It’s been a few years since I used EAC, but I recall that there was just a configuration option, a check-box on some menu, you could set. There’s also settings for where to put the pre-gaps. The default is to attach them to the end of the “Previous” track. I think, since there’s no “Track 0” to append the Track 1 pre-gap to, you just need to extract all the pre-gaps as their own WAV files, rather than just appending them to the track before or after.
I don’t remember if EAC has a DAO ripping mode, but if so, the hidden pre-gap audio will be the very first thing in the data file. (If you’re using “cdrdao” on Linux or something it’ll do this too.)
CDs are kinda non-deterministic… It’s difficult to predict how two different players will interpret the media…
So… brief summary of “Red Book Compact Disc Digital Audio”… The CD format was designed in the 1970s before the widespread availability of cheep microprocessors. So you don’t need a computer of any kind of play a CD. So, audio CDs are structured like a simplex radio broadcast… or like a tape. There’s no concept of any organizational structure, like sectors, or an absolute position. There’s a lead-in and lead-out area (two seconds of alternating bits), at the beginning an end of the disk, so the player knows about where to start, stop, and when it has seeked out too far. And everything in between is just a bunch of ones and zeros you pump into your DAC. (With a bit of 14-bit to 8-bit and Reed-Solomon decoding, same as they were already using for satellite broadcasts in the 1970s).
Early CD players were not really designed to do random seeking when the user presses a button… According to the Red Book spec, the player only need to seek to about 2 seconds within wherever it is actually trying to seek to. That’s why a Red Book compliant CD must have 2 seconds of “pre gap” between each track. Early players would commonly ‘miss’ when you tell them to reposition their laser. The pre-gap has an extremely obvious bit pattern in the P subcode, which is how the player knows that it’s in the pre-gap, and not in the regular audio portion. The player mutes its audio while trying to locate the next track, skipping ahead a bunch, and the then checking if it’s in a pre-gap or not…
Because the CD player, has no brains, and is just looking around for various sync marks to know where it is. Like a vinyl record, if you drop the laser on a random spot of the disk, it’ll read until it successfully decodes a frame without error, and then spews it out of a digital audio converter. This is also why CDs can ‘skip’, and the audio drops out for a fraction of a second, and then the player is suddenly somewhere else. (The physical “groove” of lands and pits the laser is reading has a slight wobble to help the player with tracking, which is another elaborately engineered thing you don’t need to use a computer for.)
Some players (like my first CD player) had a mode where they would automatically pause between tracks too. They look for the pre-gap to know when to do this. They don’t need to memorize a TOC or anything. All of what they need to know is encoded right there were they are currently reading from. Computer memory is expensive.
For convenience, Red Book CDs also have a “Table of Contents”, which most players read and use these days… (But it’s not actually “necessary” you can build a player that just works like an analog record player, or tape player, which starts at the beginning, and plays to the end, and you can fast forward.) It’s an array of up to 99 tracks and 99 index marks. (Index marks are what everybody was going to use to skip around within a track, because players were too dumb to make seek arbiltrarilly.)
You can point the track offsets at any arbitrary location, even off the end of the disc, but most players are smart enough to stop at the lead-out. The actual audio program only really has three pieces of information in it:
- Is this frame part of a pre-gap, or not part of a pre-gap?
- The timestamp to display to the user. (Early CD players didn’t even have their own clock.)
- A fraction of a second of PCM encoded audio.
And that’s it. The whole 2352 byte sector thing is a kludge added with the “Yellow Book” data “CD-ROM” stuff. Those sectors don’t really align with any absolute position of anything on a Red Book CD.
Every player gets to arbiltrarilly decide for itself where sector 0 will be. Most of the time it’s within a few hundred samples past the end of the lead-in, depending on whatever amount of time it takes for the player to think about things as the disc keep spinning. (Actually, I’m not sure about this part exactly, it might also just be that the player shifts the “sector” boundaries around depending to line up with the beginning of the tick of a frame in the Q-subcode, or the end… or somewhere in the middle.) (CD-ROMs have explicitly defined sectors, CDDA doesn’t.)
Index 0, is the mandatory two second long pre-gap, and index 1 is the beginning of the audio program, Indexes 2-99 can be set anywhere within the auditory part of the track. In practice, these were rarely ever used.
Every track has a pre-gap… even track 1… anyway, you know this part.
Most players will just start playing at the good part, track 1 index 1
Anyway, so don’t think of a CD as being like a hard disk, think of a CD as being like a broadcast television signal, with the video made up of a bunch of black and white dots… Because that is actually in fact exactly what it is. All of the CDs in the 1970s and 1980s were recorded onto video tape, because nobody had 800MB hard drives until the mid 90’s.
If you lived near Boston in the 1980s, WGBX would sometimes broadcast classical music, with the video being a bunch of randomly blinking black and white squares. At the time, I didn’t really know what this was, but it turns out that Sony used to sell a TV set top box to consumers, that would decode a television signal like this and spit out “CD Quality” audio for your hi-fi sound system… or whatever. Anyway, record studios and CD pressing plants used the same thing for mastering CDs.
For being a “digital” format, it almost isn’t…
Remember video LaserDiscs? Those are literally just an analog, pulse width modulated, 6MHz FM, composite NTSC television signal. You don’t need a computer to read them either. Compact Disc Audio was an upgrade of this that skipped the whole FM encoding step in the middle, and using PCM rather than PWM.
I got distracted and I forgot the point I was going to make… Basically, if CDs seems weird and don’t make any sense, this is why.