分析一段H264视频数据

分析一段H264视频数据

Posted on 2007-05-31 09:42 vcommon 阅读(1968) 评论(8) 编辑收藏 引用 <!-- <rdf:rdf xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:trackback="http://madskills.com/public/xml/rss/module/trackback/"> <rdf:description rdf:about="http://www.cnitblog.com/vcommon/archive/2007/05/31/27842.html" dc:identifier="http://www.cnitblog.com/vcommon/archive/2007/05/31/27842.html" dc:title="分析一段h264视频数据" trackback:ping="http://www.cnitblog.com/vcommon/services/trackbacks/27842.aspx" /> </rdf:rdf> -->

分析

00 00 00 01 67 42 00 1E 99 A0 B1 31 00 00 00 01

H264的数据流分为两种，一种是NAL UNIT stream(RTP),一种是 bits stream,

两者可以互相转换。我们分析的这个是 bit stream,根据Annex B

00 00 00 01 67 42 00 1E 99 A0 B1 31 是 一个NAL，在两个00 00 00 01之间

0110 0111 0100 0010 0000 0000 0001 1110 1001 1001 1010 0000 1011 0001 0011 0001

forbidden_zero_bit（1） ＝ 0

nal_ref_idc（2）＝ 11

nal_unit_type（5） ＝ 0 0111：seq_parameter_set_rbsp()

所以 processSPS

profile_idc(8):42：0100 0010

constraint_set0_flag(1):0

constraint_set1_flag(1):0

constraint_set2_flag(1):0

constraint_set3_flag(1):0

reserved_zero_4bits(4):0

level_idc(8):1E

seq_parameter_set_id(UE(V)):

ue(v): unsigned integer Exp-Golomb-coded syntax element with the left bit first. The parsing process for this descriptor is specified in subclause 9.1

uvlC: 1001：根据Table9.1 ， value= 0,只占1bit.

根据profile_idc忽略掉一部分。

log2_max_frame_num_minus4(ue(v): 001 1001,len = 5,value= 5

pic_order_cnt_type(ue(v)):01 1010,len = 3,value = 2

根据pic_order_cnt_type忽略几个参数

num_ref_frames（ue）：010,len = 3,value = 1

0000 1011 0001 0011 0001

gaps_in_frame_num_value_allowed_flag(1) = 0

pic_width_in_mbs_minus1(ue):000 1011 ,len = 7,value = 10;

pic_height_in_map_units_minus1(ue):0001 001,len = 7,value = 8

frame_mbs_only_flag(1) = 1

忽略1

direct_8x8_inference_flag（1）:0

忽略

vui_parameters_present_flag(1):0

忽略

NALU结束

68 CE 38 80 00 00 00 01

0110 1000

forbidden_zero_bit（1） ＝ 0

nal_ref_idc（2）＝ 11

nal_unit_type（5） ＝01000：pic_parameter_set_rbsp(),7.3.2.2

1100

pic_parameter_set_id (ue)=0

seq_parameter_set_id(ue)=0

entropy_coding_mode_flag(1):0, 重要的flag,0 表示编码Exp-Golomb coded and CAVLC,1表示CABAC

pic_order_present_flag(1):0

1110

num_slice_groups_minus1(ue):0

忽略

num_ref_idx_l0_active_minus1（ue）:0

num_ref_idx_l1_active_minus1(ue):0

weighted_pred_flag(1);0

0011 1000 1000 0000

weighted_bipred_idc(2):00

pic_init_qp_minus26/* relative to26 */(se):0

pic_init_qs_minus26/* relative to26 */(se):0

chroma_qp_index_offset(se):0

deblocking_filter_control_present_flag(1);0

constrained_intra_pred_flag(1):0

redundant_pic_cnt_present_flag(1):0

忽略

NALU结束

65 88 80 21 71 27 1B 88…….3888*16 byte

65：0110 0101

forbidden_zero_bit（1） ＝ 0

nal_ref_idc（2）＝ 11

nal_unit_type（5） ＝0 0101：slice_layer_without_partitioning_rbsp(),IDR浈

Slice

Slice_Header:

first_mb_in_slice(ue):0

slice_type(ue):000 1000 = 7

pic_parameter_set_id(ue) = 0

80 21：000 0000 0010 0001

frame_num(u(v): frame_num is used as an identifier for pictures and shall be represented by log2_max_frame_num_minus4+4 bits,9 bits = 0

