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H.264 畫框層級之快速模式決策方法. 研究生:李明峰 指導教授:蔣依吾 博士. 中山大學資訊工程學系 http://image.cse.nsysu.edu.tw/. Outline. H.264/AVC Mode Decision Frame-Based Fast Mode Decision Method Experimental Results. H.264/AVC. Description Advantage & Disadvantage. H.264/AVC Description. ITU-T VCEG - PowerPoint PPT Presentation
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研究生:李明峰指導教授:蔣依吾 博士
中山大學資訊工程學系 http://image.cse.nsysu.edu.tw/
H.264 畫框層級之快速模式決策方法
Outline
• H.264/AVC
• Mode Decision
• Frame-Based Fast Mode Decision Method
• Experimental Results
H.264/AVC
Description
Advantage & Disadvantage
H.264/AVC Description
JVT Joint Video TeamH.264/AVC
JVT Joint Video TeamH.264/AVC
ITU-TVCEG Video Coding Experts GroupH.264
ITU-TVCEG Video Coding Experts GroupH.264
ISO/IECMPEG Moving Picture Experts GroupMPEG-4 Part-10AVC Advanced Video Coding
ISO/IECMPEG Moving Picture Experts GroupMPEG-4 Part-10AVC Advanced Video Coding
MPEG-4MPEG-4MPEG-1
H.264/AVC Description
• 2003/5 final drafting completed
• 2005/3 Fidelity Range Extensions
MPEGStandards
JointITU-T/MPEG
Standards
ITU-TStandards H.261H.261 H.263 H.263+ H.263++H.263++
H.262MPEG-2
H.262MPEG-2 H.264H.264
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004
1990 2000
MPEG-1
ITU-T
ISO / IEC
H.261
MPEG-4
H.263
Part 2
Part 10
H.26L
AVCSame High level of commonality
Proprietary Real Video, WMV, On2, Divix, …
SMPTE VC-9
++ H.264
MPEG-2
H.262
JVT
H.264/AVC Description
Advantage
Resolution
Bit rates
Broadcast
DVD storage
RTP/IP packet networks
multimedia telephony systems
Good video qualityLow bit rates
Flexibility
High Profile High 10 High 4:2:2 High 4:4:4
Disadvantage • Complexity
編碼時間mv_search
block
refbuf
macroblock
rdopt
biariencode
cabac
memcpy
Mode Decision
Intra-mode decision
Inter-mode decision
Mode Decision
• Block Base
• Intra-mode
• Inter-mode
Intra-Mode Decision
Intra-Mode Decision
16*16 plane
4*4 horizontal
Intra-Mode Decision
原圖
處理後的圖
Inter-Mode Decision
Current Frame
Reference Frames
Inter-Mode Decision
方塊位置
Current Frame
Reference Frame
Motion Vector
巨區塊
B
C
B
CC
B
分成兩個 16*8 的區塊
A A A
不分割
Inter-Mode Decision
0
Sub macroblocktypes
4*4
0
1
0 1
0 1
2 3
0
8*8 8*4 4*8
0
1
0 1
0
2
1
3
16*16 16*8 8*16 8*8
Macroblocktypes
Mode Decision
Frame-Based Fast Mode Decision Method
Flow Description
The Method
前置處理
H.264 處理
演算法本體
概念圖
Current frameCurrent frame
Previous framePrevious frame
MB 的模式MB 的模式
概念圖
前置處理
H.264 處理
演算法本體
分群分群
正規化正規化
分群
最高細節度高細節度中細節度低細節度最低細節度
m4 m5 m1 m3
4*4Block SNR的平均值
4*4sub macro block
SNR
Previous framePrevious frame
Current frame
5 frames
Current frame
Previous framePrevious frame4 Pixels
5 frames
Frame DifferenceFrame DifferenceFrame DifferenceFrame DifferenceFrame Difference
5 frame differences
Frame DifferenceFrame DifferenceFrame DifferenceFrame DifferenceFrame Difference
53 54 37 42
53 47 40 36
49 44 33
47 46
38 57
63 72
59 70 74
71 60 69 75
58 68 65 70 76
41
5 frame differences
Frame DifferenceFrame DifferenceFrame DifferenceFrame DifferenceFrame Difference
53 54 37 42
53 47 40 36
49 44 33
47 46
38
41
34 67 58 83
34
57
63 72
59 70 74
71 60 69 75
58 68 65 70 76
Frame Difference
52 54 33 40
53 47 34 35
48 44 33
44 43
36
38
49
52 43
43 46 36
61 45 47 38
56 47 45 38 34
對所有值加以平均,得到 m1 值
m3
m1
m5
m4
m2
中細節度
最高細節度
高細節度
最低細節度
低細節度
Frame Difference
52 54 33 40
53 47 34 35
48 44 33
44 43
36
38
49
52 43
43 46 36
61 45 47 38
56 47 45 38 34
正規化
0
Sub macroblocktypes
4*4
0
1
0 1
0 1
2 3
0
8*8 8*4 4*8
0
1
0 1
0
2
1
3
16*16 16*8 8*16 8*8
Macroblocktypes
正規化細節
高細節
低細節
低細節
低
細節高
細節高
細節高
細節高
巨區塊
A
B
C
A
BB
C
C
A
分成兩個 16*8 的區塊
不分割
最佳解的可能性
C
輸出
高細節度
中細節度
低細節度
最高細節度
高細節度
中細節度
低細節度
最低細節度
Experimental Results
JM10.2 Fast mode decision
Compared with JM
JM10.2 Fast mode decision
• Homogeneous Regions DeterminationEdge detection (Sobel operator)
• Stationary Regions DetectionSAD (previous MB and present MB)
30
31
32
33
34
35
36
37
38
39
1 2 3 4 5 6
JM10.2
Proposed
0
500
1000
1500
2000
2500
1 2 3 4 5 6
JM10.2
Proposed
0102030405060708090
100
1 2 3 4 5 6
JM10.1
Proposed
ME timeME time
SnrYSnrY BitRateBitRate
FFMD FFMD
FFMD