MPEG@Digital video compression standard, defined by the Moving Picture Experts Group (an ISO/IEC committee), supported under QuickTime version 2 or higher. Types MPEG-1 and MPEG-2 exist. Like JPEG image compression, MPEG applies intraframe compression, analyzing contents of each single frame to reduce the amount of data required to represent the image; however, MPEG additionally applies intraframe compression Ñ changes between consecutive frames are also analyzed and compressed. MPEG-1 was designed to accommodate the slower transfer rates of early, "single-speed" CD-ROM drives; therefore its Standard Input Format (SIF) is 352x240 pixels (compared with 740x480 in NTSC video, and 704x576 in PAL video). MPEG-1 is used on White Book Video CDs and RCA's DSS digital home satellite dish system. MPEG-2 supports higher video resolutions, and has become more common. MPEG compression also applies to the audio portion of the captured video; the MPEG format describes synchronized audio compression, in "layers" 1, 2, and 3. Layer 2, also known as Musicam and designed by Philips, is the most popular choice; it is similar to the audio data compression method used on Philips DCC recorders (see definition). MP3 is a format for MPEG audio that has rapidly gained popularity in 98-99. See also QuickTime, White Book, DCC, MP3.@MPU-401@A card-based MIDI interface for the PC designed by Roland, which has been widely copied, becoming a de facto standard for IBM-compatibles and MIDI applications.@MSB@Most Significant Bit, in data processing, the leftmost digit in a number (especially binary numbers). The opposite of Least Significant Bit.@MSC, MIDI Show Control@An amendment to the MIDI Specification, which defines MIDI controller numbers and value ranges to be used for controlling lighting equipment and special effects for theater and live performance, such as MIDI-controlled lighting, dimmer packs, smoke and fog machines, hydraulic lifts, etc.@MSCDEX@Computing term. Software developed by Microsoft to facilitate use of ISO 9660 CD-ROM discs by MS-DOS based computers. These drivers (files which enhance the functionality the computer's basic operating system) allow an MS-DOS computer to see an attached CD-ROM disc as a DOS volume. Under Windows 95, MSCDEX is replaced by CDFS, a "virtual driver" which increases the efficiency of CD-Rom access. See ISO 9660, CD-ROM, Yellow Book.@MTBF@Mean Time Between Failures. The average time that a given type of disk or tape drive mechanism can theoretically operate continuously before failing, according to more-or-less standardized testing methods. All other things being equal, a drive with a higher MTBF will be of higher quality, perhaps featuring a more durable motor, bearings, etc. Nevertheless, there is no guarantee that a given mechanism will actually last as long as the MTBF figure implies; and the particular MTBF testing method chosen by the manufacturer may greatly inflate the resultant figure.@MTS@Multichannel Television Sound. Format for television broadcast, which permits two-channel sound to be incorporated into TV programming (usually a stereo pair) and transmitted via the standard television subcarrier wavelengths. Defined in the U.S. by the NAB (National Association of Broadcasters) and the FCC (Federal Communications Commission). MTS in fact incorporates a third audio channel, called SAP (Separate Audio Program), which can be used for alternate language tracks, etc.@Mult@A way of wiring together several jacks in a patchbay, so that a signal connected to an input is split to several outputs simultaneously. See also Half-Normalled Patchbay.@Multi-Tap@Any audio delay which allows several repetitions of the input signal at different intervals of time, without having to use "Regeneration" (passing part of the delayed output back through to the input) to achieve this effect. See Delay.@Multimedia@Very general and much-overused term coined by the computer industry to describe those projects, presentations or applications that combine various media, such as video, audio, computer graphics and animation, MIDI, remote control, etc.@Multiplexing@An encoding method for transmitting/receiving two or more separate signals, or streams of data, over a single line of communication. To put it another way, a multiplexer accepts parallel input, which it then encodes for serial output. For example, each cable attached to an AES/EBU digital audio interface transmits or receives two separate, interleaved channels of audio samples (along with other auxiliary data), which have been multiplexed together according to the scheme set forth in this specification.@Multisession CD@A CD-ROM which incorporates multiple disk volumes, often with differing file structure formats for different computers. The most common form of multisession disc is the Kodak Photo CD format (also known as "Beige Book"), see definition.@Multisync, Multiscan Monitors, Multiple Scan@A multiscan monitor can adjust its vertical scanning rate to match various input signals, also offering various resolutions for each. The first monitors of this type were the NEC Multisync monitors. Such a monitor is compatible with numerous computer graphic standards, for both PC and Macintosh; many require a small, inexpensive adapter cable in order to be connected to the monitor output of a Mac.@Multitimbral@Refers to the capacity of a MIDI instrument to respond to various incoming MIDI channels simultaneously, with different sound programs (patches, or timbres) independently responding to each. See also Polyphony, Dynamic Allocation.@Multitrack Recorder@An audio tape recorder, which can independently record and reproduce multiple signal sources to/from the same tape, with individual inputs and outputs for each. Any channel (or group of channels) can be recorded individually, while listening to the correctly synchronized playback of audio recorded on other channels. On traditional analog multitrack recorders, the head assembly incorporated a vertical stack of small record or playback heads for each channel, which corresponded to longitudinal strips of tape known as "tracks". (Most digital tape recorders are different, in that individual audio channels are not physically separated onto different areas of the tape.)@Music Only@Designation found on some blank media for CD Recorders (CD-R). "Music Only" media contains a status bit in the pre-recorded lead-in section of the CD, which is required by consumer audio CD recorders. These blank discs are slightly more expensive than generic recordable CD media (which we heartily recommend for any professional application!), because the price includes a royalty surcharge for record companies (and publishers and/or artists who may have the good fortune to get any portion of this fee). Once again, for professional CD recorders, blank media of the type used for CD-ROMs works just as well. See also CD-R, CD.@Mute@A switch which interrupts the flow of audio through a circuit, for example, the playback of audio from a specific channel of a mixing board. Software sequencers and multitrack digital audio programs such as Pro Tools, Session 8, Session, Deck, etc. provide onscreen buttons providing this capability to conveniently silence playback of each MIDI or audio track, without altering its volume setting.@
