[HN Gopher] How CD pregaps gained their hidden track superpowers
___________________________________________________________________
How CD pregaps gained their hidden track superpowers
Author : shortformblog
Score : 204 points
Date : 2024-07-09 19:38 UTC (1 days ago)
(HTM) web link (tedium.co)
(TXT) w3m dump (tedium.co)
| MOARDONGZPLZ wrote:
| I read this whole thing twice and I now know what pregaps are and
| the history but still have no idea why people would put them on a
| CD or why they're useful for hidden tracks.
| dylan604 wrote:
| Oh good, so I'm not the only one that thought the article
| failed to actually state what the superpower was. Some lame ass
| patent was granted?
| monocasa wrote:
| Basically cd audio tracks have a base sector _and_ a start
| specified. That allows sectors representing audio before
| timestamp 0:00 to be represented the track. The reason for this
| originally was probably to allow the drive to get synchronized
| before the track started. Enterprising cd masterers put actual
| hidden audio data in that area which would allow you on some CD
| players to rewind past 0:00 and then play the hidden audio at
| the negative timestamp.
| crazygringo wrote:
| How much hidden audio could be stored?
|
| Was it limited to something negligible like a couple of
| seconds?
|
| Or could you store a whole five-minute recording in there or
| something?
| boomboomsubban wrote:
| There doesn't seem to be a limit, this https://en.wikipedia
| .org/wiki/List_of_albums_with_tracks_hid... mentions a 27
| minute live recording.
| jvan wrote:
| Incredible! Songs in the Key of X was the only album I
| ever knew to do this, and it wasn't even the first. I had
| no idea so many others did the same thing.
|
| Edit: Son of a *, I've had a copy of Sister Machine Gun's
| Burn for almost 30 years and never knew there was a
| hidden track!
| ChrisArchitect wrote:
| Classic X-Files album is the one I think of too. And how
| they hinted to everyone that there even was a hidden
| track on the sleeve: "'0' is also a number". (and the
| technical fineprint about the disc possibly not being
| Redbook compliant)
| croes wrote:
| I guess the limit is some milliseconds short of 74
| minutes.
| add-sub-mul-div wrote:
| As the article says its like an easter egg, putting a hidden
| song before the first track of a CD. If the song wasn't in the
| pregap it wouldn't be hidden. It's just for fun.
|
| (Sometimes songs can also be hidden in tracks at the end of the
| CD like 99, but that feels less mysterious.)
| mattl wrote:
| Sometimes CDs would have a long piece of silence at the end
| of the last song and then another song on the same track.
|
| Other CDs really experimented with the shuffle feature. They
| Might Be Giants' Apollo 18 had a bunch of very short tracks
| that would usually play between songs when shuffle was used.
| add-sub-mul-div wrote:
| I had that CD and remember the short tracks but never
| thought of playing it on shuffle that way.
|
| I think it was nine inch nails' Broken EP that had the
| hidden tracks on 98/99 rather than after a long silence,
| but I could be wrong.
| mattl wrote:
| I think it tells you in the liner notes that you should
| use the shuffle button.
|
| My copy in the UK at the time didn't have the individual
| tracks. Just one track.
| ssl-3 wrote:
| Broken was first released as a 2-disc set. It was still
| in a many-fold Digipak case, but also included was a 3"
| mini-CD that had Suck and Physical (You're So).
|
| The regular-sized CD looked about identical to the
| 99-track version, but had only 6 tracks.
|
| (It was expensive to do this, and was never intended for
| long-term production. Later versions were generally as
| you describe.)
| gwbas1c wrote:
| I remember getting surprised by one of those. I was at a
| friend's house and forgot to turn off the CD at the end.
|
| It was funny at first, but when every other CD I bought had
| one, it became tacky.
| mikepavone wrote:
| An audio CD is mostly arranged like a single continuous
| recording. Tracks are added on top of this via the Q subcode
| channel that gives information about the current location and
| the ToC stored in the lead-in area (also using the Q subcode
| channel). In the ToC, each track will have one more indexes
| that points at a specific location on the disc by minute,
| second and "frame" (represents 1/75 of a second, basically a
| sector).
|
| If a CD is properly following the Red Book standard, index 0
| will point to a 2 second pre-gap of silentce and index 1 will
| point to the actual start of audio of the track (additional
| indices are allowed, but not common). The purpose of the pregap
| is to make life easier for less sophisticated players that
| aren't able to seek to a precise frame on the disc. They just
| have to be able to hit a 150 frame region. However, just
| because the standard says the pregap is supposed to be 2
| seconds and silent doesn't mean it actually has to be. Players
| generally don't care and by the time the format was popular,
| even inexpensive players could seek precisely. This allows you
| to stick audio data before a track that will be skipped by the
| player when it's trying to seek to that track. If you stick it
| before track 01, it will be skipped even when just playing the
| disc through unless you rewind.
| kevin_thibedeau wrote:
| The key for a hidden track at the beginning is that players
| usually start playing track 1 from index mark 1 (1.1) rather
| than index 0 as with continuous play through all subsequent
| tracks. The lead-in area for 1.0 is a holdover from grooved
| phonorecordings never meant to be played. It's a way for the
| primitive hardware of early CD players to acquire the start
| of the data stream in a safe area that doesn't have to be
| faithfully reproduced.
|
| Some players permitted you to skip back from 1.1 to 1.0 to
| hear the lead-in as a hidden pseudo-track. Typically this was
| only possible with hardware index nav. buttons rather than
| the track nav. buttons, further obfuscating the presence of
| the hidden track.
|
| The other means of "hiding" tracks is to have a bunch of
| short silent tracks until you get to track 99 (inconvenient
| to reach on a player without numeric track entry) or to have
| a long section of silence starting on the last track from
| index 1.
| crtasm wrote:
| >Typically this was only possible with hardware index nav
|
| Holding the previous track button would "rewind" playback
| and get you into the pregap on all the CD players I
| remember using, but these would have been late 80s models
| onwards.
| barrkel wrote:
| The writing is not good; I gave up part way through. It's
| weirdly elliptic and almost autistic in its focus on details
| and an almost complete absence of a big picture. It could do
| with some kind of proper context-setting introduction, at the
| very least.
| WarOnPrivacy wrote:
| This mirrors my experience. It's good content but I'd barely
| land on one splainer before being segueded into the next one.
