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Topic: Tracks and gaps on CDs - what is out there? (Read 18929 times) previous topic - next topic
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Tracks and gaps on CDs - what is out there?

I'm enduring a long period of mystification about the types of CDs that one can find; specifically the types of transitions between tracks.

I will take as an example the old Grateful Dead album Live/Dead (unsurprisingly a live recording), but I believe the issues will be found on The Beatles' Abbey Road album, or some recordings of Beethoven's Fifth Symphony.  On Live/Dead there are tracks that merge into one another, and there are other tracks that have a pause between them (i.e. the band stopped for a break or stuff was skipped).  When I rip this album I find that all of the tracks seem to merge into one another (assuming that the player is capable of providing 'gapless' playback - MediaMonkey and Foobar2000 seem fine).  I would though expect to find that on the CD the tracks will sometimes merge and sometimes be separated; however, this CD itself also plays entirely 'gapless' which is actually odd. 

Now, as far as I am aware, according to the CD standards, the 'pre-gap' can vary on a track by track basis, but do any CDs actually use this?  I would have expected that, using the example above, the first four tracks (Dark Star through Turn on Your Love Light) would have pre-gaps of 0 secs length, and the junction of tracks 4 and 5 (Turn on Your Love Light and Death Don't Have No Mercy) would have a silent pause (pre-gap of 2 or more secs) as the tracks are discontinuous.  But that does not seem to be the case.

In fact, when I look at several other CDs which have a mix of paused and non-paused track junctions, they seem to rely on recording the merged items as one track.  I find this in say Beethoven's Fifth Symphony and Mozart's Requiem.  In the case of Live/Dead, the first four tracks last for about 3/4 Hr, and thus the record company seem to have decided that they could not be lumped together, but then as the CD is gapless the later tracks are not handled correctly.  This is also found, and is even more irritating, on some recordings of Mahler's 2nd Symphony.

This is not a huge issue, just an irritant, but I am very interested in whether there are any commercial CDs out there with varying gap lengths, or have the record companies restricted themselves to the most basic ways of doing this because some CD players cannot handle the varying pre-gap length for each track (I believe by numeric data in the Q sub-codes of Index 00 ??).  It would be useful to be able to cue, or skip to the actual track start of individual items, and I for one would really like to create CDs from my LPs with truly varied gap times (0 to say 8 secs).

I am checking through my collection to see what may be there, but can anyone tell me if there are commercial CDs with varying gaps or a mixture of zero length and 2 second length gaps, or has a 'standard' evolved that avoids this feature?

Tracks and gaps on CDs - what is out there?

Reply #1 –
It may help to consider how an audio CD is actually laid out. The audio on an audio CD is one single long stream of samples. There are no gaps. Places where you hear a silent gap are simply parts of the audio stream where the samples have a value of zero.

The tracks are defined by the table of contents. This has pointers into the single long stream of audio where each index point lies. Indexes are numbered between 0 and 99 for each track. Every track MUST have an index number 1. This is where the track begins.

A track may also have an index number 0. This is the start of the "pregap", but it need not necessarily contain silence. Some live albums contain the pre-song announcements in the space between index 0 and 1. (Example: The Who Live At Leeds).

While a CD player is playing a CD, when it encounters an index 0 it starts the "countdown" that you see between tracks. When it gets to index 1, it begins the normal elapsed time display. When you ask a CD player to seek to a track, it goes straight to index point 1 (skipping the "pregap"). For CD players that also support indexes higher than 1, you'll see the index marks incrementing as it passes those places.

A CD can have arbitrary indexes wherever it likes. Although there's a standard requiring a track to be at least 4 seconds long, many CD players are happy to deal with shorter tracks. There's also a standard stating that the first track of a CD must have a pregap at least 2 seconds long, but again many CD players don't care. (Incidentally, you can place music into index 0 of the first track to create a "hidden track", because a CD player starts playing at index 1 or track 1 - you have to rewind back to hear what's in index 0 of track 1). So by arranging suitable positions of index points 0 and 1 for the various tracks, and by adding silence into the audio stream where required, you can create any mix of gaps and segues you like. But bear in mind that a "gap" is just a segue that includes some silence.

