完整的分析mpeg2 video

转自：http://www.cnitblog.com/vcommon/archive/2007/05/27/27662.html

举例分析：

首先是一段例子：

Test.m2v

 

00 00 01 B3 08 00 80 23 00 FA 20 30 00 00 01 B5

 

根据13813-2 Table 6-1 Start code values: 00 00 01 B3 为sequence_header_code.根据6.2.2节（附）                                               

horizontal_size_value(12 bits)：08 0 = 128

vertical_size_value(12 bits)：0 80 = 128

aspect_ratio_information(4 bits)  = 2

frame_rate_code (4 bits) = 3

bit_rate_value（18 bits） = 00 FA 2>>2 = 0000 0000 1111 1010 00 = 1000

marker_bit(1 bit) = 1

vbv_buffer_size_value(10 bits) = 0 0000 0011 0 = 6

constrained_parameters_flag(1 bit) = 0
load_intra_quantiser_matrix( 1bit) = 0

load_non_intra_quantiser_matrix(1bit) = 0

 

00 00 01 b5 extension_start_code

 

14 82 00 01 00 00 00 00 01 B5 23 05 05 05 02 02

04 00 00 00 00 01 B2

extension_start_code_identifier(4 bits) = 1

profile_and_level_indication(8 bit) = 48

progressive_sequence( 1 bit) = 0

chroma_format(2 bits) = 01

horizontal_size_extension(2bit) = 0

vertical_size_extension(2 bit) = 0

bit_rate_extension(12 bit) = 0 0000 0000 000

marker_bit(1 bit) = 1

vbv_buffer_size_extension(8 bits) = 00

low_delay(1 bit) = 0

frame_rate_extension_n(2 bit) = 00

frame_rate_extension_d(5 bit) = 00000

 

接着，下组是Extension and user data  ，00 00 01 B5 extension_start_code，所以接下来是extension_data( i )，

extension_start_code_identifier（4bit） = 2, Sequence Display Extension ID

video_format((3 bit) = 001

colour_description(1bit)=1

  colour_primaries(8) = 05

  transfer_characteristics(8)=05

  matrix_coefficients(8) = 05

display_horizontal_size(14) = 0000 0010 0000 00

marker_bit(1 bit) = 1

display_vertical_size(14) = 0 0000 0100 0000 0

还剩余了3bit 000

 

接下来是00 00 01 b2 user_data_start_code，user_data()，我们忽略它，因为他是用户自定义的。

 

         00 00 01 B2 4D 50 45 47 2D32 20 56 65 72

69 66 69 63 61 74 69 6F5E20 53 65 71 75 65 6E

63 65 0A 00 00 01 B8

 

00 00 01 B8 ，group_start_code, group_of_pictures_header

       00 00 01 B8 5FBF 6C 40

time_code(25): 0101 1111 1011 1111 0110 1100 0 = 49022

closed_gop(1): 1

broken_link(1):0

剩余5bit 0 0000

 

                            00 00 01 00 00

0A 58 58 00 00 01 B5

00 00 01 00, picture_start_code, picture_header

temporal_reference(10): 0000 0000 00

picture_coding_type(3): 00 1

vbv_delay(16):001 1000 1001 1

extra_bit_picture(1):0

         

        00 00 01 B5 8F FF F7 CC 00 00 00 01 01

00 00 01 B5: extension_start_code，所以接下来是extension_data( i )，

extension_start_code_identifier（4bit） = 8, Picture Coding Extension ID,6.2.3.1节

 

f_code[0][0]   /* forward horizontal */(4): F

f_code[0][1]   /* forward vertical */(4):F

f_code[1][0]   /* backward horizontal */(4):F

f_code[1][1]   /* backward vertical */(4):F

intra_dc_precision(2): 01

picture_structure(2): 11

top_field_first(1):1

frame_pred_frame_dct(1):1

concealment_motion_vectors(1):0

q_scale_type(1):0

intra_vlc_format:(1):1

alternate_scan(1);1

repeat_first_field(1):0

chroma_420_type(1):0

progressive_frame(1);0

composite_display_flag(1):0

 

所以接下来将是picture_data,即是很多slice

00 00 01 01: slice_start_code，

Sequence header中horizontal_size_value 和Sequence header extention中的horizontal_size 组成了horizontal_size。

53 D0 54 90 F1 E7 21 48 18 A0 3C24 B6 F3 4A D2

 

quantiser_scale_code(5): 0101 0 = 10

extra_bit_slice /* with the value “0” */ (1):0

接下来就是macroblock()了。

 

macroblock_address_increment(1-11) — This is a variable length coded integer coded as per Annex B Table B-1,

查表得：macroblock_address_increment  = 1

macroblock_modes()：table 6.2.51.

macroblock_type(1-9): Tables B-2 through B-8, selected by picture_coding_type and scalable_mode.

