The complete description of Advanced simple profiles (ASP) in the MPEG4 standard-chapter 04-1

Reproduced:

Fourth Chapter decoding process
This chapter is a complete introduction to the decoding process of MPEG4 ASP. First, the decoding block diagram is given, followed by the solution
Each function module is described in detail in the order of the Code.
4.1. Decoding block Diagram
Code
Flow
Solution
Analysis
Motion Vector decoding Motion compensation
VLC IZZ
IACDC IQ IDCT
VOP reconstruction
(ADD)
Rebuilding VOP
Motion data
Texture data
Figure 4-1 Decoding process for MPEG4 ASP
As shown in Figure 4-1, it gives the basic decoding process. In which, the code stream parsing is to get the header information from the code stream,
The texture data is sent to the texture decoding process, and the motion data is sent to the motion decoding process. The following are decoded in order, one by one
Be introduced. In the code stream, the motion information is given before the texture information, but the decoding process in the back is introduced
, we will introduce the texture decoding first, then introduce the motion decoding.
4.2. Code Stream parsing
The code stream parsing is the parsing of the header information from the coded stream and preserving the information that is useful to us. Then the tattoo
Data to the texture decoding module, motion data to the motion decoding module, in fact, the control of the Code flow
To them.
4.3. Texture decoding
This section describes the VOP texture decoding process, which is shown in Figure 4-2:
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Variable
Length
Decoding
Inverse Scan
Inverse DC &
AC Prediction
Inverse
Quantization
Inverse DCT Motion
Compensation
VOP Memory
Coded Data
Decoded Pels
Qfs[n]
Qf[v][u] F[y][x]
D[Y][X]
Reconstructed VOP
F[v][u] Pqf[v][u]
Figure 4-2 MPEG4 ASP Texture decoding process
4.3.1 macro block coefficients decoding
This section describes the decoding of the DCT coefficients, including the DC coefficients (n=0) and the AC coefficients (n!=0), where n refers to the
The index number of the (zigzag) of the sawtooth scan.
4.3. Decoding of DC coefficients for 1.1-frame blocks