Some CD burning programs interpret an explicit PREGAP command in the cue sheet as an instruction to insert additional silence and plonk an index 0 at the start. But that's a convenience - you can just as easily insert the required silence in the source WAV file and use INDEX 0 commands in the cue sheet to achieve the same effect.

Tracks and gaps on CDs - what is out there?

Reply #2 –
Quote from: cliveb on


Hello cliveb - thanks for taking the time to reply, and for writing such a detailed post.

Unfortunately, I think you may have assumed that I thought that audio was formatted on a CD in the same manner as PC data, but I do understand the formatting and use of Indices; I thought this would be clear from what I said in paragraphs 3 and 5, but I assume that I was unclear, and I am sorry for any confusion.

It is clear from the Red Book standards (well actually it is not exactly clear but is indicated), that the track gap can vary throughout a CD, and can vary between 0 and a large number of seconds; in addition, as you say, this gap does not have to be silent.  I was aware of the 'Live at Leeds' CD (unfortunately both of my copies are on vinyl), but the question with that would be: how does a ripper program handle those 'gaps'?  I would assume that it would just append them to the preceeding track.

But, 'Live at Leeds' may be the same as the Grateful Dead's Live/Dead album that I used as an example: that CD is gapless throughout, even though some of the track junctions should not be.  On the other hand, as I indicated in my OP, I have classical CDs that just lump the gapless sections or movements together as one track, which is the simplest method but not the most flexible.  Does 'Live at Leeds' actually have a mixture of pre-gaps, some of zero length and some of 2 secs or more, or is it like 'Live/Dead' and gapless throughout?  I am mystified as to why these two situations should occur exclusively; that is, either having no gaps where there should be some, or merged tracks.

So, do we have a situation where a CD can only be gapless or gapped; is there a flag in the TOC, say, that denotes this for the whole CD?  Or is it just that, as I said in my previous post, for compatibility reasons commercial CD makers do not use the Track Index 00 pre-gap to create gapped and gapless track junctions throughout a CD, sticking to either gapless or gapped for the complete CD.  I must confess that if such a flag is defined in the CD 'standards', I have missed it.

In order to answer this, in a spirit of pure enquiry, I am asking if anyone can answer the following questions:

  • Is there a flag, defined by the Red Book standard, that denotes a CD as completely 'gapped' or 'gapless'?
  • Are there are commercial CDs that use the pre-gap to give pauses between some tracks and no pause between others?


Once again, I apologise for any confusion I caused, and for the length of my posts, and indeed for the possible obscurity of this question.  I am checking through my CD collection, but that is quite small (only about 400) as most of my music is still on vinyl, but I am bothered by a potentially very useful function being left unused by record companies (and perhaps those creating CD copies of their LPs).

Regards,
Arthur.

Tracks and gaps on CDs - what is out there?

Reply #3 –
I just wanted to say thank you to cliveb for the post, I have often wondered myself about these things when looking at CUE files, but have never found a better and clearer explanation than this one. Thanks again

Tracks and gaps on CDs - what is out there?

Reply #4 –
arthurb,

CDs are exactly like CliveB explained, and your ripper does whatever you tell it to (or, failing that, whatever it wants).

Given this reality, your questions make no sense.


I suspect what's happening is that you haven't told your ripper what to do, and it's doing something you find unexpected.

Or else you're mystified that people decide to use the tools available in the CD standard to author CDs in different ways. This shouldn't be surprising really - you can stick index marks (and hence track splits) almost where ever you want to*. What you hear when playing the CD through depends entirely on the audio recorded on the disc - but what you see your CD player display, where hitting "next track" jumps to, and how tracks get split when ripping, depends on this (somewhat arbitrary) data, which people can author as they please.

* I even have a CD where the intro to song 5 is in track 5, but the first verse of song 5 is in track 6! Not surprisingly, subsequent track numbers don't match the track listing!

Cheers,
David.

Tracks and gaps on CDs - what is out there?