忽略

if( nal_unit_type= =5 ) //IDR frame

idr_pic_id(u(e)):0

忽略N多

ref_pic_list_reordering() 见7。3。3。1忽略，Islice,SI slice,B slice

nal_ref_idc =11 所以dec_ref_pic_marking()

nal_unit_type = 5，所以

no_output_of_prior_pics_flag（1）：0

long_term_reference_flag（1）：0

忽略

。。71 27

001 0111 0001 0010 0111

slice_qp_delta（se（v）：001 01 ，4：-2

忽略

slice_data( ):7.3.4

对I-Slice:忽略N多

进入if( moreDataFlag ) { if( MbaffFrameFlag && ( CurrMbAddr % 2= =0| | ( CurrMbAddr % 2= =1&&prevMbSkipped ) ) )mb_field_decoding_flag

macroblock_layer()}

mb_field_decoding_flag忽略

macroblock_layer()

mb_type（ue（v）：0

mb_pred( mb_type )

prev_intra4x4_pred_mode_flag[luma4x4BlkIdx] （1bit, 对babac是ae(v)）:1

1 27:0001 0010 0111

prev_intra4x4_pred_mode_flag[1] : 0001,0,001

0010 0111

prev_intra4x4_pred_mode_flag[2] : 0010,0,010

prev_intra4x4_pred_mode_flag[3] : 0111,0,111

……16个

1b 88 00 3e cf.

intra_chroma_pred_mode（ue(v)）: 最后的一个1bit:0

接下来是macroblock_layer的coded_block_pattern和run level,既系数

c0 06 ad a0 18

1100 0000 0000 0110 1010 0000 0001 1000

coded_block_pattern（me(v):0,根据Table9?4，= 47，0x2f

mb_qp_delta(se(v):):0 len =1

residual()见7.3.5.3

residual_block( LumaLevel[i8x8*4+i4x4], 16 )

coeff_token(ce(v): 00 0000 0000 0110 1

nc = 0(left block and top block 相关的)：

len: { // 0702

{ 1, 6, 8, 9,10,11,13,13,13,14,14,15,15,16,16,16,16},

{ 0, 2, 6, 8, 9,10,11,13,13,14,14,15,15,15,16,16,16},

{ 0, 0, 3, 7, 8, 9,10,11,13,13,14,14,15,15,16,16,16},

{ 0, 0, 0, 5, 6, 7, 8, 9,10,11,13,14,14,15,15,16,16},

},

{

{ 2, 6, 6, 7, 8, 8, 9,11,11,12,12,12,13,13,13,14,14},

{ 0, 2, 5, 6, 6, 7, 8, 9,11,11,12,12,13,13,14,14,14},

{ 0, 0, 3, 6, 6, 7, 8, 9,11,11,12,12,13,13,13,14,14},

{ 0, 0, 0, 4, 4, 5, 6, 6, 7, 9,11,11,12,13,13,13,14},

},

{

{ 4, 6, 6, 6, 7, 7, 7, 7, 8, 8, 9, 9, 9,10,10,10,10},

{ 0, 4, 5, 5, 5, 5, 6, 6, 7, 8, 8, 9, 9, 9,10,10,10},

{ 0, 0, 4, 5, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9,10,10,10},

{ 0, 0, 0, 4, 4, 4, 4, 4, 5, 6, 7, 8, 8, 9,10,10,10},

},

code:

