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＞＞＞解方程：5.6X-8.6=19.43.2X-1.5X=0.512X+1.2×5=7（检验）-数..
解方程：5.6X-8.6=19.43.2X-1.5X=0.512X+1.2×5=7（检验）
题型：解答题难度：中档来源：不详
（1）5.6x-8.6=19.4， 5.6x-8.6+8.6=19.4+8.6， 5.6x÷5.6=28÷5.6， x=5；（2）3.2x-1.5x=0.51， 1.7x=0.51， 1.7x÷1.7=0.51÷1.7， x=0.3；（3）2x+1.2×5=7， 2x+6=7， 2x+6-6=7-6， 2x÷2=1÷2， x=0.5．检验：将x=0.5代入方程2x+1.2×5=7的左边，得：2×0.5+1.2×5=1+6=7，方程的左右两边相等，所以x=0.5是方程的解．
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据魔方格专家权威分析，试题“解方程：5.6X-8.6=19.43.2X-1.5X=0.512X+1.2×5=7（检验）-数..”主要考查你对&&解方程&&等考点的理解。关于这些考点的“档案”如下：
现在没空？点击收藏，以后再看。
因为篇幅有限，只列出部分考点，详细请访问。
解方程：使方程左右两边相等的未知数的值叫做方程的解。 求方程的解的过程叫做解方程。 方程的解是一个值，解方程是求方程的解的演算过程。 检验方法：求出未知数的值分别代入原方程的两边计算（即含有字母的式子的值），如果原方程等号左右两边相等，则所求得的未知数的值是原方程的解。解方程依据：方程依靠等式各部分的关系，和加减乘除各部分的关系：加数+加数=和，和-其中一个加数=另一个加数，差+减数=被减数，被减数-减数=差，被减数-差=减数，因数×因数=积，积÷一个因数=另一个因数，被除数÷除数=商，被除数÷商=除数，商×除数=被除数。
发现相似题
与“解方程：5.6X-8.6=19.43.2X-1.5X=0.512X+1.2×5=7（检验）-数..”考查相似的试题有：
460861030833106741710433329775049563492334人阅读
S1: C/C++（712）
s6: 视频相关研究（68）
&&&&&&前面已经讨论过，在没有B帧的情况下如何提取P帧的运动矢量，没有考虑B帧. 现在考虑P帧，假设视频有12帧，x264对其进行编码，编码的帧结构为：IDR BBPBBPBBPBP. 故共有4个P帧.& （视频格式是qcif格式）
&&&&& 我们知道，在H.264中，P帧中可以有I宏块，本人为了便于数据处理，认为I宏块也有运动矢量，其值为零.& 与MPEG2不同的是：在H.264中，一个宏块可以继续进行分块，所以并不是一个宏块对应一个运动矢量，而是每个分块都有各自的运动的矢量，为了方便起见，仅仅考虑提取宏块最左上角的那个4*4块对应的运动矢量.
&&&&& 如此一来，4个P帧总共的宏块个数为99 * 4 = 396个， 对应396个运动矢量. 下面来看看重要的read_one_macroblock函数：
// 用x264编码12帧 宏块总数为99 * 12 = 1188
// 编码的帧结构为：IDR BBPBBPBBPBP
// 1个I帧，7个B帧，共4个P帧
int read_one_macroblock(struct img_par *img,struct inp_par *inp)
// 12帧共1188个宏块，此处被调用1188次
SyntaxElement currSE;
Macroblock *currMB = &img-&mb_data[img-&current_mb_nr];
Slice *currSlice = img-&currentS
DataPartition *dP;
int *partMap = assignSE2partition[currSlice-&dp_mode];
Macroblock *topMB = NULL;
prevMbSkipped = 0;
img_block_y;
check_bottom, read_bottom, read_
if (img-&MbaffFrameFlag)
if (img-&current_mb_nr%2)
topMB= &img-&mb_data[img-&current_mb_nr-1];
if(!(img-&type == B_SLICE))
prevMbSkipped = (topMB-&mb_type == 0);
prevMbSkipped = (topMB-&mb_type == 0 && topMB-&cbp == 0);
prevMbSkipped = 0;
if (img-&current_mb_nr%2 == 0)
currMB-&mb_field = 0;
currMB-&mb_field = img-&mb_data[img-&current_mb_nr-1].mb_
currMB-&qp = img-&
currSE.type = SE_MBTYPE;
read MB mode *****************************************************************
dP = &(currSlice-&partArr[partMap[currSE.type]]);
if (active_pps-&entropy_coding_mode_flag == UVLC || dP-&bitstream-&ei_flag)
currSE.mapping = linfo_
if(img-&type == I_SLICE || img-&type == SI_SLICE)
// 只有一个I帧（片）, 99个宏块，刚好被调用99次
// read MB aff
if (img-&MbaffFrameFlag && img-&current_mb_nr%2==0)