Reply #5 –
Quote from: arthurb on
I was aware of the 'Live at Leeds' CD (unfortunately both of my copies are on vinyl), but the question with that would be: how does a ripper program handle those 'gaps'?  I would assume that it would just append them to the preceeding track.

My experience is that most rippers' behaviour "out of the box" is to append index 0 of track N to the end of track N-1. I always found this a strange thing to do: usually whatever is in the pregap tends to be associated with the track that follows. But there again, if you want to just play track N, perhaps you aren't interested in hearing any announcements that precede it. As far as I am aware, EAC has options to append pregaps to the previous track (default mode), stick them on the front of the next track, or even discard them completely.

Quote from: arthurb on
Does 'Live at Leeds' actually have a mixture of pre-gaps, some of zero length and some of 2 secs or more

Yes, it has a mixture. For example, tracks 6/7/8 are a medley (Substitute/Happy Jack/I'm a Boy) and they segue into one another with no gap. Track 9 ("A Quick One") has an index 0 region of about 1m 50s during which Pete Townsend makes a rambling (and amusing) announcement about the storyline. (Note: my copy of Live at Leeds is the single disc aniversary version, ie. not the two-disc one with the performance of Tommy included).

Quote from: arthurb on
So, do we have a situation where a CD can only be gapless or gapped

No, absolutely not. As I said previously, there are no gaps on an audio CD.

Quote from: arthurb on
  • Is there a flag, defined by the Red Book standard, that denotes a CD as completely 'gapped' or 'gapless'?

No. All audio CDs are gapless.

Quote from: arthurb on
  • Are there are commercial CDs that use the pre-gap to give pauses between some tracks and no pause between others?

Depends what you mean by "pregap". There are plenty of commercial CDs which have an approximately 2 second or so period of silence between some (or all) tracks, and quite often that period of silence is placed into index 0, which puts it into what you call the "pregap".

But let's be clear: there is nothing on an audio CD which instructs a CD player to insert additional silence. The CD player simply plays whatever audio samples are on the disc. If those samples happen to include some silence then you hear what sounds like a "gap".

Tracks and gaps on CDs - what is out there?

Reply #6 –
Hello Clive,

Thanks for the detailed post, this is beginning to get to what I am interested in.  This will be just a quick reply as I have several other things to do, but I will be back later.

On your description of 'Live at Leeds': the use of Index 00 values to get the variation in 'gaps' is exactly what I expect to see; but it is not what I see on Live/Dead (where the track junctions are all without any pauses)

There may be confusion caused by my use of the word 'gap'.  There may be a common usage from MP3 players and PC players of MP3, AAC and other such files, but the issue of switching from one file to another, and any related issues of buffering, are not what is concerning me here.  If that is an ambiguous word to use, then I apologise.  To be clear, by 'gap' I mean any pause, or other interjection into the delivery of an otherwise continuous audio stream, that is inserted by the CD player, or other software, interpreting the values in the Index 00 data - specifically the q sub-channel values ... aargh - I HATE trying to write precisely when I am in a hurry, so I hope I am clear!  I have used the term 'gap' because descriptions that I have read of the CD 'standards' use the term pre-gap for the Index 00 value, which gives the inter-track pause, or 'gap' to me.  Perhaps pause would be better.     

I raised the issue of a universal flag, or at least one for the whole CD, as a reply to a query I raised elsewhere seemed to indicate there might be one, which would have surprised me.

Damn; I have to go.

Thanks for your time Clive, and others who have contributed.
I will come back here later.

Regards,
Arthur.

Tracks and gaps on CDs - what is out there?

Reply #7 –
Quote from: arthurb on
On your description of 'Live at Leeds': the use of Index 00 values to get the variation in 'gaps' is exactly what I expect to see; but it is not what I see on Live/Dead (where the track junctions are all without any pauses)

I don't know the Grateful Dead CD in question, but my guess is that it simply has no index 0 marks anywhere. The audio is a continuous stream, and index 1 marks are placed at the positions where each new track begins.

Quote from: arthurb on
To be clear, by 'gap' I mean any pause, or other interjection into the delivery of an otherwise continuous audio stream, that is inserted by the CD player, or other software, interpreting the values in the Index 00 data

Software media players might do all kinds of peculiar things with a long CD rip and a cue sheet - that's entirely up to them.