 

1 1101 0000  

查表得：macroblock_type = 1,I picture,no scale

              macroblock_quant = 0

              macroblock_motion_forward = 0

              macroblock_motion_backward = 0

              macroblock_pattern = 0

              macroblock_intra = 1

              spatial_temporal_weight_code_flag = 0

              permitted spatial_temporal_weight_classes:0 ,Intra

所以没有其他结构，block_count = Table 6-20(并根据chroma_format’10’ = ‘4:2:0‘ see Table 6-5 8-5) 全是block = 6。

 

VLC见7.2节：

对于前4个blcok，cc = 0.cc = 0，使用B-12,cc!=0,使用B13

First DCT coefficient(3-24)即是DC系数，根据B-12,B13.

First DCT coefficient = 110, dct_dc_size_luminance = 4,所以dct_dc_differential(=4bit)

dct_dc_differential = 1 000

pattern_code[i] = 1 默认?

First DCT coefficient应该 = 预测值+differential，预测值初始化0,然后[i]的预测值变为1000 = 8, intra_dc_precision((picture_coding_extension) = 01, 所以Precision (bits) = 9， 由7.4.1得

First DCT coefficient = 8*4 = 32。

 

 

然后是接下来的AC系数。

53 D0 54        90       F1       E7       21      

48      18        A0       3C      24

B6      F3      4A        D2

0 0101 0100 1001 0000 1111 0001 1110 0111 0010 0001

0100 1000 0001 0100 1010 0000 0011 1100 0010 0100

1011 0110 1111 0011 0100 1010 1101 0010 

根据b-14,B-15得：

AC：intra_vlc_format (picture_coding_extension) = 1,macroblock_intra = 1,所以使用B-15

quantiser_scale_code (slice header)= 10, q_scale_type(picture_coding_extension) = 0, quantiser_scale[q_scale_type] = 20.根据7.4.2.3 intra_block,加权系数根据6.2.3.2决定,或6.3.11有个默认矩阵。矩阵z字型对应alternate_scan(picturecodeing_extension)决定。

val = val * quantiser_scale[q_scale_type] * w[]/16;

00101: run 2 level 1 len5,run代表0的个数。,AC[1] = 0,AC[2] = 0

0：signed,所以AC[3] = 1 计算= 1* 20* 22/16 = 27

10:run 0 level 1 len 2,

0:signed,AC[4]=1 计算 =1*20*16/16 = 20

0 1001

。。。。。。。

最后得到一个block:

32 20 23 27 32 -33 0 0

0 20 0 0 0 0 0 0

0 0 0 0 36 0 0 0

27 0 0 33 0 0 0 0

-27 0 0 0 0 0 0 0

0 -33 36 0 87 0 -60 0

0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0

 

 

根据alter的z-zig的排列，dc = 32, ac[1] = 0,ac[2] = 0,ac[3] = 27,ac[4] = 20,……图II2-7.3

 

然后经过IDCT:

38 4 -35 7 28 -15 -9 18

…….

 

然后把所有变成一个范围内的Clip.

把所有的block到结束时，就行成了一个完整的Frame.

