What is M4A

MPEG-4 Audio (M4A) is a container format managed by Motion Pictures Experts Group. It is actually an audio-only compression file and a filename extension created as a subtype of the MP4 extension. M4A is developed to distinguish from MP4 which contains both video and audio data since it has been widely introduced by Apple iTunes and iPod, specified to handle audio formats only.

Typically, audio with the M4A file extension is encoded with AAC (Advanced Audio Coding) lossy compression and Apple's ALE/ ALAC lossless compression. So the major music hardware support for AAC has been growing commonly and indeed, AAC M4A is the default format for the hot gadgets, including iPad, iPhone, iPod, iTunes and more.

Generally, compared with MP3, M4A is partially designed to replace MP3 (MPEG-3 Audio) as the most popular audio format, with advantages like higher quality, low bitrates and file size.

Advantages and Disadvantages of M4A

Pros:

• M4A is a compressed file with lossless quality that renders users smaller file size with original sound quality. (An M4A file with ALAC codec has the best original sound quality. Even AAC M4A delivers better quality than MP3 audio at the same bit rate.)
• M4A audio can be directly set as iPhone ringtone by resetting the file extension from M4A to M4R (the specified format of iPhone Ringtone) with iTunes.
• As M4A is an unprotected audio file ---has no Digital Rights Management (DRM)protection, it can be edited and transferred more smoothly and flexibly.

Cons:

• Poor compatibility: only be well recognized by iTunes, iPod and other Apple devices and can't be widely played on many other mainstream devices or popular media players.

Compatible Devices and Players

• Apple Devices: iPhone, iPad, iPod, etc.
• Apple Media Players: iTunes, Quicktime.
• Other Limited M4A Players: Windows Media Player, VLC, Roxio Popcorn, etc.