| I kept thinking I missed the part they delved into hidden
| tracks.
| nayuki wrote:
| A CD audio frame is defined as exactly 1/75th of a second
| (588 samples per channel). I don't know why the article
| waffles around with these poor wordings (emphasis mine):
|
| > These albums all had a pregap of either 32 or 33 "frames,"
| with a frame representing a length of _about 1 /75th_ of a
| second, per Hydrogen Audio's Wiki.
|
| > To offer a small correction to the original question now
| that we know we're talking _about 74_ frames per second
| rather than 60 or 100
|
| It's needlessly confusing and undermines my confidence of the
| entire article.
| omar_alt wrote:
| I recall a CD of mine had hidden audio before track one circa
| 1997, a coffee table jungle breakbeat on a Symphonic Black Metal
| album:
|
| https://www.discogs.com/release/373044-Arcturus-La-Masquerad...
|
| Also on the topic of trying to push the compact disc to its
| limits a Grindcore group who had a bonus track where "All efforts
| were made to exceed typical limitations of 16 bit linear digital
| technology compression, limiting, and equalization curves have
| been created to deliver maximum gain structure"
|
| https://www.discogs.com/release/4305023-Exit-13-Ethos-Musick
|
| I had a period of bad luck in my youth where I believed all these
| new enhanced CD's and shaped CD's were damaging the tracking of
| the lens on my CD player so I gave Exit-13 a swerve and started
| to listen to safer music ;)
| fortran77 wrote:
| What's the "A.C." band?
| K7PJP wrote:
| https://en.wikipedia.org/wiki/Anal_Cunt
| zdw wrote:
| I've been using https://github.com/whipper-team/whipper to
| digitize CD's, and it supports identifying Hidden Track One Audio
| (HTOA) when it exists and is not blank.
|
| Add in MusicBrainz Picard and Navidrome and you have a really
| nice solution.
| chuckufarley wrote:
| Whipper user here also. If you've not yet encountered it, as
| it's not as prevalent in repos as Whipper, Cyanrip is always
| very much worth a look and has come on in leaps and bounds,
| with recent updates adding (non compliant) .cue sheet support.
| dec0dedab0de wrote:
| I remember my friend accidentally found the negative track on a
| CD and called me up out of breath like aliens just landed. I
| think it was one of the early AFI albums.We spent the whole
| weekend checking for negative tracks on every CD we could find.
|
| The negatives between songs were also pretty cool sometimes,
| Mediocre Generica by Leftover Crack makes very good use of them.
| Listening to it over streaming or even mp3s ruins the effect,
| unless someone captured the entire album as one file.
| Lammy wrote:
| > I think it was one of the early AFI albums
|
| I wouldn't call it an "early" album but I found one of these
| (untitled 18-second intro) on AFI - DECEMBERUNDERGROUND:
| https://i.imgur.com/XAsFMSR.png
|
| Some others I've run across in my CD collection include...
|
| -- on Jonathan Katz - Caffeinated
| https://i.imgur.com/4ghQadv.jpeg
|
| -- the track "Every Time Is The Last Time" on Bloc Party's
| Silent Alarm https://i.imgur.com/knhbZhA.png
|
| -- a kid606 remix hidden in the first track pregap of The
| Locust's eponymous https://i.imgur.com/sXVFrQI.jpeg
|
| -- the "Theme of Coon" (aka Riki) on the third disc of the SaGa
| Frontier soundtrack https://i.imgur.com/CqTTqpV.png
|
| > The negatives between songs were also pretty cool sometimes
|
| And one of these, the interlude at the end of "High Roller" on
| TCM's Vegas which is part of the pregap for "Comin' Back"
| https://i.imgur.com/G5PSCy3.jpeg
| dec0dedab0de wrote:
| _I wouldn 't call it an "early" album but I found one of
| these (untitled 18-second intro) on AFI -
| DECEMBERUNDERGROUND_
|
| I think it was answer that and stay fashionable. We all
| stopped listening to them when black sails came out, so if im
| right about it being AFI, it was one of the first 3 albums,
| or the all hallows EP.
| nammi wrote:
| AFI almost always had a "hidden" track after silence following
| the last track, I figured following the Misfits' tradition
| xxr wrote:
| "Midnight Sun" at the end of Black Sails always gets me
| guerrilla wrote:
| This makes me wonder how I ever found the hidden tracks on the
| X-Files soundtrack. Must have been an accident.
|
| https://www.youtube.com/watch?v=nYyA1Mc3KZM
| WarOnPrivacy wrote:
| > Mediocre Generica by Leftover Crack
|
| Those names are a rabbit hole event horizon. Album released
| 9/11, working title of Shoot The Kids At School was rej by
| label. Follow up was F WTC. Band lives in C-Squat...
| exabrial wrote:
| I remember discovering "hidden tracks" on the Beastie Boys
| intergalactic album with my cousins... we were like what on earth
| is happening as the CD player display glitched out and played
| this stuff we hadn't heard.
| snvzz wrote:
| Abusing the standard to put songs in gaps was such a bad idea.
|
| I have no idea how they got a patent for such a thing and, even
| worse, anyone ever did it on actual commercial discs.
| ssl-3 wrote:
| Why? Are easter eggs like this harmful to consumers or
| something?
| snvzz wrote:
| It's abusing the standard, which can break compliant
| implementations.
|
| Especially bad since most Audio CD players are opaque
| hardware without update-able firmware.
| ssl-3 wrote:
| Has this been shown to be actually-problematic in the three
| decades since Willy Nelson's album contained a song in the
| pregap of track 1?
| zarmin wrote:
| of course not.
| lampiaio wrote:
| Yes, there's been a serious issue recently reported.
| Apparently, it has triggered bureaucrats on the internet
| who can't acknowledge something innocuous that's never
| caused any problem for decades.
| thelastparadise wrote:
| Link?
| egypturnash wrote:
| https://news.ycombinator.com/item?id=40922903
| zarmin wrote:
| You're right. We should start a letter-writing campaign to
| President Bush. Maybe it will make the nightly news.
|
| Sent from my Discman
| afavour wrote:
| One memorable album using this was Queens of the Stone Age's
| Songs for the Deaf. If you rewound from the start of the first
| track you got 90 seconds of strange sounding (but tuneful)
| rumbles and bleeps and bloops.
