[Rafal]

HI All,

I have my music archived in Apple lossless but would like to now have it archived in lossless uncompressed format (like aiff). If I convert the Apple Lossless to aiff will I have the same file (data) as if I were to rip the CDs directly into aiff? If so, it woudlsave me a lot of time.

Any help would be appreciated.

Cheers,
Rafal

[bside123]

HI All,

I have my music archived in Apple lossless but would like to now have it archived in lossless uncompressed format (like aiff). If I convert the Apple Lossless to aiff will I have the same file (data) as if I were to rip the CDs directly into aiff? If so, it woudlsave me a lot of time.

Any help would be appreciated.

Cheers,
Rafal

Rafal: I recently converted all of my Apple Lossless files to AIFF without any problem, except for the time it takes. The AIFF files are a little larger than the Lossless. The way that it was described to me is that AIFF are "unzipped" Lossless files. I now rip using AIFF directly. Sound quality is superb. Hope this helps. Din

[seadogs1]

Sorry to tell you this but I believe all you did was use up more memory. You CANNOT go from a lower format to a higher format. It would be the same as trying to convert a mp3 file to an aiff file.

[srb]

Sorry to tell you this but I believe all you did was use up more memory. You CANNOT go from a lower format to a higher format. It would be the same as trying to convert a mp3 file to an aiff file.

Apple Lossless or FLAC files are not a "lower" format.  They contain all of the bits that an uncompressed AIFF or WAV file does.  It is not the same as converting a compressed MP3 file to an AIFF file.

If the file conversion software is working correctly, the files will be bit-perfect.
 
Steve

[kittyboy]

You can do this and the files will be bit-perfect, but it's unnecessary, like storing a gallon of gas in a two-gallon jug...

[srb]

You can do this and the files will be bit-perfect, but it's unnecessary, like storing a gallon of gas in a two-gallon jug...

Actually it would be more analagous to storing a gallon of gas in a 1-1/2 gallon jug.
 
Steve

[bside123]

Apple Lossless or FLAC files are not a "lower" format.  They contain all of the bits that an uncompressed AIFF or WAV file does.  It is not the same as converting a compressed MP3 file to an AIFF file.

If the file conversion software is working correctly, the files will be bit-perfect.
 
Steve

This concurs with my understanding. An Apple Lossless file contains all of the bit information and is in no way a "lower format." For use with my DAC, it was recommending by the manufacturer to "unzip" or convert all of the music files to AIFF as an optimized format. Apparently the thinking is that the computer has "less to do" when playing back a file, such as have to unzip on the fly (is this vulgar?). Nonetheless, both Lossless and AIFF sound fantastic.

[skunark]

Aiff, Flac, alac, and wave all get "converted" to PCM or whatever format the dac supports in the end.  Flac and alac both have several key advantages since the current computing bottlenecks are disk io and network io and the CPU spends more times waiting on data the it does unzipping the file. But in the end audio is such a small amount of data, you would have to go out of your way to hurt the overall sound quality on a given system between formats.   If you stream data or use a NAS then you might experience data loss with any of those formats.  That is easy to detect as you can hear the music cut out.

[joeling39]

What is a good software to convert apple lossless to AIFF ?

Regards,
Joe Ling

[roscoeiii]

I have used max and was pleased with the quality of the conversion. And it is both free and very versitile

[Mike Nomad]

You can do it within iTunes. Go into Preferences, and under the General tab, change the import settings. You can then do a control+click (right mouse click) on any files in your library, and you will get an option in the context menu to create an AIFF version of the file (you can block select multiple files).

I've also used Max for comparison, and could not hear any difference.

[Johnny2Bad]

They're the same thing; that is they contain the exact same musical data, but store it differently.


So are AIFF and WAV. The differences between AIFF and WAV formats is not in the musical data they contain (they are identical) but in certain aspects of the file format. For example, one might have information at the beginning of the file, one at the end, but the actual music data is in the middle of the file.


The differences are in things you might call "housekeeping"; ie lets say AIFF and WAV formats want to store the file name. Both formats allow for that, places it where it's expected to be for a file of that type, and wraps that around the music data, which is the same in both. Note that "AIFF" (Audio Interchange File Format) is not an "Apple format"; it's an open format that Apple adopted 20+ years ago and was used, at the time, by every computer OS. Microsoft, for reasons you'll have to ask them about, invented their own audio format that contains essentially the same data as AIFF. "WAV" is a Microsoft format.