{ 1, 5, 7, 7, 7, 7,15,11, 8,15,11,15,11,15,11, 7,4},

{ 0, 1, 4, 6, 6, 6, 6,14,10,14,10,14,10, 1,14,10,6},

{ 0, 0, 1, 5, 5, 5, 5, 5,13, 9,13, 9,13, 9,13, 9,5},

{ 0, 0, 0, 3, 3, 4, 4, 4, 4, 4,12,12, 8,12, 8,12,8},

},

{

{ 3,11, 7, 7, 7, 4, 7,15,11,15,11, 8,15,11, 7, 9,7},

{ 0, 2, 7,10, 6, 6, 6, 6,14,10,14,10,14,10,11, 8,6},

{ 0, 0, 3, 9, 5, 5, 5, 5,13, 9,13, 9,13, 9, 6,10,5},

{ 0, 0, 0, 5, 4, 6, 8, 4, 4, 4,12, 8,12,12, 8, 1,4},

},

{

{15,15,11, 8,15,11, 9, 8,15,11,15,11, 8,13, 9, 5,1},

{ 0,14,15,12,10, 8,14,10,14,14,10,14,10, 7,12, 8,4},

{ 0, 0,13,14,11, 9,13, 9,13,10,13, 9,13, 9,11, 7,3},

{ 0, 0, 0,12,11,10, 9, 8,13,12,12,12, 8,12,10, 6,2},

},

根据表查的：

code = 13,len = 15，i= 12，j=2

所以numcoeff = 12,numtrailingones = 2

010 0000 0001 1000: totalzeros:根据numcoeff

int lentab[TOTRUN_NUM][16] =

{

{ 1,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9},

{ 3,3,3,3,3,4,4,4,4,5,5,6,6,6,6},

{ 4,3,3,3,4,4,3,3,4,5,5,6,5,6},

{ 5,3,4,4,3,3,3,4,3,4,5,5,5},

{ 4,4,4,3,3,3,3,3,4,5,4,5},

{ 6,5,3,3,3,3,3,3,4,3,6},

{ 6,5,3,3,3,2,3,4,3,6},

{ 6,4,5,3,2,2,3,3,6},

{ 6,6,4,2,2,3,2,5},

{ 5,5,3,2,2,2,4},

{ 4,4,3,3,1,3},

{ 4,4,2,1,3},numcoeff开始

{ 3,3,1,2},

{ 2,2,1},

{ 1,1},

};

int codtab[TOTRUN_NUM][16] =

{

{1,3,2,3,2,3,2,3,2,3,2,3,2,3,2,1},

{7,6,5,4,3,5,4,3,2,3,2,3,2,1,0},

{5,7,6,5,4,3,4,3,2,3,2,1,1,0},

{3,7,5,4,6,5,4,3,3,2,2,1,0},

{5,4,3,7,6,5,4,3,2,1,1,0},

{1,1,7,6,5,4,3,2,1,1,0},

{1,1,5,4,3,3,2,1,1,0},

{1,1,1,3,3,2,2,1,0},

{1,0,1,3,2,1,1,1,},

{1,0,1,3,2,1,1,},

{0,1,1,2,1,3},

{0,1,1,1,1}, numcoeff开始

{0,1,1,1},

{0,1,1},

{0,1},

};

Code = 1,len = 2,i=2,j = 0, totzeros = 2

Read run: 0 0000 0001 1000根据totzeros = 2

int lentab[TOTRUN_NUM][16] =

{

{1,1},

{1,2,2},

{2,2,2,2},

{2,2,2,3,3},

{2,2,3,3,3,3},

{2,3,3,3,3,3,3},

{3,3,3,3,3,3,3,4,5,6,7,8,9,10,11},

};

int codtab[TOTRUN_NUM][16] =

{

{1,0},

{1,1,0},

{3,2,1,0},

{3,2,1,1,0},

{3,2,3,2,1,0},

{3,0,1,3,2,5,4},

{7,6,5,4,3,2,1,1,1,1,1,1,1,1,1},

Code = 1,len =1,I = 0,j = 0

0.1.1 Slice data syntax

slice_data() {	C	Descriptor
if( entropy_coding_mode_flag )
while( !byte_aligned() )
cabac_alignment_one_bit	2	f(1)
CurrMbAddr = first_mb_in_slice * ( 1 + MbaffFrameFlag )
moreDataFlag = 1
prevMbSkipped = 0
do {
if( slice_type!=I&&slice_type!=SI )
if( !entropy_coding_mode_flag ) {
mb_skip_run	2	ue(v)
prevMbSkipped = ( mb_skip_run > 0 )
for( i="0"; i<mb_skip_run; i++ )
CurrMbAddr = NextMbAddress( CurrMbAddr )
moreDataFlag = more_rbsp_data()
} else {
mb_skip_flag	2	ae(v)
moreDataFlag = !mb_skip_flag
}
if( moreDataFlag ) {
if( MbaffFrameFlag && ( CurrMbAddr % 2= =0| | ( CurrMbAddr % 2= =1&&prevMbSkipped ) ) )
mb_field_decoding_flag	2	u(1) | ae(v)
macroblock_layer()	2 | 3 | 4
}
if( !entropy_coding_mode_flag )
moreDataFlag = more_rbsp_data()
else {
if( slice_type!=I&&slice_type!=SI )
prevMbSkipped = mb_skip_flag
if( MbaffFrameFlag&&CurrMbAddr % 2= =0 )
moreDataFlag = 1
else {
end_of_slice_flag	2	ae(v)
moreDataFlag = !end_of_slice_flag
}
}
CurrMbAddr = NextMbAddress( CurrMbAddr )
} while( moreDataFlag )
}

se(v): CABAC正式介绍。根据Table 9 5 – coeff_token mapping to TotalCoeff( coeff_token ) and TrailingOnes( coeff_token )。

chroma_format_idc 无

Bit string form	Range of codeNum
1	0
0 1 x0	1-2
0 0 1 x1 x0	3-6
0 0 0 1 x2 x1 x0	7-14
0 0 0 0 1 x3 x2 x1 x0	15-30
0 0 0 0 0 1 x4 x3 x2 x1 x0	31-62
…	…