|
| When I looked it up online I found out it was called "The Real
| Song for the Deaf". It was literally a song for deaf people, the
| idea was that if they turned it up enough they'd be able to hear
| the vibrations forming a song.
|
| For those interested to listen via a more accessible method:
| https://www.youtube.com/watch?v=XEU01LrnWng
| leonard-slass wrote:
| I have the hardware _and_ the CD. I did not know you could
| rewind to negative seconds of the first track. Thank you, you
| have made my day!
| d332 wrote:
| This inspired me to read up on the low-level details of CD
| structure. I'm curious if anybody scanned an entire CD and shared
| the results, so that we could work with a raw image of disc that
| contains all its quirks, as opposed to the typical .iso format?
| ssl-3 wrote:
| Audio CDs were never ripped/transferred as ISO files. ISO-9660
| is a filesystem that came years later, and Redbook audio CDs
| simply do not contain files.
|
| If you want to look at the structure of a whole audio CD, then
| one way is to rip it with a decent tool (perhaps cdrdao or EAC)
| and generate a bin/cue file pair as an output.
| d332 wrote:
| But that's not my goal. I'd like to be able to observe every
| grove, the physical encoding of data, and see if I could
| implement decoding from scratch. First problem is though that
| I don't know how to get a microscopic image of the disc.
| ssl-3 wrote:
| You don't need a microscopic image of a disc to do that; a
| two-dimensional photograph is of essentially no advantage
| here.
|
| All you need is the unmolested data from that disc. The
| data is arranged on a singular spiral groove starting from
| the center and slowly winding its way towards the outside.
|
| The data is completely linear: It begins at the beginning,
| and continues to the very end without interruption. This is
| all akin to (although opposite of) how a single-track vinyl
| record is physically laid out. The entire CD -- whatever it
| contains -- is just a continuous string of pits and lands.
|
| And to observe that string as it appears on a real disc,
| all you need to get started is a regular old-school CD
| player and some appropriate data acquisition gear, and
| maybe an oscilloscope to help figure out what you're
| looking at.
|
| The optics and basic motor controls are already solved
| problems, and it doesn't even have to be particularly fast
| data acquisition gear by today's standards to record what
| is happening.
| hunter2_ wrote:
| The "unmolested data" would still have undergone error
| correction though, wouldn't it? I don't think a bin/cue
| rip would contain the redundant stuff, which GP seems
| interested in, nor the subcodes (of which _some_ are
| represented in the cue file, while the bin file is PCM
| audio).
|
| And at the risk of taking us well beyond the rainbow
| books, I'll just leave this here:
| https://www.psxdev.net/forum/viewtopic.php?f=70&t=1266
| ssl-3 wrote:
| There is a layer betwixt the optical reflection and the
| audio output that exists only as raw signals, before any
| molestation/error correction occurs.
|
| There cannot _not_ be this layer.
|
| (And with a sufficiently-old-school CD player, it is
| probably not even challenging to get to it. The less-
| integrated the parts are, the better.)
| hunter2_ wrote:
| Ah, I see. So what kind of capture hardware could read
| from that point? I assume it's a digital signal taking
| the form of 2-voltages, flipping on the order of 3.6 MHz
| (16 billion pits to read over 74*60 seconds). With Red
| Book audio at 1.4 Mbps, more than half of the raw data
| must be devoted to things like redundancy and other non-
| PCM stuff, if my interpretation that pits==bits isn't far
| off.
|
| Aside: is your username inspired by Secure Socket Layer
| or Solid State Logic?
| ssl-3 wrote:
| I'm getting off into the weeds of what I know here, so
| take this all with a grain of salt. (I probably used to
| know more about all of this than I do right now.)
|
| The difference between a pit and a land is an optical
| phase change. The pits and lands vary in length, and
| there are 9 valid variations in their lengths. This
| combined phase/temporal situation eventually (thanks,
| science folks from 1970-something!) turns into a serial
| binary electrical signal inside of a CD player.
|
| This binary electrical signal can be recorded.
|
| Recorded with what, you asked?
|
| CDs have a lot more going on than just audio data:
| Remember, there's forward error correction at play and
| (by spec, IIRC) a player is supposed to be able to
| _completely_ recover data even if there is a gap of 1mm
| due to a scratch or other interruption. (There 's also
| room for tricks like CD+G to live in the background, and
| certainly what may seem like an inordinate amount of data
| used just for clocking: CDs are CLV, so playing them
| happens at a continuously-varying rotational speed in a
| tightly closed loop because buffer RAM was expensive to
| buy, and expensive to manage, and tight speed control was
| cheaper to implement. Remember, this was a finished
| digital product that was released in 1981.)
|
| I find old references[0] that suggest that the raw data
| rate of a CD (it does not matter what kind) is 4.3218
| Mbps.
|
| So, to posit some example hardware: With careful loops
| and decent wiring, accurately capturing this seems like
| it would be well within the purvey of an RP2040's PIO's
| DMA modes to get that data into RAM, and also well within
| one of its 133MHz 32-bit ARM core's ability to package up
| and deliver that data over USB 2 to a host machine that
| can store it for later analysis -- plus or minus a
| transistor or two, or maybe a pullup resistor in just the
| right spot.
|
| (But that's just my opinion as a home hacker who has
| dabbled in RP2040 PIO assembler, and who is at or a bit
| beyond their knowledge of compact discs. I may wake up
| tomorrow and decide that the above is all bullshit and
| wish I could erase all of it. If in doubt, Phillips
| datasheets for CD player chipsets from the first half of
| the 1980s can probably help a lot more than I can.)
|
| ---
|
| As to the username: It's old. It predates Secure Socket
| Layer, but it's way newer than Solid State Logic. I was
| just a young kid with a new modem when I dialed into a
| Telegard BBS and started to sign up for an account, and
| got stuck at the prompt to enter a "Handle". I didn't
| know what a handle was in this new-to-me context.
|
| The sysop saw that I was stuck and dragged me into chat,
| as good sysops (hi Shawn!) tended to do upon seeing such
| a thing. We chatted for a bit, and I wasn't feeling
| creative, so he suggested that maybe I could look around
| for inspiration since most people used a made-up handle
| on his particular BBS.
|
| I found a 5.25" floppy disk on the desk that I'd borrowed
| from the local public library. It was labeled "Selective
| Shareware Library, Volume 3." (It was also almost
| certainly infected with the Stoned virus[1]).
