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

iTunes10On 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.

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.

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Top Rated Comments

arn Avatar
179 months ago
The main advantage of using competing lossless formats is that they are supported by ALL devices. ...even ipods and iphones!

This is wrong. iPods and iPhones don't support FLAC other lossless formats, unless you are talking uncompressed.

arn
Score: 50 Votes (Like | Disagree)
arn Avatar
179 months ago
Can someone explain what "half as much" means? I though the ALAC didn't create fidelity loss. Or is some compression possible without such?
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
Score: 40 Votes (Like | Disagree)
JonathanK81 Avatar
179 months ago
The main advantage of using competing lossless formats is that they are supported by ALL devices on any platform.
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.


Can someone explain what "half as much" means? I though the ALAC didn't create fidelity loss. Or is some compression possible without such?
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.
Score: 23 Votes (Like | Disagree)
arn Avatar
179 months ago
Android's market share has long surpassed that of iOS. I'd say theres little debate over which open source format will have more success.

Not to start a platform argument, but Android's marketshare may be bigger than the iPhone's. But if you include all iPods (non iOS ones), iPod Touches, and iPads, that market size is certainly still bigger than Android. In terms of devices which support ALAC.

arn
Score: 20 Votes (Like | Disagree)
batchtaster Avatar
179 months ago
Good news for widespread support, but one wonders why Apple didn't just go with FLAC in the first place.

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?

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.

Fixed.
Score: 18 Votes (Like | Disagree)
*LTD* Avatar
179 months ago
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.
Score: 18 Votes (Like | Disagree)