MPEG2whitepaper

MPEG-2 White Paper
- Pinnacle technical documentation -

Vers.: 0.5 Pinnacle Systems

1 INTRODUCTION.......................................................................................................................... 2
1.1 MPEG IDEA AND STANDARD ...................................................................................................... 2
1.2 MPEG-2 DIGITAL VIDEO SPECIFICATIONS ....................................................................................... 2
1.3 THE WORLDWIDE MPEG-2 STANDARD .......................................................................................... 2
2 PROFILES AND LEVELS ............................................................................................................. 3
2.1 DESCRIPTION ........................................................................................................................... 3
2.2 PROFILES ............................................................................................................................... 3
2.2.1 Description of the five profiles .......................................................................................... 3
2.3 LEVELS .................................................................................................................................. 4
2.3.1 Description of a level....................................................................................................... 4
2.3.2 Level according quality .................................................................................................... 4
2.4 PRACTICAL USAGE OF LEVELS AND PROFILES ................................................................................ 5
2.4.1 Typical Main Level bit rates for common applications ......................................................... 5
2.4.2 Typical picture size and application .................................................................................. 5
3 COMPRESSION .......................................................................................................................... 7
3.1 THE ENCODING PROCESS ............................................................................................................ 7
3.1.1 Compression details........................................................................................................ 8
3.2 GROUP OF PICTURES (GOP) ....................................................................................................... 9
3.2.1 GOP length for distribution purposes ................................................................................ 9
3.2.2 GOP length for editing purposes......................................................................................10
3.3 MOTION ESTIMATION PREDICTION .................................................................................................10
4 VARIABLE BIT RATE FOR VIDEO ENCODING.............................................................................12
4.1 FIXED BIT RATE ENCODING..........................................................................................................12
4.2 ADVANTAGES OF USING A VARIABLE BIT RATE ...............................................................................12
5 MPEG AUDIO.............................................................................................................................14

6 MPEG-2 AND DVD......................................................................................................................15

7 DISCUSSING MPEG-2 I, IP, IBP ................................................................................................16
7.1 MPEG-2 I FRAMES COMPARED .................................................................................................16
7.2 MPEG-2 IP METHOD ..............................................................................................................17
7.3 MPEG-2 IBP METHOD............................................................................................................19
7.4 A COMPARISON OF THE INDIVIDUAL COMPRESSION METHODS ............................................................20
7.5 SELECTION OF A SUITABLE METHOD ............................................................................................20

MPEG-2 White Paper - Pinnacle Page:1/1 29-Feb-00

MPEG-2 White Paper


1 Introduction

1.1 MPEG idea and standard

The Moving Pictures Experts Group abbreviated MPEG is part of the International Standards
Organisation (ISO), and defines standards for digital video and digital audio. The primal task of
this group was to develop a format to play back video and audio in real time from a CD1.
Meanwhile the demands have raised and beside the CD the DVD2 needs to be supported as well
as transmission equipment like satellites and networks. All this operational uses are covered by
a broad selection of standards. Well known are the standards MPEG-1, MPEG-2, MPEG-4 and
MPEG-7. Each standard provides levels and profiles to support special applications in an
optimised way.

1.2 MPEG-2 digital video specifications

MPEG-2 video is an ISO/IEC3 standard that specifies the syntax and semantics of an enclosed
video bitstream. These include parameters such as bit rates, picture sizes and resolutions which
may be applied, and how it is decoded to reconstruct the picture. What MPEG-2 does not define
is how the decoder and encoder should implemented, only that they should be compliant with the
MPEG-2 bitstream. This leaves designers free to develop the best encoding and decoding
methods whilst retaining compatibility. The range of possibilities of the MPEG-2 standard is so
wide that not all features of the standard are used for all applications.

1.3 The worldwide MPEG-2 standard

The MPEG-2 video standard allows MPEG-2 compatible equipment to inter-operate, because the
bitstreams are standardized. However, the way the actual encoding process is implemented to
generate the bitstream is up to the encoder designer. Therefore, all equipment will not
necessarily produce the same quality video (at a given bit rate) there will be a range of products
available, at different price levels, which the consumer can choose from to suit their own
application.