0.1.1.1 Slice layer without partitioning RBSP syntax

slice_layer_without_partitioning_rbsp() {	C	Descriptor
slice_header()	2
slice_data()/* all categories of slice_data() syntax */	2 | 3 | 4
rbsp_slice_trailing_bits()	2
}

0.1.1.2 Sequence parameter set RBSP syntax

seq_parameter_set_rbsp() {	C	Descriptor
profile_idc	0	u(8)
constraint_set0_flag	0	u(1)
constraint_set1_flag	0	u(1)
constraint_set2_flag	0	u(1)
constraint_set3_flag	0	u(1)
reserved_zero_4bits /* equal to0 */	0	u(4)
level_idc	0	u(8)
seq_parameter_set_id	0	ue(v)
if( profile_idc= =100| |profile_idc= =110| | profile_idc= =122| |profile_idc= =144 ) {
chroma_format_idc	0	ue(v)
if( chroma_format_idc= =3 )
residual_colour_transform_flag	0	u(1)
bit_depth_luma_minus8	0	ue(v)
bit_depth_chroma_minus8	0	ue(v)
qpprime_y_zero_transform_bypass_flag	0	u(1)
seq_scaling_matrix_present_flag	0	u(1)
if( seq_scaling_matrix_present_flag )
for( i = 0; i < 8; i++ ) {
seq_scaling_list_present_flag[ i ]	0	u(1)
if( seq_scaling_list_present_flag[ i ] )
if( i < 6 )
scaling_list( ScalingList4x4[ i ], 16, UseDefaultScalingMatrix4x4Flag[ i ])	0
else
scaling_list( ScalingList8x8[ i–6 ], 64, UseDefaultScalingMatrix8x8Flag[ i–6 ] )	0
}
}
log2_max_frame_num_minus4	0	ue(v)
pic_order_cnt_type	0	ue(v)
if( pic_order_cnt_type= =0 )
log2_max_pic_order_cnt_lsb_minus4	0	ue(v)
else if( pic_order_cnt_type= =1 ) {
delta_pic_order_always_zero_flag	0	u(1)
offset_for_non_ref_pic	0	se(v)
offset_for_top_to_bottom_field	0	se(v)
num_ref_frames_in_pic_order_cnt_cycle	0	ue(v)
for( i = 0; i < num_ref_frames_in_pic_order_cnt_cycle; i++ )
offset_for_ref_frame[i]	0	se(v)
}
num_ref_frames	0	ue(v)
gaps_in_frame_num_value_allowed_flag	0	u(1)
pic_width_in_mbs_minus1	0	ue(v)
pic_height_in_map_units_minus1	0	ue(v)
frame_mbs_only_flag	0	u(1)
if( !frame_mbs_only_flag )
mb_adaptive_frame_field_flag	0	u(1)
direct_8x8_inference_flag	0	u(1)
frame_cropping_flag	0	u(1)
if( frame_cropping_flag ) {
frame_crop_left_offset	0	ue(v)
frame_crop_right_offset	0	ue(v)
frame_crop_top_offset	0	ue(v)
frame_crop_bottom_offset	0	ue(v)
}
vui_parameters_present_flag	0	u(1)
if( vui_parameters_present_flag )
vui_parameters()	0
rbsp_trailing_bits()	0
}

Table7?1 – NAL unit type codes

nal_unit_type	Content of NAL unit and RBSP syntax structure	C
0	Unspecified
1	Coded slice of a non-IDR picture slice_layer_without_partitioning_rbsp()	2, 3, 4
2	Coded slice data partition A slice_data_partition_a_layer_rbsp()	2
3	Coded slice data partition B slice_data_partition_b_layer_rbsp()	3
4	Coded slice data partition C slice_data_partition_c_layer_rbsp()	4
5	Coded slice of an IDR picture slice_layer_without_partitioning_rbsp()	2, 3
6	Supplemental enhancement information (SEI) sei_rbsp()	5
7	Sequence parameter set seq_parameter_set_rbsp()	0
8	Picture parameter set pic_parameter_set_rbsp()	1
9	Access unit delimiter access_unit_delimiter_rbsp()	6
10	End of sequence end_of_seq_rbsp( )	7
11	End of stream end_of_stream_rbsp( )	8
12	Filler data filler_data_rbsp()	9
13	Sequence parameter set extension seq_parameter_set_extension_rbsp()	10
14..18	Reserved
19	Coded slice of an auxiliary coded picture without partitioning slice_layer_without_partitioning_rbsp()	2, 3, 4
20..23	Reserved
24..31	Unspecified