                     

 

 

 

附录，主要

Table 6-1 — Start code values

Name	start code value (hexadecimal)
picture_start_code	00
Slice_start_code	01 through AF
Reserved	B0
Reserved	B1
User_data_start_code	B2
sequence_header_code	B3
sequence_error_code	B4
extension_start_code	B5
Reserved	B6
Sequence_end_code	B7
group_start_code	B8
system start codes (see note)	B9 through FF
NOTE - system start codes are defined in Part 1 of this specification

 

6.2.2节：

video_sequence() {

next_start_code()

sequence_header()

if ( nextbits() == extension_start_code ) {

sequence_extension()

do {

extension_and_user_data( 0 )

do {

if (nextbits() == group_start_code) {

group_of_pictures_header()

Extension_and_user_data( 1 )

}

picture_header()

picture_coding_extension()

extensions_and_user_data( 2 )

picture_data()

} while ( (nextbits() == picture_start_code) ||

(nextbits() == group_start_code) )

if ( nextbits() != sequence_end_code ) {

sequence_header()

sequence_extension()

}

} while ( nextbits() != sequence_end_code )

} else {

/* ISO/IEC 11172-2 */

}

sequence_end_code

}

6.2.2.1            Sequence header

sequence_header() {	No. of bits	Mnemonic
sequence_header_code	32	bslbf
horizontal_size_value	12	uimsbf
vertical_size_value	12	uimsbf
aspect_ratio_information	4	uimsbf
frame_rate_code	4	uimsbf
bit_rate_value	18	uimsbf
marker_bit	1	bslbf
vbv_buffer_size_value	10	uimsbf
constrained_parameters_flag	1
load_intra_quantiser_matrix	1
if ( load_intra_quantiser_matrix )
intra_quantiser_matrix[64]	8*64	uimsbf
load_non_intra_quantiser_matrix	1
if ( load_non_intra_quantiser_matrix )
non_intra_quantiser_matrix[64]	8*64	uimsbf
next_start_code()
}

 

6.2.2.3            Sequence extension

sequence_extension() {	No. of bits	Mnemonic
extension_start_code	32	bslbf
extension_start_code_identifier	4	uimsbf
profile_and_level_indication	8	uimsbf
progressive_sequence	1	uimsbf
chroma_format	2	uimsbf
horizontal_size_extension	2	uimsbf
vertical_size_extension	2	uimsbf
bit_rate_extension	12	uimsbf
marker_bit	1	bslbf
vbv_buffer_size_extension	8	uimsbf
low_delay	1	uimsbf
frame_rate_extension_n	2	uimsbf
frame_rate_extension_d	5	uimsbf
next_start_code()
}

 

6.2.2.2            Extension and user data

extension_and_user_data( i ) {	No. of bits	Mnemonic
while ( ( ( i != 1) && ( nextbits()== extension_start_code ) ) ||
( nextbits()== user_data_start_code ) ) {
if ( nextbits()== extension_start_code )
extension_data( i )
if ( nextbits()== user_data_start_code )
user_data()
}
}

Table 6-2. extension_start_code_identifier codes.

extension_start_code_identifier	Name
0000	reserved
0001	Sequence Extension ID
0010	Sequence Display Extension ID
0011	Quant Matrix Extension ID
0100	Copyright Extension ID
0101	Sequence Scalable Extension ID
0110	reserved
0111	Picture Display Extension ID
1000	Picture Coding Extension ID
1001	Picture Spatial Scalable Extension ID
1010	Picture Temporal Scalable Extension ID
1011	reserved
1100	reserved
...	...
1111	reserved

 

6.2.2.4            Sequence display extension

sequence_display_extension() {	No. of bits	Mnemonic
extension_start_code_identifier	4	uimsbf
video_format	3	uimsbf
colour_description	1	uimsbf
if ( colour_description ) {
colour_primaries	8	uimsbf
transfer_characteristics	8	uimsbf
matrix_coefficients	8	uimsbf
}
display_horizontal_size	14	uimsbf
marker_bit	1	bslbf
display_vertical_size	14	uimsbf
next_start_code()
}

 

6.2.2.2.2   User data

user_data() {	No. of bits	Mnemonic
user_data_start_code	32	bslbf
while( nextbits() != ‘0000 0000 0000 0000 0000 0001’) {
user_data	8
}
next_start_code()
}

 

6.2.2.6            Group of pictures header

group_of_pictures_header() {	No. of bits	Mnemonic
group_start_code	32	bslbf
time_code	25	bslbf
closed_gop	1	uimsbf
broken_link	1	uimsbf
next_start_code()
}

 

