ITE 210 - Fall 2011 - Chapter 6

Article Review: “After seven years, Apple open sources its Apple Lossless Audio Codec”

By Chris Foresman

http://arstechnica.com/apple/news/2011/10/

Compression is a technique that reduces the number of bits used to encode data, such as a file or stream of audio from the Internet. Compression can be either lossless, meaning it doesn’t change from the compression/decompression process, or lossy, meaning it does. MP3, a common standard for audio files, is an example of lossy compression and is used because it speeds up download times without a noticeable change for most people.

This article is about Apple’s Lossless Audio Codec (ALAC) that was introduced in 2004 with iTunes 4.5 and is supported on all Apple’s iPod and iOS devices. It is similar to an open lossless format, Free Lossles Audi Codec (FLAC), but it uses an MPEG 4 compliant QuickTime container. Apple has now made the code for the encoder and decoder open source through the Apache 2.0 open source license.