ALE

ALE (Apple Lossless Encoder) is an lossless audio format from Apple, also known as ALAC, Apple Lossless Audio Codec, or simply Apple Lossless. It will typically have a .mp4a extension.

features

• Supports: 16 & 24 bit, multi channel (such as 5.1) & high frequency audio
• Has iPod and iTunes support but limited support outside the Apple tool set.
• Stored in MPEG 4 container but so is AAC making it difficult to tell which you have.
• standard encoding but fast decoding
• Apple Lossless can compress CD quality audio file to roughly half its original size.
• normally played by Quicktime.

Thought to be based loosely on FLAC (Free Lossless Audio Codec) however Apple has not released any details on the format.

metadata

It is tagged using the Quicktime / Apple iTunes tagging format, a relatively simple tagging format, supports Unicode characters (UTF-8). Any ID tag name can be added. The maximum length of each tag value is 255 characters. Multiple artists, etc are supported as is embedded album art.