File Formats

There are any audio file formats in coarse use. There are fewer video file formats, but audio video file extensions can be confusing. This is just a brief description of what the more commonly used audio and video file formats and systems are.

Aac:Advanced Audio Coding This is the audio file format used by Apple for the iTunes Music Store, and it may appear with the M4A filename extension. It is best than Mp3 for sound quality. It was industrialized as part of the Mpeg4 group owned by Dolby (see below).

Au: This audio file format is the proper used by Java, Sun and Unix.

Mpeg: arresting Pictures specialist Group There are a amount of Mpeg types now, described below.

Mpeg-1: This is used in digital cameras and camcorders for small video clips. Vhs ability playback can be unbelievable from Mpeg-1.

Mpeg-2: Used for digital satellite Tv, pro movie recording and recording of home Dvd recordings. Provides provision for multi-channel surround sound recordings.

Mpeg-3: Mpeg-3 was suggest as an entity, but ultimately merged into Mpeg-2.

Mpeg-4: This is the newest Mpeg law and is used for streaming internet content. It is also used in movable video recorders and for internet downloads. Required for DivX. It improves digital broadcasting and interactive graphics and multimedia.

Mp3: Digital audio files, most commonly used to store and playback music. It compresses the files to about 10% of a normal audio file, and a normal music track will be about 5 -6 Mb in size. Mp3 stands for Mpeg-1 Audio Layer 3, not Mpeg-3 as many habitancy think. A typical Mp3 audio file is near Cd quality.

Ogg: An audio file format supporting a collection of codecs, the most beloved of which is the audio codec Vorbis. However, Mp3 files are much more broadly supported than Vorbis.

Ra: Real Audio This format is designed for streaming audio over the Internet. It is a self-contained file format with all the audio facts stored within the file itself.

Wav: The simplest of the audio file formats, industrialized by Microsoft and Ibm, and built into Windows 95. It is an uncompressed audio file format with large file sizes (10 x Mp3), and does not need added processing to play. The Wav file consists of three blocks of information: The Riff block which identifies the file as a Wav file, The Format block which identifies parameters such as sample rate and the Data block which contains the actual data, or music sample.

Wma: Windows Media Audio A digital law invented by Microsoft, and is used in movable digital audio players. Using Wma, a file can be programmed so that it cannot be copied, and can be used to safe copyright.

Wmf: Windows Media Format These are audio-video files comprising Wma and video codecs. They contribute high ability and media safety for streaming and download and play applications on computers.

Wmv: Windows Media Video Used in the Windows media Player, this is used to stream and download and play audio and video content.

When dealing with audio and video file formats, you will sometimes consideration the term 'codec'. A codec is simply short for encoder-decoder (or compressor - decompressor). A main function of a codec is to compress audio or video data streams so that transmission of digital audio samples and video frames can be speeded up and storage space reduced.

The objective of all codecs is to cut the file size to a minimum while maintaining audio and video quality. A quick indication of the codec's place in the path of transmission and reception is:

Video device (e.g. Camcorder) - video capture card - video digitized - codec (compresses digital info) - result (Mpeg2, Avi, Wmv etc) - codec (decompress) - video frames - display device.

Between the two codecs the compressed result is transferred to the display device transmitted, stored on file, etc). So to preserve the flow even further, we could basically reveal it as:

raw data - codec - send - codec - play

This is simplistic, but it shows where the codecs are used. Therefore, in order to play a movie, video or piece of music of a obvious format, you need a codec in your computer to allow you to decompress the file and play it.

Here is some free software which checks what codec a video law uses, and what codec your law needs to play it:

Codec Tool.

The separate video file formats are required to meet the requirements of assorted video devices. Similarly, audio file formats are designed to meet the needs of the specific delivery methods and storage and playback devices introduced by large corporations such as Microsoft, Sony and Apple. Thus, Sony invented the Umd (Universal Media Disk) for the Psp (Playstation Portable), and Apple introduced Aac (M4A) for its iPod.