Apparatus and method of encoding/decoding a coded block pattern
View Patent ↗The present invention selectively applies one of VLC tables stored in a memory for encoding a coded block pattern of a macroblock according to the number of blocks having an object within the macroblock, the number of blocks obtained using shape information, thereby reducing the amount of data transmitted and increasing coding efficiency. The present invention also selectively applies one of VLD tables stored in a memory for decoding a coded block pattern of a macroblock according to the number of blocks having an object within the macroblock, the number of blocks obtained using shape information.
1. An apparatus for coding luminance information in a block format by adaptively using different variable length code (VLC) tables according to the number of non transparent blocks in a macroblock to be coded, said apparatus comprising:
a coded block pattern decision unit for determining a coded block pattern for luminance(CBPY) indicating whether or not coded texture data is transmitted for each of plural luminance blocks;
a VLC table memory for storing the different VLC tables corresponding to the number of non transparent blocks in the macroblock, each of VLC tables having variable length codes representing each of coded block patterns for luminance; and
a multiplexer for multiplexing the variable length code corresponding to the coded block pattern for luminance(CBPY) along with another macroblock header information.
2. The apparatus as recited in claim 1 , wherein the non transparent blocks represent luminance blocks with at least one non intra DC transform coefficient in a macroblock.
3. The apparatus as recited in claim 1 , wherein the plural luminance blocks comprise four blocks of 8 by 8 pixel size.
4. The apparatus as recited in claim 1 , wherein said VLC table memory stores:
a first VLC table for one non-transparent block in a macroblock;
a second VLC table for two non-transparent blocks in a macroblock;
a third VLC table for three non-transparent blocks in a macroblock; and
a fourth VLC table for four non-transparent blocks in a macroblock.
5. The apparatus as recited in claim 4 , wherein the first VLC table is represented as follows:
CBPY(INTRA)
CBPY(INTER)
CODE
0
1
01
1
0
1.
6. The apparatus as recited in claim 4 , wherein the second VLC table is represented as follows:
CBPY(INTRA)
CBPY(INTER)
CODE
00
11
0001
01
10
001
10
01
01
11
00
1.
7. The apparatus as recited in claim 4 wherein the third VLC table is represented as follows:
CBPY(INTRA)
CBPY(INTER)
CODE
000
111
011
001
110
000001
010
101
00001
011
100
010
100
011
00010
101
010
00011
110
001
001
111
000
1.
8. The apparatus as recited in claim 4 , wherein the fourth VLC table is represented as follows:
CBPY(INTRA)
CBPY(INTER)
CODE
0000
1111
0011
0001
1110
00101
0010
1101
00100
0011
1100
1001
0100
1011
00011
0101
1010
0111
0110
1001
000010
0111
1000
1011
1000
0111
00010
1001
0110
000011
1010
0101
0101
1011
0100
1010
1100
0011
0100
1101
0010
1000
1110
0001
0110
1111
0000
11.
9. An apparatus for decoding luminance information in a block format by adaptively using different variable length code (VLC) tables according to the number of non transparent blocks in a macroblock to be decoded, said apparatus comprising:
a de-multiplexer for retrieving a coded pattern for luminance(CBPY) for the macroblock from a received bitstream, wherein the coded block pattern indicates which of plural luminance blocks have DC transform coefficient data in the macroblock;
a texture decoder for decoding coded texture data using the coded block pattern for luminance(CBPY) for the macroblock, by skipping decoding for luminance blocks with no transmitted DC transform coefficients upon the coded block pattern for luminance(CBPY).
10. The apparatus as recited in claim 9 , wherein non transparent blocks represent luminance blocks with at least one non intra DC transform coefficient in a macroblock.
11. The apparatus as recited in claim 9 , wherein said variable length code(VLC) tables comprise:
a first VLC table for one non-transparent block in a macroblock;
a second VLC table for two non-transparent blocks in a macroblock;
a third VLC table for three non-transparent blocks in a macroblock; and
a fourth VLC table for four non-transparent blocks in a macroblck.
12. The apparatus as recited in claim 11 , wherein the first VLC table is represented as follows:
CBPY(INTRA)
CBPY(INTER)
CODE
0
1
01
1
0
1.
13. The apparatus as recited in claim 11 , wherein the second VLC table is represented as follows:
CBPY(INTRA)
CBPY(INTER)
CODE
00
11
0001
01
10
001
10
01
01
11
00
1.
14. The apparatus as recited in claim 11 wherein the third VLC table is represented as follows:
CBPY(INTRA)
CBPY(INTER)
CODE
000
111
011
001
110
000001
010
101
00001
011
100
010
100
011
00010
101
010
00011
110
001
001
111
000
1.
15. The apparatus as recited in claim 11 , wherein the fourth VLC table is represented as follows:
CBPY(INTRA)
CBPY(INTER)
CODE
0000
1111
0011
0001
1110
00101
0010
1101
00100
0011
1100
1001
0100
1011
00011
0101
1010
0111
0110
1001
000010
0111
1000
1011
1000
0111
00010
1001
0110
000011
1010
0101
0101
1011
0100
1010
1100
0011
0100
1101
0010
1000
1110
0001
0110
1111
0000
11.