TRACE_STRING(&mb_field_decoding_flag&);
if (active_pps-&entropy_coding_mode_flag == UVLC || dP-&bitstream-&ei_flag)
currSE.len = 1;
readSyntaxElement_FLC(&currSE, dP-&bitstream);
currSE.reading = readFieldModeInfo_CABAC;
dP-&readSyntaxElement(&currSE,img,inp,dP);
currMB-&mb_field = currSE.value1;
if(active_pps-&entropy_coding_mode_flag
CheckAvailabilityOfNeighborsCABAC();
read MB type
TRACE_STRING(&mb_type&);
currSE.reading = readMB_typeInfo_CABAC;
dP-&readSyntaxElement(&currSE,img,inp,dP);
currMB-&mb_type = currSE.value1;
if(!dP-&bitstream-&ei_flag)
currMB-&ei_flag = 0;
}// I帧内的宏块到此为止
// non I/SI-slice CABAC
else if (active_pps-&entropy_coding_mode_flag == CABAC)
// read MB skipflag
if (img-&MbaffFrameFlag && (img-&current_mb_nr%2 == 0||prevMbSkipped))
field_flag_inference();
CheckAvailabilityOfNeighborsCABAC();
TRACE_STRING(&mb_skip_flag&);
currSE.reading = readMB_skip_flagInfo_CABAC;
dP-&readSyntaxElement(&currSE,img,inp,dP);
currMB-&mb_type = currSE.value1;
if (img-&type==B_SLICE)
currMB-&cbp = currSE.value2;
if(!dP-&bitstream-&ei_flag)
currMB-&ei_flag = 0;
if ((img-&type==B_SLICE) && currSE.value1==0 && currSE.value2==0)
img-&cod_counter=0;
// read MB aff
if (img-&MbaffFrameFlag)
check_bottom=read_bottom=read_top=0;
if (img-&current_mb_nr%2==0)
check_bottom =
(img-&type!=B_SLICE)?
(currMB-&mb_type == 0):
(currMB-&mb_type == 0 && currMB-&cbp == 0);
read_top = !check_
read_bottom = (img-&type!=B_SLICE)?
(topMB-&mb_type == 0 && currMB-&mb_type != 0) :
((topMB-&mb_type == 0 && topMB-&cbp == 0) && (currMB-&mb_type != 0 || currMB-&cbp != 0));
if (read_bottom || read_top)
TRACE_STRING(&mb_field_decoding_flag&);
currSE.reading = readFieldModeInfo_CABAC;
dP-&readSyntaxElement(&currSE,img,inp,dP);
currMB-&mb_field = currSE.value1;
if (check_bottom)
check_next_mb_and_get_field_mode_CABAC(&currSE,img,inp,dP);
if(active_pps-&entropy_coding_mode_flag
CheckAvailabilityOfNeighborsCABAC();
// read MB type
if (currMB-&mb_type != 0 )
currSE.reading = readMB_typeInfo_CABAC;
TRACE_STRING(&mb_type&);
dP-&readSyntaxElement(&currSE,img,inp,dP);
currMB-&mb_type = currSE.value1;
if(!dP-&bitstream-&ei_flag)
currMB-&ei_flag = 0;
// VLC Non-Intra
if(img-&cod_counter == -1)
TRACE_STRING(&mb_skip_run&);
dP-&readSyntaxElement(&currSE,img,inp,dP);
img-&cod_counter = currSE.value1;
if (img-&cod_counter==0)
// read MB aff
if ((img-&MbaffFrameFlag) && ((img-&current_mb_nr%2==0) || ((img-&current_mb_nr%2) && prevMbSkipped)))
TRACE_STRING(&mb_field_decoding_flag&);
currSE.len = 1;
readSyntaxElement_FLC(&currSE, dP-&bitstream);
currMB-&mb_field = currSE.value1;
