MP4 - How MP4 Works

MP4 is the latest generation of portable entertainment devices which are capable of playing video as well as audio and are generally referred to as MP4 players. So, what is MP4, how does MP4 work and how is MP4 different from MP3?

How MP4 Works

MP4 means 'MPEG-4 part 14' and is a container format for a variety of multimedia content including video, audio, subtitles and still images. The 'MPEG' part of MP4 stands for Motion Picture Experts Group, a coalition of industry members responsible for setting technical standards for digital audio and video.

Contrary to popular belief, MP3 does not mean MPEG-3 - there is no such format. MP3 actually stands for MPEG-1 Layer 3.

MPEG-4 was built on technology developed for the Apple QuickTime format. It is specifically designed for data 'streaming' - transmitting data streams which can be viewed and heard on the receiving device (usually a computer connected to the Internet) in real-time. It supports a number of different formats for video (MPEG-4, MPEG-2, MPEG-1), audio (MP3, MP2, AAC), still images (JPEG, PNG) and subtitles.

MPEG-4 is designed to be expandable so it can be adapted to include new technologies as they are developed. As a container, it can be scaled for various data transmission rates. This means that it is useful for most types of streaming from dial-up modems to Ethernet networks.

Although streaming is the method of delivery, MP4 files can be stored for later use. This makes the format suitable for portable devices of which a number of new models are hitting the market. MP4 players are the new wave of portable entertainment devices allowing consumers to watch videos virtually anywhere.

Since MP4 is not limited to video, MP4 players are also used for listening to audio files. They tend to be a bit bulkier than MP3 players because of the bigger screen required for viewing videos.

MP4 players usually have a hard drive because the storage requirements for videos are quite high. The hard drive can also be used to store computer data and the unit behaves as a removable hard drive when connected to a computer.

MP4 files are recognized by the file extension .mp4, although a number of other extensions are also used. Audio files usually have an .mp4 or .m4a extension and video can use the .mp4 or .m4v extension. Video files are sometimes saved as .mp4v files.

Does MP4 mark the end of MP3? Not really, because MP4 supports MP3. But MP3 is starting to show its age and other formats such as WMA, AAC, Ogg Vorbis and MP3 Pro offer similar sound quality with smaller file sizes than MP3.

Your MP3 player is not about to become obsolete because you can continue to encode audio files in whatever format you wish. But if you are looking to expand your portable entertainment so that it includes video, you may find yourself eyeing a new MP4 player in a year or two. By that time, they are sure to be a mainstream item.