|
| Anyhow, that was sufficiently inspiring, so ssl-3 it was.
|
| ---
|
| 0: https://www.geocities.ws/columbiaisa/cd_specs.htm
|
| 1: https://en.wikipedia.org/wiki/Stoned_(computer_virus)
| banish-m4 wrote:
| Not necessarily. It depends if you're extracting
| data+subchannel data or corrected track data only.
| AkBKukU wrote:
| Look into the Domesday Duplicator project for Laserdiscs
| as an example of how what ssl-3 is talking about can be
| done using a high sample rate input. That exact process
| is possible and with enough storage and processing power
| can be used to get the most "low level" access to the
| data. It is not for the faint of heart though, and can
| take around 1TB of storage and hours of CPU time to
| process full movies in this way, I know because I've done
| it.
|
| I believe I've seen there is work being done to attempt
| this on CDs but it would have still been in the
| exploratory phases and not yet ready to start archiving
| with. It might seem like overkill to do this to something
| meant to be digitally addressed but I've experienced
| enough quirks with discs and drives when ripping that I
| would 100% be willing to switch over to a known complete
| capture system to not have to worry about it anymore.
| Post process decoding also allows for re-decoding data
| later if better methods are found.
| sho wrote:
| this seems responsive:
| https://superuser.com/questions/140874/is-it-technically-
| pos...
| qingcharles wrote:
| I wonder if you could just tear the controller out of a
| CD/DVD drive and build a new one from scratch, kind of
| like the new floppy controllers being used now to read
| the raw magnetic data. You could just command the head to
| move to the center, find the beginning of the data and
| just keep reading until you hit the buffers.
| ssl-3 wrote:
| Sorta, kinda? It's a bit of a different game.
|
| Floppies (most of them, anyway) have fixed track widths,
| and these tracks are arranged cylindrically, and these
| cylinders align with the steps of the stepper motor that
| is used to actuate the head assembly.
|
| It's relatively easy, with the right ratio betwixt step
| advancement and track width, to get the head moving
| properly on a new implementation of a floppy controller.
| Want to read track 1? Step to the head N times to reach
| track 1 from wherever it started, and read it. Next, want
| to read track 33? Step the head N times to track 33, and
| read that.
|
| But tracking the spiral groove of a CD is a very
| different problem to solve. Steps tend to lose their
| meaning. Instead of electromagnetic steps, it involves 3
| different laser beams: Two to continuously keep the head
| centered where it needs to be on the ever-changing groove
| using a servo feedback loop, and a third to read the data
| from the pits and lands from the middle of that groove.
|
| Is it do-able? Sure! People with far less advanced tech
| than we on HN might have laying around did it 40+ years
| ago.
|
| It's just a very different nut to crack than reading a
| floppy is, even if the mechanical and optical bits are
| recycled.
|
| (And that's just head positioning. The pits and lands
| still needs to be read, and those reflect back from the
| disc as optical phase shifts, not as changes in magnetic
| polarity and/or amplitude.)
| banish-m4 wrote:
| Why? You can extract raw data and raw subchannel data
| directly from a CD/DVD drive. This isn't the case with
| how floppy drives work.
| ssl-3 wrote:
| The "why" was covered in a parent comment:
| https://news.ycombinator.com/item?id=40923030
| banish-m4 wrote:
| I can read, thanks. There is no benefit to it. If the
| desire were to look at them out of curiosity, a
| microscope would do.
| thristian wrote:
| It's really difficult. Unlike floppy disks, where you tell the
| drive to seek and get back raw magnetic pulses (so you can
| produce raw flux images), or hard disks where you tell the
| drive to read an arbitrary sector and get a blob of data (so
| you can produce sector-level images), the protocol for talking
| to a CD ROM involves asking for track/sector addresses, which
| means you have to trust the drive to interpret all the track
| metadata and error-correction for you - you generally can't
| just dump the "raw" data and do the interpretation yourself.
|
| That's why the most robust CD image format is the BIN/CUE
| format. The BIN file contains all the sectors the drive allows
| us to read, the CUE file contains the disc metadata as
| interpreted for us by the drive firmware.
|
| There are some drives which support extra "raw read" commands,
| but they're incredibly rare and consequently in great demand by
| CD preservation projects like redump.org.
|
| Some people have used the contents of BIN/CUE data to
| _reconstruct_ what should actually be on the disk, but that 's
| not quite the same thing. Here's a great explanation of the CD
| structure in all its complexity:
|
| https://github.com/higan-emu/emulation-articles/tree/master/...
| AkBKukU wrote:
| Even BIN/CUE is not enough. It cannot store subchannel data
| like CD+G and is only able to hold a single session which
| breaks bluebook CDs with audio and data.
|
| We do not currently have a widely supported CD standard for
| storing data from a CD that can properly hold all data. Aaru
| [0] is close, but still has to output back to other formats
| like BIN/CUE to use the contents of the disc.
|
| [0] https://www.aaru.app/#/
| Jedd wrote:
| This specification anomaly sounds like the polycarbonate
| equivalent of vinyl's multiple-groove capability. [0]
|
| I'd first heard of this for a Monty Python record (wikipedia
| notes this is in fact the most famous use case) but checked to
| see if people went for >2 grooves, and seemingly they did. I
| expect the casting for the pressing was horrendously expensive,
| which is why it didn't happen an awful lot.
|
| I suppose both mediums shared the less-well-hidden feature where
| a long silence separated the penultimate from the ultimate track.
|
| [0] https://en.wikipedia.org/wiki/Multisided_record
| alanfalcon wrote:
| This is supremely cool, thanks for sharing. I'm probably
| missing something obvious but why would the casting be any more
| expensive than any other pressing?
| Jedd wrote:
| Not terribly informed about the pressing process, but as I
| understand it, it is (or was) effectively a player-process in
| reverse.
|
| A needle creates the groove(s), replete with bumps for sound,
| in a not-quite-set (slightly soft) master disc - and I
| _speculate_ those follow a specific path defined by the
| mastering tool.
|
| In comparison, playback just drops the needle in the track,
| and it necessarily follows the extant spiral form.
|
| Making the master of a multi-groove record I'm assuming would
| require recalibration of the groove-defining mechanism
| (doubtless carefully designed for conventional layout), once
| for each of the grooves you want to make, ensuring they each
| stay within the boundaries defined by the previous grooves.