// read MB type
TRACE_STRING(&mb_type&);
dP-&readSyntaxElement(&currSE,img,inp,dP);
if(img-&type == P_SLICE || img-&type == SP_SLICE)
currSE.value1++;
currMB-&mb_type = currSE.value1;
if(!dP-&bitstream-&ei_flag)
currMB-&ei_flag = 0;
img-&cod_counter--;
img-&cod_counter--;
currMB-&mb_type = 0;
currMB-&ei_flag = 0;
// read field flag of bottom block
if(img-&MbaffFrameFlag)
if(img-&cod_counter == 0 && (img-&current_mb_nr%2 == 0))
TRACE_STRING(&mb_field_decoding_flag (of coded bottom mb)&);
currSE.len = 1;
readSyntaxElement_FLC(&currSE, dP-&bitstream);
dP-&bitstream-&frame_bitoffset--;
currMB-&mb_field = currSE.value1;
else if(img-&cod_counter & 0 && (img-&current_mb_nr%2 == 0))
// check left macroblock pair first
if (mb_is_available(img-&current_mb_nr-2, img-&current_mb_nr)&&((img-&current_mb_nr%(img-&PicWidthInMbs*2))!=0))
currMB-&mb_field = img-&mb_data[img-&current_mb_nr-2].mb_
// check top macroblock pair
if (mb_is_available(img-&current_mb_nr-2*img-&PicWidthInMbs, img-&current_mb_nr))
currMB-&mb_field = img-&mb_data[img-&current_mb_nr-2*img-&PicWidthInMbs].mb_
currMB-&mb_field = 0;
dec_picture-&mb_field[img-&current_mb_nr] = currMB-&mb_
img-&siblock[img-&mb_x][img-&mb_y]=0;
if ((img-&type==P_SLICE ))
// inter frame
interpret_mb_mode_P(img);
else if (img-&type==I_SLICE)
// intra frame
interpret_mb_mode_I(img);
else if ((img-&type==B_SLICE))
// B frame
interpret_mb_mode_B(img);
else if ((img-&type==SP_SLICE))
// SP frame
interpret_mb_mode_P(img);
else if (img-&type==SI_SLICE)
// SI frame
interpret_mb_mode_SI(img);
if(img-&MbaffFrameFlag)
if(currMB-&mb_field)
img-&num_ref_idx_l0_active &&=1;
img-&num_ref_idx_l1_active &&=1;
//====== READ 8x8 SUB-PARTITION MODES (modes of 8x8 blocks) and Intra VBST block modes ======
if (IS_P8x8 (currMB))
currSE.type
= SE_MBTYPE;
dP = &(currSlice-&partArr[partMap[SE_MBTYPE]]);
for (i=0; i&4; i++)
if (active_pps-&entropy_coding_mode_flag ==UVLC || dP-&bitstream-&ei_flag)
currSE.mapping = linfo_
currSE.reading = readB8_typeInfo_CABAC;
TRACE_STRING(&sub_mb_type&);
dP-&readSyntaxElement (&currSE, img, inp, dP);
SetB8Mode (img, currMB, currSE.value1, i);
if(active_pps-&constrained_intra_pred_flag && (img-&type==P_SLICE|| img-&type==B_SLICE))
// inter frame
if( !IS_INTRA(currMB) )
img-&intra_block[img-&current_mb_nr] = 0;
//! TO for Error Concelament
//! If we have an INTRA Macroblock and we lost the partition
//! which contains the intra coefficients Copy MB would be better
//! than just a grey block.
//! Seems to be a bit at the wrong place to do this right here, but for this case
//! up to now there is no other way.
