Sound File Formats

.WAV (or WAVE) is an uncompressed sound format, developed (or bought?) by the MicrosoftCorporation.

Microsoft Pulse Code Modulation format.

Resources: A compressed .Wav format is AdaptiveDifferentialPulseCodeModulation? (ADPCM, see http://www.bdti.com/faq/2.htm#23)

Other uncompressed SoundFileFormats are: .AU (Sun Microsystems) and .AIFF (Apple)

Well, you all know what way a sound can be pictured in a frequency curve. Wav, au and aiff files also represent the curve in an exact way, but, as a computer only can make discrete calculations, not in a continuous way, but cut up in tiny steps. Both the time, and the height of the curve is cut up in tiny steps. Sample rate tells what way the time is cut up. Bitdepth tells what way the height is cut up.


.MIDI is a format that is developed to make electronical instruments communicate. So not the sound itself is encoded, but the actions; what key is pressed, the duration of a tone, et cetera.

Midi Resources:
A .wav file is similar to a .bmp or a jpeg; it is a recording.

A .midi file is similar to a vector picture. You create a vector picture by drawing lines. You create a midi by playing an electronical instrument.

A midi and a wav are not 'played' in the same way; a midi is generated in a synthesizer, a wav is decoded from digital to analog.

When a midi is converted to a wav file, the midi file is played and the music is recorded as a .wav file. Similar if you write code to draw some lines, and save it as a bmp, not the lines are recorded, but the resulting picture is recorded.


Apart from these formats there are also compressed formats; MP3 is the best known nowadays. This is an MPEG format (MovingPicturesExpertGroup?). They use several smart algorithms, in three layers to encode a sound so they are experts indeed.

Streaming media Audio Files are huge. Streams make use of a buffer, so you can listen to a file, without having loaded the complete file. These streams are developed for use on on the internet extensions. Streams are also compressed.
Open format Many of these formats are or were encumbered by IP/TM/patent issues that restricted their use. Free equivalents include:
Also see:

AnonymousDonor, ThankYou so much for that link! -- KarlKnechtel


CategorySound

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