6.2.3   Picture header

picture_header()  {	No. of bits	Mnemonic
picture_start_code	32	bslbf
temporal_reference	10	uimsbf
picture_coding_type	3	uimsbf
vbv_delay	16	uimsbf
if ( picture_coding_type == 2 || picture_coding_type == 3) {
full_pel_forward_vector	1
forward_f_code	3	uimsbf
}
if ( picture_coding_type == 3 ) {
full_pel_backward_vector	1
backward_f_code	3	uimsbf
}
while ( nextbits() == '1' ) {
extra_bit_picture        /* with the value “1”*/	1	uimsbf
extra_information_picture	8
}
extra_bit_picture        /* with the value “0” */	1	uimsbf
next_start_code()
}

 

6.2.3.1            Picture coding extension

picture_coding_extension() {	No . of bits	Mnemonic
extension_start_code	32	bslbf
extension_start_code_identifier	4	uimsbf
f_code[0][0]  /* forward horizontal */	4	uimsbf
f_code[0][1]  /* forward vertical */	4	uimsbf
f_code[1][0]  /* backward horizontal */	4	uimsbf
f_code[1][1]  /* backward vertical */	4	uimsbf
intra_dc_precision	2	uimsbf
picture_structure	2	uimsbf
top_field_first	1	uimsbf
frame_pred_frame_dct	1	uimsbf
concealment_motion_vectors	1	uimsbf
q_scale_type	1	uimsbf
intra_vlc_format	1	uimsbf
alternate_scan	1	uimsbf
repeat_first_field	1	uimsbf
chroma_420_type	1	uimsbf
progressive_frame	1	uimsbf
composite_display_flag	1	uimsbf
if ( composite_display_flag ) {
v_axis	1	uimsbf
field_sequence	3	uimsbf
sub_carrier	1	uimsbf
burst_amplitude	7	uimsbf
sub_carrier_phase	8	uimsbf
}
next_start_code()
}

 

6.2.3.6            Picture data

picture_data() {	No. of bits	Mnemonic
do {
slice()
} while ( nextbits() == slice_start_code )
next_start_code()
}

 

6.2.4   Slice

slice() {	No. of bits	Mnemonic
slice_start_code	32	bslbf
if (vertical_size > 2800)
slice_vertical_position_extension	3	uimsbf
if ( <sequence_scalable_extension() is present in the bitstream> )
if (scalable_mode == “data partitioning” )
priority_breakpoint	7	uimsbf
quantiser_scale_code	5	uimsbf
if ( nextbits() == '1' ) {
intra_slice_flag	1	bslbf
intra_slice	1	uimsbf
reserved_bits	7	uimsbf
while ( nextbits() == '1' ) {
extra_bit_slice     /* with the value “1”*/	1	uimsbf
extra_information_slice	8
}
}
extra_bit_slice     /* with the value “0” */	1	Uimsbf
do {
macroblock()
} while ( nextbits() != '000 0000 0000 0000 0000 0000' )
next_start_code()
}

 

B.1    Macroblock addressing

Table B-1 --- Variable length codes for macroblock_address_increment

macroblock_address_ increment VLC code	increment value	macroblock_address_ increment VLC code	increment value
1	1	0000 0101 01	18
011	2	0000 0101 00	19
010	3	0000 0100 11	20
0011	4	0000 0100 10	21
0010	5	0000 0100 011	22
0001 1	6	0000 0100 010	23
0001 0	7	0000 0100 001	24
0000 111	8	0000 0100 000	25
0000 110	9	0000 0011 111	26
0000 1011	10	0000 0011 110	27
0000 1010	11	0000 0011 101	28
0000 1001	12	0000 0011 100	29
0000 1000	13	0000 0011 011	30
0000 0111	14	0000 0011 010	31
0000 0110	15	0000 0011 001	32
0000 0101 11	16	0000 0011 000	33
0000 0101 10	17	0000 0001 000	macroblock_escape

Note:              The “macroblock stuffing” entry that is available in ISO/IEC11172-2  is not available in this specification.

B.2    Macroblock type

The properties of the macroblock are determined by the macroblock type VLC according to these tables.