dP = &(currSlice-&partArr[partMap[SE_CBP_INTRA]]);
if(IS_INTRA (currMB) && dP-&bitstream-&ei_flag && img-&number)
currMB-&mb_type = 0;
currMB-&ei_flag = 1;
for (i=0;i&4;i++) {currMB-&b8mode[i]=currMB-&b8pdir[i]=0; }
dP = &(currSlice-&partArr[partMap[currSE.type]]);
//! End TO
//--- init macroblock data ---
init_macroblock
// 此处被调用1188次
// 下面这个部分是提取运动矢量的重头戏
// 1188个宏块如何分配呢？
// 1188 = 325 + 78 + 785
if (IS_DIRECT (currMB) && img-&cod_counter &= 0)
// 此处被调用325次
// 由于涉及到B宏块，所以，不理它
currMB-&cbp = 0;
reset_coeffs();
if (active_pps-&entropy_coding_mode_flag ==CABAC)
img-&cod_counter=-1;
return DECODE_MB;
if (IS_COPY (currMB)) //keep last macroblock
// IS_COPY表示skip形式的P宏块（不表示skip形式的B宏块）
// 用H.264visa观察到4个P帧共有78个skip形式的P宏块
// 此处刚好被调用78次
int i, j, k, pmv[2];
int zeroMotionA
int zeroMotionL
PixelPos mb_a, mb_b;
a_mv_y = 0;
a_ref_idx = 0;
b_mv_y = 0;
b_ref_idx = 0;
list_offset = ((img-&MbaffFrameFlag)&&(currMB-&mb_field))? img-&current_mb_nr%2 ? 4 : 2 : 0;
getLuma4x4Neighbour(img-&current_mb_nr,0,0,-1, 0,&mb_a);
getLuma4x4Neighbour(img-&current_mb_nr,0,0, 0,-1,&mb_b);
if (mb_a.available)
= dec_picture-&mv[LIST_0][mb_a.pos_x][mb_a.pos_y][1];
a_ref_idx = dec_picture-&ref_idx[LIST_0][mb_a.pos_x][mb_a.pos_y];
if (currMB-&mb_field && !img-&mb_data[mb_a.mb_addr].mb_field)
a_ref_idx *=2;
if (!currMB-&mb_field && img-&mb_data[mb_a.mb_addr].mb_field)
a_ref_idx &&=1;
if (mb_b.available)
= dec_picture-&mv[LIST_0][mb_b.pos_x][mb_b.pos_y][1];
b_ref_idx = dec_picture-&ref_idx[LIST_0][mb_b.pos_x][mb_b.pos_y];
if (currMB-&mb_field && !img-&mb_data[mb_b.mb_addr].mb_field)
b_ref_idx *=2;
if (!currMB-&mb_field && img-&mb_data[mb_b.mb_addr].mb_field)
b_ref_idx &&=1;
zeroMotionLeft
= !mb_a.available ? 1 : a_ref_idx==0 && dec_picture-&mv[LIST_0][mb_a.pos_x][mb_a.pos_y][0]==0 && a_mv_y==0 ? 1 : 0;
zeroMotionAbove = !mb_b.available ? 1 : b_ref_idx==0 && dec_picture-&mv[LIST_0][mb_b.pos_x][mb_b.pos_y][0]==0 && b_mv_y==0 ? 1 : 0;
currMB-&cbp = 0;
reset_coeffs();
img_block_y
= img-&block_y;
if (zeroMotionAbove || zeroMotionLeft)
// 这些skip形式的P宏块的运动矢量为零
fprintf(myMV, &%-4d %-4d &, 0, 0);
for(i=0;i&BLOCK_SIZE;i++)
for(j=0;j&BLOCK_SIZE;j++)
for (k=0;k&2;k++)
dec_picture-&mv[LIST_0][img-&block_x+i][img-&block_y+j][k] = 0;
SetMotionVectorPredictor (img, pmv, pmv+1, 0, LIST_0, dec_picture-&ref_idx, dec_picture-&mv, 0, 0, 16, 16);
// 这些skip形式的P宏块的运动矢量为(pmv[0], pmv[1])
fprintf(myMV, &%-4d %-4d &, pmv[0], pmv[1]);
for(i=0;i&BLOCK_SIZE;i++)
for(j=0;j&BLOCK_SIZE;j++)
for (k=0;k&2;k++)
dec_picture-&mv[LIST_0][img-&block_x+i][img_block_y+j][k] = pmv[k];
for(i=0;i&BLOCK_SIZE;i++)
for(j=0;j&BLOCK_SIZE;j++)
dec_picture-&ref_idx[LIST_0][img-&block_x+i][img_block_y+j] = 0;
dec_picture-&ref_pic_id[LIST_0][img-&block_x+i][img_block_y+j] = dec_picture-&ref_pic_num[img-&current_slice_nr][LIST_0 + list_offset][dec_picture-&ref_idx[LIST_0][img-&block_x+i][img_block_y+j]];