byte_stream_nal_unit(NumBytesInNALunit) {	C	Descriptor
while( next_bits(24)!=0x000001 && next_bits( 32 ) != 0x00000001 )
leading_zero_8bits/* equal to 0x00 */		f(8)
if( next_bits( 24 ) != 0x000001 )
zero_byte/* equal to0x00 */		f(8)
start_code_prefix_one_3bytes/* equal to0x000001 */		f(24)
nal_unit(NumBytesInNALunit )
while( more_data_in_byte_stream( ) && next_bits( 24 ) != 0x000001 && next_bits( 32 ) != 0x00000001 )
trailing_zero_8bits/* equal to 0x00 */		f(8)
}

0.1.1.3 Picture parameter set RBSP syntax

pic_parameter_set_rbsp() {	C	Descriptor
pic_parameter_set_id	1	ue(v)
seq_parameter_set_id	1	ue(v)
entropy_coding_mode_flag	1	u(1)
pic_order_present_flag	1	u(1)
num_slice_groups_minus1	1	ue(v)
if( num_slice_groups_minus1 > 0 ) {
slice_group_map_type	1	ue(v)
if( slice_group_map_type= =0 )
for( iGroup = 0; iGroup <= num_slice_groups_minus1; iGroup++ )
run_length_minus1[iGroup]	1	ue(v)
else if( slice_group_map_type= =2 )
for( iGroup = 0; iGroup < num_slice_groups_minus1; iGroup++ ) {
top_left[iGroup]	1	ue(v)
bottom_right[iGroup]	1	ue(v)
}
else if(slice_group_map_type= =3| | slice_group_map_type= =4| | slice_group_map_type= =5 ) {
slice_group_change_direction_flag	1	u(1)
slice_group_change_rate_minus1	1	ue(v)
} else if( slice_group_map_type= =6 ) {
pic_size_in_map_units_minus1	1	ue(v)
for( i = 0; i <= pic_size_in_map_units_minus1; i++ )
slice_group_id[i]	1	u(v)
}
}
num_ref_idx_l0_active_minus1	1	ue(v)
num_ref_idx_l1_active_minus1	1	ue(v)
weighted_pred_flag	1	u(1)
weighted_bipred_idc	1	u(2)
pic_init_qp_minus26/* relative to26 */	1	se(v)
pic_init_qs_minus26/* relative to26 */	1	se(v)
chroma_qp_index_offset	1	se(v)
deblocking_filter_control_present_flag	1	u(1)
constrained_intra_pred_flag	1	u(1)
redundant_pic_cnt_present_flag	1	u(1)
if( more_rbsp_data( ) ) {
transform_8x8_mode_flag	1	u(1)
pic_scaling_matrix_present_flag	1	u(1)
if( pic_scaling_matrix_present_flag )
for( i = 0; i < 6 + 2* transform_8x8_mode_flag; i++ ) {
pic_scaling_list_present_flag[ i ]	1	u(1)
if( pic_scaling_list_present_flag[ i ] )
if( i < 6 )
scaling_list( ScalingList4x4[ i ], 16, UseDefaultScalingMatrix4x4Flag[ i ] )	1
else
scaling_list( ScalingList8x8[ i–6 ], 64, UseDefaultScalingMatrix8x8Flag[ i–6 ] )	1
}
second_chroma_qp_index_offset	1	se(v)
}
rbsp_trailing_bits()	1
}

