实时传送协议（Real-time Transport Protocol或简写RTP，也可以写成RTTP）是一个网络传输协议，它是由IETF的多媒体传输工作小组1996年在RFC 1889中公布的.
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 00 00 00 01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
老毕的书154
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从语法上描述或分析 解析 剖析 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 == 68
forbidden_zero_bit（1） ＝ 0
nal_ref_idc（2）＝ 11
nal_unit_type（5） ＝01000：pic_parameter_set_rbsp( ),7.3.2.2
1100 C
pic_parameter_set_id (ue)=0 P156老毕
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 E
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 ==38 80
weighted_bipred_idc(2):00
pic_init_qp_minus26 /* relative to 26 */(se):0
pic_init_qs_minus26 (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
难道从这里可以看出是什么数据吗？
从169页的nal_unit_type表7.20
这里是5 说明是IDR图片中的片 IDR图像不能使用片分区
Slice 88
Slice_Header: 片头 P158
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
P159 参考帧队列重排列
ref_pic_list_reordering( ) 见7。3。3。1忽略，I slice,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 表7.13 p161
对I-Slice:忽略N多
进入
if(moreDataFlag)//p162
{
if( MbaffFrameFlag && (CurrMbAddr % 2 = = 0 ||( CurrMbAddr % 2 = = 1 && prevMbSkipped )))
mb_field_decoding_flag
macroblock_layer()
}
mb_field_decoding_flag 忽略
macroblock_layer()//p163
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,即系数
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 残差语句 p164
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