return DECODE_MB;
}// skip形式的P宏块结束
if(currMB-&mb_type!=IPCM)
// 有785个宏块进入到此处，此处被调用785次
// intra prediction modes for a macroblock 4x4 **********************************************
read_ipred_modes(img,inp);
// read inter frame vector data *********************************************************
if (IS_INTERMV (currMB))
// 此处被调用632次
// 下面这个是一个极为关键的函数
// B宏块和P宏块都有可能进入该函数
// 如果只提取P帧的运动矢量，则要加限制
readMotionInfoFromNAL (img, inp);
// 下面这些else if是本人加的，目的是为了方便数据处理
// 认为P帧中I宏块的运动矢量为(0, 0)，便于统一操作
// 785 - 632 = 153, 153 = 99 + 37 + 17
else if(img-&type == I_SLICE)
// 此处被调用99次，刚好是I帧中的宏块数
NULL; // 空语句
else if(img-&type == P_SLICE)
// 此处被调用37次
// 4个P帧的I宏块刚好37个
// 为了数据对齐，认为P帧中I宏块的运动矢量为零
fprintf(myMV, &%-4d %-4d &, 0, 0);
else if(img-&type == B_SLICE)
// 此处被调用17次
// 7个B帧的B_Direct_16x16宏块刚好17个
// read CBP and Coeffs
***************************************************************
readCBPandCoeffsFromNAL (img,inp);
//read pcm_alignment_zero_bit and pcm_byte[i]
// here dP is assigned with the same dP as SE_MBTYPE, because IPCM syntax is in the
// same category as MBTYPE
dP = &(currSlice-&partArr[partMap[SE_MBTYPE]]);
readIPCMcoeffsFromNAL(img,inp,dP);
return DECODE_MB;
&&&&&& 接着看重要的函数readMotionInfoFromNAL函数：
void readMotionInfoFromNAL (struct img_par *img, struct inp_par *inp)
int controlFlag = 0;
int i,j,k;
int step_h,step_v;
Macroblock *currMB
= &img-&mb_data[img-&current_mb_nr];
SyntaxElement currSE;
Slice *currSlice
= img-&currentS
DataPartition *dP;
int *partMap
= assignSE2partition[currSlice-&dp_mode];
int bframe
= (img-&type==B_SLICE);
int partmode
= (IS_P8x8(currMB)?4:currMB-&mb_type);
int step_h0
= BLOCK_STEP [partmode][0];
int step_v0
= BLOCK_STEP [partmode][1];
int mv_mode, i0, j0,
int pmv[2];
int j4, i4, ii,
int mv_scale = 0;
int list_offset = ((img-&MbaffFrameFlag)&&(currMB-&mb_field))? img-&current_mb_nr%2 ? 4 : 2 : 0;
co_located_
co_located_ref_
co_located_ref_
if ((img-&MbaffFrameFlag)&&(currMB-&mb_field))
if(img-&current_mb_nr%2)
moving_block = Co_located-&bottom_moving_
co_located_mv = Co_located-&bottom_
co_located_ref_idx = Co_located-&bottom_ref_
co_located_ref_id = Co_located-&bottom_ref_pic_
moving_block = Co_located-&top_moving_
co_located_mv = Co_located-&top_
co_located_ref_idx = Co_located-&top_ref_
co_located_ref_id = Co_located-&top_ref_pic_
moving_block = Co_located-&moving_
co_located_mv = Co_located-&
co_located_ref_idx = Co_located-&ref_
co_located_ref_id = Co_located-&ref_pic_
if (bframe && IS_P8x8 (currMB))
if (img-&direct_type)
int imgblock_y= ((img-&MbaffFrameFlag)&&(currMB-&mb_field))? (img-&current_mb_nr%2) ? (img-&block_y-4)/2:img-&block_y/2: img-&block_y;
int fw_rFrameL, fw_rFrameU, fw_rFrameUL, fw_rFrameUR;
int bw_rFrameL, bw_rFrameU, bw_rFrameUL, bw_rFrameUR;
PixelPos mb_left, mb_up, mb_upleft, mb_
int fw_rFrame,bw_rF