0.1.2 Slice header syntax

slice_header() {	C	Descriptor
first_mb_in_slice	2	ue(v)
slice_type	2	ue(v)
pic_parameter_set_id	2	ue(v)
frame_num	2	u(v)
if( !frame_mbs_only_flag ) {
field_pic_flag	2	u(1)
if( field_pic_flag )
bottom_field_flag	2	u(1)
}
if( nal_unit_type= =5 )
idr_pic_id	2	ue(v)
if( pic_order_cnt_type= =0 ) {
pic_order_cnt_lsb	2	u(v)
if( pic_order_present_flag &&!field_pic_flag )
delta_pic_order_cnt_bottom	2	se(v)
}
if( pic_order_cnt_type = = 1 && !delta_pic_order_always_zero_flag ) {
delta_pic_order_cnt[ 0 ]	2	se(v)
if( pic_order_present_flag&&!field_pic_flag )
delta_pic_order_cnt[ 1 ]	2	se(v)
}
if( redundant_pic_cnt_present_flag )
redundant_pic_cnt	2	ue(v)
if( slice_type= =B )
direct_spatial_mv_pred_flag	2	u(1)
if( slice_type = = P | | slice_type = = SP | | slice_type = = B ) {
num_ref_idx_active_override_flag	2	u(1)
if( num_ref_idx_active_override_flag ) {
num_ref_idx_l0_active_minus1	2	ue(v)
if( slice_type = =B )
num_ref_idx_l1_active_minus1	2	ue(v)
}
}
ref_pic_list_reordering()	2
if( ( weighted_pred_flag&&( slice_type = = P| |slice_type = = SP ) )| | ( weighted_bipred_idc= =1&&slice_type= =B ) )
pred_weight_table()	2
if( nal_ref_idc != 0 )
dec_ref_pic_marking()	2
if( entropy_coding_mode_flag&&slice_type!=I&&slice_type!=SI )
cabac_init_idc	2	ue(v)
slice_qp_delta	2	se(v)
if( slice_type = =SP| |slice_type= =SI ) {
if( slice_type= =SP )
sp_for_switch_flag	2	u(1)
slice_qs_delta	2	se(v)
}
if( deblocking_filter_control_present_flag ) {
disable_deblocking_filter_idc	2	ue(v)
if( disable_deblocking_filter_idc!=1 ) {
slice_alpha_c0_offset_div2	2	se(v)
slice_beta_offset_div2	2	se(v)
}
}
if( num_slice_groups_minus1 > 0&& slice_group_map_type >= 3&&slice_group_map_type <= 5)
slice_group_change_cycle	2	u(v)
}

0.1.3 Slice data syntax

slice_data() {	C	Descriptor
if( entropy_coding_mode_flag )
while( !byte_aligned() )
cabac_alignment_one_bit	2	f(1)
CurrMbAddr = first_mb_in_slice * ( 1 + MbaffFrameFlag )
moreDataFlag = 1
prevMbSkipped = 0
do {
if( slice_type!=I&&slice_type!=SI )
if( !entropy_coding_mode_flag ) {
mb_skip_run	2	ue(v)
prevMbSkipped = ( mb_skip_run > 0 )
for( i="0"; i<mb_skip_run; i++ )
CurrMbAddr = NextMbAddress( CurrMbAddr )
moreDataFlag = more_rbsp_data()
} else {
mb_skip_flag	2	ae(v)
moreDataFlag = !mb_skip_flag
}
if( moreDataFlag ) {
if( MbaffFrameFlag && ( CurrMbAddr % 2= =0| | ( CurrMbAddr % 2= =1&&prevMbSkipped ) ) )
mb_field_decoding_flag	2	u(1) | ae(v)
macroblock_layer()	2 | 3 | 4
}
if( !entropy_coding_mode_flag )
moreDataFlag = more_rbsp_data()
else {
if( slice_type!=I&&slice_type!=SI )
prevMbSkipped = mb_skip_flag
if( MbaffFrameFlag&&CurrMbAddr % 2= =0 )
moreDataFlag = 1
else {
end_of_slice_flag	2	ae(v)
moreDataFlag = !end_of_slice_flag
}
}
CurrMbAddr = NextMbAddress( CurrMbAddr )
} while( moreDataFlag )
}

The variable MbaffFrameFlag is derived as follows.

MbaffFrameFlag = ( mb_adaptive_frame_field_flag&&!field_pic_flag ) (7-22)

0.1.4 Macroblock layer syntax

macroblock_layer() {	C	Descriptor
mb_type	2	ue(v) | ae(v)
if( mb_type= =I_PCM ) {
while( !byte_aligned() )
pcm_alignment_zero_bit	2	f(1)
for( i = 0; i < 256; i++ )
pcm_sample_luma[i]	2	u(v)
for( i = 0; i < 2 * MbWidthC * MbHeightC; i++ )
pcm_sample_chroma[i]	2	u(v)
} else {
noSubMbPartSizeLessThan8x8Flag = 1
if( mb_type!=I_NxN&& MbPartPredMode(mb_type,0)!=Intra_16x16&& NumMbPart(mb_type)= =4 ) {
sub_mb_pred( mb_type )	2
for( mbPartIdx = 0; mbPartIdx < 4; mbPartIdx++ )
if( sub_mb_type[mbPartIdx]!=B_Direct_8x8 ) {
if( NumSubMbPart(sub_mb_type[mbPartIdx])>1 )
noSubMbPartSizeLessThan8x8Flag = 0
} else if( !direct_8x8_inference_flag )
noSubMbPartSizeLessThan8x8Flag = 0
} else {
if( transform_8x8_mode_flag&&mb_type= =I_NxN )
transform_size_8x8_flag	2	u(1) | ae(v)
mb_pred( mb_type )	2
}
if( MbPartPredMode(mb_type,0)!=Intra_16x16 ) {
coded_block_pattern	2	me(v) | ae(v)
if( CodedBlockPatternLuma > 0&& transform_8x8_mode_flag&&mb_type!=I_NxN&& noSubMbPartSizeLessThan8x8Flag&& ( mb_type!=B_Direct_16x16| |direct_8x8_inference_flag ) )
transform_size_8x8_flag	2	u(1) | ae(v)
}
if( CodedBlockPatternLuma > 0| |CodedBlockPatternChroma > 0| | MbPartPredMode(mb_type,0)= =Intra_16x16 ) {
mb_qp_delta	2	se(v) | ae(v)
residual()	3 | 4
}
}
}