1 CD: Compact Disk
2 DVD: Digital Versatile Disk
3 ISO: International Standards Organization, IEC: International Electrotechnical Commission


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2 Profiles and Levels

2.1 Description

MPEG-2 video is a family of systems, each having an arranged degree of commonality and
compatibility. It allows four source formats, or ‘Levels’, to be coded, ranging from Limited
Definition (about today’s VCR4 quality), to full HDTV 5 – each with a range of bit rates.
In addition to this flexibility in source formats, MPEG-2 allows different ‘Profiles’. Each profile
offers a collection of compression tools that together make up the coding system. A different
profile means that a different set of compression tools is available.

2.2 Profiles

There are currently five profiles in the MPEG-2 system. Each profile is progressively more
sophisticated and adds additional tools to the previous profile. This means that each will do more
than the last, but is likely to cost more to make, and thus cost more to the customer.

2.2.1 Description of the five profiles

• The profile which has the fewest tools is called the Simple Profile. The Simple profile offers
the basic toolkit for MPEG-2 encoding. This is intra and predicted frame encoding and
decoding (see page 7 for more details) with a color sub sampling of YUV 6 4:2:0.
• The following profile is called Main Profile. It has all the tools of the Simple Profile plus one
more (termed bi-directional prediction). It will give better (maximum) quality for the same bit
rate than the Simple Profile, but will cost more IC7 surface area. A Main Profile decoder will
decode both Main and Simple Profile-encoded pictures. This backward compatibility pattern
applies to the succession of profiles.
A refinement of the Main Profile, sometimes unofficially known as Main Profile Professional
Level or MPEG 422, allows line-sequential colour difference signals (4:2:2) to be used, but not
the scaleable tools of the higher Profiles.
• The two Profiles after the Main Profile are, successively, the SNR8 Scaleable Profile and
the Spatially Scaleable Profile. These add tools which allow the coded video data to be
partitioned into a base layer and one or more ‘top-up’ signals. The top-up signals can either
improve the noise (SNR Scalability) or the resolution (Spatial Scalability). These Scaleable
systems may have interesting uses. The lowest layer can be coded in a more robust way,
and thus provide a means to broadcast to a wider area, or provide a service for more difficult
reception conditions. Nevertheless there will be a premium to be paid for their use in receiver
complexity. Owing to the added complexity, none of the Scaleable Profiles is supported by

4 VCR: Video Cassette Recorder
5 HDTV: High Definition Television
6 YUV: Signal with the components Luminance (Y) and Color Difference (U,V)
7 IC: Integrated Circuit
8 SNR: Signal to Noise Ratio


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DVB9. The inputs to the system are YUV component video. However, the first four profiles
code the colour difference signals line-sequentially.
• The final profile is the High Profile. It includes all the previous tools plus the ability to code
line-simultaneous colour-difference signals. In effect, the High Profile is a ‘super system’,
designed for the most sophisticated applications, where there is no constraint on bit rate.

Profile SIMPLE MAIN 422*) SNR SPATIALLY HIGH
Tool SCALABLE SCALABLE
I-Frames ü ü ü ü ü ü
P-Frames ü ü ü ü ü ü
B-Frames ü ü ü ü ü
4:2:2 ü ü ü ü
SNR scalable ü ü ü
Spatially ü ü
scalable

Table 1: MPEG-2 Profiles and Coding Tool Functionalities
*)Refinement of the Main Profile

2.3 Levels

2.3.1 Description of a level

A level is the definition for the MPEG standard for physical parameters such as bit rates, picture
sizes and resolutions. There are four levels specified by MPEG2: High level, High 1440, Main
level, and Low level. MPEG-2 Video Main Profile and Main level has sampling limits at ITU-R10
601 parameters (PAL and NTSC). Profiles limit syntax (i.e. algorithms) whereas Levels limit
encoding parameters (sample rates, frame dimensions, coded bitrates, buffer size etc.).
Together, Video Main Profile and Main Level (abbreviated as MP@ML) keep complexity within
current technical limits, yet still meet the needs of the majority of applications. MP@ML is the
most widely accepted combination for most cable and satellite systems, however different
combinations are possible to suit other applications.

2.3.2 Level according quality

Levels are associated with the source format of the video signal, providing a range of potential
qualities, from limited definition to high definition:
• Low Level has an input format which is one quarter of the picture defined in ITU-R
Recommendation BT.601.
• Main Level has a full ITU-R Recommendation BT. 601 input frame.

9 DVB: Digital Video Broadcasting
10 ITU-R: International Telecommunications Union - Recommendation


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• High-1440 Level has a High Definition format with 1440 sample/line.
• High Level has a High Definition format with 1920 samples/line.

