The following copied from
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http://www.hydrogenaudio.org/forums/lofiversion/index.php/t38817.htmlAlex B
Nov 16 2005, 10:10
QUOTE(Otto42 @ Nov 16 2005, 05:22 PM)
When it comes to lossless formats, they *all* have gapless playback support, as far as the format goes. If it didn't, then it couldn't be "lossless".
Yes, the player itself has to have gapless support for it to work, and iTunes lacks that, but this has nothing to do with the format's support for "gapless". It's lossless. It's gapless by definition.
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ALAC files encoded with iTunes 5/QT7 or newer simply don't have gapless playback support at the moment. (Unless a player that I'm not aware of can do it.)
A couple of weeks ago when I tested the iTunes de-emphasis function I actually couldn't find any program that can play the current ALAC format besides iTunes and J. River Media Center, which uses the external QT engine for decoding ALAC files. (MC can play gaplessly only internally decoded formats.)
It is possible to convert the lossless & gapless ALAC files to wave (or AIFF) format with iTunes and play the converted files gaplessly with other players, but that would not be ALAC playback anymore.
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Edit: typo
davechapman
Nov 16 2005, 10:36
QUOTE(Alex B @ Nov 16 2005, 05:39 AM)
In practice, from the user point of view ALAC is not lossless at the moment, because there are no players that can play the current version gaplessly.
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The format itself provides everything a player needs to implement gapless, and there is an open source decoder available. So there is no technical reason preventing gapless ALAC.
Rockbox enables the iriver H1x0 DAPs to play back ALAC gaplessly. Ports of Rockbox to the iriver H3x0 and the iPod are in progress, and when they are finished, those devices will also be able to play ALAC gaplessly.
I thought foobar had an ALAC decoder, or was that abandoned?
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Otto42
Nov 16 2005, 11:13
QUOTE(Duble0Syx @ Nov 16 2005, 10:55 AM)
FLAC is supported on just about every player and is supported on every platform.
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I think you missed my point. People don't really need "cross platform compatibility" quite as much as they need "compatibility with the hardware that they have". Yes, it's nice that FLAC plays on lots of things. But if you don't actually have any of those things, then it's rather a moot point, isn't it? The Squeezebox is a fine device, and if I owned one, I might care about what it would play. I don't own one though. I do own an iPod, however.
QUOTE(Alex B @ Nov 16 2005, 11:10 AM)
ALAC files encoded with iTunes 5/QT7 or newer simply don't have gapless playback support at the moment. (Unless a player that I'm not aware of can do it.)
Which just points to what I said earlier. It's not the format, it's the player of that format.
AAC files encoded with iTunes lack gapless support in the format itself. There's a null padding on the beginning/end of the file and no indication of where that song actually begins/ends. Therefore it's actually *impossible* to play these files with true gapless support. In any player. Ever. Nero gets around this by a tricky bit in the MPEG4 wrapper, so Nero-encoded AAC files do support gapless.
Same goes for MP3 files. Gapless MP3 files are done by adding code to the LAME header which signals where the end of the song really is. The MP3 format itself pads the audio to an integer multiple of 1152 samples. Without that LAME header, MP3 is not gapless.
ALAC files encoded with iTunes, on the other hand, actually decode to the original data. Bit for bit. That's what lossless means. So if a player implemented gapless playback and could playback these files, then it could play them back gaplessly. The format itself supports gapless playback (as all lossless formats do).
Whether or not any player actually *does* this is irrelevant. The format itself remains unchanged whether a player implements it a certain way or not. If you say that the ALAC format does not support gapless, then you're just wrong. What you mean is that no current player will play them back gaplessly. But the format itself supports gapless, by design. Again, all lossless formats support gapless. They have to, they're "lossless".
And even then you're not entirely correct, as the open source ALAC format plugin implemented for foobar 2000 would support gapless playback, if it worked properly. I don't know what the status on that plugin is. It worked at one point, then there were issues with it. But nevertheless, it would do gapless, if it was working. It's the player, not the format.