Long runs of no changes is generally undesirable because it makes it harder to know where the reader is. So you’d want some type of coding to make sure you see changes occasionally regardless of where you are. For CDs, it seems like each byte is converted into 14 bits, where the longest run of zeroes is 10.
Comment on Feeling that groove
ChaoticNeutralCzech@feddit.org 16 hours ago
Records are very easy to understand. Even without a microscope, you can see periodic patterns on test vinyls with beeps.
You can even see tracks starting and ending on pressed CDs under the right lighting with your own eyes. I wonder, is the encoding of silence (approx. 2 seconds) really that different or does the density of grooves or pit/land pattern specifically differ to help the player seek there faster? I know that uncompressed audio naturally results in a repeated pattern when silence is encoded but given the 8-to-14 modulation and other error correctiion techniques, I find it hard to believe it would result in significantly different density unless they specifically added a special mode just for encoding silence that makes the track brighter-colored for easier coarse seeking.
CookieOfFortune@lemmy.world 15 hours ago
ChaoticNeutralCzech@feddit.org 9 hours ago
I know, among other things there is a time code inserted very frequently between audio data, without which seeking would not be possible at all. However, the audio uses over 90 % of the data so it’s largely responsible for the overall appearance of the track.
CookieOfFortune@lemmy.world 8 hours ago
It doesn’t seem like there’s a pseudorandom coding applied, so repeated patterns should show up visibly. I’ve never really examined it myself though.
ChaoticNeutralCzech@feddit.org 2 hours ago
Madison420@lemmy.world 15 hours ago
Theres a graphic somewhere I’ll try to find that shows a bird call as a sound wave then a picture of record topography of the same call that makes it fairly obvious.
Gramophones are also fairly illustrative given that the needle directly acts on a diaphragm that is directly connected to a bell shaped horn.
ABetterTomorrow@sh.itjust.works 13 hours ago
Would love to see that