Lossless formatting is different from those two formats in that it does not store the music data itself, it stores information about the music data found in an AIFF or WAV file ( which itself is data about the original music). But, the music data can be completely re-constructed from that information, so you can always convert it to an uncompressed lossless format that stores the music data directly. Or, if you can play Apple Lossless directly, the reconstruction is done in real time, as you play, by the CPU. So, Apple Lossless or FLAC are smaller in file size, but you can always expand that to the original AIFF or WAV. Note that there is an older lossless format called "Shorten" that, for whatever reason, nobody really adopted; FLAC is not the Granddaddy of lossless compression, like some suggest.


A (crude) example of file compression:


Example:
[some song][2 minute space][another song], and its a megabyte per minute to store the data
Original Data = [continuous recording of 10 minutes] = 10 MB


We run it through the compression routine:
Compressed Data = [continuous recording of 4 minutes][2ms][continuous recording of 4 minutes]
"2ms" is the compressed format's code for "2 minutes of silence", so:
Compressed Data = 4MB + 16 bits + 4MB = about 8 MB


Compression reduces file size by 20%


De-compression:
Read 8MB of data; instruction is to add 2MB of silence between track 1 and track 2
Output: [some song][2 minutes silence][some song], make continuous
Uncompressed Data = [continuous recording of 10 minutes] = 10MB


Compare orignal to uncompressed = no difference bit for bit


Now, when i said this was a "crude example" I really meant it.


A format like FLAC is going to be compressing every aspect of the file at the data level. So, if the data is
10000011
… it's going to compress it to "xyz" which is the format's shorthand for "a one, five zeros, two ones", and might be represented as 01 00 11 and written:
010011 … instead of writing them out "longhand" as 10000011. The thing is one is shorter than the other and saves data, but the de-compression still knows that means "write a 1, throw in five zeros, and add two 1's" and gives the uncompressed output of:
10000011.
Note that this is still a crude simplification, but unless you want to write a compression program, you already know more than most if you get the concept outlined above. All you need to take out of this is one is shorter than the other (saves data) and you can still reconstruct the original from it. Voila: Lossless compression.


That's essentially how all file compression works, which is also why almost any two compression formats, assuming they're both lossless, pretty much end up the same size, more or less. You're not going to get a 10 MB file out of FLAC if Apple Lossless gets 80MB on a 100 MB file. You might get 69MB and 72 MB, but no huge differences. That's also why making a .zip file of a FLAC file is a waste of time ... the FLAC format already is as compact as possible. You could, if you wanted, make a .zip file of the uncompressed WAV file (for example). It will make a smaller file. But, your audio program won't be able to uncompress it in real time; the FLAC format is made to be quickly dealt with by an audio program. So you use the appropriate format instead. There's only so many ways to take out the redundant without throwing away data, which no lossless format will allow itself to do.


AIFF and WAV (again a gross simplification)
One format = [some stuff about file][continuous recording of 10 minutes][this is the end of file]
Other format = [this is the beginning of the file][continuous recording of 10 minutes][some stuff about the file]


My final gross simplification:
Lossy compression schemes change the music data itself, and throws away the stuff the developer of the format decides is unimportant.
What is important or unimportant is based on research that tries to discover which cues matter to the listener.


So, if it's found that in a loud passage most listeners can't discern high frequency information below, say, 50 dB, then they throw out all high frequency information below 50 dB. If it's found that that most listeners can discern high frequency information below 50 dB when the average level is only 40 dB, then they keep it under that condition. ** Don't read that to mean that's how an mp3 would actually decide on what to throw away ... it's just an example of the concept. If you get the concept, you don't need the details, and if you want the details, you can do more research on your own. **


In either case, the file size is lower (threw away data) and the cues that listeners use to discern "the music" remains. So, most people think it sounds OK. Note that there are lots of lossy formats ... some throw away less to preserve more cues (like a 320 kb/s format might) while others go for just legibility (like a 64 kb/s format might).


If you then put that file on a high resolution system, that can easily allow listeners to hear that original high frequency information during a loud passage even though the information is below -50dB in level, it still won't be there; it's been thrown away. Thus some listeners under some conditions will be able to discern the lossy compressed file is not as good as the original uncompressed format, and how often that happens depends somewhat on how aggressive the lossy compression is.


If they play it on a TV/DVD player combo, which can't really deal with that missing information in the first place, it still might sound OK to even a discerning listener. Thus mp3's for the $10 speakers (and I'm being generous here) that the average PC user has. Sounds "just as good", they might say. But that's not because the file format sounds "just as good", it's because the playback equipment can't resolve the difference, so even if it were present, it would still be missing on that system. And, if you get all that, it should be clear to you that what matters is not "compression" but whether it's lossless or lossy compression.

[tomjtx]

Johny2Bad,

That is the best explanation of lossy and lossless compression for the non-technical(me) that I have ever seen.

Thanks for that . It should be made a sticky.

[joeling39]

To all the contributors of this thread - thank u. This discussion has been helpful to me.

Regards,
Joe Ling