Missing iTunes 4.5 feature
When I looked this morning (5:45am CDT), iTunes 4.5 was supposed to have a feature that would eliminate gaps between songs when playing (like w/ compilations/mix CDs). The picture on apple.com showed a grouping line where the checkbox to the left of the song name now is. Now I see no mention of it, either on the web site or in iTunes itself (can't figure out a way to make it work).
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Handy Concept for Concept Rock
Many music CDs contain songs that blend into each other, and importing them to iTunes may create a small gap between songs that interrupts the flow. If you use the iTunes Join Tracks feature, the program melds two or more songs into one, continuous gap-free track. So now you can enjoy listening to classical music, concept rock albums and extended dance mixes without the silent treatment.
http://www.apple.com/itunes/import.html
It sounds like the same old "join" feature with an updated UI.
Originally posted by Wrong Robot
can you do this with already imported music? I just bought an album from iTMS(Stravinsky) it has like 30 tracks but they are all parts of bigger pieces, do I have to burn to disc then reimport if I want to join tracks?
If you want this problem fixed, please join me with feedback to Apple asking that they work on it.
Unless you have the original CD in hand, you can't properly fix the between-track gap problem yourself.
(For those tempted at this point, please DO NOT erroneously suggest that the iTunes CROSSFADE feature solves the gap problem).
Merely burning and reimporting music won't do it. With some effort using an audio editor, and with a generational loss of sound quality if you recompress your edited results, you can get rid of gaps, but this is far from a satifactory solution.
The problem is padding. For technical reasons, AAC, MP3, and most other lossy codecs add tiny bit of silence to the beginning and ending of every encoded audio file. The little dropouts you hear when one track is supposed to flow into the next are caused by that padding.
By joining tracks when you rip a CD you create a single file that still has padding at its start and end, but no padding between the joined tracks.
The problem with some music on iTMS, however, is that it has already been ripped as separate tracks, and already has padding added in. To fix such tracks, you not only need to burn them and re-import them, but re-import them as AIFF, then carefully edit and join the reimported AIFF tracks where needed, and then live with either very large AIFF files, smaller but still very large "Apple Lossless" files, or re-encode to AAC or another such format, suffering a generation loss in sound quality.
There are ways that ACC, MP3, and other such formats can be extended so that padding is hidden and joins between tracks can be made seamless, but Apple (nor anyone else that I know of selling music online, for that matter) hasn't implemented any such extentions, and even if they do, they'd need to go back and fix the gap-plagued tracks that are already on the store (which will only help future buyers, not past buyers).
Originally posted by BuonRotto
Isn't this a limitation of the file technology? That is, AIFF files and CD-A files are gapless but MP3's, AAC, apparently Apple lossless, etc. are simply unable to do this? I thought I heard that somewhere.
I haven't tested it, but I would think that Apple Lossless should work as well as AIFF for gap-free playback. Such files are supposed to expand to exactly the same audio data as the source data, so there shouldn't be any padding. Besides, I don't think the "frame" concept, which applies to lossy encoders and leads to padding and gaps, even makes sense in the context of Apple Lossless or other FLAC-like encoders.
There are solutions, but Apple has to decide implement them, and has to do it on both the encoding and decoding side of the equation, with iTMS support, with iTunes support, and with iPod support. Unless Apple hears a loud and clear demand for solving the gap problem, I don't know if they'll bother to do any of this.
There might be some single-ended, playback-only solutions, but such single-ended solutions can't work as well as implementing extensions to lossy file formats, designed specifically to support gapless placback.
You should be able to import your whole CD as one track then have it separated into many different "start/stop" sections. For instance, when you hit Get Info on a track you can tell it a time to start and a time to stop...well imagine this but have there be multiple times for the one whole track. That way you can divide one big audio file into sections if you want to hear just 1 song or you can play it continuously with no gaps.
Originally posted by PBG3
I have a good idea.
You should be able to import your whole CD as one track then have it separated into many different "start/stop" sections. For instance, when you hit Get Info on a track you can tell it a time to start and a time to stop...well imagine this but have there be multiple times for the one whole track. That way you can divide one big audio file into sections if you want to hear just 1 song or you can play it continuously with no gaps.
This is the idea behind CUE sheets. EAC for example on Windows creates such cue sheets that has start/stop information that can be read by Foobar2000 or Winamp. There is apparently nothing similar available for Mac at the moment..
PBg3, yours is an idea I remember wishing for last time iTunes had a major update, It just so happened that at the time I was working on separating one really big long track and I would have loved that feature.
