Mac Codecs & Encoders

A codec is a piece of software that encodes raw video or audio to reduce the file size for storage or transmission. Many codecs exist for this purpose, but most Apple media utilizes one of three specific Mac-friendly encoders for data compression. As these codecs have matured, they have found use outside of Apple-centric applications, and even Windows users rely on their formats from time to time.

QuickTime

The definitive Mac encoder is QuickTime. Originally developed in 1991, it features the ability to encode audio-only as well as audiovisual data in a variety of formats. QuickTime’s capacity to encode video in a framework suitable for streaming video led to its widespread adoption on the Web. QuickTime video typically uses the MOV suffix, but M4V can designate video and M4A audio. Today, the encoder includes many legacy formats, and you can use it to create many different types of files. In 1998, the International Organization for Standardization chose QuickTime as the basis for the MPEG-4 video standard.

Advanced Audio Codec

For audio, Apple utilizes the Advanced Audio Codec, or AAC file type. Originally introduced as a variant of the MPEG-2 codec, AAC was a lossy codec that nonetheless offered some advantages over the dominant MP3 format. AAC offers more frequency and sampling options than MP3, as well as greater compression efficiency to reduce file size without sacrificing more data. Apple adopted the AAC format for its iTunes music store, encoding the files with an additional layer of security and releasing tracks in with the suffix M4P. After consumer backlash about digital rights management issues, Apple eventually began releasing content in unencrypted AAC.

Apple Lossless Audio Codec

Apple also maintains a lossless audio codec, the Apple Lossless Audio Codec. Apple Lossless is similar to other lossless codecs in that its primary goal is to maintain all the audio fidelity of the original, uncompressed track, to allow decompression without any loss of data. ALAC-encoded files typically take up about half the space of raw audio data and utilize a simple decoding algorithm well suited for devices with limited processing power, such as iPods.

Other Codecs

In addition to Apple’s own codecs and encoders, Mac users can also take advantage of many other encoders on the market. MP3, MPEG and many other popular codecs are already part of QuickTime’s software package, and you can install many other non-Apple codecs simply by downloading the proper programs and installing them on your Mac. If you encounter a file that QuickTime can't play, check Show Movie Info under the Window menu to determine the codec you need.