| caf wrote:
| When I was very young, my parents had a game called 'wacky
| races' that was based on a multi-groove vinyl. It was a horse-
| racing game - I can't recall exactly how the gameplay worked,
| but the vinyl contained racing calls where the races would
| start the same way but the outcome would be somewhat random
| depending on which groove the needle ended up following.
| TonyTrapp wrote:
| Techmoan has a video on a similar horse racing game (maybe
| it's even the same just with a different name) and how it
| works: https://www.youtube.com/watch?v=I5l75romOXY
| ssl-3 wrote:
| One less-secretive way I've seen pregaps used is for live
| recordings.
|
| The crowd noise betwixt songs can be contained in a pregap, so
| that it is only ever heard when listening to the album straight-
| through (instead of in shuffle or track-program mode).
|
| ---
|
| Another fun feature of audio CDs is indexes.
|
| A disc can have 99 tracks, and each track can have some pregap
| (including track 1, as the article discusses). And each of these
| 99 tracks can be further subdivided with 99 index markers.
|
| This gives a CD the _theoretical_ ability to have 9,801
| selectable audio segments.
|
| Although realistically, I've only owned a couple of CD players
| that even displayed index numbers and exactly one CD player (a
| Carver TL-3300) that allowed a person to seek to a given index
| number within a track.
|
| (And I've only known one CD to actually make use of indexes in
| any useful manner, which was a sound effects CD from the early
| 1980s that had a _lot_ more than 99 sounds on it -- all organized
| by tracks, and sub-organized by index marks. I just can 't think
| of the name right now.)
| cainxinth wrote:
| > _Broken_ was re-released as one CD in October 1992, having
| the bonus songs heard on tracks 98 and 99 respectively, without
| any visual notice except for the credits, and tracks 7-97 each
| containing one second of silence.
|
| https://en.wikipedia.org/wiki/Broken_(Nine_Inch_Nails_EP)#Pa...
|
| _Amarok_ (1990) by Mike Oldfield is a single hourlong track
| with 53 index marks.
|
| https://en.wikipedia.org/wiki/Amarok_(Mike_Oldfield_album)#T...
| egypturnash wrote:
| Broken was absolutely perfect to put into a multi-disc player
| along with TMBG's _Apollo 18_ , which contains "Fingertips",
| a suite of 21 very short songs. Set it to shuffle songs from
| everything in the player, and enjoy your sonic whiplash
| eyelidlessness wrote:
| If you want sonic whiplash without so much effort, you can
| also listen to a Fantomas album in its original order.
| tecleandor wrote:
| This could be fun :)
|
| https://en.wikipedia.org/wiki/Short_Music_for_Short_Peopl
| e
| egypturnash wrote:
| There wasn't really much effort involved. Pick a few
| discs off the CD rack that I thought will clash
| interestingly, load up the cd tray of the cheap all-in-
| one turntable/tape deck/radio/cd unit I had in my room,
| hit the 'shuffle' button until it tells me it's gonna
| shuffle everything together, hit play.
|
| Looking Fantomas up on Wikipedia makes it sound like
| they'd go pretty well with "twenty tracks that sound like
| the choruses of twenty different songs" and "ninety-
| something 1s blank tracks plus a few industrial songs",
| though.
| ssl-3 wrote:
| Was this better with the crazily fast-loading chonka-chonk
| slam-slam nature of a Pioneer 6-disc cartridge changer, or
| with something slower and perhaps more-civilized like a
| period-correct Technics 5-disc changer, with its nearly-
| silent and relatively exquisite, seemingly-careful
| demeanor?
|
| (Both have their merits, but I unfortunately have neither
| at hand. And I only have one of these 2 albums. And one of
| those albums is the original Broken, which only has 6+2
| tracks across two discs instead of 99 tracks on one disc.
|
| And how do the 91 silent tracks on a more-common release of
| Broken affect things compared to the 26 musical tracks that
| the original 6+2+18 track-count ensemble may entail, in
| terms of inter-song delay or any other such thing on a real
| multi-disc changer?
|
| I know TMBG fairly well, and NIN very well, and I enjoy the
| fuck out of gear, but I have so many questions.)
|
| (I vaguely jest above, but Spotify only shows me 18 tracks
| on Apollo 18. And only one of them is Fingertips. Am I
| looking at this wrong?)
| egypturnash wrote:
| Presumably Spotify has glommed all the Fingertips into
| one file. On the original CD release it was twenty-one
| separate tracks; there was a bit in the liner notes that
| explicitly encouraged you to put it on shuffle.
| https://tmbw.net/wiki/Fingertips
|
| I could not tell you what brand the all-in-one
| turntable/radio/tape deck/cd player I had at the time
| was. There was a big tray with room for five CDs and I
| have absolutely no memory of how much noise it made when
| switching from one disc to another, and every physical
| object involved in this affair is long gone in a
| hurricane.
|
| I suspect both CDs should be easy to find used copies of,
| if you have the appropriate hardware and want to
| experience the tension of not knowing if the next song
| you hear is going to be Trent bitching, a brief moment of
| silence, a Fingertip, or whatever else you put in the
| player. Given my tastes at the time this would have
| probably been Skinny Puppy, Ozric Tentacles, and Bjork,
| but do whatever feels like the most interesting possible
| choice; I have a disc lying around now that's nothing but
| forty iterations of Satie's _Vexations_ and that would
| have certainly been a prime choice for this little game.
| kevin_thibedeau wrote:
| My personal CD ripping script is configured to leave all
| pregaps after track one at the end of the preceding track when
| splitting them out as individual files. It gets ripped in one
| DAO pass for guaranteed preservation of all samples when using
| gapless playback on live recordings. Track navigation then
| works just like a real CD without having to listen to an
| incongruous section of audio meant to link the previous track
| on sequential play or, even worse, missing it altogether.
|
| I have a classical CD from the 80's with index marks for
| different movements within within the individual compositions
| represented by a handful of tracks. My understanding is that DG
| was the only publisher routinely using them. That required some
| manual intervention to convert the indices to separate tracks.
| Sony was pretty good about providing index nav. on their full
| size stereo players. At least until their perpetually cruddy
| remotes eventually failed.
| ssl-3 wrote:
| That's probably the best way to do it, given common toolsets
| and players. I also rip pregaps as lead-outs (rather than the
| lead-ins that the structure may appear to suggest).
