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Re: Questions on HLSL scanlines feature.....
06/07/11 11:53 PM
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> > * Added a 43-tap-wide FIR-based NTSC filter with tunable Y, I and Q frequency > > response. > > It's intended for MESS, but if we ever want to redump the laserdiscs to be the raw > NTSC signal (which would probably result in 200+ GB CHDs) it'll happily decode the > image with no CPU time required.
Wow, that's pretty cool stuff!
Storing un-decoded composite video can actually be smaller, at least before you try doing lossless compression on it. The chroma is modulated and embedded in the upper portion of the luma range, so you are effectively only storing the Y channel.
That's what D2 (composite digital) decks used to do at the same sample rate as D1 4:2:2 YUV, which is the standard we're using now. It's only half the size, but it won't compress well with standard techniques, since it looks like black and white video with tons of checkerboard dots all over it. The "entropy" of the information is going to be about the same.
This isn't totally 'raw' video, though. It's time-base corrected and doesn't contain the colorburst at the start of scanlines. If it's handled well during capture, this isn't a huge limitation.
Storing raw RF from the disc along with servo feedback information to do TBC later is a different story, but of course you guys can waste disk space with impunity. Anyone have access to an electron microscope?
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