0.1.4.1 Macroblock prediction syntax

mb_pred( mb_type ) {	C	Descriptor
if( MbPartPredMode(mb_type,0)= =Intra_4x4| | MbPartPredMode(mb_type,0)= =Intra_8x8| | MbPartPredMode(mb_type,0)= =Intra_16x16 ) {
if( MbPartPredMode(mb_type,0)= =Intra_4x4 )
for( luma4x4BlkIdx=0; luma4x4BlkIdx<16; luma4x4BlkIdx++ ) {
prev_intra4x4_pred_mode_flag[luma4x4BlkIdx]	2	u(1) | ae(v)
if( !prev_intra4x4_pred_mode_flag[luma4x4BlkIdx] )
rem_intra4x4_pred_mode[luma4x4BlkIdx]	2	u(3) | ae(v)
}
if( MbPartPredMode(mb_type,0)= =Intra_8x8 )
for( luma8x8BlkIdx=0; luma8x8BlkIdx<4; luma8x8BlkIdx++ ) {
prev_intra8x8_pred_mode_flag[luma8x8BlkIdx]	2	u(1) | ae(v)
if( !prev_intra8x8_pred_mode_flag[luma8x8BlkIdx] )
rem_intra8x8_pred_mode[luma8x8BlkIdx]	2	u(3) | ae(v)
}
if( chroma_format_idc!=0 )
intra_chroma_pred_mode	2	ue(v) | ae(v)
} else if( MbPartPredMode(mb_type,0)!=Direct ) {
for( mbPartIdx = 0; mbPartIdx < NumMbPart(mb_type); mbPartIdx++)
if( ( num_ref_idx_l0_active_minus1 > 0| | mb_field_decoding_flag ) && MbPartPredMode(mb_type,mbPartIdx)!=Pred_L1 )
ref_idx_l0[mbPartIdx]	2	te(v) | ae(v)
for( mbPartIdx = 0; mbPartIdx < NumMbPart(mb_type); mbPartIdx++)
if( ( num_ref_idx_l1_active_minus1>0| | mb_field_decoding_flag ) && MbPartPredMode(mb_type,mbPartIdx)!=Pred_L0 )
ref_idx_l1[mbPartIdx]	2	te(v) | ae(v)
for( mbPartIdx = 0; mbPartIdx < NumMbPart(mb_type); mbPartIdx++)
if( MbPartPredMode (mb_type,mbPartIdx)!=Pred_L1 )
for( compIdx = 0; compIdx < 2; compIdx++ )
mvd_l0[mbPartIdx][0][compIdx]	2	se(v) | ae(v)
for( mbPartIdx = 0; mbPartIdx < NumMbPart(mb_type); mbPartIdx++)
if( MbPartPredMode(mb_type,mbPartIdx)!=Pred_L0 )
for( compIdx = 0; compIdx < 2; compIdx++ )
mvd_l1[mbPartIdx][0][compIdx]	2	se(v) | ae(v)
}
}