But in the case of a CD player, it NEVER creates pauses/gaps/other interjections when playing a CD as a result of seeing an index (or for any other reason). Once again: the audio on a CD is a single continuous stream and the CD player plays it exactly as it is. The index points are just convenient pointers into that stream to assist the CD player seeking to particular places when asked, and to generate its display.

Tracks and gaps on CDs - what is out there?

Reply #8 –
Arthurb, I think if you completely drop your somewhat quirky understanding of what gaps are and then just thoroughly read again what cliveb has written in his first answer, your incomprehension will go away.

Tracks and gaps on CDs - what is out there?

Reply #9 –
Quote from: rpp3po on
Arthurb, I think if you completely drop your somewhat quirky understanding of what gaps are and then just thoroughly read again what cliveb has written in his first answer, your incomprehension will go away.


What incomprehension do you think I have?

Tracks and gaps on CDs - what is out there?

Reply #10 –
First, there is no such thing as any interjection of or insertion into a continuous audio stream and index 00 values are not interpreted in such a way. But I'm not willing to spend too much time explaining it anything further. It has really much all already been said - in great detail.

Tracks and gaps on CDs - what is out there?

Reply #12 –
To Clive:

Quote from: cliveb on
Quote from: arthurb on
On your description of 'Live at Leeds': the use of Index 00 values to get the variation in 'gaps' is exactly what I expect to see; but it is not what I see on Live/Dead (where the track junctions are all without any pauses)

I don't know the Grateful Dead CD in question, but my guess is that it simply has no index 0 marks anywhere. The audio is a continuous stream, and index 1 marks are placed at the positions where each new track begins.


Yes, that would be my suspicion too, and I hope to use EAC to look more closely at that CD in the next few days.  Essentially, what I see with Live/Dead is a poorly produced CD (oh God, before someone misunderstands that too: 'produced' does not imply the Producer, just how the music has been put together - that's what I am interested in here).  It is a poorly produced CD because there are no gaps, or 'silent intervals', between songs/tracks where there should be.  It's almost as though someone has decreed: this CD shall be 'gapless', and lo, there are no gaps between any tracks.  'Live at Leeds' would appear to be what I would have expected.

Quote
Quote from: arthurb on
To be clear, by 'gap' I mean any pause, or other interjection into the delivery of an otherwise continuous audio stream, that is inserted by the CD player, or other software, interpreting the values in the Index 00 data

Software media players might do all kinds of peculiar things with a long CD rip and a cue sheet - that's entirely up to them.


Clive I genuinely appreciate your efforts in response to my questions, but you should really have ignored that statement.  Please, to quote the first half of a sentence, just up to the point where I say: '... aargh - I HATE trying to write precisely when I am in a hurry, so I hope I am clear', is a bit pointless.  I had just decided that I had started writing one sentence and finished by writing a different one (rather like one can sometimes concatenate two halves of different words that mean the same thing when speaking and thinking, so that you create a new nonsense word).  I am sorry for that sentence, and for ever introducing the words 'numeric' and 'value' earlier.  What I am talking about, as with the section above is 'silent intervals' introduced by the creators of the CD, which may inappropriately add pauses where there should be none, or vice versa.     

Quote
But in the case of a CD player, it NEVER creates pauses/gaps/other interjections when playing a CD as a result of seeing an index (or for any other reason). Once again: the audio on a CD is a single continuous stream and the CD player plays it exactly as it is. The index points are just convenient pointers into that stream to assist the CD player seeking to particular places when asked, and to generate its display.


Yes, conceptually, a CD is one stream and the pre-gap is a certain amount of time, which may be zero, either placed into the audio stream and which may be silent or not, or just encapsulating some part of the audio stream. 

So, with 'Live at Leeds', you have shown me an example of a CD with varying gaps in the music, which is what I was keen to find; I would like to know if this is common or rare, but at least I can burn CDs with a similar format knowing that they are still standard CDs.  As I said, all of my commercial CDs, that could have been made with gaps varying from 0 secs to, say 4, have been produced as either entirely gapless or with merged tracks.  Where pre-gaps are specified, the rippers I use append them to the preceeding track, which is just fine; I think I should burn my own version of 'Live/Dead' with the pauses as they should be.   

