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Chapter · November 016 doi: 10. 5772/64833 citation reads 396 authorsBog'liq 57-INTECHpoglavlje20162. MPEG-2 standard
2.1. The principles of the MPEG-2 standard
Other standard developed by the MPEG group is ISO/IEC IS 13818: Generic Coding of Moving
Pictures and Associated Audio, so-called MPEG-2 standard. It is aimed to professional digital
television [8, 9], adopted in 1999, produced on the disadvantages of the standard MPEG-1. It
is compatible with MPEG-1 standard, using the same tools and adding some new.
Basic innovations with the MPEG-2 standard are as follows: an increased bit rate, picture
formats with and without thinning, scalability of quality and time, improved methods of
quantization and coding, etc. Since it is primarily designed for TV signal compression, MPEG-2
standard allows the use of both types of image scanning: progressive scanning and scan by
line spacing. In the compression process, all three types of pictures can be coded as I, P and B
pictures. Standard encoder structure comprises a mixture of I, P and B frames in a way that I
frame appears after every 10–15 frames, and two B frames between two adjacent I frame.
Usually, a group of pictures (GOP) has one I frame or more P and B frames.
2.2. Profiles and levels MPEG-2 standard
Since the complete syntax of the MPEG-2 standard is complex and difficult for practical
implementation on a single silicon chip, the MPEG-2 standard defines five subsets of the full
syntax, called profiles, which are designed for a variety of applications. These are simple
(simple) profile, main (main) profile, signal-to-noise ratio (SNR) scalable profile, spatial
scalability (spatial scalable) and high profile (high) profile. Later, another is created, 4:2:2
profile, and definition of another (multiview) profile is in progress.
The profile is defined by four levels, which regulate the choice of available parameters during
the hardware implementation. The levels determine the maximum bit rate, and according to
the bit rate the speed of transmission of TV programs and resolutions of the system are chosen,
and they are, on the other hand, determined by the number of samples per line, number of
lines per image and the number of frames per second. There are four levels: high level (HL)
H14L (H 1440 level), main level (ML) and low level (LL) [2]. Parameter limitations by levels
are shown in Table 3 [3].
Recent Advances in Image and Video Coding
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