I agree with you that the audio signal on a CD is continuous, like an LP or a cassette tape. And I agree with you that the CD has a Table of Contents that has addresses to that continuous audio signal. And I agree that the Table of Contents uses the terms “Track” and “Index”.
But I think we might be getting tangled in the difference between meaning of the word “track”. There is one meaning, as understood by Artists making albums and fans listening to albums. That is, the “track” is the part with audible sound, and the “gap” is silence between the audible sound. The silence is not the “track”, it separates tracks. Then there is a second meaning, as understood by people reading the CD format specifications and using fancy ripping software. There, every second audio on the CD is part of a “track” in the TOC.
Do you agree that Artists and mastering pros treat the audio content between index 0 and 1 within a CD TOC’s “track” differently than the other audio content? For instance, when you tell a physical CD player to go to the “start of a track”, it goes to the address of index 1, not the address of index 0? Doesn’t that indicate to you that CD player treats the content between indexes 0 and 1 differently?
I am advocating that we add metadata to describe the common-sense, listener meaning of “track” and “gap”. I’m not talking about the technical CD TOC meaning of “track”. Especially, I am in favour of a way of saying with metadata, “there is no gap here”.
There is no such thing as an inter-track gap on an audio CD. There is only the pregap which is at the beginning of the tracks (called pause in the compact disc specification). Pregap is optional for all tracks except the first, as are all subdivisions/indices beyond 01. When ripping a CD everything should be included in the ripped audio somewhere.
I drew a picture with some made up numbers, maybe this helps to show the structure:
Edit: on review, I think I have the disc timestamp row wrong in the diagram, looking at the spec it looks like it should start counting up from 0 right from the start of the track 1 pause/pregap, so add 2s to all the timestamps on the top row.
I think it is accurate to say that all split-out tracks ripped from an audio CD must have this gapless tag in order for your player to work correctly, without exception. In no cases should the player add any silence or delay between ripped CD tracks if the goal is to reproduce an actual CD listening experience.
By without delay I mean literally zero delay, i.e., what you are calling “gapless”.
Escuse me if I’m oversimplifying again, but the discussion also seems to be audio vs. music. All music is audio, but not all audio is music. The database is still called MusicBrainz, not AudioBrainz
Yes, “All music is audio, but not all audio is music”. But I think that is not relevant. All this discussion concerns music Releases, e.g. The Ship, Dark Side of the Moon, most complete operas like Tristan und Isolde.
Please see my reply to @jesus2099 about the multiple meanings of “track” between ordinary listeners and the technical CD specification. When I say “track” and “gap”, I mean as ordinary listeners understand these terms.
I am familiar with the technical CD structure and its terms “track” and “index”. Note that CD players, and people mastering CDs, treat the sound between index=0 and index=1 specially. That is the part of the audio which I am calling “gap”.
This thread is already on lots of tangents… so off down a rabbit hole the OP has picked on
I have just been doing work on a strange compilation CD. It consisted of a bootlegger lifting lots of Album tracks. He then chopped the gaps from the ends of the tracks. And then trimmed the tracks agressivly by removing many intros and outros of the actual music. He was making a gapless release of tracks that originally had gaps between them, squeezing more onto one CD-R.
Playback of the rips of the original album had gaps between tracks. Playback of his compilation had music piled on top of music with barely any space between end of one and start of the next.
Due to this research I was listening to both tracks being played at the same time and then directly comparing times on my copies of VLC/Audacity and the MB database. This is why I was pointing to the gaps being in the ripped recordings. And it is these ripped recording times that get uploaded.
In this case I was also working from discIDs too. It was due to variations between the recordings and the original discIDs I dived into this. The discID times are the same ones as you see on your media player. These are the lengths of the rips that EAC produces.
As noted with your earlier links, this is showing the problem lies with your source and choice of media player. You should nag Apple Music to sell you the music in the format the artist intended. This is not data that MB should be storing to make up for the failings in the source data.
Buy CDs, rip with EAC, playback with a decent media player and you will get your gapless perfection. I know that’s what I do with very little effort. (And I have far too many gapless albums)
As repeated by many other people above - look at using a better media player. iTunes and Apple Music are the faults here. Geek software written by music geeks always handles things like Gapless better than a Mega-Company seller like Apple.
I am still curious as to how you suggest this data is retrieved. The only accurate way I can see of doing it is for every editor to upload their tracks into Audacity and then note the length of the gaps. A stopwatch is not going to be accurate enough to record the differing lengths of the gaps, and as pointed out above by @draconx there is nothing in the discID that actually notes the lengths of these gaps. The times in a discID used by MB includes the gap or lack of gap as part of the track length.
Being the kind of mad \ curious geek I am I’m about to reload a few tracks into Audactiy and double check the gaps at the ends, then compare to DiscIDs TOCs. just to double check my post above.
Following my earlier post, I have been throwing a few tracks of an example album into Audacity to look at the gaps at the ends. The FLAC lengths are the same as the TOC lengths. And this example album (nsfw) is an interesting one as all the gaps are of differing lengths, and sometimes there is no gap due to all kinds of extra samples and content between the songs.