Table B-2 — Variable length codes for macroblock_type in I-pictures

macroblock_type VLC code
	macroblock_quant
		macroblock_motion_forward
			macroblock_motion_backward
				macroblock_pattern
					macroblock_intra
						spatial_temporal_weight_code_flag
							permitted spatial_temporal_weight_classes
							Description
1	0	0	0	0	1	0	Intra	0
01	1	0	0	0	1	0	Intra, Quant	0

 

Table B-3 — Variable length codes for macroblock_type in P-pictures

macroblock_type VLC code
	macroblock_quant
		macroblock_motion_forward
			macroblock_motion_backward
				macroblock_pattern
					macroblock_intra
						spatial_temporal_weight_code_flag
							permitted spatial_temporal_weight_classes
							Description
1	0	1	0	1	0	0	MC, Coded	0
01	0	0	0	1	0	0	No MC, Coded	0
001	0	1	0	0	0	0	MC, Not Coded	0
0001 1	0	0	0	0	1	0	Intra	0
0001 0	1	1	0	1	0	0	MC, Coded, Quant	0
0000 1	1	0	0	1	0	0	No MC, Coded, Quant	0
0000 01	1	0	0	0	1	0	Intra, Quant	0

 

Table B-4 — Variable length codes for macroblock_type in B-pictures

macroblock_type VLC code
	macroblock_quant
		macroblock_motion_forward
			macroblock_motion_backward
				macroblock_pattern
					macroblock_intra
						spatial_temporal_weight_code_flag
							permitted spatial_temporal_weight_classes
							Description
10	0	1	1	0	0	0	Interp, Not Coded	0
11	0	1	1	1	0	0	Interp, Coded	0
010	0	0	1	0	0	0	Bwd, Not Coded	0
011	0	0	1	1	0	0	Bwd, Coded	0
0010	0	1	0	0	0	0	Fwd, Not Coded	0
0011	0	1	0	1	0	0	Fwd, Coded	0
0001 1	0	0	0	0	1	0	Intra	0
0001 0	1	1	1	1	0	0	Interp, Coded, Quant	0
0000 11	1	1	0	1	0	0	Fwd, Coded, Quant	0
0000 10	1	0	1	1	0	0	Bwd, Coded, Quant	0
0000 01	1	0	0	0	1	0	Intra, Quant	0

 

Table B-5 — Variable length codes for macroblock_type in I-pictures with spatial scalability.

macroblock_type VLC code
	macroblock_quant
		macroblock_motion_forward
			macroblock_motion_backward
				macroblock_pattern
					macroblock_intra
						spatial_temporal_weight_code_flag
							permitted spatial_temporal_weight_classes
							Description
1	0	0	0	1	0	0	Coded, Compatible	4
01	1	0	0	1	0	0	Coded, Compatible, Quant	4
0011	0	0	0	0	1	0	Intra	0
0010	1	0	0	0	1	0	Intra, Quant	0
0001	0	0	0	0	0	0	Not Coded, Compatible	4

 

Table B-6 — Variable length codes for macroblock_type in P-pictures with spatial scalability.

macroblock_type VLC code
	macroblock_quant
		macroblock_motion_forward
			macroblock_motion_backward
				macroblock_pattern
					macroblock_intra
						spatial_temporal_weight_code_flag
							permitted spatial_temporal_weight_classes
							Description
10	0	1	0	1	0	0	MC, Coded	0
011	0	1	0	1	0	1	MC, Coded, Compatible	1,2,3
0000 100	0	0	0	1	0	0	No MC, Coded	0
0001 11	0	0	0	1	0	1	No MC, Coded, Compatible	1,2,3
0010	0	1	0	0	0	0	MC, Not Coded	0
0000 111	0	0	0	0	1	0	Intra	0
0011	0	1	0	0	0	1	MC, Not coded, Compatible	1,2,3
010	1	1	0	1	0	0	MC, Coded, Quant	0
0001 00	1	0	0	1	0	0	No MC, Coded, Quant	0
0000 110	1	0	0	0	1	0	Intra, Quant	0
11	1	1	0	1	0	1	MC, Coded, Compatible, Quant	1,2,3
0001 01	1	0	0	1	0	1	No MC, Coded, Compatible, Quant	1,2,3
0001 10	0	0	0	0	0	1	No MC, Not Coded, Compatible	1,2,3
0000 101	0	0	0	1	0	0	Coded, Compatible	4
0000 010	1	0	0	1	0	0	Coded, Compatible, Quant	4
0000 011	0	0	0	0	0	0	Not Coded, Compatible	4

