Graphics Reference
In-Depth Information
Tabl e 8. 16
BD-rate performance of CABAC transform coefficient coding in HEVC compared to
the extended CABAC transform coefficient coding of H.264/AVC
Resolution and
class of test sequences
Intra
Random Access
Low Delay B
Low Delay P
Class A: 2560 1600
4:08
2:86
n/a
n/a
Class B: 1920 1080
4:18
3:16
3:17
2:89
Class C: 832 416
3:79
2:82
3:31
3:13
Class D: 416
240
4:15
2:61
2:43
2:33
Class E: 1280 720
4:92
n/a
2:94
2:69
Class F: Screen content
7:74
6:44
5:79
5:65
Average
4
:
78
3
:
56
3
:
54
3
:
35
Tabl e 8. 17
Coding efficiency impact of adopted TU coding tools
Tool
HM
Benefit
BD-rate
Neighbor based context selection for SIG [
102
]
1.0
coding gain
2:8%to
1:4%
Group bypass sign [
9
]
1.0
throughput
0.0%
Mode dependent coefficient scanning [
106
]
2.0
coding gain
1:2%to
0:1%
Reduce neighboring dependency for SIG [
18
]
2.0
throughput
0:1%to0.0%
Reduce regular coded level bins [
54
,
59
]
3.0
throughput
0:1%to0.0%
Last position coding [
73
]
3.0
throughput
0:1%to0.0%
Group bypass level [
87
]
4.0
throughput
0.0%
Diagonal Scan [
86
]
4.0
throughput
0:1%to0.0%
CSBF & subblock scan [
56
,
76
]
5.0
throughput
0:1%to0.1%
Reduce regular coded level bins per 4
4 [
16
]
6.0
throughput
0:1%to0.1%
Sign Bit Hiding [
104
]
0:6%
Use CSBF of neighboring subblocks for SIG [
41
] 7.0 throughput 0.1% to 0.2%
Note that positive BD-rate values indicate coding loss and negative BD-rate values indicate coding
gain
6.0
coding gain
0:9%to
Tab le
8.17
summarizes the individual coding efficiency impact of various
adopted tools for HEVC. Note, however, that the majority of adopted tools focused
on throughput improvements with minimal coding loss, as will be discussed in the
following.
8.8.2
Throughput Analysis
This section describes throughput of HEVC relative to H.264/AVC. The impact of
the techniques, outlined in Sect.
8.3.3
, are discussed. Analysis was also done for the
worst case throughput which is defined as the case with the maximum number of
bins per 16
16 coding tree unit (CTU) or macroblock. The results for both common
conditions and worst case are summarized in Tables
8.18
and
8.19
, respectively.
