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Lossy Audio Compression => AAC => AAC - Tech => Topic started by: proun on 2010-11-22 11:29:42

Title: FLAC Conversion to Apple Lossless
Post by: proun on 2010-11-22 11:29:42
Hi, I was wondering if somebody could answer some questions for me.

I have a library of FLAC files and wanted to convert them to Apple Lossless

The way i have done this so far is convert them from FLAC to AIFF using XLD and then once they have been added to iTunes from XLD in AIFF format
I convert them to Apple Lossless using iTunes encoder.

Question #1: Am I losing quality doing it this way? (FLAC > AIF > ALAC)

Now, I know I can convert from FLAC to Apple Lossless directly in XLD but when I did a comparison test some of the files were smaller than when i did it the other way... for example

when doing it the first way (FLAC> AIF> ALAC) - using XLD & iTunes was 906 kpbs
and the second way (FLAC> ALAC) - using just XLD it was 859 kpbs

Any comments, suggestions or opinions on this?

Thanks!

Title: FLAC Conversion to Apple Lossless
Post by: Stephan37 on 2010-11-22 13:17:13
Hi!

I've done this before using dbpoweramp, which can do it just fine, i.e. keeping all the tag info in the files (except album covers).
I know it's not free, but I think it is a very solid piece of software for any ripping/conversion.

By definition BOTH Flac and Apple Lossless are lossless - so there shouldn't be any loss whatsoever. At least none to worry about as far as I'm concerned.

Hope this was helpful!

Stephan

Title: FLAC Conversion to Apple Lossless
Post by: mixminus1 on 2010-11-22 14:54:30
I haven't done the iTunes/XLD ALAC comparison myself, but my guess is that XLD may be passing slightly different parameters to the ALAC encoder than iTunes does in order to get better compression (just like with FLAC where you can specify a compression level from 0 to 8, as well as many other parameters if you so desire).

Regardless of whether that actually is the case or not, a very easy way to verify that XLD is compressing losslessly is to take an ALAC created in iTunes from an AIFF, and an ALAC created directly via XLD, decompress them both to WAV/AIFF in iTunes, and then do a binary comparison of the two PCM files using the "cmp" command from Terminal.
Title: FLAC Conversion to Apple Lossless
Post by: ramicio on 2010-11-24 19:28:17
I have (and continue to) used dbPoweramp to transcode FLAC to ALAC and FLAC to AAC and with both resultant formats it has kept every bit of tagging information and album art that was present in the FLAC's tag.
Title: FLAC Conversion to Apple Lossless
Post by: greynol on 2010-11-24 19:30:21
I think he's looking for a native application instead of one that runs on Windows.
Title: FLAC Conversion to Apple Lossless
Post by: ramicio on 2010-11-24 19:34:02
I see now that he is on Mac.  Maybe find a nice friend with a PC to transcode all of your files so you don't have to deal with the headache.  I would say it probably has to do with parameters being passed onto the encoder, as well.  I would maybe check the checksums of a decompressed FLAC vs. a decompressed FLAC>ALAC and FLAC>AIFF>ALAC.