What should I do with the pregaps in a CD? EAC appends them to the previous track, but I don't think this is what the artist meant to do with the song. Is leaving them out the best solution?

If they have digital silence, I skip them. If they contain music, I append them.

The way it's pressed on the CD is the way ment by the artist. So appending them to the previous track like EAC does by default is the most sensible choice, since it emulates the behaviour of a standalone CD player.

Don't leave them just out ! They can contain music data.
Perform EAC's "detect gaps" function, then "test gaps on silence". Gaps reported to be not 100% silence should be added to the previous track, 100% should be left out. In almost all cases you'll be safe with that.

For the hard core perfectionists: "test gaps on silence" is not exact. I've found a gap with a non-null sample, but reported to be 100% silence.

I don't think on CDs there's much that's ment by artists. The artist wants to get money.
The gaps are set by the engineer, not because he wants to set them, but because it's part of the redbook standard. (I remember reading somewhere that redbook originally contained only track indices ?) On almost all modern CDs there are gaps between all tracks, they are all silence and all are 2 seconds long. Artificial usage of non 01-subindices (=track index) is very rare.

edit:spelling

Ah, thanks, Precisionist's post makes more sense, I hadn't noticed the "Test gaps on silence" feature. Thanks again.

I disagree. In a CD, some pauses are intentionally inserted between the tracks. When a slow track in A minor ends, and another fast one in C major begins, a small silence between them prevents the two tracks to interfere. It is not advised to play the first note of a track immediately when the last one of the previous track ends.
Thus, you should not leave out gaps, even when they are silent. They are there for a reason.

Moreover, you destroy this way about one million of audio samples. I don't understand why people are so anal about Andre's offsets (that are completely different than nearly all commercial offsets anyway) of 1000 samples at most, while they throw away 1000 times more data in the meantime, by leaving out gaps !

When you detect them, you have to append them to previous track. Don't detect them and save you the work of deciding how to handle them ! The info on their position is completely unuseful anyway ! No player uses it to change anything to the playback. The only exeptions are when you program a playback in a predefined order on a standalone CD player (And I think that even in this case, the gap info should be ignored so that the gaps are played), and when you detect a hidden track looking at the first gap lenght.

Hi there!

I agree with both of you...

Yes, there are gaps which are reported as 100% silence but when you look at them in the detail they are not 100% silent. This is due to the fact that EAC is guessing the possition of the gaps and that's the reason, why it detects the gaps for a while. It is in no way affected by offsets, so there would be a gap in a certain length with 100% silence but the indexes of the song are wrong and don't fit it.

This is the reason why I'm doing so perfectionist's work with my rips...
I rip the songs then I delete silence, but I must know the exact lenght of it. I also delete the noise which is sometimes present in the record instead of silence and for my insurance I add 2 frames of silence in the beginnig and in the end of the track and I add or delete a certain amount of samples to have my track fit in the frame size.

I store my silences in the cue-sheet althought they are not present in the original recording. Then I burn CD from a cue sheet and also make MP3 through Monkey's Audio front-end.

Yes I don't add the aditional 2 frames of silence when I want to burn a CD where there are no silences between tracks...

So I don't play my MP3's gapless (If I want I'm making a 1 big MP3 and play it by MP3cue) so the sounds of the begining of the next track and the end of the previous track don't interfere.

Edit: Poor english

I append them to the previous track if they are silence or not. I don't mind "gaps" between tracks if that is the way the album is mastered. I only care about gapless playback if the album itself was gaplessly mastered!

When I read the title of the thread I thought it was going to be about how people handle the gap before track 1 (that is what I think of as the "pre-gap.") And if you've read any of the other pre-gap threads then you know that is a subject I'm obsessive about!

I had been switching the gap handling to append the gaps to the next track when I found a non-silent pre-gap. But I'm not sure I like that solution. My aim is not only to have the pre-gap to listen to but also to be able to recreate the CD properly if I need to.

I think the ideal would be a combination of index-based separation and appending to the previous track. So you would have one file for the pre-gap and then all other gaps would be appended to the previous track. Could you edit the cue sheet to understand this and recreate the CD correctly?

Any advice?

