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fun fact, CDs are literal spirals with one long track, not sectors like a hard drive. they are designed to be able to play with no buffering so the bits can go directly from the laser to the DAC. it’s basically a phonograph but with digital encoding.
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Jan 25, 2024 03:27
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| # ¿ Sep 16, 2024 20:52 |
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thats not exactly true, there’s also to 8-to-14 decoder and the time codes. but still basically no ram required.
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Jan 25, 2024 03:30
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Internet Old One posted:You sound smart. What was meant by the “8 times oversampling” that my cd player was so proud of itself for? no loving clue echinopsis posted:so as opposed to this, what’s a sector on a hard disk, in a physical sense? a hard drive is rings (“cylinders”) cut into slices (“sectors”). then there’s a third dimension (“heads”) because platters are double-sided and there is often more than one, and each has its own read-write head. cds are not constant rate of spin, but not continuous either. they have 3 zones (inner, middle, and outer) and the disc changes speeds between them. the encoding is set to match the rotational velocity, not linear velocity of the disc. I.e. the holes get elongated as you approach the outer edge of the disc
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Jan 27, 2024 07:53
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op your thread is infested with vinyl fetishists. I have no choice but to recommend gassing to keep them from spreading.
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Jan 27, 2024 17:03
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when do iPods come back in style? I have a few ready to be used
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Jan 29, 2024 02:35
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Farmer Crack-rear end posted:how do tracks work? i.e. how does the player know where to advance to when you hit 'next track' CDs have a table of contents at the start that lists the tracks, kind of like a partition table. however, there are no discrete blocks on audio CDs. instead they use time codes. there is a very low bitrate signal encoded in the data stream that contains the current time ( a cd player doesn’t need to keep track of what the current track is or the time, it can display the track and time codes directly from the disc with no processing. sometimes you’ll see a cd player show -1 seconds before a track starts. that’s literally in the time codes on the disc. The Management fucked around with this message at 21:32 on Jan 31, 2024 |
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Jan 31, 2024 21:23
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CDs were designed to be read by extremely simple ASICs with basically no compute power. like I said, they’re basically phonograph records with digital encoding.
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Jan 31, 2024 21:36
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graph posted:are audiophile morons yes
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Jan 31, 2024 21:49
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I have no devices capable of playing a cd at my house. I do still own many CDs though for reasons
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Feb 1, 2024 03:34
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echinopsis posted:with cd rom did that have much more redundancy and whatever compared to the phonograph nature of audio cd CD ROM dedicated 256 bytes out of every block (2304 bytes) to error correction data. the cross-interleaved reed-solomon encoding ECC made them very resilient to clustered errors. this means that they are very good at recovering from errors caused scratches on the disc surface, even if the scratch is parallel to the track path.
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Feb 8, 2024 18:16
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echinopsis posted:cds are great tho they doubled it for a very precise reason, the Nyquist–Shannon sampling theorem, which is a fundamental rule of digital sampling. it basically says you can perfectly encode any analog signal if you sample it at twice the maximum frequency.
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Feb 8, 2024 18:24
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Internet Old One posted:Aren’t Sony CD DACs just good in general? no, they suck
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Feb 8, 2024 18:25
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