NegativeKarmaForever | 13 points | Sep 23 2017 18:11:45

[Meta] Interesting and useful encoding considerations from a different site

collection keeps that sweet nostalgia content safe from degradation of the magnetic tape, which starts to go downhill within 10 to 25 years. He's capturing them in HD using a 1080p upscaler, at a full 50fps frame rate by converting to HDMI before grabbing -- a higher frame rate than many standard commercial digitizing devices that capture at 30fps -- so that no frames are missed.

Why?

VHS only has about 333x480 (NTSC) or 335x576 (PAL) resolution in luminosity, much lower color resolution. There is no point capturing it at higher resolution - you're just wasting storage space with duplicated or made-up pixels.

The framerate thing I can sorta understand - both NTSC and PAL were interlaced. So for example, the actual resolution of NTSC VHS was 333x240 @ 60 fps interlaced, which when deinterlaced (the alternate lines of video interpolated) created 333x480 frames @ 60 fps. While modern computer video formats do support interlacing, I've noticed annoying artifacts when they're converted badly (you'll see horizontal lines during quick panning or quick horizontal movement). So I can understand.capturing at 333x480 @ 60 fps when it only contains 333x240 @ 60 fps of information.

Maybe if he had access to the original Betacam tapes I could understand capturing in HD. Those had 720x480 or 720x576 resolution with 10-bit 4:2:2 chroma compression. But if your source media is plain VHS...

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