Digital Signal Processing Reference
In-Depth Information
One or more GOPs produce a sequence, each of which also starts with a
header. At the sequence header level, it is possible to change essential
video parameters such as the quantization table. If an MPEG encoder uses
its own table which differs from the standard, this is where it will be found
or, respectively, where the decoder is informed of this.
The structure of the video PES stream described above is embedded
wholly or partially in the video PES packets. The manner of this embed-
ment and the length of a PES packet are determined by the video encoder.
On mass storage devices such as the DVD, the PES packets are addition-
ally inserted in so-called packs. PES packets and packs also start with a
header.
Video Production DVCPRO
Home Video MiniDV
Motion JPEG
1985
1988
1991
1993
1995
2002
JPEG
DCT
ITUT
H.120
H.261
H.262
H.263
H.264
=
=
=
MPEG1
Part 2
MPEG2
Part 2
MPEG4
Part 2
MPEG4
Part 10
AVC
ISO/IEC
1992
1994
1998
2003
ISO/IEC
111722
ISO/IEC
138182
ISO/IEC
144962
ISO/IEC
1449610
Windows Media 9
Fig. 7.30.
History of the development of video coding
7.4 More Recent Video Compression Methods
Time has not stood still. Today, more modern, more advanced compres-
sion methods such as MPEG-4 Part 10 Advanced Video Coding (AVC)
(H.264) or Windows Media 9 (= VC-1) are already available. With data
rates which are lower by a factor of 2 to 3, a better image quality than with
MPEG-2 can be achieved in many cases. Although the basic principle of
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