But fine, having pre-gaps of 0 and positive values on one CD is legitimate; it is very sad that almost all CDs that need that do not have it.  I wonder how many other CDs do it, especially classical and Opera?

Clive, thank you for your time, I'm sorry that in trying to draw a distinction between gaps in the music and gaps in the data I introduced confusion.  I am still wondering though just what percentage of CDs have been poorly produced, when they could have been done properly.


Tracks and gaps on CDs - what is out there?

Reply #13 –
Quote from: arthurb on
To Clive:

Quote from: cliveb on
Quote from: arthurb on
On your description of 'Live at Leeds': the use of Index 00 values to get the variation in 'gaps' is exactly what I expect to see; but it is not what I see on Live/Dead (where the track junctions are all without any pauses)

I don't know the Grateful Dead CD in question, but my guess is that it simply has no index 0 marks anywhere. The audio is a continuous stream, and index 1 marks are placed at the positions where each new track begins.


Yes, that would be my suspicion too, and I hope to use EAC to look more closely at that CD in the next few days.  Essentially, what I see with Live/Dead is a poorly produced CD (oh God, before someone misunderstands that too: 'produced' does not imply the Producer, just how the music has been put together - that's what I am interested in here).  It is a poorly produced CD because there are no gaps, or 'silent intervals', between songs/tracks where there should be.  It's almost as though someone has decreed: this CD shall be 'gapless', and lo, there are no gaps between any tracks.  'Live at Leeds' would appear to be what I would have expected.

Quote
Quote from: arthurb on
To be clear, by 'gap' I mean any pause, or other interjection into the delivery of an otherwise continuous audio stream, that is inserted by the CD player, or other software, interpreting the values in the Index 00 data

Software media players might do all kinds of peculiar things with a long CD rip and a cue sheet - that's entirely up to them.


Clive I genuinely appreciate your efforts in response to my questions, but you should really have ignored that statement.  Please, to quote the first half of a sentence, just up to the point where I say: '... aargh - I HATE trying to write precisely when I am in a hurry, so I hope I am clear', is a bit pointless.  I had just decided that I had started writing one sentence and finished by writing a different one (rather like one can sometimes concatenate two halves of different words that mean the same thing when speaking and thinking, so that you create a new nonsense word).  I am sorry for that sentence, and for ever introducing the words 'numeric' and 'value' earlier.  What I am talking about, as with the section above is 'silent intervals' introduced by the creators of the CD, which may inappropriately add pauses where there should be none, or vice versa.     

Quote
But in the case of a CD player, it NEVER creates pauses/gaps/other interjections when playing a CD as a result of seeing an index (or for any other reason). Once again: the audio on a CD is a single continuous stream and the CD player plays it exactly as it is. The index points are just convenient pointers into that stream to assist the CD player seeking to particular places when asked, and to generate its display.


Yes, conceptually, a CD is one stream and the pre-gap is a certain amount of time, which may be zero, either placed into the audio stream and which may be silent or not, or just encapsulating some part of the audio stream. 

So, with 'Live at Leeds', you have shown me an example of a CD with varying gaps in the music, which is what I was keen to find; I would like to know if this is common or rare, but at least I can burn CDs with a similar format knowing that they are still standard CDs.  As I said, all of my commercial CDs, that could have been made with gaps varying from 0 secs to, say 4, have been produced as either entirely gapless or with merged tracks.  Where pre-gaps are specified, the rippers I use append them to the preceeding track, which is just fine; I think I should burn my own version of 'Live/Dead' with the pauses as they should be.   

But fine, having pre-gaps of 0 and positive values on one CD is legitimate; it is very sad that almost all CDs that need that do not have it.  I wonder how many other CDs do it, especially classical and Opera?

Clive, thank you for your time, I'm sorry that in trying to draw a distinction between gaps in the music and gaps in the data I introduced confusion.  I am still wondering though just what percentage of CDs have been poorly produced, when they could have been done properly.


