Video Compression

1.

Video Compression
Dr. Prof. Vitaly O. Groppen
e-mail: [email protected]
North-Caucasian Institute of Mining and
Metallurgy, Institute of Theoretical and
Experimental Informatics. Vladikavkaz.

2.

CONTENTS
•Preface
•Physical representation
•Formal problem statement 3 pages
2

3.

Preface
The main differences between this method and methods,
which are used, is the usage of both compressions, such as
interframe compression and intraframe compression. Video
stream represents such as single multicopy image.
Thus the main purpose will be conclude in finding of
optimal number of frames in whole stream? Where
compression or quality will be the best. And compression
will be come inside this chain of frames.
3

4.

Physical representation
key frame
Intraframe compression
Interfame compression
4

5.

• Formal
problem statement
•According to key frame frequency results in compression F and in quality Q will
be different. The main purpose will be definition of the optimal values for
foregoing F and Q.
•Y- key frame ratio
•F- compression ratio
•a1- intraframe compression ratio parameter
•a2-interframe compression ratio parameter
•Q – quality
•B1-intraframe quality parameter
•B2 –interframe quality parameter
F ai y
y 1
bi
Q y i
y 1
i
5

6.

Optimal key frame frequency. (Q- const)
• Formal problem statement:
F a1 a2 y max
b2
b1 y Qconst ;
y 1
•Problem-solving
L1 a1 a2 y Qconst b1 b2 ;
y
•optimal key frame frequency
L1
0
y
L1
0
yoptimal
Qconst b1
b2
Qconst b0
yoptimal max{1;
}.
b1
6

7.

Optimal key frame frequency. (F- const)
• Formal problem statement:
b2
Q
b
max;
1
y
a a y F
const
1 2
y 1
•Problem-solving
L2 b1
b2
Fconst a1 a2 y ;
y
•optimal key frame frequency
L2
0
y
L2
0
yoptimal max{1,
yoptimal
Fconst a1
a2
Fconst a1
}.
a1
7