Level Frame size Maximum Significance
(PAL / NTSC) Bitrate
Low 352x288 4 Mb/s CIF, consumer tape equiv.
352x240
Main 720x576 15 Mb/s ITU-R 601, Studio TV
720x480
High 1440 1440x1152 60 Mb/s 4x 601, consumer HDTV
1440x1080
High 1920x1152 80 Mb/s prod. smpte
1920x1080

Table 2: The four Levels with frame size and maximum bit rate defined for each level

2.4 Practical usage of Levels and Profiles

2.4.1 Typical Main Level bit rates for common applications

MPEG-2 video at the appropriate storage medium can easily adjusted to the quality of many of
the current video distribution formats. Even at a low bit rate it still maintains a perfect quality. The
following table provides an overview about bit rates compared to current distribution formats. The
MPEG-2 video is coded ML@MP with IPB frames.

Coded rate (IBP) Application
2 MBit/s Equivalent to VHS
4 MBit/s PAL Broadcast Quality
10 Mbit/s DVD Quality
15 Mbit/s Equivalent to DV Quality

Table 3: MPEG-2 bit rates compared to common video distribution formats

2.4.2 Typical picture size and application

MPEG-2 defines a range of picture sizes to suit a range of different applications: It shows also
that MPEG-2 video is still compatible with the current video formats.

PAL NTSC
352x288 352x240 SIF, CD White Book Movies, Video Games
352x576 352x480 Half Horizontal Resolution (VHS equiv.)


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544x576 544x480 Laserdisk, D2, Band Limited Broadcast
-- 640x480 Square Pixel NTSC
720x576 720x480 ITU-R 601, D1

Table 4: PAL and NTSC resolutions which MPEG-2 video supports

Summary

Profiles limit syntax (compression tools, i.e. algorithms)

Levels limit encoding parameters (sample rates, frame dimensions,
coded bitrates, buffer size etc.)


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3 Compression

3.1 The encoding process

Encoding of video information is achieved by using two main techniques. These are termed
spatial and temporal compression. Spatial compression involves analysis of a picture to
determine redundant
I
information within that
picture, for example by
discarding frequencies that
are not visible to the human
eye. Temporal
compression is achieved P
by only encoding the
difference between
successive pictures.
P
Imagine a scene where at
first there is no movement,
then an object moves I
across the picture. The first
picture in the sequence
contains all the information
required until there is any
movement, so there is no
need to encode any of the
information after the first
picture until the movement
occurs. Thereafter, all that
needs to be encoded is the
part of the picture that
contains movement. The rest of the scene is not effected by the moving object because it is still
the same as the first picture. The means by which is determined how much movement is
contained between two successive pictures is known as motion estimation prediction. The
information obtained from this process is then used by motion compensated prediction to
define the parts of the picture that can be discarded.
This means that pictures cannot be considered in isolation. A given picture is constructed from
the prediction from a previous picture, and may be used to predict the next picture.
There is also the need to have pictures which are not used in any reference for random access.
Therefore MPEG-2 defines three picture types:

I (Intraframe) pictures. These are encoded without reference to another picture to
allow for random access
P (Predictive) pictures are encoded using motion compensated prediction on the
previous picture therefore contain a reference to the previous picture. They may
themselves be used in subsequent predictions


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B (Bi-directional) pictures are encoded using motion compensated prediction on the
previous and next pictures, which must be either a B or P picture. B pictures are not
used in subsequent predictions.

The I, P and B pictures can be formed into a group of pictures (GOP).

Each picture type (I, P, B) provides increased opportunity of redundancy. An I picture is encoded
with little compression (only spatially redundant information). P and B pictures also use motion
compensation to remove temporally redundant information. B pictures offer the most
compression.
Typical bit allocations are shown below:

Picture Type Bit Allocation Bit Allocation
30 Hz SIF @ 1.15 Mbit/sec 30 Hz ITU-R 601@ 4 MBit/sec
Intra 150 Kbit 400 KBit
Predictive 50 Kbit 200 KBit
Bi-directional 20 Kbit 80 KBit

Table 5: Pictures of a Standard Test Sequence with a I-Frame distance of 15 and a P-Frame distance
of 3

3.1.1 Compression details

Spatial compression is achieved in practice by use of a DCT which converts the information in the
picture to be e ncoded in the frequency domain. This transform is used to remove redundant
information within the picture itself, by removing frequencies with negligible amplitudes and
rounding frequency co-efficients to standard values. At higher frequencies, contrast is less
perceptible by the human eye, therefore these frequencies we cannot detect can be removed.
More compression can also be achieved by using a process called run length encoding. This is
an operation that searches for regularly occurring patterns in the frequency information obtained
from the DCT. If a pattern is detected, it can be replaced by a shorter representative pattern,
providing even more compression efficiency.