I get the impression you believe there should be some arbitrary length of silence between tracks to fit into your definition of 'not poorly produced'. I've recorded some live organ concerts and have separated the tracks, sometimes with no silence betweeen them but you can get to a specific section if you like. Is this 'poorly produced'? If you just play the disc the timings are as they were during the performance. I believe that is as is should be and is what I expect from a recording of a live performance.

G²

Tracks and gaps on CDs - what is out there?

Reply #14 –
Arthur, I think I now have a clearer understanding of your confusion. It seems to me that it's based around some kind of belief that the CD standard may in some way limit the choices in laying out tracks. Apart from a requirement that tracks must be at least 4 seconds long (which in any case most CD players do not enforce), there are none.

Forget for a moment that CD is the target medium. Consider instead how the producer/artist might want to sequence the tracks on their album. It may be that they would like all of the tracks to merge seamlessly into one another. Or they might want periods of silence between tracks. And if they do want silence, the amount might vary from track to track. They might want a mixture of seamless segues and silences.

So, having decided how they want the tracks sequenced, the producer should insert whatever periods of silence are required so as to generate the desired flow. That natural flow should be present on the final product, regardless of the delivery medium (CD, vinyl LP, cassette tape, etc).

Now we come to laying out the CD itself:
1. The already sequenced music, including any additional silences, is left as it is and placed on the CD as one single stream.
2. Index 1 marks are placed to allow the CD player to seek to the start of the tracks.
3. Optionally, index 0 marks are placed to mark the beginning of the transition from one track to another. If there are silent periods between tracks, many producers choose to place index 0 marks at the start of those silent interludes, but this is by no means mandatory. If there *is* an index 0, the CD player will display a "count-down" to the following track. If there isn't, it simply changes its display to the next track number when it gets to index 1.
4. Optionally, index 2-99 marks are placed to mark sections of interest within tracks. This is fairly rarely done these days.

Quote from: arthurb on
Essentially, what I see with Live/Dead is a poorly produced CD (oh God, before someone misunderstands that too: 'produced' does not imply the Producer, just how the music has been put together - that's what I am interested in here).  It is a poorly produced CD because there are no gaps, or 'silent intervals', between songs/tracks where there should be.  It's almost as though someone has decreed: this CD shall be 'gapless', and lo, there are no gaps between any tracks.

Let me begin by admitting that I'm probably one of the few people on the planet not to have heard Live/Dead. But assuming it's a live concert album, I would defend the producer's choice not to insert artificial periods of silence between the tracks. It is probably sequenced deliberately to give the listener the impression of being at a concert (where of course there are unlikely to be any periods of silence). The fact that they haven't bothered to place index 0 marks at the start of the transitions between tracks could be argued as being a little lazy, but that's a minor issue. Had they actually gone ahead and inserted silence, I suspect there would have been an outcry by the majority of listeners.

Quote from: arthurb on
So, with 'Live at Leeds', you have shown me an example of a CD with varying gaps in the music, which is what I was keen to find

Live at Leeds does *not* have any "gaps" (ie. periods of silence) between the tracks. The space between them is occupied by various non-musical audio, mainly announcements by the players. The fact that the producer has chosen to place these inter-song announcements within the index 0 area is entirely up to them. I happen to applaud their decision. But if there had been no index 0 marks on this disc, it would still sound exactly the same.

Tracks and gaps on CDs - what is out there?

Reply #15 –
Quote from: Glenn Gundlach on
... I've recorded some live organ concerts and have separated the tracks, sometimes with no silence betweeen them but you can get to a specific section if you like. Is this 'poorly produced'? If you just play the disc the timings are as they were during the performance. I believe that is as is should be and is what I expect from a recording of a live performance.

G²


Glenn,

no, that is not poorly produced, but if you added two 'movements' (for want of a better word), that is, passages that have a pause between them, and you create them without a pause just because that is the way you did the preceeding 'tracks', then that would be 'poorly produced'.  That is what I have found, and what I was describing, and is what I have been asking questions about. 

