Page 40 - DCAP303_MULTIMEDIA_SYSTEMS

Multimedia Systems

notes • .aiff — the standard audio file format used by Apple. It is like a wav file for the Mac.
• .vox — the vox format most commonly uses the Dialogic ADPCM (Adaptive Differential
Pulse Code Modulation) codec. Similar to other ADPCM formats, it compresses to 4-bits.
Vox format files are similar to wave files except that the vox files contain no information
about the file itself so the codec sample rate and number of channels must first be specified
in order to play a vox file. Vox a very old file type and is pretty poor. We do not recommend
it for anything except for supporting legacy systems.
• .raw — a raw file can contain audio in any codec but is usually used with PCM audio data.
It is rarely used except for technical tests.

Wave files encoded with a variety of codecs to reduce the file size (for example
the GSM or mp3 codec’s).

proprietary formats (supported by our software)

• wma — the popular Windows Media Audio format owned by Microsoft. Designed with
Digital Rights Management (DRM) abilities for copy protection.
• .aac — the Advanced Audio Coding format is based on the MPEG4 audio standard owned
by Dolby.
• atrac (.wav) — the older style Sony ATRAC format. It always has a .wav file extension. To
open these files simply install theATRAC3 drivers.
• .ra — a Real Audio format designed for streaming audio over the Internet. The .ra format
allows files to be stored in a self-contained fashion on a computer, with all of the audio
data contained inside the file itself.
• .ram — a text file that contains a link to the Internet address where the Real Audio file is
stored. The .ram file contains no audio data itself.
• dss — Digital Speech Standard files are an Olympus proprietary format. It is a fairly old
and poor codec. Prefer gsm or mp3 where the recorder allows.

• msv — a Sony proprietary format for Memory Stick compressed voice files. You might need
a Sony plugin to load this.
• dvf - a Sony proprietary format for compressed voice files; commonly used by Sony dictation
recorders. You might need a Sony plugin to load this.
formats not supported at this stage
• none

other formats
• atrac (.oma, .omg, .atp) — the newer style Sony proprietary format designed for minidisc
use. It always has a .oma, .omg or .atp file extension. It is similar to mp3 and probably only
useful if you are reading files from minidiscs or writing for minidiscs. Note most of these
files are rights managed so you cannot open them in any software programs.

• mid — the midi file is not an audio file format at all. It is just a list of musical notes which
a synthesizer can play.

• ape — the file format from Monkey’s Audio is claimed to give about 50% compression
without loss in audio quality.

Change the quality of a sound file to PCM Format and 11.025 kHZ 16 bit stereo.
Compare the original file with the changed file.

34 LoveLy professionaL University