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s0 y1 b1
+ DCT Q1 VLC

IDC

+

MCP

(i)DCT: (Inverse) Discrete Cosine Transformation
Q1: Quantisation
VLC: Variable Length Coding
MCP: Motion Compensation Prediction
Figure 1: Generalized MPEG-2 Encoder

Motion compensated prediction is used to exploit redundant temporal information that is not
changing from picture to picture. The images in a video stream do not generally change much
within small time intervals. The idea of motion compensated prediction is to encode a video frame
based on other video frames temporally close to it.

3.2 Group of pictures (GOP)

This is the grouping of I and P, I and B or I, B and P pictures into a specified sequence known as
a group of pictures (GOP). The group must start and end with an I picture to allow for random
access to the group, and contains P and/or B pictures in between in a specified sequence
(determined by the designer). A group can be made of different lengths to suit the type of video
being encoded and the application the video is used for.

3.2.1 GOP length for distribution purposes

For example it is better to use a shorter group lengths for a film which contains a lot of fast
moving action with complex scenes. A group lengths is typically between 8-24 pictures.
Commonly used GOP sizes are 12 for 50 Hz systems, 16 for 60 Hz systems. GOPs are optional
in an MPEG-2 bitstream, but are mandatory in DVD video, to achieve an SMPTE 11 timebase. A
bitstream with no GOP header can be directly accessed at a specific point using the sequence
header.

11 SMPTE: Society of Motion Picture and Television Engineers


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I B B P B B P B B P B B P B B

Figure 2: Typical GOP structure and size for a IBP encoded video stream used for video distribution
formats

3.2.2 GOP length for editing purposes

When it comes to editing typically IP-Frames are used. Some systems who not really need to
take the advantage of MPEG-2 choose I-Frames only.
A typical IP GOP length for non linear postproduction can be set to 3 or 4 frames. Any additional
P frame will not gain a significant decrease in data rate.

I P P P

Figure 3: Typical GOP structure and size for a IP encoded video stream used for video editing formats

3.3 Motion estimation prediction

Motion estimation prediction is a method of determining the amount of movement contained
between two pictures. This is achieved by dividing the picture to be encoded into sections known
as macroblocks. The size of a macroblock is 16 x 16 pixels. Each macroblock is searched for
the closest match in the search area of the picture it is being compared with. Motion estimation
prediction is not used on I pictures, however B and P pictures can refer to I pictures. For P
pictures, only the previous picture is searched for matching macroblocks. In B pictures both the
previous and next pictures are searched. When a match is found, the offset (or motion vector)
between them is calculated. The matching parts are used to create a prediction picture, by using
the motion vectors. The prediction picture is then compared in the same manner to the picture to
be encoded. Macroblocks which have a match have already been encoded, and are therefore
redundant. Macroblocks which have no match to any part of the search area in the picture to be
encoded represent the difference between the pictures, and these macroblocks are encoded.

Summary

Encoding is achieved by using spatial and temporal compression – this
compression is GOP based
Two methods are used in conjunction when encoding a GOP:
1. Intra-frame compression: compression of complete single frames


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2. Inter-frame compression: Check for correlations between subsequent
frames, discard redundant information, store the rest

-> This results in I, P and B frames


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4 Variable bit rate for video encoding
In any given video section, certain parts contain more movement than others or more fine detail.
For example a clear blue sky is simpler to encode than a picture of a tree. As a result the
number of bits needed to faithfully encode without artefacts varies with the video material. In order
to encode in the best possible way, it is advantageous to save bits from the simple sections and
use them to encode complex ones. This is, in a simple way, what variable bit rate encoding
does, however the process by which the bit rates are calculated is complex.
Variable bit rate encoding can be carried out in one or two passes of the video data. For fixed
size storage applications such as DVD12, the amount of encoded video information must be
known in advance, therefore two passes of the video information are required. This ensures that
the amount of data is not too small (quality compromised) or too large (not enough storage
space). The first pass is used to analyse and store encoding information about the video data,
the second pass uses the information to perform the actual encoding. Where the amount of
encoded data produced is not so critical, encoding can be carried out in one pass of the input
video.