|
| It's things like this that make me wish that we'd landed on
| on a good, popular way to store _albums_ (with metadata!)
| instead of individual tracks -- or to at least reassemble
| individual tracks ' files properly into whole albums without
| glitches and weirdness. (FLAC/cue can do some of this, but
| hardware player support is nearly nonexistant.)
|
| I've been told that this is a stupid thing to want, and I
| want it anyway.
|
| I'm old enough to remember listening to albums the _whole way
| through_ by default since anything else would take extra
| steps, and perhaps fortunate-enough to have generally
| preferred listening to albums where that is a thing that is
| also worth doing intentionally.
|
| (And yet, I am young enough to still be bitter about Lars
| killing Napster. My dissatisfaction is multifaceted.)
| kevin_thibedeau wrote:
| In addition to lossy compressed track files I also generate
| a FLAC with embedded cue as a master copy of the original.
| It's useful for recreating the whole recording for mass
| editing. I have a few discs mastered with preemphasis that
| needed correction. I too hope there will be a day when all
| FLAC players support track navigation. The reality is the
| music album has had its day in the sun and will largely be
| a forgotten curiosity like the typewriter or rotary phone.
| ssl-3 wrote:
| You're not wrong. New music isn't frequently recorded
| with the intent for it to be heard in an album-oriented
| way.
|
| But the albums I like to listen to as albums will remain
| cohesive albums for an eternity.
|
| Lots of stuff from Roger Waters is cohesive in that way,
| which is perhaps something a person might expect me to
| say.
|
| But _also_ lots of stuff from Maynard James Keenan, Trent
| Reznor, and even Marilyn Manson is also this way, which
| is perhaps less expected.
|
| (And sure, I can rip an album as an album and convert
| that to a singular MP3 that I can play as an album almost
| anywhere, and it needs to be a single file since MP3s
| can't be perfectly concatenated. But then, I can't easily
| skip around on that singular album when it behooves me to
| do so.
|
| I could do both things when it was still in CD format.)
| caf wrote:
| Billy Eilish's latest is intended to be listened as a
| complete album (but of course the fact that this is known
| as an exception proves the general rule...)
| ssl-3 wrote:
| That.... that makes sense.
|
| Her recordings are _excellent_. They generally sound
| simply fantastic. When turned up on the big stereo, they
| tickle every auditory input I have -- including the
| usually-strictly-tactile ones.
|
| I've heard that her brother, who is probably (and perhaps
| obviously) her biggest fan, generally has a huge part in
| producing and mixing her music. It is apparent that they
| work well together.
|
| Anyhow, thanks. That album is on the list for the next
| time the neighbors have left for the weekend.
| qingcharles wrote:
| I'd love a new solution that wasn't "break the CD data into
| pieces."
|
| I've never looked inside a CUE file, but it's just text and
| I don't think it supports meta data, right?
|
| We need like a new CUE file to go with the FLAC, right?
|
| p.s. https://news.ycombinator.com/item?id=40923646
| ssl-3 wrote:
| Ideally, I think I'd want a singular container (of
| whatever sort) that has the album's audio, the music-
| related timing metadata (as applicable), and whatever
| other metadata may be appropriate (lyrics? liner note
| graphics? music videos? sure!).
|
| The audio should be able to be FLAC. But it should also
| be able to be anything else, like Vorbis or MP3 or AAC or
| IDK. It needs to be able to be played continuously
| without aberration (which can't actually be done with a
| group of MP3 streams).
|
| The audio needs to be able to be seekable, like a CD is
| also seekable. By track. By index. (With pregaps, where
| appropriate -- because CDs also have pregaps.)
|
| Other potential metadata must be able to include whatever
| subcodes are involved in things like CD+G[0] and HDCD and
| CD Text, since all of those are supersets of the regular
| datastream and playback is compatible with any CD player.
|
| And it needs to be a singular container file
| because...well, that's just easier to keep track of as
| the years go by and data migrates.
|
| Only then, will we have the beginning of a valid archive
| format for audio CDs as they actually still exist on
| [some] store shelves today.
|
| (Some stuff can be optional, just as lots of things are
| optional inside of an MKV container for a film.)
|
| [0]: Almost nobody ever used this outside of the 1990s
| karaoke world, but Information Society's self-titled
| album includes an illustrated sequence, with lyrics, that
| is completely implemented in CD+G and that runs for the
| entire length of the album. And I should be able to
| render that locally here in 2024 from a container on my
| pocket supercomputer instead of watching a bad rip from a
| Sega Genesis: https://www.youtube.com/watch?v=b89sSa8QlLg
| piperswe wrote:
| You mentioned MKV - Matroska (MKA for audio, MKV for
| video) could honestly work quite well for this situation
| with just a little extra standardization.
|
| Audio codecs: use a single stream of whatever codec you'd
| like. FLAC/Vorbis/MP3/AAC/Opus/etc. can all go into
| Matroska.
|
| Seekable: Use chapters for tracks, and nested chapters
| for indices. Matroska documentation even gives an example
| of using ChapterPhysicalEquiv 20 for CD tracks and
| ChapterPhysicalEquiv 10 for CD indices.
|
| Other metadata can be muxed into the stream as well.
|
| Lyrics can be included as text in metadata (lyric tag) or
| as a subtitle stream.
|
| Liner note graphics (and basically anything else) can be
| included as embedded files.
|
| Music videos can be video streams in the Matroska file.
| xyzzy_plugh wrote:
| I'm glad to see this mentioned. This was first thought I
| had as I progressed through this thread. I'm surprised
| this isn't a popular, supported standard already.
| ssl-3 wrote:
| Nested chapters can work for index markers, especially if
| a player supports them right.
|
| I mean: As mentioned, these have almost never been usable
| with real CD players in the wild. Maybe not much is lost
| there. (But the format must still accept these things,
| and allow them to be usable! An archival format must
| respect all aspects of the item being archived, including
| those that are unpopular or disused. I am willing to die
| on this hill.)
|
| What of things like CD+G? Here in 2024, they're very
| simple graphics using 35+-year-old tech, and they should
| be archived neatly, precisely, and without
| interpretation, to be rendered client-side at a later
| point. I think I've mentioned it, but we literally have
| pocket supercomputers in common use today. If we can make
| the complexities of MAME work for the past couple of
| decades, and do it with direct ROM dumps, we can do this
| for CD+G.
