What is M4A, M4B, AAC format music file?
Definition of M4A, M4B, AAC file extension M4A: Files in .M4A format are actually the audio layer of (non-video) MPEG 4 movies. M4A is slated to become the new standard for audio file compression. This format is also known as Apple Lossless, Apple Lossless Encoder, or ALE. It is a new codec designed to provide lossless encoding in less storage space. M4B: Files in .M4B is 100 percent identical to .M4A, but just with different name. So, .m4b is, like .m4a, an audio file wrapped within MPEG-4 container format. The audio encoding can be virtually anything, but most collomly used encoding for both, .m4a and .m4b, files is the AAC. The only reason for the duplicate naming convention is so that the Apple’s iTunes software and iPod players can recognize the file as an audio book rather than a normal audio track and thus allow “bookmarking” the file. AAC: Advanced Audio Coding (AAC) is a standardized, lossy compression and encoding scheme for digital audio. AAC is promoted as the successor to
