2. Basics

2.1 Terminology and symbols

(1) Configuration of MPEG device

MPEG device─┬─MPEG decoder────┬─MPEG/Video decoder
            │                 └─MPEG/Audio decoder
            ├─MPEG frame buffer───set of frame banks
            └─MPEG sector buffer───set of MPEG sectors

(2) Definition of terms

Table 2.1 defines the terms used.

MPEG

Abbreviation for Moving Picture Experts Group, referring to the ISO/IEC JTC1/SC29/WG11 committee. The standard is an international standard for high-efficiency video encoding.

MPEG buffer

Memory area managed by MPEG/Video LSI.

MPEG frame buffer

Area where decoded image data is stored.
Consists of multiple frame banks (number of sides).

Output mode	resolution	Number of sides
NTSC normal resolution	352×240	4
PAL normal resolution	352×288	3
NTSC high-definition still image	704×480	1
PAL high-definition still image	704×576	1

frame bank

An area where image data for one picture of an MPEG video stream is expanded.

frame buffer window

A rectangular area set for the MPEG frame buffer.
This area becomes the output target.

display window

A rectangular area on a display (TV monitor) where MPEG video is output.
The frame buffer window data is output.

image data

Full color data with 24 bits per pixel obtained by decoding an MPEG video stream.
It is transferred to the host area as 15-bit color data.

image data window

A rectangular area defined within an MPEG frame buffer for accessing image data.

Bright spot

The smallest display unit (one dot) on the display.

pixel

Display unit of image data. Consists of multiple bright spots.
Normal resolution: 2 x 2 bright spots, high-definition resolution: 1 x 1 bright spots

system layer

An MPEG stream in which video and audio are synchronized and multiplexed.
(Multiplex stream)

video layer

An MPEG stream consisting only of video data.

audio layer

An MPEG stream consisting only of audio data.

picture

One screen data.

I picture

Intra-coded image. Only the information within the frame is encoded.

P picture

Forward predictive encoded image. Encoded by prediction from past I and P pictures.

B picture

Bidirectional predictive encoded image. Encoded by prediction from past or future I, P pictures.

D picture

DC encoded image. It has only a DC component and is used for searching.

G.O.P.

A collection of multiple pictures that includes at least one I picture at the beginning.
Random access is possible in GOP units.
It usually consists of pictures of about 0.5 seconds (15 pictures).

field

Display screen for one vertical scanning section. (NTSC: 60Hz, PAL: 50Hz)

flame

One display screen. A normal TV consists of two fields.

interlace

Interlaced scanning method. Two fields, an even field and an odd field, constitute one display screen.

non-interlaced

Sequential scanning method. One field constitutes one display screen.

PSC (Frame Buffer Start Code)

Picture layer start code. (00000100H)

SHC (sequence header code)

Video sequence layer start code. (000001B3H)

SEC (system end code) │ │

A code that signifies the end of a system layer stream. (000001B9H)
It is specified as iso_11172_end_code.
*SEC is sometimes used as an abbreviation for sequence end code (000001B7H), but in this document it is used as an abbreviation for system end code.

Time code (TC)

Information indicating the time from the beginning of the sequence.

Timestamp (PTS)

Time management information for playback output of each frame.
In contrast to PTS, the timestamp for decoding time management is called DTS.

Temporal Reference (TR)

Information indicating the display order within the GOP. A remainder value of 1024 that is reset at the beginning of the GOP.

VBV buffer

Area used to decode MPEG video streams.
Allocated within the MPEG buffer.

STD buffer size

Buffer size specified by the system target decoder. Before starting playback, it is necessary to secure data for this buffer size.

W.B.C.

Block that manages decode banks and display banks.
Refers to the contents of the MPEG frame buffer waiting to be displayed (decoded).

Pause

Please stop decoding. As a result, screen output also stops.

Freeze

Please stop screen output. The decoding operation continues.

Decode synchronization signal (DSYNC)

Decoding instructions given from the host to the decoder during host synchronized playback.
Send instead of VSYNC as decode timing.

MPEG sector

A unit of data for accessing the MPEG buffer in MPEG sector buffer mode. (2048 bytes)
The MPEG sector buffer is configured as a collection of MPEG sectors.

MPEG sector position

The location of the MPEG sector within the MPEG sector buffer.
Takes a value from 0 to (total number of MPEG sectors - 1).
MPEG sectors are accessed using the MPEG sector position as a key.

(3) List of symbols and abbreviations

Table 2.2 List of symbols and abbreviations

Symbols/abbreviations	Meaning	Explanation
B	Bidirectionally predictivecodedpicture	Bidirectionally predictive coded picture
D	DCcodedpicture	DC coded picture
DTS	DecodingTimeStamp	Decoding Time Stamp
GOP	GroupOfPictures	Group of pictures
I	Intracodedpicture	Intracoded picture
P	Predictivecodedpicture	Forward predictive coded picture
PSC	PictureStartCode	Picture start code
PTS	PresentationTimeStamp	Playback output timestamp
SEC	SystemEndCode	System end code (abbreviation in this document)
(SEC)	(SequenceEndCode)	(Sequence End Code)
SHC	SequenceHeaderCode	Sequence header code
STD	SystemTargetDecoder	System target decoder
VBV	VideoBufferingVerifier	Video Buffering Verifier
WBC	WriteBufferControl	MPEG frame buffer waiting for display
actst	MPEGactionstatus	MPEG action status
vcnt	VSYNCcounter	Operation section counter
pict	pictureinformation	Picture information
stat_a	MPEG/Audiostatus	MPEG/Audio status
stat_v	MPEG/Videostatus	MPEG/Video status
mpstat	MPEGstatusinformation	MPEG status information
mptc	MPEGtimecode	Timecode
mpcon	MPEGconnectparameter	MPEG decoder connection parameter
mpstm	MPEGstreamparameter	MPEG stream parameter
mpvef	MPEGvideoeffect	Screen special effect parameters

2.2 MPEG-1 Standard

For the MPEG-1 standard, please refer to the standards document below.

Table 2.3 List of MPEG-1 standards

Item	Standard	Standard name
MPEG-1 standard	ISO/IEC 11172	1993 Information technology - Coding of moving pictures and associated audio for digital storage media up to about 1.5 Mbit/s
MPEG/System layer	ISO/IEC 11172-1	Same as above - Part1:Systems
MPEG/Video layer	ISO/IEC 11172-2	Same as above - Part2:Video
MPEG/Audio layer	ISO/IEC 11172-3	Same as above - Part3:Audio