If this padding is really the issue, and is inherent in all compressed mediums, what solution could there be? is the padding determined by song length? or is it a fixed value, if it's a fixed value the solution would be really simple, but if it varies, I'm not sure what could be done
(this is a feature I've wanted in iTunes for a while that has finally be included)
the little gray arrows that link you to the iTMS from your library, when option+clicked, they jump you to that song/artist/album in your library.
just fyi
Originally posted by Wrong Robot
If this padding is really the issue, and is inherent in all compressed mediums, what solution could there be? is the padding determined by song length? or is it a fixed value, if it's a fixed value the solution would be really simple, but if it varies, I'm not sure what could be done
Perceptual encoders like AAC and MP3 break music down into "frames", which, just like video frames, have a fixed duration. If each frame is, say, 1/50 sec., then all music which doesn't have a duration which is exactly divisible by 1/50 will be padded to fill an exact number of frames. Most songs would have an average 1/100 sec. padding added to fill out such a frame size evenly.
In addition to filling out an even number of frames, some silence is typically added to the beginning and ending of each track, which I think sort of "primes the pump" for the encoding algorithms.
The simplest way to get rid of this padding on playback is to have saved information in the audio file's header which specifies the exact sample positions where the "real" audio data begins and ends, allowing you to skip around the padding.
I'm guessing that you might want to have a little more help than just these exact start/stop sample positions, however, to ensure a seamless joining of two separate tracks. Since perceptual encoding does not render an exact duplicate of an original audio signal, I imagine there might be a possible audible glitch when the last inexact sample value of one track meets up with the first inexact sample of the next track that it's meant to flow into.
Saving just a tiny bit of uncompressed lead-in and lead-out signal should be able to fix this problem -- maybe just one frame's worth at either end of the file would be enough, not anywhere near enough to make a substantial impact on file size. I'd think that crossfading this uncompressed data with the compressed data at the beginning and ending of track playback would do nicely to create a smooth inter-track seam.
File header extensions for this kind of thing can be added which are simply ignored by older decoders, but used to full advantage by newer encoders which understand how to use the extra data.
Originally posted by Wrong Robot
interesting about the padding thing, I'd never heard of that, however(though my memory might fail me) I'm fairly sure I've used windows based machines that had no gaps inbetween tracks, while I can't remember if I'm making that up or not, the fact that many windows converts I have spoken to(including the 2 I live with) express a level of surprise that there is a gap at all.
As an experiment, I just ripped Dark Side of the Moon using Windows Media Player, ripping to WMA 9 at 128K.
I made sure that crossfade was turned off, and then scanned to just before the end of each track to listen how it sounded playing into the next.
A couple of the transitions sounded fine, a couple of them glitched with a sound like a small vinyl scratch, and one of the transitions was smooth in the sense of not producing a drop-out or click, but instead sounding like there was a beat missing somewhere.
My guess is that WMP is doing something, maybe like a tiny amount of crossover that you can't switch off, to try to smooth out inter-track seams -- but the trick isn't always successful.
Here's an article about gapless playback that I found. The article's focus is MP3 players, but the information is pertinent to playback software as well. According to this, the Rio Karma MP3 player does a pretty good job of faking gapless playback even without truly gapless source material. The Rio also supports the Ogg Vorbis format, which provides true gapless playback without tricks.
(I'm not sure when this article was written, but my 3G iPod certainly doesn't force a full second silence between songs during playback!)
Originally posted by Wrong Robot
the little gray arrows that link you to the iTMS from your library, when option+clicked, they jump you to that song/artist/album in your library.
Cool! Thanks for the info.
Originally posted by shetline
As an experiment, I just ripped Dark Side of the Moon using Windows Media Player, ripping to WMA 9 at 128K.
By experiment you mean you dont actually import with WMA on a regular basis right??? Please say yes.
Originally posted by ipodandimac
By experiment you mean you dont actually import with WMA on a regular basis right??? Please say yes.
I think this was perhaps the second time in my life that I've ripped a CD on Windows to any format. The first time I was trying to figure out if WMP would import to anything other than WMA.
Nothing to worry about here.
Originally posted by Jeremiah Rich
I have re-imported my collection this past week in Apple Lossless, and just tried a couple of tracks that run into another one, and it is still presenting a gap for me.....
Via iPod playback, or iTunes playback? I don't know that the iPod does gapless playback even with AIFF files. When I've gotten gapless playback from iTunes with AIFF, I've had crossfade turned off -- as opposed to being on but with a duration of zero.
If you're burning a CD, you have to make sure that the option which adds deliberate gaps between tracks is turned off, or there will be, of course, no hope of getting a gapless CD copy.
Even playing back through iTunes with the settings that worked for me with AIFF, Apple Lossless isn't giving me gapless playback.
This lossless format should easily be capable of being used for gapless playback, but it doesn't seem that anyone thought it worth the effort to make sure it would be gapless.
Barto