4.1 Fixed bit rate encoding

For some applications, it is necessary to transmit the encoded video information with a fixed bit
rate. For example, in broadcast mediums (satellite, cable, terrestrial etc.), practical limitations
mean that current transmission is restricted to using a fixed bit rate. This is why fixed bit rate
MPEG-2 encoders are available. It is true that a fixed bit rate encoder is not as efficient as the
variable bit rate system, however the MPEG-2 system still provides very high quality video for
both encoding methods. Very importantly, fixed bit rate encoding can also be carried out in real
time, i.e. one pass of the video information. For live broadcasts, and satellite linkups etc. the real
time encoding capability is essential.

4.2 Advantages of using a variable bit rate

The advantage of using a variable bit rate is mainly the gain it gives in encoding efficiency. For
fixed storage mediums (e.g. DVD) the variable bit rate is ideal. By reducing the amount of space
needed to store the video (whilst retaining very high quality), it leaves more space on the medium
for inclusion of other features e.g. multiple language soundtracks, extra subtitle channels,
interactivity, etc.
The other important feature of the variable bit rate system is that it gives constant video quality for
all complexities of program material. A constant bit rate encoder provides variable quality.

Summary

Variable bit rate = constant quality
Constant bit rate = variable quality

12 DVD: Digital Versatile Disk


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5 MPEG Audio
Audio compression is based on the principle of leaving out those parts of the sound that are
imperceptible to the human ear.
An audio CD, for example, has a quantizing depth of 16 bits at 44,000 samples per second. This
is enough to eliminate background noise in even the quietest passages or breaks. Background
noise present in loud passages would be covered up by the music, making it possible to reduce
the resolution without an audible loss in quality. So depending on the characteristics of the
music, the resolution can be more or less reduced in order to achieve data reduction and better
rates of compression.

The MPEG standard provides for three audio compression methods, audio layers 1 through 3.
Each layer is compatible with the format of the layer(s) below it and has its own file name
extensions. As with MPEG video, however, this standard stipulates the format and decoder for
each layer, but not the encoding algorithm. Thus it is possible to develop varying algorithms that
also deliver varying results and levels of quality. Layer 1 is the simplest version with the lowest
rate of compression. The standard calls for a bit rate of 192 KBits per second and audio channel.
Layer 2 is a compromise between sound quality and the complexity of the encoding algorithm.
The specification for this layer calls for up to 128 KBits per second and channel. In stereo,
therefore, the targeted rate of 250 KBits per second is attained. This method is generally used in
audio in MPEG movies. Layer 3 is for low bit rates up to 64 KBits per second and channel. This
layer is intended to achieve maximum sound quality at minimal bit rates. It is primarily used in
digital connections such as ISDN.


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6 MPEG-2 and DVD
The characteristics of the DVD data medium and the MPEG-2 video codec make a good match
when it comes to permanent storage of video with long playing times and high quality. The
technical characteristics of DVDs and DVD drives may serve as outline conditions for assessing
the quality and data rate aspects.

CD DVD
AV Format 74 minutes of digital audio 135 minutes of MPEG-2 video
Capacity 650 MB 4.7 GB
Transfer rate 150 KB/s 600 KB/s
Table 6 : CD and DVD compared

Capacity
1 side 2 sides Dual Layer
DVD-ROM Read only Memory e.g., DVD Video 4.7 GB 9.4 GB 17 GB
DVD-R Write Once 3.95 GB 7.9 GB -
DVD-RAM Rewritable 2.6 GB 5.2 GB 5.6 GB
Table 7: The storage capacities of the various DVD formats

Even if the transfer performance of future DVD drives increases considerably and the capacity of
the data medium can be further increased, DVD video with a maximum of 600 KB/s will probably
become standard over the long term and become the higher-quality, digital counterpart of the
VHS cassette.
To produce video for this data medium, the final product should have a data rate not exceeding
600 KB/s, in order to guarantee compatibility with players.
The MPEG-2 IBP method is predestined for this data rate. It attains the necessary compression.
The productions are always saved in one continuous file, which is then prepared for the data
medium by DVD authoring software.