 

Table B-7 — Variable length codes for macroblock_type in B-pictures with spatial scalability.

macroblock_type VLC code
	macroblock_quant
		macroblock_motion_forward
			macroblock_motion_backward
				macroblock_pattern
					macroblock_intra
						spatial_temporal_weight_code_flag
							permitted spatial_temporal_weight_classes
							Description
10	0	1	1	0	0	0	Interp, Not coded	0
11	0	1	1	1	0	0	Interp, Coded	0
010	0	0	1	0	0	0	Back, Not coded	0
011	0	0	1	1	0	0	Back, Coded	0
0010	0	1	0	0	0	0	For, Not coded	0
0011	0	1	0	1	0	0	For, Coded	0
0001 10	0	0	1	0	0	1	Back, Not Coded, Compatible	1,2,3
0001 11	0	0	1	1	0	1	Back, Coded, Compatible	1,2,3
0001 00	0	1	0	0	0	1	For, Not Coded, Compatible	1,2,3
0001 01	0	1	0	1	0	1	For, Coded, Compatible	1,2,3
0000 110	0	0	0	0	1	0	Intra	0
0000 111	1	1	1	1	0	0	Interp, Coded, Quant	0
0000 100	1	1	0	1	0	0	For, Coded, Quant	0
0000 101	1	0	1	1	0	0	Back, Coded, Quant	0
0000 0100	1	0	0	0	1	0	Intra, Quant	0
0000 0101	1	1	0	1	0	1	For, Coded, Compatible, Quant	1,2,3
0000 0110 0	1	0	1	1	0	1	Back, Coded, Compatible, Quant	1,2,3
0000 0111 0	0	0	0	0	0	0	Not Coded, Compatible	4
0000 0110 1	1	0	0	1	0	0	Coded, Compatible, Quant	4
0000 0111 1	0	0	0	1	0	0	Coded, Compatible	4

 

Table B-8 — Variable length codes for macroblock_type in I-pictures, P-pictures and B-pictures with SNR scalability.

macroblock_type VLC code
	macroblock_quant
		macroblock_motion_forward
			macroblock_motion_backward
				macroblock_pattern
					macroblock_intra
						spatial_temporal_weight_code_flag
							permitted spatial_temporal_weight_classes
							Description
1	0	0	0	1	0	0	Coded	0
01	1	0	0	1	0	0	Coded, Quant	0
001	0	0	0	0	0	0	Not Coded	0

 

Note               There is no differentiation between picture types, since macroblocks are processed identically in I, P and B-pictures. The "Not coded" type is needed, since skipped macroblocks are not allowed at beginning and end of a slice.

 

B.3    Macroblock pattern

Table B-9 --- Variable length codes for coded_block_pattern.

coded_block_pattern VLC code	cbp	coded_block_pattern VLC code	cbp
111	60	0001 1100	35
1101	4	0001 1011	13
1100	8	0001 1010	49
1011	16	0001 1001	21
1010	32	0001 1000	41
1001 1	12	0001 0111	14
1001 0	48	0001 0110	50
1000 1	20	0001 0101	22
1000 0	40	0001 0100	42
0111 1	28	0001 0011	15
0111 0	44	0001 0010	51
0110 1	52	0001 0001	23
0110 0	56	0001 0000	43
0101 1	1	0000 1111	25
0101 0	61	0000 1110	37
0100 1	2	0000 1101	26
0100 0	62	0000 1100	38
0011 11	24	0000 1011	29
0011 10	36	0000 1010	45
0011 01	3	0000 1001	53
0011 00	63	0000 1000	57
0010 111	5	0000 0111	30
0010 110	9	0000 0110	46
0010 101	17	0000 0101	54
0010 100	33	0000 0100	58
0010 011	6	0000 0011 1	31
0010 010	10	0000 0011 0	47
0010 001	18	0000 0010 1	55
0010 000	34	0000 0010 0	59
0001 1111	7	0000 0001 1	27
0001 1110	11	0000 0001 0	39
0001 1101	19	0000 0000 1	0 (NOTE)
NOTE — This entry shall not be used with 4:2:0 chrominance structure