int pmvfw[2]={0,0},pmvbw[2]={0,0};
getLuma4x4Neighbour(img-&current_mb_nr, 0, 0, -1,
0, &mb_left);
getLuma4x4Neighbour(img-&current_mb_nr, 0, 0,
0, -1, &mb_up);
getLuma4x4Neighbour(img-&current_mb_nr, 0, 0, 16, -1, &mb_upright);
getLuma4x4Neighbour(img-&current_mb_nr, 0, 0, -1, -1, &mb_upleft);
if (!img-&MbaffFrameFlag)
fw_rFrameL = mb_left.available ? dec_picture-&ref_idx[LIST_0][mb_left.pos_x][mb_left.pos_y] : -1;
fw_rFrameU = mb_up.available ? dec_picture-&ref_idx[LIST_0][mb_up.pos_x][mb_up.pos_y] : -1;
fw_rFrameUL = mb_upleft.available ? dec_picture-&ref_idx[LIST_0][mb_upleft.pos_x][mb_upleft.pos_y] : -1;
fw_rFrameUR = mb_upright.available ? dec_picture-&ref_idx[LIST_0][mb_upright.pos_x][mb_upright.pos_y] : fw_rFrameUL;
bw_rFrameL = mb_left.available ? dec_picture-&ref_idx[LIST_1][mb_left.pos_x][mb_left.pos_y] : -1;
bw_rFrameU = mb_up.available ? dec_picture-&ref_idx[LIST_1][mb_up.pos_x][mb_up.pos_y] : -1;
bw_rFrameUL = mb_upleft.available ? dec_picture-&ref_idx[LIST_1][mb_upleft.pos_x][mb_upleft.pos_y] : -1;
bw_rFrameUR = mb_upright.available ? dec_picture-&ref_idx[LIST_1][mb_upright.pos_x][mb_upright.pos_y] : bw_rFrameUL;
if (img-&mb_data[img-&current_mb_nr].mb_field)
fw_rFrameL = mb_left.available ?
img-&mb_data[mb_left.mb_addr].mb_field
|| dec_picture-&ref_idx[LIST_0][mb_left.pos_x][mb_left.pos_y] & 0?
dec_picture-&ref_idx[LIST_0][mb_left.pos_x][mb_left.pos_y] :
dec_picture-&ref_idx[LIST_0][mb_left.pos_x][mb_left.pos_y] * 2: -1;
fw_rFrameU = mb_up.available ?
img-&mb_data[mb_up.mb_addr].mb_field || dec_picture-&ref_idx[LIST_0][mb_up.pos_x][mb_up.pos_y] & 0?
dec_picture-&ref_idx[LIST_0][mb_up.pos_x][mb_up.pos_y] :
dec_picture-&ref_idx[LIST_0][mb_up.pos_x][mb_up.pos_y] * 2: -1;
fw_rFrameUL = mb_upleft.available ?
img-&mb_data[mb_upleft.mb_addr].mb_field || dec_picture-&ref_idx[LIST_0][mb_upleft.pos_x][mb_upleft.pos_y] & 0?
dec_picture-&ref_idx[LIST_0][mb_upleft.pos_x][mb_upleft.pos_y] :
dec_picture-&ref_idx[LIST_0][mb_upleft.pos_x][mb_upleft.pos_y] *2: -1;
fw_rFrameUR = mb_upright.available ?
img-&mb_data[mb_upright.mb_addr].mb_field || dec_picture-&ref_idx[LIST_0][mb_upright.pos_x][mb_upright.pos_y] & 0 ?
dec_picture-&ref_idx[LIST_0][mb_upright.pos_x][mb_upright.pos_y] :
dec_picture-&ref_idx[LIST_0][mb_upright.pos_x][mb_upright.pos_y] * 2: fw_rFrameUL;
bw_rFrameL = mb_left.available ?
img-&mb_data[mb_left.mb_addr].mb_field || dec_picture-&ref_idx[LIST_1][mb_left.pos_x][mb_left.pos_y]
dec_picture-&ref_idx[LIST_1][mb_left.pos_x][mb_left.pos_y] :
dec_picture-&ref_idx[LIST_1][mb_left.pos_x][mb_left.pos_y] * 2: -1;
bw_rFrameU = mb_up.available ?
img-&mb_data[mb_up.mb_addr].mb_field || dec_picture-&ref_idx[LIST_1][mb_up.pos_x][mb_up.pos_y]
dec_picture-&ref_idx[LIST_1][mb_up.pos_x][mb_up.pos_y] :
dec_picture-&ref_idx[LIST_1][mb_up.pos_x][mb_up.pos_y] * 2: -1;
bw_rFrameUL = mb_upleft.available ?