If you were to record Beethoven's Fifth Symphony, how would you create that CD?


Tracks and gaps on CDs - what is out there?

Reply #16 –
Arthur,

The Crystal Method's Legion of Boom album is constructed like you say. Transitions between some tracks are gapless and other track changes are not.

I'm not sure if this is helpful to you; like the others I'm a little confused what you're driving at. I think I do, but you seem very particular about the music you're listening to.

Tracks and gaps on CDs - what is out there?

Reply #17 –
Quote from: cliveb on
Arthur, I think I now have a clearer understanding of your confusion. It seems to me that it's based around some kind of belief that the CD standard may in some way limit the choices in laying out tracks. Apart from a requirement that tracks must be at least 4 seconds long (which in any case most CD players do not enforce), there are none.
...


Well, not quite Clive - you're close, but it's sort of the other way round.  I started by being sure that there was no such standard, but then I found several CDs where I would have expected the producers/engineers or whatever to have created multiple tracks with varying 'gaps' between them - varying between 0 and about 3 or 4 seconds or so.  But I didn't find the varied 'gaps', and then I didn't find them in a friend's collection either.  As this included the examples that I have given before (Live/Dead and Beethoven's Fifth) and several others, I was surprised, and then just a little concerned as I wished to create CD versions of LPs using just such varying 'gaps'.  Hence my original question, which was very simple (I would disagree, but understand, if you used the word banal) because I started to worry that there may be either a true standard, or just a de facto standard, to avoid a mix of 0 length and +ve length 'gaps' perhaps for obscure 'compatibility' reasons.  All of the CDs that I have so far found in my limited CD collection have either all tracks without 'gaps' or all tracks with 'gaps'.  Sometimes that is fine, such as my live recording of Mahler's 2nd which is continuous and divided into numerous tracks (the interval happens naturally because there are 2 CDs - neat), but sometimes with other records it gives too little cueing control (i.e. when tracks have been merged), or weird results with separate tracks playing 'gaplessly' when inappropriate.  These latter are what I described as 'poorly produced'.

Clive, you have given generously of your time and it has been greatly appreciated, but I think I should not take more.  I remain surprised that so many CDs have been created 'incorrectly' (e.g. Live/Dead), or not as well as they could have been (e.g. the Beethoven), but I think you are reassuring me that there is no reason why 0 length and multi-second length 'gaps' cannot co-exist on one single CD, provided by different length pre-gaps/Index 00 data; or for that matter, mixed with other such 'gaps' containing music, applause, anecdotes from the performers or screams from back-stage or anything else the producer wants to include in the 'gaps' - even possibly silence.  As you say: '... having decided how they want the tracks sequenced, the producer should insert whatever periods of silence are required so as to generate the desired flow'.  Exactly; that is both what I expected, and what I did not find, and as I do not want to create 'CDs' that are non-standard and/or do not play on some CD players I thought I would ask here whether some 'standard' existed that I was not aware of. 

I would still like to hear of CDs with pre-gaps/Index 00 lengths of 0 and 1 or more seconds to reassure me, but I trust your assurance that they can exist.

Thank you.
   
   

     

Tracks and gaps on CDs - what is out there?

Reply #18 –
Quote from: Canar on
Arthur,

The Crystal Method's Legion of Boom album is constructed like you say. Transitions between some tracks are gapless and other track changes are not.

I'm not sure if this is helpful to you; like the others I'm a little confused what you're driving at. I think I do, but you seem very particular about the music you're listening to.


Thanks for the info Canar.  Just to be sure, I take it you see, on the CD player, a pre-gap countdown at the start of some tracks, and none with others (i.e. the 'gapless' junctions)?



Tracks and gaps on CDs - what is out there?

Reply #19 –
CD players do not care whether or not tracks have 00 indices, and I would assume they don't even care where they are placed, though I've never tested something like a 70 minute track with a 00 index for the next track placed one frame after the track starts.

Regarding the Live/Dead CD, I have both the original and the remaster and think you're making a mountain out of a mole hill.  Would you be so kind as to tersely tell me which mastering it is that you find so reprehensible?

Tracks and gaps on CDs - what is out there?

