Graphics Reference
In-Depth Information
P/B
1
P/B
3
P/B
5
P/B
7
P/B
2
P/B
6
…
I
0
P/B
8
P/B
4
time
Coding order
QP offset
0
1
2
3
4
5
6
7
8
0
3
2
3
1
3
2
3
1
Fig. 9.3
The prediction structure of low-delay P and B configurations
9.2.4
Test Sequences
Test sequences are defined according to the picture size and applications and they
are classified into six classes (class A to class F). Class A is the set of sequences
with higher resolution than 1080p HDTV. The sequences are used to evaluate the
coding performance of 4K/8K video. To reduce computation time, picture sizes
are cropped to 2,560
1,600 pixels. Class B is for coding performance evaluation
of 1080p HDTV and the set contains HDTV sequences, with a picture size of
1,920
1,080 pixels. Classes C and D are the set of test sequences with picture sizes
of 832
480 pixels and 416
240 pixels, respectively. Test sequences in these two
classes are for coding performance evaluation of mobile applications. Class E is the
set of test sequences with a picture size of 1,280
720 pixels. It is used to evaluate
coding performance of low-latency applications such as visual communications.
CTC, in addition, defines class F sequences for coding performance evaluation of
non-camera captured content such as video screen content, containing, for example,
text and computer graphic. The test sequences are listed in Table
9.1
.
In addition to the test sequences defined in CTC, 4K test sequences listed in
Tab le
9.2
are used for both objective and subjective quality performance analysis in
this chapter.
9.2.5
Test Cases and Bit Depth
Two test cases Main and Main 10 are defined to evaluate coding performance of
8-bit and 10-bit video. All test cases are summarized in Table
9.3
.
In Main10 configuration, an 8-bit video is converted first to a 10-bit video
by a 2-bit left shift, and it is then encoded as 10-bit video. Likewise, in Main
configuration, a 10-bit video is first converted to an 8-bit video by a 2-bit right shift,