The Production Process
Step Format
Recording 422P@ML, IP Frames
Editing 422P@ML, IP Frames
Rendering ML@MP, IBP Frames
DVD Authoring ML@MP, IBP Frames


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7 Discussing MPEG-2 I, IP, IBP

7.1 MPEG-2 I Frames Compared

MPEG-2 Intra frame compression

Raw (uncompressed)
810 KB per 720 PAL frame,
Mbit/s: 158
MB/s: 19.76

Compression ratio: 5:1
I I I 162 KB per PAL Bild,
Mbit/s: 32
MB/s: 4

Motion JPG compression
Uncompressed 810 KB pro 720
PAL frame,
Mbit/s: 158
MB/s: 19,76

MJPG MJPG MJPG
162 KB per PAL frame,
Mbit/s: 32
MB/s: 4

DV compression
Exactly 150 KB per PAL frame

Mbit/s: 29
MB/s: 3.6

DV DV DV


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All frames were encoded individually. Intraframe compression.
At a compression ratio of 5:1 or higher, all data rates are considerably higher than 3 MB/s or 25
Mbit/s.

7.2 MPEG-2 IP Method

A method that uses forward references. P-Frames are so-called predicted frames that point to
the future.

The IPPP method
starts the
compression
procedure for the
group of pictures
with a compressed
individual frame
I (I Frame)

In the next step, a
P frame is
generated that
contains a motion
vector for the car
I P object – the only
area of the picture
that has moved.

The part of the
scene that was
covered by the car
I P before and now is
visible is copied
from the original
material to the P-
frame.

I P P
The procedure is
repeated for
additional

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7.3 MPEG-2 IBP Method

Method that uses forward and backward references. B frames are so-called bi-directional
frames, that point to the future and the past.

The IBP method
starts the
compression
procedure for the
group of images
with a compressed
individual frame (I-
I frame)

In the next step, the
last frame of a GOP
is generated as a
P-Frame that
contains a
I P movement vector
for the auto object
as well as that area
of the scenery that
was previously
hidden and is now
visible.

The B frames are
set up by saving
I B P movement vectors
for the objects in
motion.

The B frames are
I B P completed by
copying previously
hidden areas from
the future

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7.4 A Comparison of the Individual Compression Methods

MJPEG DV MPEG2 MPEG2 MPEG2 MPEG2
I-Frame IP IB IBP
Editability good good good good good difficult

Data rate 4..10 3.6 4..6 2 2 0.5..1.5
MB/s MB/s MB/s MB/s MB/s MB/s
Com- 2..5 : 1 5:1 3..6 : 1 9:1 9:1 15..30 :1
pression

7.5 Selection of a Suitable Method

For non-linear video editing on standard computers, a method is required with a data rate that is
less than the maximum bandwidth offered by these systems. Of course, this threshold varies
from one computer to the next and is higher with high-performance systems. This is why the
threshold value should be determined empirically.
The miroVIDEO DC50 can be used as a known system load. It is can process up to 7 MB/s (56
Mbit/s) and marks the performance threshold of many computer configurations.

Single Stream
Maximum Bandwidth: 50 Mbits/s

A real-time editing system must deliver the same quality but be capable of showing two videos
simultaneously. The only systems even worthy of consideration are those with compression that
reduces the data rate by at least half with negative effects on quality.
The DV method nearly fulfills this demand, but takes it for granted that the necessary bandwidth
will still be always be achieved, since the data rate is fxed. To ensure satisfactory operation,
i
only selected systems should be used for a DV Dual Stream system.

The MPEG-2 IP method offers ideal preconditions for dual-stream operation on nearly all
computers. Moreover, the adjustable data rate permits fine tuning. At a maximum data rate of 25
Mbit/s video channel, Dual Stream operation with real-time video effects is possible on modern
computers.

Dual Stream
Maximum bandwidth: 2 x 25 Mbit/s


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Often used abbreviations
422P@ML 422 Profile at Main Level – MPEG 422
CD Compact Disk
DCT Discrete Cosines Transformation
DVB Digital Video Broadcasting
DVD Digital Versatile Disk
HDTV High Definition Television
IC Integrated Circuit
ISO International Standards Organisation
ITU International Telecommunications Union
JPEG Joint Picture Expert Group
MP@ML Main Profile at Main Level
MPEG Moving Pictures Experts Group
MPEG 422 422 Profile at Main Level, Studio MPEG
MPEG-2 ISO Standard 13818
RLE Run Length Encoding
SMPTE Society of Motion Picture and Television Engineers
SNR Signal to Noise Ratio
VCR Video Cassette Recorder
YUV Signal incorporating the components Luminance (Y) and Color Difference (U,V)


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