 

 

6.2.5.1            Macroblock modes

macroblock_modes() {	No. of bits	Mnemonic
macroblock_type	1-9	vlclbf
if ( ( spatial_temporal_weight_code_flag == 1 ) &&
( spatial_temporal_weight_code_table_index != ‘00’) ) {
spatial_temporal_weight_code	2	uimsbf
}
if ( macroblock_motion_forward ||
macroblock_motion_backward ) {
if ( picture_structure == ‘frame’ ) {
if ( frame_pred_frame_dct == 0 )
frame_motion_type	2	uimsbf
} else {
field_motion_type	2	uimsbf
}
}
if ( ( picture_structure == “Frame picture” ) &&
( frame_pred_frame_dct == 0 ) &&
( macroblock_intra || macoblock_pattern) ){
dct_type	1	uimsbf
}
}

 

 

block( i )  {	No. of bits	Mnemonic
if ( pattern_code[i] ) {
if ( macroblock_intra )  {
if ( i<4 ) {
dct_dc_size_luminance	2-9	vlclbf
if(dct_dc_size_luminance != 0)
dct_dc_differential	1-11	uimsbf
} else {
dct_dc_size_chrominance	2-10	vlclbf
if(dct_dc_size_chrominance !=0)
dct_dc_differential	1-11	uimsbf
}
} else {
First DCT coefficient	3-24
}
while ( nextbits() != End of block )
Subsequent DCT coefficients	2-24
End of block	2 or 4	vlclbf
}
}

B.3    Macroblock pattern

Table B-9 --- Variable length codes for coded_block_pattern.

coded_block_pattern VLC code	cbp	coded_block_pattern VLC code	cbp
111	60	0001 1100	35
1101	4	0001 1011	13
1100	8	0001 1010	49
1011	16	0001 1001	21
1010	32	0001 1000	41
1001 1	12	0001 0111	14
1001 0	48	0001 0110	50
1000 1	20	0001 0101	22
1000 0	40	0001 0100	42
0111 1	28	0001 0011	15
0111 0	44	0001 0010	51
0110 1	52	0001 0001	23
0110 0	56	0001 0000	43
0101 1	1	0000 1111	25
0101 0	61	0000 1110	37
0100 1	2	0000 1101	26
0100 0	62	0000 1100	38
0011 11	24	0000 1011	29
0011 10	36	0000 1010	45
0011 01	3	0000 1001	53
0011 00	63	0000 1000	57
0010 111	5	0000 0111	30
0010 110	9	0000 0110	46
0010 101	17	0000 0101	54
0010 100	33	0000 0100	58
0010 011	6	0000 0011 1	31
0010 010	10	0000 0011 0	47
0010 001	18	0000 0010 1	55
0010 000	34	0000 0010 0	59
0001 1111	7	0000 0001 1	27
0001 1110	11	0000 0001 0	39
0001 1101	19	0000 0000 1	0 (NOTE)
NOTE — This entry shall not be used with 4:2:0 chrominance structure

 

Table B-14 --- DCT coefficients Table zero

Variable length code (NOTE1)	run	level
10 (NOTE 2)	End of Block
1 s (NOTE 3)	0	1
11 s (NOTE 4)	0	1
011 s	1	1
0100 s	0	2
0101 s	2	1
0010 1 s	0	3
0011 1 s	3	1
0011 0 s	4	1
0001 10 s	1	2
0001 11 s	5	1
0001 01 s	6	1
0001 00 s	7	1
0000 110 s	0	4
0000 100 s	2	2
0000 111 s	8	1
0000 101 s	9	1
0000 01	Escape
0010 0110 s	0	5
0010 0001 s	0	6
0010 0101 s	1	3
0010 0100 s	3	2
0010 0111 s	10	1
0010 0011 s	11	1
0010 0010 s	12	1
0010 0000 s	13	1
0000 0010 10 s	0	7
0000 0011 00 s	1	4
0000 0010 11 s	2	3
0000 0011 11 s	4	2
0000 0010 01 s	5	2
0000 0011 10 s	14	1
0000 0011 01 s	15	1
0000 0010 00 s	16	1
NOTE1 - The last bit 's' denotes the sign of the level, '0' for positive '1' for negative. NOTE2 - “End of Block” shall not be the only code of t he block. NOTE3 - This code shall be used for the first (DC) coefficient in the block NOTE4 - This code shall be used for all other coefficients

