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Apple's Lossless Audio Codec (ALAC) Now Open Source

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Apr 12, 2001
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On MacOSForge, Apple has announced that they are releasing the Apple Lossless Audio Codec as an open source project:
The Apple Lossless Audio Codec (ALAC) is a lossless audio codec developed by Apple and deployed on all of its platforms and devices for some years now. Apple is making the Apple Lossless Audio Codec (ALAC) available as an open source project. Full details can be found on the Apple Lossless Audio Codec project page.
Click to expand...
The Apple Lossless Audio Codec is a similar to other "lossless" codecs such as FLAC which offer audio compression without any loss in audio information. ALAC is said to compress files only by "about half" as compared to the originals.

Formats such as MP3 and AAC are considered "lossy" and result in much greater compression but at the cost of some fidelity. The main advantage of using ALAC over competing lossless formats is that ALAC is supported by all of Apple's iPods and iOS devices. The format had already been reverse engineered prior to this release, but this opens the door to even more products supporting both ALAC creation and playback.

The project has been released under the Apache license.

Article Link: Apple's Lossless Audio Codec (ALAC) Now Open Source
 
Article Link
https://www.macrumors.com/2011/10/27/apples-lossless-audio-codec-alac-now-open-source/
The main advantage of using ALAC over competing lossless formats is that ALAC is supported by all of Apple's iPods and iOS devices.

This is key. And especially appropriate considering how massive the iOS ecosystem is.
 
*LTD* said:
The main advantage of using ALAC over competing lossless formats is that ALAC is supported by all of Apple's iPods and iOS devices.

This is key. And especially appropriate considering how massive the iOS ecosystem is.
Click to expand...

The main advantage of using competing lossless formats is that they are supported by ALL devices on any platform.

This is key. And especially appropriate how massive the market share is compared to a single device centred around the closed source iOS.
 
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*LTD* said:
The main advantage of using ALAC over competing lossless formats is that ALAC is supported by all of Apple's iPods and iOS devices.

This is key. And especially appropriate considering how massive the iOS ecosystem is.
Click to expand...

In reality it should be able to be supported on just about anything now.

Of course the FOSS nerds will still complain about patents.
 
wikus said:
The main advantage of using competing lossless formats is that they are supported by ALL devices. ...even ipods and iphones!
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This is wrong. iPods and iPhones don't support FLAC other lossless formats, unless you are talking uncompressed.

arn
 
This is fantastic news.

The most popular lossless compression standard in general use is FLAC, and there's long been a debate in audio circles whether ALAC should be used - given that it's format has been proprietary.

There's little to choose between them on a technical basis - although ALAC can be decoded on lower power devices.

Hopefully by open sourcing ALAC, this will speed it's adoption on non-Apple hardware!
 
wikus said:
The main advantage of using competing lossless formats is that they are supported by ALL devices on any platform.
Click to expand...

They're not. Many devices do not natively support FLAC. iOS devices will natively support ALAC, so that will outnumber "all devices" as you put it.


ParisParamus said:
Can someone explain what "half as much" means? I though the ALAC didn't create fidelity loss. Or is some compression possible without such?
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It doesn't create loss in sound. It's a lossless format. What they mean by compression is the file size. So if the original file is 30MB, ALAC compression will make it 15MB in file size but still sound like the original, with no loss of audio.
 
illegalprelude said:
You would hope that Apple would then move all files from iTunes Match to ALAC and not 256kps..
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That'd be nice, but don't see it happening. Just so much bandwidth for people downloading the files from the cloud. Interested to see if this means anything that would affect me. I don't use ALAC anymore because I'm running out of space on my classic so I encoded all my ALAC to 320 AAC, so can't imagine it really will.
 
ParisParamus said:
Can someone explain what "half as much" means? I though the ALAC didn't create fidelity loss. Or is some compression possible without such?
Click to expand...

Sure, of course, some compression is possible without data loss. ALAC files are roughly 50% of uncompressed.

.zip is lossless. If it wasn't all your programs would break after going through compression/decompression.

Think of this: AAAAAAAA compresses to 8A which can be uncompressed to AAAAAAAA without any data loss.

arn
 
Jonathan360 said:
They're not. Many devices do not natively support FLAC. iOS devices will natively support ALAC, so that will outnumber "all devices" as you put it.
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You can get FLAC to work on all devices but it takes effort, something that almost everyone doesn't want to exert when most have no idea what lossless even means.
 
Jonathan360 said:
They're not. Many devices do not natively support FLAC. iOS devices will natively support ALAC, so that will outnumber "all devices" as you put it.
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And apple does not support the more popular FLAC format, or any of the other open source formats (OGG?). Cowon (iAudio) for example supports a lot of the formats. Their J3 and S9 mp3 players completely trounce any iPod ever released.

I dont see why apple cant offer support for FLAC when the others can if they so chose to.
 
In my experience the bit rate of Apple Lossless ranges from about 790-1050 kbps (but generally closer to 1000 kbps... my computer's not in front of me right now). Half of AIFF/WAV/LPCM/yougettheidea would be a stretch.

It would be nice if they smartened up and offered lossless on their store (at least as an option). There are a few albums I'd even pay double for a 24 bit, 48 KHz version of (or 96). Yes, most people don't have the ears or equipment to sort of surpass the current level of "audio transparency", but some of us do.

In terms of audio fidelity, the Compact Disc was a step backwards from vinyl. ~20 years later, 128/256 kbps AAC through the iTunes store once again was a step back. We have phones and such that are absolutely unreal nowadays, so why should audio reproduction be such an afterthought?
 
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Jonathan360 said:
It doesn't create loss in sound. It's a lossless format. What they mean by compression is the file size. So if the original file is 30MB, ALAC compression will make it 15MB in file size but still sound like the original, with no loss of audio.
Click to expand...

Indeed. A year ago when I was choosing between an iPhone 4 or a Droid X, one of the reasons I went with the 4 is because the Droid X doesn't support Lossless audio.
 
KnightWRX said:
Good news for widespread support, but one wonders why Apple didn't just go with FLAC in the first place.
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As with most things Apple, presumably because they thought they could do better. They don't tend to do anything that they don't think is an improvement on something that already exists. If I recall correctly, isn't ALAC about half the file size?

wikus said:
The main advantage of using competing lossless formats is that they are supported by ALL devices on any platform*.

* actual value of "all" and "any" may vary.
Click to expand...

Fixed.
 
arn said:
Sure, of course some compression is possible without data loss. ALAC files are roughly 50% of uncompressed.

Think of this

AAAAAAAA

compresses to

8A

which can be uncompressed to

AAAAAAAA

without any data loss.

arn
Click to expand...
Interesting example, but yes you can compress WAV files. Not every audio file has the same amount of data in it. For example, songs with a lot of silence won't have as much information and don't need to be a constant huge bitrate to include the data. It's similar for mp3s as well. If you use the LAME encoder and set to V0 (high quality VBR) instead of 320kbps you can get much smaller files with almost no loss in audio quality. I've seen 96kbps vbr mp3s that are basically as good as 320kbps mp3 just because there are huge gaps of silence. Obviously there is always data loss with mp3 though. With ALAC I've seen 400ish kbps and over 1100kbps. WAV just maximizes the bitrate throughout giving parts of a song a lot of data where there basically isn't any need and same with with 320mp3 vs VBR.
 
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