on the "stabilizer" (which disengages the uber's tbc in exchange for a processor that tries to hold the vsync on the picture). bingo - the image was stabile through the standalone tbc, which allowed it to be captured. it's still really nothing to look at - distortion everywhere - but the fact that i didn't drop any frames due to the bad signal means there can be a full framerate (hq) version and a dvd version of this run.

here's to my over $600 in technology truly being worth every penny once and for all.

Posted by njahnke at September 12, 2005 9:18 PM


Holy cow. That IS one impressive piece of technology.

Posted by: Forgotten One at September 14, 2005 4:10 PM

I'm thinking the waterfalls made things so much worse because it's the only place in the game with large swaths of animation. (There's the quicksand, too, but that's pretty slow and subtle, so I guess that's why it didn't do anything.)

Posted by: Yoshi348 at September 17, 2005 5:00 PM

that's a good observation ... would have to know more about the analog signal and/or ntsc to say for sure. the reason radix singled out the waterfall was that a similar waterfall (start of bubble man's stage in the mm2 run) prevented him from properly capturing another run long ago (it was no problem for the uber, though).

Posted by: nate at September 17, 2005 5:06 PM

Can you split it into channels? not necessarily by colour, but HSV? See here for why I think it might help:

Posted by: sn at September 17, 2005 10:43 PM

I think Radix's card uses hardware compression(probably MPEG or MPEG-2). If so, that would explain the stuttering on the Bubble Man stage. That's a lot of motion to be encoding in real-time without help from the CPU.

Posted by: andyo at September 17, 2005 11:55 PM

whoa, sn, nice link. i don't understand all of it, but i understand enough to realize that the nes is a pos and the fact that the card can take that crap it produces at all is a miracle. no wonder i needed a full frame tbc to capture pal nes without dropping 43843432 frames ...

and andyo, radix confirms his unit does hardware compression, and he gets different framerates from different sources. not sure if it or the info in sn's link is to blame for the bubble man trouble, though ... that tape was so bad i couldn't even capture it before i got the tbc in the uber vcr, so it could easily be the unit that recorded the tape putting down a crap signal complicated by it being wacky originally (from the nes).

Posted by: nate at September 18, 2005 4:00 PM

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