 

Table B-14 --- DCT coefficients Table zero (continued)

Variable length code (NOTE)	run	level
0000 0001 1101 s	0	8
0000 0001 1000 s	0	9
0000 0001 0011 s	0	10
0000 0001 0000 s	0	11
0000 0001 1011 s	1	5
0000 0001 0100 s	2	4
0000 0001 1100 s	3	3
0000 0001 0010 s	4	3
0000 0001 1110 s	6	2
0000 0001 0101 s	7	2
0000 0001 0001 s	8	2
0000 0001 1111 s	17	1
0000 0001 1010 s	18	1
0000 0001 1001 s	19	1
0000 0001 0111 s	20	1
0000 0001 0110 s	21	1
0000 0000 1101 0 s	0	12
0000 0000 1100 1 s	0	13
0000 0000 1100 0 s	0	14
0000 0000 1011 1 s	0	15
0000 0000 1011 0 s	1	6
0000 0000 1010 1 s	1	7
0000 0000 1010 0 s	2	5
0000 0000 1001 1 s	3	4
0000 0000 1001 0 s	5	3
0000 0000 1000 1 s	9	2
0000 0000 1000 0 s	10	2
0000 0000 1111 1 s	22	1
0000 0000 1111 0 s	23	1
0000 0000 1110 1 s	24	1
0000 0000 1110 0 s	25	1
0000 0000 1101 1 s	26	1
NOTE - The last bit 's' denotes the sign of the level, '0' for positive, '1' for negative.

 

Table B-14 --- DCT coefficients Table zero (continued)

Variable length code (NOTE)	run	level
0000 0000 0111 11 s	0	16
0000 0000 0111 10 s	0	17
0000 0000 0111 01 s	0	18
0000 0000 0111 00 s	0	19
0000 0000 0110 11 s	0	20
0000 0000 0110 10 s	0	21
0000 0000 0110 01 s	0	22
0000 0000 0110 00 s	0	23
0000 0000 0101 11 s	0	24
0000 0000 0101 10 s	0	25
0000 0000 0101 01 s	0	26
0000 0000 0101 00 s	0	27
0000 0000 0100 11 s	0	28
0000 0000 0100 10 s	0	29
0000 0000 0100 01 s	0	30
0000 0000 0100 00 s	0	31
0000 0000 0011 000 s	0	32
0000 0000 0010 111 s	0	33
0000 0000 0010 110 s	0	34
0000 0000 0010 101 s	0	35
0000 0000 0010 100 s	0	36
0000 0000 0010 011 s	0	37
0000 0000 0010 010 s	0	38
0000 0000 0010 001 s	0	39
0000 0000 0010 000 s	0	40
0000 0000 0011 111 s	1	8
0000 0000 0011 110 s	1	9
0000 0000 0011 101 s	1	10
0000 0000 0011 100 s	1	11
0000 0000 0011 011 s	1	12
0000 0000 0011 010 s	1	13
0000 0000 0011 001 s	1	14
NOTE - The last bit 's' denotes the sign of the level, '0' for positive, '1' for negative.

 

Table B-14 --- DCT coefficients Table zero (concluded)

Variable length code (NOTE)	run	level
0000 0000 0001 0011 s	1	15
0000 0000 0001 0010 s	1	16
0000 0000 0001 0001 s	1	17
0000 0000 0001 0000 s	1	18
0000 0000 0001 0100 s	6	3
0000 0000 0001 1010 s	11	2
0000 0000 0001 1001 s	12	2
0000 0000 0001 1000 s	13	2
0000 0000 0001 0111 s	14	2
0000 0000 0001 0110 s	15	2
0000 0000 0001 0101 s	16	2
0000 0000 0001 1111 s	27	1
0000 0000 0001 1110 s	28	1
0000 0000 0001 1101 s	29	1
0000 0000 0001 1100 s	30	1
0000 0000 0001 1011 s	31	1
NOTE - The last bit 's' denotes the sign of the level, '0' for positive, '1' for negative.