Do you have a question about how Audio&Vedio or Audio&Vedio Software works? Want to find software to perform a certain task? Find it here. If we don't have an answer to your question, please let us know. Work in progress, check back soon for even more information.

AAC (.aac) - "Advanced Audio Coding", next generation audio codec developed by Fraunhofer that seeks to preserve audio quality at lower bitrates. High licensing costs have kept this audio codec from the mainstream

AIFF (.aiff) - default sound file on Macintosh computers

ADPCM - Compressed WAV format. ADPCM (Adaptive Differential Pulse Code Modulation) is an audio compression scheme which compresses from 16-bit to 4-bit for a 4:1 compression ratio.

ALAW - Compressed WAV format. A-Law (or CCITT standard G.711) is an audio compression scheme common in telephony applications. It is a slight variation of the u-Law compression format, and is found in European systems. This encoding format compresses original 16-bit audio down to 8 bits (for a 2:1 compression ratio) with a dynamic range of about 13-bits. Thus, a-law encoded waveforms have a higher s/n ratio than 8-bit PCM, but at the price of a bit more distortion than the original 16-bit audio. The quality is higher than you would get with 4-bit ADPCM formats. Encoding and decoding is rather fast and generally, widely supported.

ALF2CD - Compressed WAV format. ACM codec developed by the NCT Company. Good for keeping of CD-quality music.

audiophile - one with extreme interest in high quality sound

bitrates - speed at which audio data travels per second

BURN-Proof - short for "Buffer Underrun Proof", this technology was developed by Sanyo to combat the most common problem in burning CDs. If a data stream is interrupted while burning, the cd creation process is often ruined. BURN-Proof combats this by connecting the data seamlessly between the recorded point and the recording start point

burning - term for writing data to a cd

codec - short for "compression/decompression", basically an algorithm or system of rules to transform a file.

.cda - not a file format but a way of displaying audio tracks, much like a menu

CDDB - "Compact Disc Database", online lookup tool for retrieving album, artist, and track information, especially helpful for completing MP3 ID3 tags

cd-r - short for "cd-recordable", this media type allows you to record audio or data files and does not allow erasing. Recording audio files allows for compatibility with car and home stereo systems.

cd-rw - short for "cd rewriteable". These discs can record and erase audio and data up to 1,000 times. However, most car and home stereos do not support this media type yet.

cd text - disc and track info embedded on an audio CD

CCIT U-Law - Compressed WAV format.

constant bit rate (CBR) - bit rate remains the same throughout the audio file. Compare with variable bit rate (VBR)

converter - software program that transforms one file format to another

decoding - making a format readable. MP3 players "decode" MP3 by being able to play the data format as audio. However, the term usually refers to the process of converting MP3 to WAV

disc-at-once (DAO) - single session burning process that cannot be interrupted and does not allow any data to be added once burned on a disc. Does not add 2 second gaps between tracks as does track-at-once recording

DSP - Compressed WAV format. DSP Group True Speech (TM) format.

encoding - the process of converting any audio format to MP3

GSM - Compressed WAV format. Good for keeping of human speech.

G.726 - Used for computer telephony. Good for keeping of human speech.

ID3 - small file that can be attached to an MP3 that contains album, artist, track, and other info.

jitter correction - jitter occurs with digital audio extraction (ripping)or when digital audio is converted to analog. This correction feature helps restore the audio to its original condition

kbps - "kilobytes per second", a measurement that is used to judge the size of an audio file. Uncompressed audio such as WAV format is 1411 kbps, MP3 compresses this size to about 1/10 on average (varies depending on user settings when encoding)

MP3 (.mp3) - MPEG Layer III, digital audio compression format achieving smaller file sizes by eliminating sounds the human ear can't hear or doesn't easily pick up.

mp3pro - audio codec developed by Thomson Multimedia that attempts to achieve the same audio quality in smaller file sizes than MP3

normalizing - the process of making audio files the same volume

OGG Vorbis - open source audio codec designed to compete with MP3. Since it is not licensed like MP3, software using this codec does not have to pay royalties.

psychoacoustics - study of what sounds the human ear can detect. MP3 exploits the limits of human psychoacoustics to get smaller file size with limited detectable quality loss.

PCM - Standard Windows WAV format for noncompressed audio files. Pulse Code Modulation (PCM) is the standard method of digitally encoding audio. It is the basic uncompressed data format used in file types such as Windows .wav.

RA (.ra) - "Real Audio" file type from Real Networks. Usually produced by any of Real Networks' proprietary software.

RAW - Raw format of audio files. Doesn't contain header of an audio file.

ripping - also called digital audio extraction, this is the process of taking CD audio and recording it to a computer in any file format. When the transfer is from CD to MP3, the process is both ripping and encoding.

RM (.rm) - "Real Media", fie type from Real Networks.

track-at-once (TAO) - this burning process can write tracks individually, up to 99 total. Automatically places 2 second gaps between tracks.

ULAW - Compressed WAV format. u-Law (or CCITT standard G.711) is an audio compression scheme and international standard in telephony applications. u-Law is very similar to A-Law, a variation of u-Law found in European systems. This encoding format compresses original 16-bit audio down to 8 bits (for a 2:1 compression ratio) with a dynamic range of about 13-bits. Thus, u-Law encoded waveforms have a higher s/n ratio than 8-bit PCM, but at the price of a bit more distortion than the original 16-bit audio. The quality is higher than you would get with 4-bit ADPCM formats. Encoding and decoding is rather fast and generally, widely supported.

VOX - Dialogic ADPCM format. The Dialogic ADPCM format is commonly found in telephony applications, and has been optimized for low sample rate voice. It will only save mono 16-bit audio, and like other ADPCM formats, it compresses to 4-bits/sample (for a 4:1 ratio). This format has no header, so any file format with the extension .VOX will be assumed to be in this format.

variable bit rate (VBR) - encoding process where the codec makes the choice for how many bits are used on each segment of music. More complex segments get more bits. VBR was created with the goal of efficient use of file sizes.

WAV (.wav) - uncompressed audio format developed by IBM and Microsoft. Became standard audio file used on PCs.

WMA (.wma) - "Windows Media Audio", Microsofts proprietary audio codec designed to compete with MP3. Claims competitive sound quality at lower bitrates