Just that one random example shows you can’t have a “per release” setting for “gapless”. And every gap is a different length. Also when is a gap a gap or just a quieter section?
Rip accurately. Problem solved.
Edited to add: Argh! CUE Sheets I was about to fire up EAC to generate a CUE sheet, and then remembered last time I looked at this. So instead I now run away and leave you with a help page on EAC and Gaps https://wiki.hydrogenaud.io/index.php?title=EAC_Gap_Settings
The point is that normal CD rips split into tracks include all the pregap audio (except track 1) so all such CD rips are inherently “gapless” (that is to say: all such files should be played back to back without delay between them to reproduce exactly the original CD audio waveform).
Doing anything else requires special tools to dump and interpret the playback timestamps from the program area.
That’s why I believe tracking detailed CD program timestamp information in MB does nothing to help set this “gapless” flag in your tagger: the medium format is sufficient for the task.
This is not accurate: normal CD players do not give the pregaps any special treatment. The only practical difference the pregaps have during playback is how the timestamps are displayed (since the track timestamps during the pregap are negative, and some [rare?] CD players will also display the track subdivision index).
You cannot discuss CD structure by looking at extracted files and calling the playback in a digital player “gapless”. That is comparing apples with oranges.
Well, the CD structure has been very very well described, I think, by @draconx already.
Now he addresses your issue of playing gapless files.
It’s really a matter of what encoder and player you use, IMO.
On Windows, I advise doing both ripping (LAME MP3 or FLAC) and playing with foobar2000, as it works.
I don’t have enough experience on other platforms to make advice.
iTunes should transition seamlessly from one track to the next, regardless of any metadata tags. Here are a couple of things that may be preventing seamless transitions:
Make sure that Crossfade Songs is turned off (check under Preferences > Playback).
If you are checking transitions by jumping to the last few seconds of a track, the software may not have time to pre-load the start of the next track. Try giving it 10 seconds or more.
Well, this needs to be part of the discussion. As I wrote above the ability to playback multiple audio files without introducing a short artificial pause is exactly what many players mean when they advertise to support gapless playback.
And actually for many users that is all they need to be able to playback their CD rips exactly as they experience the CD. That’s because default rips always include the pregap of the next track in the previous track.
This is a wrong assumption. Most ripping software includes the pregap as explained above. See also the excellent EAC page @IvanDobsky linked above . For many simpler rippers it is the only mode. And actually this is also how digital downloads are usually done.
It makes sense, because otherwise you would have missing silences or even missing audio in between.
That also means that the majority of users don’t have this issue at all. It just works as expected. You only get into this trouble if you rip without pregaps. And I think this alone explains a lot why many above doubt the need for this
It’s so interesting to me how much of this discussion has turned to how software can deal with the rips… it doesn’t seem common for MB, which is usually always trying to represent the medium itself. I don’t really have a horse in this race, but I am quite surprised. Or probably just not quite understanding the discussion.
On a basic level: If it is recommended to rip with a cue sheet for the most ‘accurate’ representation of a CD, why would it not be helpful for MB to store (for instance, for the most basic comparison) this cue sheet?
It’s how the discussion started: How, if you have files ripped without the gaps, can one tell a player to add gaps? Maybe there are some tags for this? Could this be stored in MB to make it available to taggers? It’s not surprising that the following discussions circle around the technical details of CDs, rippers and players then
I was going to suggest that uploading a CUE sheet would solve the question. And then started to re-read that EAC link I posted a couple of replies back. There are at least three types of CUE sheets - gaps before a track, after a track or part of the track. And the default one that EAC puts out doesn’t include these gaps as the gaps are already in the ripped music files.
You can’t because the gaps are different for every track, even on one album. Only if a ripping tool has been altered to not rip gaps and then a CUE file supplied with those gaps listed separtely. And then you could reassemble music and gaps separately.
Or just let the decent ripping tools deal with gaps and gapless playback like that have done for years.
Thread like this are a prime example of why cue sheets shouldn’t exist. They serve no purpose and complicate things far beyond what most people understand. When CDs are ripped properly (gaps appended to the previous track as silence), there is no need and you have a perfect audio copy (so long as the files are lossless and you use a competent ripper!).
These can always be compared to original CDs using tools like foo_bitcompare for foobar2000 or you can perform online lookups against what other people have ripped to make sure it’s bit for bit identical. See AccurateRip, CUEtools database etc.
Or you could stop pedalling horse poop about something you have no clue about.
I hate Apple as a company but they’ve done the right for many years regarding gapless playback - at least with Apple Lossless and AAC. Long before the iphone was ever a thing, ipods were probably the only mainstream portable devices that had proper gapless playback support when used with AAC files.
Geek software written by music geeks always handles things like Gapless better than a Mega-Company seller like Apple.
I was about to fire up EAC to generate a CUE sheet, and then remembered last time I looked at this. So instead I now run away and leave you with a help page on EAC and Gaps