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Chapter · November 016 doi: 10. 5772/64833 citation reads 396 authorsBog'liq 57-INTECHpoglavlje2016Level
Maximum pixel number
Maximum line number
Maximum frames/s
Low level
352
288
30
Main level
720
576
30
H 1440 level
1440
1152
60
H 1920 level
1920
1080
60
Table 3. Limits of parameters in the levels of MPEG-2 standard.
Simple profile is designed to simplify the transmitter encoder and receiver decoder, with
reductions in binary rate (transfer speed), and the inability bidirectional prediction (B pictures
do not exist) supports only I and P prediction. As such it is suitable only for low-resolution
terrestrial television. The maximum bit rate is 15 Mb/s.
The main profile is the optimal compromise between compression ratio and price. It supports
all three types of prediction I, P, B, which automatically leads to the complexity of the encoder
and decoder. Main profile supports all four levels, with a maximum bit rates of 4, 15, 60 and
80 Mb/s, for low, main, high-1440 and 1920 high level, respectively. The majority of broadcast
applications are scheduled for operation in the main profile. Terrestrial digital TV uses the
main profile and main level (MP and ML). SNR scalable supports profile only for low and main
levels with a maximum bit rate of 4 and 15 Mb/s, respectively.
Spatially scalable profile supports only high-1440 level with a maximum flow rate of 60 Mb/s,
of which 15 Mb/s is part of the base layer. It allows the transfer of basic image quality depending
on the spatial resolution (spatial) or quantization accuracy, with addition of supporting
information (enhanced layer). This allows simultaneous broadcasting of a program in ele-
mentary and higher resolution, so that in case of difficult reception conditions the signal of
lower quality can be received (lower resolution) instead of higher. They are intended for
extended-definition TV (EDTV).
High profile (also known as professional) is designed for later use with hierarchical coding for
applications with extremely high definition (HDTV—high-definition TV) in format sampling
4:2:2 or 4:2:0. High profile supports the main, high-1440 and 1920 high level, with a maximum
flow rates of 20, 80 and 100 Mb/s, respectively. The flow of the base layer is 4, 20 and 25 Mb/s,
respectively.
4:2:2 profile has been introduced to allow working with color images in 4:2:2 format, which is
necessary for studio equipment. Although, during the development of MPEG-2 standard,
studio uses have not been taken into account, it showed that the MPEG-2 standard is suitable
for this purpose. 4:2:2 profile has allowed the use of existing tools for coding and in studio
applications, which requires a higher bit rate.
Multiview profile (MVP) is introduced in order to enable efficient coding of two video
sequences derived from two cameras which are recording the same scene, and which are set
at a slight angle (stereovision). This profile also uses existing tools for encoding, but with a
new purpose. There is also reverse compatible decoder which means a higher level still can
play lower level profile, while compatibility in the opposite direction is not possible. Present
Implementation of Video Compression Standards in Digital Television
http://dx.doi.org/10.5772/64833
203
stage of development uses a combination profile and level of main profile at main level.
Maximum number of pixels that can theoretically be transmitted by MPEG-2 encoder is 16,383
× 16,383 = 22,657,689.
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