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Fun Fact: I own porn I can't watch

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Re: Fun Fact: I own porn I can't watch

#153

Post by nonrandomstring »

zokier wrote: post #147
nonrandomstring wrote: post #120

Earlier quoted context omitted.

This seems quite possible in principle, despite the different helical scanning, tape widths, speeds and whatnot. A device at the British Library archival research did similar for wax cylinders and old disc records, scanning the physical surface with a small wavelength laser interferometer. AFAIK it generated an obscene amount of point cloud data. My thought is that, if you could develop a sensor capable of sampling m…

> My thought is that, if you could develop a sensor capable of sampling magnetic alignment at sub-micrometer resolution it would also generate unbelievable amounts of data that would first need compressing or decoding into AV signals. Hard disk drive read head sweeping across the tape? Hard disk track widths are well below 1 micron so presumably the potential for high resolution is there?

Nice idea. I think you'd have a problem with shedding. A HD head is designed to fly/float above a clean platter. Old tape is icky, flaky mess of brown dust and wobbly plastic that would foul up the head PDQ. But rather than scanning maybe you could encapsulate a bunch of old HD densely together in some kind of epoxy/glass to make a high-res tape head?

Re: Fun Fact: I own porn I can't watch

#155

Post by midasuni »

WorldMaker wrote: post #108
delecti wrote: post #70

Earlier quoted context omitted.

You might be surprised at how the signals are actually recorded on tapes. For VHS tapes for example, it's actually a series of stacked "diagonal" lines of signal. Imagine a sequence of symbols like \\\\\\\\\\\, except at any given horizontal point along the tape there are about 5 stacked traces of signal. They're also diagonal on audio cassettes, but much less "slanted" relative to the tape's length. I don't remember…

One of the terms was interlaced, the nearly forgotten "i" next to something like 480i (versus 480p). Individual magnetic lines of a VHS tape would only describe half a frame and the two halves would be interlaced back together.

I think one major network in the US is 720p60, but the vast majority of broadcast transmissions globally is 1080i25 or 1080i30*

Of course sadly so much content is produced at 1080p24 nowadays for that “film” effect it’s rather meaningless for display purposes.

Online of course it tends to be p50 or more commonly p60 (even in 50hz countries). YouTubeers tend to be able to afford more lights and clearer microphones than big budget productions too.

* 30000/1001

Re: Fun Fact: I own porn I can't watch

#159

Post by betamaxthetape »

Animats wrote: post #134
betamaxthetape wrote: post #131

Earlier quoted context omitted.

Do you have any more information on this? It sounds really interesting, and I'd love to learn more!

The play counter? Lots of patents in the 1980s. 3M, IBM, CBS, Polaroid. Dead end commercially. [1] https://patents.google.com/patent/US4586101A/en

Interesting. But was it ever developed commercially? I can't find any consumer products actually using the counter (either for rental or for lock/jam-after-certain-plays). But that could just be because I'm using the wrong search term - I imagine that there is a brand-specific term and searching "VHS tape play counter" isn't helpful since all the results are for either repairing VCRs, or for accessing the tape counter functionality in the VCR.
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