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zbuf | 1 year ago

The records used by xwax have about 100 kilobytes of data on each side of a 12" record. However, the goals are very different here; it's designed to decode the position under specific conditions such as being moved very fast, in reverse and changing direction rapidly. There would be a more efficient encoding if your goal was to fit as much data as possible and relax the other requirements.

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hedora|1 year ago

Yeah; I'm imagining the record sits in a basement for 100 years, and has mildew + scratches. Each error correction block has to be (I'd guess) at least 10x wider than a scratch, assuming the codes can correct 1 bit out of 10.

CDs use Reed Solomon, configured for a 1:10000 bit error rate, but NAND storage uses LDPC, which is much more robust.

Anyway, reading such a block would likely take the record player 10's-100's of milliseconds, and xwax seems to target 1ms.