0.1.4.2 Residual data syntax

residual() {	C	Descriptor
if( !entropy_coding_mode_flag )
residual_block = residual_block_cavlc
else
residual_block = residual_block_cabac
if( MbPartPredMode(mb_type,0)= =Intra_16x16 )
residual_block( Intra16x16DCLevel, 16 )	3
for( i8x8 = 0; i8x8 < 4; i8x8++ )/* each luma 8x8 block */
if( !transform_size_8x8_flag| |!entropy_coding_mode_flag )
for( i4x4 = 0; i4x4 < 4; i4x4++ ) {/* each 4x4 sub-block of block */
if( CodedBlockPatternLuma & ( 1 << i8x8 ) )
if( MbPartPredMode(mb_type,0)= =Intra_16x16 )
residual_block( Intra16x16ACLevel[i8x8*4+i4x4], 15 )	3
else
residual_block( LumaLevel[i8x8*4+i4x4], 16 )	3 | 4
else if( MbPartPredMode(mb_type,0)= =Intra_16x16 )
for( i = 0; i < 15; i++ )
Intra16x16ACLevel[i8x8*4+i4x4][i] = 0
else
for( i = 0; i < 16; i++ )
LumaLevel[i8x8*4+i4x4][i] = 0
if( !entropy_coding_mode_flag&&transform_size_8x8_flag )
for( i = 0; i < 16; i++ )
LumaLevel8x8[i8x8][4*i+i4x4] = LumaLevel[i8x8*4+i4x4][i]
}
else if( CodedBlockPatternLuma & ( 1 << i8x8 ) )
residual_block( LumaLevel8x8[i8x8], 64 )	3 | 4
else
for( i = 0; i < 64; i++ )
LumaLevel8x8[i8x8][i] = 0
if( chroma_format_idc!=0 ) {
NumC8x8 = 4 / ( SubWidthC * SubHeightC )
for( iCbCr = 0; iCbCr < 2; iCbCr++ )
if( CodedBlockPatternChroma & 3 )/* chroma DC residual present */
residual_block( ChromaDCLevel[iCbCr], 4 * NumC8x8 )	3 | 4
else
for( i = 0; i < 4 * NumC8x8; i++ )
ChromaDCLevel[iCbCr][i] = 0
for( iCbCr = 0; iCbCr < 2; iCbCr++ )
for( i8x8 = 0; i8x8 < NumC8x8; i8x8++ )
for( i4x4 = 0; i4x4 < 4; i4x4++ )
if( CodedBlockPatternChroma & 2 ) /* chroma AC residual present */
residual_block( ChromaACLevel[iCbCr][i8x8*4+i4x4], 15)	3 | 4
else
for( i = 0; i < 15; i++ )
ChromaACLevel[iCbCr][i8x8*4+i4x4][i] = 0
}

residual_block_cavlc( coeffLevel, maxNumCoeff ) {	C	Descriptor
for( i = 0; i < maxNumCoeff; i++ )
coeffLevel[i] = 0
coeff_token	3 | 4	ce(v)
if( TotalCoeff( coeff_token ) > 0 ) {
if( TotalCoeff( coeff_token ) > 10&&TrailingOnes( coeff_token ) < 3 )
suffixLength = 1
else
suffixLength = 0
for( i = 0; i < TotalCoeff( coeff_token ); i++ )
if( i < TrailingOnes( coeff_token ) ) {
trailing_ones_sign_flag	3 | 4	u(1)
level[i] = 1 – 2 * trailing_ones_sign_flag
} else {
level_prefix	3 | 4	ce(v)
levelCode = ( Min( 15, level_prefix ) << suffixLength )
if( suffixLength > 0| |level_prefix >= 14 ) {
level_suffix	3 | 4	u(v)
levelCode += level_suffix
}
if( level_prefix> =15&&suffixLength= =0 )
levelCode += 15
if( level_prefix> =16 )
levelCode += ( 1 << ( level_prefix – 3 ) ) – 4096
if( i= =TrailingOnes( coeff_token )&& TrailingOnes( coeff_token ) < 3 )
levelCode += 2
if( levelCode % 2= =0 )
level[ i ] = ( levelCode + 2 ) >> 1
else
level[ i ] = ( –levelCode – 1 ) >> 1
if( suffixLength= =0 )
suffixLength = 1
if( Abs( level[ i ] )>( 3 << ( suffixLength – 1 ) )&& suffixLength < 6 )
suffixLength++
}
if( TotalCoeff( coeff_token ) < maxNumCoeff ) {
total_zeros	3 | 4	ce(v)
zerosLeft = total_zeros
} else
zerosLeft = 0
for( i = 0; i < TotalCoeff( coeff_token ) – 1; i++ ) {
if( zerosLeft > 0 ) {
run_before	3 | 4	ce(v)
run[ i ] = run_before
} else
run[ i ] = 0
zerosLeft = zerosLeft – run[ i ]
}
run[ TotalCoeff( coeff_token ) – 1 ] = zerosLeft
coeffNum = ?1
for( i = TotalCoeff( coeff_token ) – 1; i >= 0; i-- ) {
coeffNum += run[ i ] + 1
coeffLevel[ coeffNum ] = level[ i ]
}
}
}