|
| But the CD+G must be rendered synchronously with CD audio
| data on playback. This applies whether it is my
| Goldilocks example of an Information Society album, or
| whether it is a CD+G karaoke disk with Garbage's _I 'm
| only happy when it rains_ (and twelve other crowd
| pleasers from that month of 1995).
|
| How will that work with MKA?
|
| And how will pregaps work?
|
| (Maybe MKA isn't an ideal container if it does not
| already include avenues that lead to this kind of
| functionality in ways that are compatible with the
| original article.)
| Uvix wrote:
| Can't an MP4 container do most or all of that already?
| (Pregaps would probably need to become a full-fledged
| chapter in their own right, with the current spec.)
| sumtechguy wrote:
| You are almost describing the MAME CHD format. As they
| have the problem that the object (hard drive, cd, dvd,
| etc) must be in one file. Have the ability to do
| differences (writable in some cases). But also compressed
| (compressed hunks of data). They also need that sub track
| data too as some systems do interesting things with that
| sub data. As some even hide their encryption format in
| the SBI fields. The CHD format is more like a container
| that acts like whatever media it was. Depending on what
| system they hook it up to. The downside is there is no
| concept of 'metadata' to find different things in CHD. It
| is up to the system it is hooked up to to interpret what
| that data stream is.
| kevin_thibedeau wrote:
| Cue is a bodge that should never have become a defacto
| standard. Joerg Schilling's cdrdao tool has its own TOC
| format that faithfully captures everything including
| index marks, various flags, and multilingual CD text but
| it was ignored by everything else in the heyday of the
| ripping era. Nowadays we'd be better off with a standard
| yaml/json format that duplicates what cdrdao provides.
| mikepurvis wrote:
| This is an issue for movie discs too. Some mkv rips will
| preserve chapter data (though player support is spotty),
| but in the end it's still a big linear file-- menus,
| intros, trailers, optional features, etc are all gone once
| it's ripped unless you rip that stuff to separate video
| files.
|
| Which I get on the one hand, but it's a bummer that in all
| these cases (CD, DVD, Blu-Ray) the metadata for the larger
| structure of the production got inextricably tied to the
| specific physical media implementing it, such that the only
| real way to preserve that data was to rip a full disc copy.
| op00to wrote:
| > At least until their perpetually cruddy remotes eventually
| failed.
|
| For me, Sony remotes were made of the same stuff as early
| Nokia phones - indestructible! Surprised to hear someone
| thought they were cruddy.
| kevin_thibedeau wrote:
| They were physically robust but the carbon button contacts
| always became dodgy for me. I tried to avoid Sony products
| for this reason because I encountered it so often in other
| people's gear. I have a remote from the late 00's that saw
| virtually zero use and it conked out with age alone.
| alliao wrote:
| Japanese called it Sony Timer...some call it urban legend
| but this seems like yet another independently verified
| data point
| layer8 wrote:
| There is/was carbon spray that you could use to refresh
| the contacts.
| albrewer wrote:
| I had a set of cds that went with an intro to music theory
| textbook around ~2009. It did also made heavy use of indices
| in tracks to do exactly the same thing. My car stereo listed
| each index as a track.
|
| I wish I could remember the name of the textbook because I
| really liked a lot of the baroque music on the CDs and can't
| remember who they were by or the titles of the songs...
| benjaminpv wrote:
| Do you remember if the textbook was orange (possibly with a
| two-tone cover design)? I had a really good textbook in
| college that had a... 4? CD set (with the big jewel case)
| that had a bunch of tracks and like you I really enjoyed
| it.
| albrewer wrote:
| It was a reddish (could be orange, could have been
| maroon) color lightly mottled in black with a picture of
| a violin (or cello, idk) set in the lower 2/3 of the
| cover. I'm somewhat certain it had 6 cds because it
| filled my disc changer in my stereo, although that detail
| is fuzzy too.
| pseudosavant wrote:
| I mastered a CD in 2000 for a band that wanted a secret track
| at the end. I came up with a novel way to do it.
|
| There were a dozen regular tracks. A bunch of empty ones. And
| the final track over about a dozen tracks of varying length
| with no gap. Used all 99 tracks.
|
| I could only pull it off with this CD burning software that
| didn't have a UI. It took a text file as input at the command
| line. But it could do everything from almost every color of
| spec (Red Book, Blue Book, etc) for CDs.
| ssl-3 wrote:
| I've had visions of putting a CD together that was that way,
| but with pregaps and indexes utilized as well.
|
| "WTF? The time counter keeps going forward, and then
| sometimes it goes backwards! And using the track seek buttons
| completely eliminates some parts that I can hear if I don't
| touch anything!
|
| It's a whole different song entirely when you program tracks
| 39, 40, and 52 in a loop, and IDFK what it is with this
| _Index_ number that only always showed "1" before.
|
| Oh wait. Srsly? From tracks 71-93, it's using the index to
| count beats...and the track number to count measures? No,
| that can't be it. Except...."
| pseudosavant wrote:
| I thought I'd really (ab)used the CD specs, but don't
| recall ever trying indexes. Curious how most CD players,
| which only had a two-digit track indicator, handled
| indexes. I would have used that if I had known about it.
| chaboud wrote:
| The Nine Inch Nails "Broken" EP had a couple of tracks at the
| end of 99, though the middle tracks were all 1-second blanks.
| AkBKukU wrote:
| I'm curious if you have a specific example of an album with the
| crowd noise between tracks like that? I collect and rip
| hundreds of CDs and am always on the look out for edge case
| discs to further hone my tools.
|
| On your pregap + 99 indexes remark, the "pregap" is the space
| between index 00 and 01 which continues on up to index 99.
| Players seek to index 01 as the start point of the track. There
| is no separate pregap designation. I've paid special attention
| to this because it is a difficult problem to solve as many
| discs have space between tracks stored in index 00-01 but
| rarely is there anything audible in there after the first
| track. The only example I have of this is a specialty music
| sample disc, Rarefaction's A Poke In The Ear With A Sharp
| Stick, that has over 500 samples on the disc accessed by track
| + index positions.
