What Is the Difference between MP3 and MP4?

The Internet is filled with content that is either audio or a mix of audio/video and multimedia. The files and sites that contain this type of information are often quite large and consume a large amount of bandwidth. More bandwidth consumption leads to slow transfer speeds between sender and receiver. Compression techniques help in reducing the size of the files so that transfer rates are decreased. MP3 and MP4 are designed to compress certain types of files.

MP3 and MP4 are specific CODEC’s that were designed to deal with compressing and decompressing files that contain audio and audio/video/multimedia content, respectively. MP3 was released in 1999 and MP4 in 2003. The rules for how the files are compressed and uncompressed are all contained in the CODEC.

During the compression of MP3 files, audio information contained within the file is lost. The lost information is out of normal hearing range, therefore although some sound quality is lost, most listeners can’t tell the difference. The audio produced by a file that has been converted to an MP3 file still sounds like a faithful reproduction of the original file. The compression performed by the MP3 CODEC reduces the original audio file by a factor of 11. MP3 file conversion has the ability to limit the quality of the audio information by setting the amount of storage space that is used per second of audio content. By setting the “bit rate”, as it is called, to a lower value, the sound quality falls off. The values that are available for setting the bit rate during compression are between 16 and 320 kbps. The most common rate used is 128 kbps.

Difference Between MP3 and MP4

The MP4 CODEC is used primarily for the compression of multimedia content and video with audio content. Movies are a great example of the types of content where MP4 file compression is applied. Many satellite providers have used MP4 compressed files to transmit on their feeds. The equipment at the subscribers end then decompresses the MP4 in the hardware of the tuner and displays the movie or programming. There are two different types of MP4 CODEC available. The “Simple” version is mainly used for transmission of low quality video and audio via the Internet. The more complex CODEC for MP4 is called MP4 AVC. This CODEC is used for the transmission of faster high quality information such as HDTV.

Using MP3 and MP4 Files

In order to view either MP3 or MP4 information, you must use a piece of hardware equipped with the ability to decompress the data and play the resulting files. Many handheld MP3 players are available on the market and the expansion of the technology has allowed most car stereos to play MP3 CD’s as well.

MP4 players contain hardware that is able to take the MP4 compressed file and decompress it before playing it for the user. The creators and designers of MP4 envision that it will be capable of transmitting information for use in video telecommunications, video email and cordless video cameras. Hardware is the easiest way to deal with these types of content because there is no need for human intervention to accomplish the task. Software is another option for those hoping to make use of the MP3 and MP4 type files. By loading specially designed software onto your computer, you can play and view the content contained in the compressed files. To see a practical example of how useful MP3 is, look at the number of song tracks that can be stored on a normal CD. A CD is able to store 685 MB of data. One disk this size can hold the complete average audio tracks of at most about 13 songs.

If you use MP3 compression and save the files on the CD in MP3 format, the disk will hold approximately 105 song tracks. Assuming each track is 3 minutes long, 13 songs would amount to 42 minutes of audio pleasure with a standard CD but using MP3 compressed files it would amount to 5 hours and 15 minutes. This assumes, of course, that your car stereo is capable of playing MP3 files.