img-&mb_data[mb_upleft.mb_addr].mb_field || dec_picture-&ref_idx[LIST_1][mb_upleft.pos_x][mb_upleft.pos_y]
dec_picture-&ref_idx[LIST_1][mb_upleft.pos_x][mb_upleft.pos_y] :
dec_picture-&ref_idx[LIST_1][mb_upleft.pos_x][mb_upleft.pos_y] *2: -1;
bw_rFrameUR = mb_upright.available ?
img-&mb_data[mb_upright.mb_addr].mb_field || dec_picture-&ref_idx[LIST_1][mb_upright.pos_x][mb_upright.pos_y]
dec_picture-&ref_idx[LIST_1][mb_upright.pos_x][mb_upright.pos_y] :
dec_picture-&ref_idx[LIST_1][mb_upright.pos_x][mb_upright.pos_y] * 2: bw_rFrameUL;
fw_rFrameL = mb_left.available ?
img-&mb_data[mb_left.mb_addr].mb_field || dec_picture-&ref_idx[LIST_0][mb_left.pos_x][mb_left.pos_y]
dec_picture-&ref_idx[LIST_0][mb_left.pos_x][mb_left.pos_y] && 1 :
dec_picture-&ref_idx[LIST_0][mb_left.pos_x][mb_left.pos_y]: -1;
fw_rFrameU = mb_up.available ?
img-&mb_data[mb_up.mb_addr].mb_field || dec_picture-&ref_idx[LIST_0][mb_up.pos_x][mb_up.pos_y]
dec_picture-&ref_idx[LIST_0][mb_up.pos_x][mb_up.pos_y] && 1 :
dec_picture-&ref_idx[LIST_0][mb_up.pos_x][mb_up.pos_y] : -1;
fw_rFrameUL = mb_upleft.available ?
img-&mb_data[mb_upleft.mb_addr].mb_field || dec_picture-&ref_idx[LIST_0][mb_upleft.pos_x][mb_upleft.pos_y] & 0 ?
dec_picture-&ref_idx[LIST_0][mb_upleft.pos_x][mb_upleft.pos_y]&& 1 :
dec_picture-&ref_idx[LIST_0][mb_upleft.pos_x][mb_upleft.pos_y] : -1;
fw_rFrameUR = mb_upright.available ?
img-&mb_data[mb_upright.mb_addr].mb_field || dec_picture-&ref_idx[LIST_0][mb_upright.pos_x][mb_upright.pos_y]
dec_picture-&ref_idx[LIST_0][mb_upright.pos_x][mb_upright.pos_y] && 1 :
dec_picture-&ref_idx[LIST_0][mb_upright.pos_x][mb_upright.pos_y] : fw_rFrameUL;
bw_rFrameL = mb_left.available ?
img-&mb_data[mb_left.mb_addr].mb_field || dec_picture-&ref_idx[LIST_1][mb_left.pos_x][mb_left.pos_y] & 0 ?
dec_picture-&ref_idx[LIST_1][mb_left.pos_x][mb_left.pos_y] && 1 :
dec_picture-&ref_idx[LIST_1][mb_left.pos_x][mb_left.pos_y] : -1;
bw_rFrameU = mb_up.available ?
img-&mb_data[mb_up.mb_addr].mb_field || dec_picture-&ref_idx[LIST_1][mb_up.pos_x][mb_up.pos_y] & 0 ?
dec_picture-&ref_idx[LIST_1][mb_up.pos_x][mb_up.pos_y] && 1 :
dec_picture-&ref_idx[LIST_1][mb_up.pos_x][mb_up.pos_y] : -1;
bw_rFrameUL = mb_upleft.available ?
img-&mb_data[mb_upleft.mb_addr].mb_field || dec_picture-&ref_idx[LIST_1][mb_upleft.pos_x][mb_upleft.pos_y]
dec_picture-&ref_idx[LIST_1][mb_upleft.pos_x][mb_upleft.pos_y] && 1 :
dec_picture-&ref_idx[LIST_1][mb_upleft.pos_x][mb_upleft.pos_y] : -1;
bw_rFrameUR = mb_upright.available ?