|
| As a sidebar based on the later comments in the thread, I've
| made it a habit to rip and store every audio CD as BIN/CUE+TOC
| using cdrdao. This allows me to go back and re-process discs I
| may have missed something on. But that is imprecise even
| because it usually breaks bluebook discs with multiple sessions
| to store data due to absolute LBA addressing. Also the ways
| different CD/DVD drives handle reading data between index 00-01
| on track 1 is maddening. Some will read it, some will error,
| and the worst is those that output fake blank data.
| meindnoch wrote:
| >I'm curious if you have a specific example of an album with
| the crowd noise between tracks like that? I collect and rip
| hundreds of CDs and am always on the look out for edge case
| discs to further hone my tools.
|
| E.g. the Japanese version of Flying Lotus' album "Until The
| Quiet Comes" has a pregap of 5 seconds before the 19th track,
| to separate it from the rest of the album, as it's a
| Japanese-exclusive bonus track.
| hcs wrote:
| Seven minute pregap on disc 1 track 4 of
| https://vgmdb.net/album/5549 , it's a whole long discussion
| with some audience cheering. VGMdb follows the "append pregap
| to previous track" convention, that's why track 3 looks so
| long.
|
| Cuesheet looks like: TRACK 04 AUDIO
| INDEX 00 00:00:00 INDEX 01 07:34:43
|
| Edit: Probably covered by your sfx disc, but this one has 17
| indexes on track 1: https://vgmdb.net/album/3091
|
| That messed with a tool that only anticipated one index in
| track 1 for detecting hidden pregap audio, cuesheet is like:
| TRACK 01 AUDIO INDEX 00 00:00:00 INDEX 01
| 00:00:37 INDEX 02 00:11:40 INDEX 03
| 00:37:33 ...
| davidgay wrote:
| I have an early CD (Bach's Goldberg variations, played by Glenn
| Gould) which is one track with 31 index markers.
|
| My (early) Philips CD player dealt with it fine, but since then
| it's been a bit of a problem...
| indus wrote:
| In the age of attention deficit infused dopamine---who has the
| time for an Easter egg?
|
| Instead, engineers and product managers, slow roll quirkiness on
| social media.
| RiverCrochet wrote:
| If you are interested in this topic, locked grooves may also
| interest you.
|
| https://en.wikipedia.org/wiki/Unusual_types_of_gramophone_re...
| fnord77 wrote:
| that whole article went into a lot of detail about the history of
| pregaps, but never says what was actually put on the pregap
| qingcharles wrote:
| I was responsible for some of the first digital content ingestion
| for the world's record labels back in the late 90s, which was all
| based around trucks filled with retail CDs being fed into CD-ROM
| drives and an army of young folks grinding hundreds of track
| names into a database. (what happens when a truck full of East
| Asian CDs turns up? what about all those albums by Aphex Twin and
| Sigur Ros with untypeable names? https://www.treblezine.com/wp-
| content/uploads/2014/08/aphex-... )
|
| I love these hidden tracks to death, especially the two hidden
| pregap tracks on Ash's first album, but they caused me unending
| pain and suffering.
|
| Not only are they an absolute nightmare to rip, often with more
| than one song per track (so the WAVs have to be edited), the
| names of the songs are often totally unknown, even to the record
| labels. What do you even number the things in the metadata?
|
| Added to that, you nearly always didn't even know they were
| there, so the negative numbered tracks would fail to get ripped
| and all the other ones in between or at the end would get ripped
| in weird ways and confuse all the data folk.
|
| https://www.discogs.com/release/984235-Ash-1977
|
| "Help, computer."
| LeoPanthera wrote:
| Semi-related: "Minidisc" is an album by Gescom (who are really
| Autechre in disguise) released, as the name suggests, only on
| Minidisc, containing 88 tracks which are designed to be played on
| shuffle, because Minidisc, unlike CD or any other physical
| format, can be shuffled with no audible gap between tracks.
|
| Each track is designed to segue into any other so the album is
| different every time you play it.
| kstenerud wrote:
| One compact disc extension I remember well is CD+G. It was pretty
| wild plugging an Information Society CD into a CDTV and watching
| the (admittedly crappy) graphics while you listened to music and
| samples of Leonard Nimoy and DeForest Kelley...
| comprev wrote:
| "Korn - Follow The Leader" (1998) album started on track 13.
|
| https://www.discogs.com/release/369188-Korn-Follow-The-Leade...
| Neil44 wrote:
| I had a Rammstein ablum, that if you rewound before track 1 there
| was a black box audio recording of a plane crash were everyone
| died. It was pretty macabre. I think the CD cover was like a
| plane's black box if I remember correctly.
| 10729287 wrote:
| I'm not into this band but that could be related to this famous
| event :
| https://en.wikipedia.org/wiki/Ramstein_air_show_disaster
| hnbad wrote:
| No, that's what they were named after. They released an
| epinomous song on their first album ( _Herzeleid_ ) that
| played with the visual imagery of that disaster ("Rammstein -
| a human burns / Rammstein - the smell of meat in the air /
| Rammstein - a child dies / Rammstein - the sun is shining").
| They apparently initially wanted to name the band _Rammstein
| Flugschau_ ( "Rammstein flight show") before shortening it to
| _Rammstein_. The difference in spelling was accidental but
| _Rammstein_ is evocative (literally "ramming stone") so it
| stuck.
|
| The album the parent mentions is _Reise, Reise_ , which is
| travel themed (in a broad sense of the word), the cover being
| styled after a black box (being bright orange of course). The
| flight recording in the pregap literally comes from a black
| box of a plane crash so that fits.
| Loughla wrote:
| Reuse, Reise is the album. It was a Japanese aircraft crash. It
| was on every album but those released in Japan I'm pretty sure.
|
| It's mostly just scrambled alarms and some Japanese yelling.
| Without the context it's pretty hard to understand what you're
| listening to.
| londons_explore wrote:
| Things like CD's with their large number of partly-compatible
| extensions shoehorned in remind me that whenever one is writing a
| specification, one should make sure that every combination of
| bits/bytes is either valid with defined behaviour, or invalid.
|
| The one exception is a field for "extensions", which should have
| some bits for 'compatible' extensions (ie. there will be extra
| data ignored by readers which don't understand them), and other
| bits for 'incompatible' extensions (ie. you have put a DVD into a
| CD player).
| sziring wrote:
| The domain name is how I felt after trying to read the article.
| tombert wrote:
| IIRC Blink 182 had a hidden track "Fuck a Dog" on their album
| Take Off Your Pants and Jacket.
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