Reply #20 –
Quote from: greynol on
CD players do not care whether or not tracks have 00 indices, and I would assume they don't even care where they are placed, though I've never tested something like a 70 minute track with a 00 index for the next track placed one frame after the track starts.

Regarding the Live/Dead CD, I have both the original and the remaster and think you're making a mountain out of a mole hill.  Would you be so kind as to tersely tell me which mastering it is that you find so reprehensible?



Greynol - you said: 'Would you be so kind as to tersely tell me ...'; are you actually asking me to be rude to you?  If so, I could suggest that I don't really care if you think I am 'making a mountain out of a molehill'.

Of course, if you are just asking me to be brief, and hopefully succinct, I would respectfully point out that I have repeatedly stated that my questions are very simple.  In fact, I am beginning to believe that the great majority of responses in this thread are from people who have not actually read what I have written.  Some, probably all, of this has been done from very good motives, basically a genuine desire to help others and to spread knowledge.  But, much here has had at best only a tangential relationship to the questions that I have asked; your first sentence above is a case in point.  Your second sentence would appear to be a question, but, after reading it several times, it is still very unclear; could you explain what you are trying to tell me about your copies of Live/Dead?  Are you, for instance, telling me that on both of your copies there is a mix of 'gaps' and no-gaps' between the tracks (i.e. no-gaps between tracks 1 - 4 and gaps between the rest)?  As to what I ' ... find so reprehensible', I have explained that in previous posts, with examples, and what I have said in the preceeding sentence should make it clear. 

In any case, the purpose of my questions was to find out why none of the CDs in my, and a friend's, collection use varied 'pre-gaps' even when they usefully could.  As this surprised me, I sought to establish whether any standard existed that said CDs must either have 'gaps' or 'no-gaps', but not both; however, I was not expecting to find one.  Please note that such 'mixed' CDs will always be a minority of those in circulation, and thus I am only interested in that minority.

I hope that this helps to make things clear...

Tracks and gaps on CDs - what is out there?

Reply #21 –
I don't quite understand your A: meaning or B: apparent outrage. Do you use "gap" to describe any pre/between-track audio region that is defined as such in the CD's table of contents, e.g. pre-song banter by the artist, rather than a period of silence? If so, you seem disproportionately offended that some CDs don't cause your player to display a countdown between some tracks. No one mention the loudness war; none of us will make it out alive…

Tracks and gaps on CDs - what is out there?

Reply #22 –
Quote from: dv1989 on
I don't quite understand your A: meaning or B: apparent outrage. Do you use "gap" to describe any pre/between-track audio region that is defined as such in the CD's table of contents, e.g. pre-song banter by the artist, rather than a period of silence? If so, you seem disproportionately offended that some CDs don't cause your player to display a countdown between some tracks. No one mention the loudness war; none of us will make it out alive…


If your post is directed at me, which is unclear, then I can assure you that I have no 'outrage', apparent or otherwise.  As to the rest of your post, please read all of the preceeding posts, which should make the whole question clear.

Tracks and gaps on CDs - what is out there?

Reply #23 –
All I can do is offer my understanding of pregaps. Mastering engineers can define or not define pregaps on a per-track basis. Pregaps may denote silent pauses between tracks, pre-song banter by the artist, any audio at all. That a CD has pauses (indexed as pregaps, I presume) between tracks, and stores multi-part works in single tracks rather than separate tracks without pauses, does not mean the engineer couldn't have done the latter if they had wanted to. So, there's nothing to stop you from laying out your own CDs however you see fit. I suspect you've been confused by a few idiosyncratic CDs into making incorrect generalisations about indices.

Tracks and gaps on CDs - what is out there?

Reply #24 –
Quote from: arthurb on
I would still like to hear of CDs with pre-gaps/Index 00 lengths of 0 and 1 or more seconds to reassure me, but I trust your assurance that they can exist.
They don't have a length of zero - if they're "zero", they aren't there at all!

You should have no problems setting indexes for your vinyl transfers on CD however you like, with suitable software.

You can even re-do the commercial CDs you don't like!

Cheers,
David.