分析
00 00 00 01 67 42 00 1E <?xml:namespace prefix = st1 />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 to 26 */(se):0
pic_init_qs_minus26 /* relative to 26 */(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Table 9?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 to 0 */ | 0 | u(4) |
level_idc | 0 | u(8) |
seq_parameter_set_id | 0 | ue(v) |
if( profile_idc = = 100 | | profile_idc = = 110 | | |
|
|
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, | 0 |
|
else |
|
|
scaling_list( ScalingList8x8[ i – 6 ], 64, | 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 ) { |
|
|
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 |
|
} |
|
|
Table 7?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 | 2, 3, 4 |
2 | Coded slice data partition A | 2 |
3 | Coded slice data partition B | 3 |
4 | Coded slice data partition C | 4 |
5 | Coded slice of an IDR picture | 2, 3 |
6 | Supplemental enhancement information (SEI) | 5 |
7 | Sequence parameter set | 0 |
8 | Picture parameter set | 1 |
9 | Access unit delimiter | 6 |
10 | End of sequence | 7 |
11 | End of stream | 8 |
12 | Filler data | 9 |
13 | Sequence parameter set extension | 10 |
14..18 | Reserved |
|
19 | Coded slice of an auxiliary coded picture without partitioning | 2, 3, 4 |
20..23 | Reserved |
|
24..31 | Unspecified |
|
byte_stream_nal_unit( NumBytesInNALunit ) { | C | Descriptor |
while( next_bits( 24 ) != 0x000001 && |
|
|
leading_zero_8bits /* equal to 0x00 */ |
| f(8) |
if( next_bits( 24 ) != 0x000001 ) |
|
|
zero_byte /* equal to 0x00 */ |
| f(8) |
start_code_prefix_one_3bytes /* equal to 0x000001 */ |
| f(24) |
nal_unit( NumBytesInNALunit ) |
|
|
while( more_data_in_byte_stream( ) && |
|
|
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_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 to 26 */ | 1 | se(v) |
pic_init_qs_minus26 /* relative to 26 */ | 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, | 1 |
|
else |
|
|
scaling_list( ScalingList8x8[ i – 6 ], 64, | 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 ) ) | | |
|
|
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_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( ) |
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|
} else { |
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|
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 | | |
|
|
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 | | |
|
|
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 | | |
|
|
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 | | |
|
|
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 ] = |
|
|
} |
|
|
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 ) |
|
|
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 ) && |
|
|
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++ |
|
|
} |
|
|
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 ] |
|
|
} |
|
|
} |
|
|
} |
|
|
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