Adtec Edje 4000, User Manual, Page: 44 / 51

I-frame
Intra-coded frame, or a picture encoded without reference to any other picture. I-frames provide a reference
for Predicted and Bidirectionally predicted frames in a compressed video stream.
IRD Integrated Receiver Decoder. This is a receiver with an MPEG-2 decoder, also known as a set-top box.
ISO International Standardization Organization
ITU International Telecommunications Union (UTI)
LVDS
Low Voltage Differantial Signal. An electrical specification used by some manufactures, usually on a parallel
interface. It is a balanced interface with a low signal voltage swing (about 300mV)
Macroblock
A group of 16x16 pixels used for motion estimation in temporal encoding of MPEG-2 video. MFN - Multiple
Frequency Network (DVB-T).
MGT
Master Guide Table. This table is part of the ATSC PSIP. It defines sizes, types, PIDs, and version numbers
for all of the relevant tables within the transport stream. The PID value for this table is 0x1FFB.
MHEG
Multimedia and Hypermedia Expert Group. MIP - Megaframe Initialization Packet. This packet is used by
DVB-T to synchronize the transmitters in a multi-frequency network.
MP@HL
Main Profile at High Level. MPEG-2 specifies different degrees of compression vs. quality. Of these, Main
Profile at High Level is the most commonly used for HDTV.
MP@ML
Main Profile at Main Level. MPEG-2 specifies different degrees of compression vs. quality. Of these, Main
Profile at Main Level is the most commonly used. MPEG - Moving Picture Experts Group, also called Motion
Picture Experts Group.
MPEG-2
ISO/IEC 13818 standard defining motion video and audio compression. It applies to all layers of
transmission (video, audio and system)
MPTS
Multiple Program Transport Stream. An MPEG-2 transport stream containing several programs that have
been multiplexed.
Multiplex (n)
A digital stream including one or more services in a single physical channel. (v)-To sequentially incorporate
several data streams into a single data stream in such a manner that each may later be recovered intact.
Network - The set of MPEG-2 transport streams transmitted via the same delivery system
NIT
Network Information Table (NIT).The DVB table that contains information about a network’s orbit,
transponder, etc. It is always located on PID 0x0010. DVB specifies two types of NITs, the NIT Actual and
the NIT Other. The NIT Actual is a mandatory table containing information about the physical parameters of
the network actually being accessed. The NIT Other contains information about the physical parameters of
other networks. The NIT Other is optional.
NTSC Nation TV Standard Committee Colour TV System (USA and 60 Hz countries).
NvoD
Near Video on Demand. This service allows for a single TV program to be broadcast simultaneously with a
few minutes of difference in starting time. For example, a movie could be transmitted at 9:00, 9:15 and 9:30.
Packet Packet - See Transport Packet.
PAL Phase Alternating Line.
PAT
Program Association Table. This MPEG-2 table lists all the programs contained in the transport stream and
shows the PID vale for the PMT associated with each program. The PAT is always found on PID 0x0000.
Payload - All the bytes in a packet that follow the packet leader.
PCR
Program Clock Reference. A time stamp in the transport stream that sets the timing in the decoder. The
PCR is transmitted at least every 0.1 seconds.
PES
Packetized Elementary Stream. This type of stream contains packets of unidentified length. These packets
may be comprised of video or audio data packets and ancillary data.
PES Packet The structure used to carry elementary stream data (audio and video). It consists of a header and payload.
PES Packet
Header
The leading bytes of a PES packet, which contain ancillary data for the elementary stream.
PID
Packet Identifier. This unique integer value identifies elements in the transport stream such as tables, data,
or the audio for a specific program. PLL - Phase Lock Loop. This locks the decoder clack to the original
system clock through the PCR.
PMT
Program Map Table. This MPEG-2 table specifies PID values for components of programs. It also
references the packets that contain PCR.
39 Appendix