I don't know if this was addressed to me but... Yes, I can recreate the CD but not an exact bit-by-bit copy and I'm not aware of it... I don't mind that I change the CD, that it wouldn't be recognized by CDDB because I always burn it with CD-Text... I'm saying that I'm actualy doing a 110% copy of the CD because of lack of inaudiable noise between tracks, corrected offsets and CD-Text...

This is a question of belief...

That's the rare artificial usage I mentioned. From my experience, it appears on no modern pop CDs. My impression is that the tracks have enough silence at their ends and beginnings, the gaps are just additional and useless. It depends on one's plans, too. If one wants to write the rips back as an audio CD, it may be sensible to add the gaps. If the rips are to stay in the file system, it's better to have no gaps. Players can add them.
On many old CDs which I mostly rip gaps contain music. I guess I actually add 70% of all gaps to their previous track.
A self-written CD without gaps and leftout gaps during ripping can contain more audio data and audio players are able to add pauses between the tracks.


The reason why I'm anal about offsets and leave out some gaps, though, is that the offset in principle could contain audio data, so I don't have to check the files' ends and beginnings. Actually I test every gap manually before I allow myself to leave it out.


And don't learn that EAC recognizes the pregap of the audio session...
But seriously: you learn more about audio CDs if you detect gaps.
Not detecting doesn't save any work. The gap can be made of anything that belongs to the previous, next track, or both (or even neither).

EAC's "extract selected tracks index-based" will extract every subindex to a single file (This has no CRC test !)

I think that we completely misunderstand each other.
I'm not talking about anything special, but about the standard case, present on 95 % of modern CDs, where the gaps are silent.
And myself I don't understand what you mean with gaps in addition of silence. Usually, the gaps are all that is silent.




Why would you destroy some info, if you recreate some artifical one instead in order to replace it ? The one you recreate won't match the original one, the player will only add the amount of silence that you specify, while the mastering engineer can choose different lenghts for the gaps in order to match the mood of each track.
It nearly sounds like clipping the sound, then apply a clipping restoration process to me. You remove the gaps, then let the player try to guess what they were in order to recreate them.



Of course, when you keep gaps, the player must not add some more. Anyway, I would never use a gap plugin in order to play silence between my files, because I would have to manually disable it every time I listen to a gapless CD, and I have many of them.



Uh ? Are you trying to say that when you correct offsets, the music doesn't overlap in the next or previous track ? This is completely wrong ! The vast majority of commercial CDs do not respect offsets.
Only once you have checked the ends of every track, then burn a copy of your CD with offset correction, you can rip this copy with offset correction and with confidence, because you know that you yourself mastered it according to EAC's offset reference.



Only twice among 200 CD I have found a gap with something from the next track : Mike Oldfield-Discovery (only track 1, that begins in the lead-in), and AmGod - Half Rotten and Decayed, whose mastering is completely messed up.
Both of them show an abnormal behaviour in standalone players : when you start a track, it misses the beginning and starts inside the track.

As I already said, this dicussion develops into a question of belief (or faith ?)

In my understanding, a silent gap does not belong to any track. I think it's there for the reason of inaccuracy during the CD creation process (either burnt or pressed, CD writers may have problems with gaps which are too short). Thus they don't belong to the original audio data and shouldn't be added, thus changing the original audio data. A track's subindeces 01(the track index) and 00 (the following gap beginning subindex from the next track) mark the part I call "original audio data". I care for offsets in order to get it as precisely as possible.
Usually, I don't keep the order of the tracks after ripping, tracks from different CDs are mixed on burnt ones and in the file system. Thus keeping a gap for the reason "these two tracks should be devided" is senseless.
(everything under the condition that the gap is 100% null samples)


Usually, tracks contain 1/3 second of silence at their beginnings and at the ends a bit more. I think that's enough, regardless some small parts at the end and beginning, containing only inaudible (too quiet) noise.


Yes, that's the order of magnitude. But it's frequent enough to care for it.

