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View Full Version : Going to do an ABX this weekend between ALAC and FLAC



mrtaber
2006-05-18, 08:53
I know, I know, they both are lossless. However, ALAC is transcoded on the server to AIFF, while FLAC can be transcoded to WAV on the server, or decoded directly on the Squeezebox.

It's the transcoding (using this 'mov123') that I want to test. Can I hear a difference? My brother (an audio producer) will be setting up the playlists for me--and he's going to let me set up playlists for him.

I don't know why I'm even posting this; I guess, since I love my Squeezeboxen, I hang around this forum alot, and I felt like sharing ;)

If anything interesting comes up, I will post that, too. I don't have an audiophile setup, by any means (I use the Niro [as in Niro Nakamichi] little surround sound setup he's selling these days). It's quite good, actually, on jazz and classical; it requires some adjustment for dense rock, electronica, etc. And it is really nice on movies, without devouring my whole living room in cables and equipment.

Mark :)

cepheid
2006-05-18, 13:07
I know, I know, they both are lossless. However, ALAC is transcoded on the server to AIFF, while FLAC can be transcoded to WAV on the server, or decoded directly on the Squeezebox.

Just so you know, AIFF and WAV are both uncompressed formats, and they're both just wrappers for PCM data. The difference is that WAV is little-endian while AIFF is big-endian, and they use different headers. The data they contain should be identical however. (And when I say identical, I mean actual identical bits, just in a different byte-ordering. ALAC and FLAC are not identical although they should decompress to identical files, but AIFF and WAV are, essentially, as close as you can get to being identical without actually being duplicates.)

If you hear any difference between the formats it would be due to bugs in the decoders, not differences in any of the file formats. Do know that there is a bug that affects ALAC files that causes the first few tenths-of-a-second to be cut off from songs. A similar bug affects FLAC that causes the last fraction of a second to be skipped.

mrtaber
2006-05-18, 13:49
Thanks, Cepheid. Yes, I was aware of the ALAC and the FLAC bugs (I voted for the one!). I'll mainly be listening for decoder differences. I don't have golden ears (I'm 48, so silver...perhaps tin by this time), though my brother does.

My main concern (if you can call it a real concern) is mov123. What exactly does this do? Does it do the decoding itself? Or (as I suspect) does it pass the data off to the actual decoder (Quick Time in ALAC's situation)?

I'm seriously considering ALAC (multiple iPods, building a complete Apple solution at home). That's why I'm doing the ABX. My FLAC sounds very good. I want to make absolutely sure that, for my ears, I'm not stepping down with the ALAC/mov123 combination.

I ought to start another thread about how much my Squeezeboxes have changed music listening at my house. Before, digging through 100's of CDs for something to listen to, etc., etc. I just quit, basically. I listened 99% of the time on my iPod(s). Now, I have music on all the time--especially with MusicIP Mixer's kick*ss playlist creation. I love my 'Boxen!

Thanks,
Mark :)

andyg
2006-05-18, 13:57
Source code for mov123: http://svn.slimdevices.com/trunk/tools/mov123/

It uses Quicktime libraries to do the actual decoding.

Mark Lanctot
2006-05-24, 14:52
Well, the weekend's come and gone. What were your findings? :-)

ModelCitizen
2006-05-24, 15:48
I know, I know, they both are lossless. However, ALAC is transcoded on the server to AIFF, while FLAC can be transcoded to WAV on the server, or decoded directly on the Squeezebox.
It's the transcoding (using this 'mov123') that I want to test. Can I hear a difference? My brother (an audio producer) will be setting up the playlists for me--and he's going to let me set up playlists for him.
I don't have an audiophile setup,
Can we take bets on this? A pony goes on you cannot tell the difference in sound quality.
MC

mrtaber
2006-05-24, 21:28
Sorry, had to postpone the test, since work got really busy really quickly. I'm thinking the results should be consonant with chance--i.e., I can't tell the difference. One good thing did come out of the postponement, though. I'm typing this from my brand new 17" MacBook Pro. I'm loving it. Anyway, I will post some results, when I have some to show.

Mark :)