I think these might be useful guides to understanding how EAC works with these gaps.
http://www.rarewares.org/wiki/index.php/Gap_settings
http://www.rarewares.org/wiki/index.php/EAC_CUE_Sheets

The answer to this thread probably depends on what do you want to achieve:

1. Will you play back the complete album, or
2. Are you just interested in one or more tracks on the CD?

Only in case 2 you may wish to leave out the gaps. In case 1, you will want to keep them, as dev0 and Pio2001 said, and the question here is HOW (appended to previous/next track or hidden in an image?). Dev0's answer to that is:

The less practical CD image format is probably the best emulation, but beside that I share your opinion.

Is there any other solution to test wavs if their contain 100% null samples? I dont ask for Cooledit. If i want to test it manually, i will use it. But im asking for something simpler. I dont want to use shotgun to kill an ant. A command line software maybe?

I use shntool's trim mode. It will give an error if the file only contains silence and output a new file if not.

Thank you for your answer.

how come eac locks up on a cd with some extra's (data files) after detecting pregaps for the 2nd song lol is it copy protected?

i think there's a bug in eac, because foobar rips the cds just fine...its the same band and record company that i got problems with...it just kind of stops when its detecting pregaps...i'll see if the same happens with a different drive

How can you say this when foobar doesn't perform gap detection?!?

Anyhow, to answer the original question, "what do I do with my pregaps?" I print out all my CUE sheets and keep them in a safe deposit box. When I feel lonely I go down to the bank, pull them out and covet them. I get immense enjoyment out of watching my CD player count down to the beginning of a track and get all depressed when I find a disc that doesn't do this. Also, I find it terribly upsetting when a track ends with an intro to the next song. When I find that I get different gaps between different drives or when different methods in EAC produce different results I just want to kill myself!

Kudos to RamonSalazar for digging up a three-year-old post with an off-topic question.

ah so its the drive then that messes up on certain cds?

I have a TON of cds where the gaps have music in them... I have many cds with entire tracks in the pregap. For instance, Out Out - Voiceprint has at least 2 tracks completely in the pregap that are even listed on te cd as actual tracks. On the cd Satyricon - Rebel Extravaganza, There is an entire track prior to the first track in the pregap- I only have 1 drive that can read that track even.

So whoever it was that made the generalization that the artist does not care about the pregaps, it is just that , a generalization. plenty do and plenty make good use of them. I have several live cds where the pregap is used for the crowd screaming between tracks or whatever else is going on between the songs of a lie set.

I'd say it's the combination of the drive and EAC and would consider it a compatibility issue rather than a bug. Are you able to find at least one method and accuracy level that doesn't cause your drive to hang?

I haven't looked at foobar as a ripper for quite a few versions now; am I correct in assuming that foobar still doesn't perform gap detection?

There was a discussion here about how bad EAC detects gaps if theyre 100% null s. Ive read almost all topic here about this, and ive made a question about how to detect it another way (not manually). Whats wrong with that? There are thousends of topics here, because every new member opens one instead of searching for the most relevant topic for his/her question.

Greetz
RS

Well i tried to rip the cds that started to hang in eac with my pioneer 111, and it ripped just fine. It was just a few cds that started to hang when detecting pregaps. Not quite sure but i dont think foobar performs gap detection.

Huh?

Gap detection has nothing to do with null samples!

People who suggest this do not know what they're talking about.

EAC has a function to omit leading and trailing silent blocks. The blocks must consist entirely of null samples or they won't be removed. Low level noise does not qualify as null samples.

EAC's test gaps for silence feature, which is completely unrelated to the removal of silent blocks, does not distinguish low level noise from null samples. This feature has no bearing on gap detection.

If you want to find a program that can do what you're looking for, I'd start a new topic!

Thanks for reckoning me as a complete idiot.

Sorry for my bad english:

There was a discussion here about how bad EAC reports gaps if theyre 100% null s. And if sy sais EAC doesnt do it good, and i ask what does it in a simple way, is not off-topic.

When you resurrect a thread that is three years old, it ought to relate back to the original post which is about what people do with pregaps. It's just my opinion of course. Regardless, this thread is not about how to remove silence from a track.

It's unfortunate that precisionist decided to obscure the issue by talking about testing gaps for silence and expressing a very limited and incorrect point of view about how gaps are placed in real world CD mastering. This ultimately led to k.eight.a responding with something that was completely untrue. From your post, it seemed like you believed this garbage which is why I responded the way I did. This is often how misinformation is spread.