img-&mb_data[mb_upright.mb_addr].mb_field || dec_picture-&ref_idx[LIST_1][mb_upright.pos_x][mb_upright.pos_y] & 0 ?
dec_picture-&ref_idx[LIST_1][mb_upright.pos_x][mb_upright.pos_y] && 1:
dec_picture-&ref_idx[LIST_1][mb_upright.pos_x][mb_upright.pos_y] : bw_rFrameUL;
fw_rFrame = (fw_rFrameL &= 0 && fw_rFrameU &= 0) ? min(fw_rFrameL,fw_rFrameU): max(fw_rFrameL,fw_rFrameU);
fw_rFrame = (fw_rFrame &= 0 && fw_rFrameUR &= 0) ? min(fw_rFrame,fw_rFrameUR): max(fw_rFrame,fw_rFrameUR);
bw_rFrame = (bw_rFrameL &= 0 && bw_rFrameU &= 0) ? min(bw_rFrameL,bw_rFrameU): max(bw_rFrameL,bw_rFrameU);
bw_rFrame = (bw_rFrame &= 0 && bw_rFrameUR &= 0) ? min(bw_rFrame,bw_rFrameUR): max(bw_rFrame,bw_rFrameUR);
if (fw_rFrame &=0)
SetMotionVectorPredictor (img, pmvfw, pmvfw+1, fw_rFrame, LIST_0, dec_picture-&ref_idx, dec_picture-&mv, 0, 0, 16, 16);
if (bw_rFrame &=0)
SetMotionVectorPredictor (img, pmvbw, pmvbw+1, bw_rFrame, LIST_1, dec_picture-&ref_idx, dec_picture-&mv, 0, 0, 16, 16);
for (i=0;i&4;i++)
if (currMB-&b8mode[i] == 0)
for(j=2*(i/2);j&2*(i/2)+2;j++)
for(k=2*(i%2);k&2*(i%2)+2;k++)
int j6 = imgblock_y+j;
j4 = img-&block_y+j;
i4 = img-&block_x+k;
if (fw_rFrame &= 0)
(!fw_rFrame
&& ((!moving_block[i4][j6]) && (!listX[1+list_offset][0]-&is_long_term)))
dec_picture-&mv
[LIST_0][i4][j4][0] = 0;
dec_picture-&mv
[LIST_0][i4][j4][1] = 0;
dec_picture-&ref_idx[LIST_0][i4][j4] = 0;
dec_picture-&mv
[LIST_0][i4][j4][0] = pmvfw[0];
dec_picture-&mv
[LIST_0][i4][j4][1] = pmvfw[1];
dec_picture-&ref_idx[LIST_0][i4][j4] = fw_rF
dec_picture-&mv
[LIST_0][i4][j4][0] = 0;
dec_picture-&mv
[LIST_0][i4][j4][1] = 0;
dec_picture-&ref_idx[LIST_0][i4][j4] = -1;
if (bw_rFrame &= 0)
(bw_rFrame==0 && ((!moving_block[i4][j6])&& (!listX[1+list_offset][0]-&is_long_term)))
dec_picture-&mv
[LIST_1][i4][j4][0] = 0;
dec_picture-&mv
[LIST_1][i4][j4][1] = 0;
dec_picture-&ref_idx[LIST_1][i4][j4] = 0;
dec_picture-&mv
[LIST_1][i4][j4][0] = pmvbw[0];
dec_picture-&mv
[LIST_1][i4][j4][1] = pmvbw[1];
dec_picture-&ref_idx[LIST_1][i4][j4] = bw_rF
dec_picture-&mv
[LIST_1][i4][j4][0] = 0;
dec_picture-&mv
[LIST_1][i4][j4][1] = 0;
dec_picture-&ref_idx[LIST_1][i4][j4] = -1;
if (fw_rFrame &0 && bw_rFrame &0)
dec_picture-&ref_idx[LIST_0][i4][j4] = 0;
dec_picture-&ref_idx[LIST_1][i4][j4] = 0;
for (i=0;i&4;i++)
if (currMB-&b8mode[i] == 0)
for(j=2*(i/2);j&2*(i/2)+2;j++)
for(k=2*(i%2);k&2*(i%2)+2;k++)
int list_offset = ((img-&MbaffFrameFlag)&&(currMB-&mb_field))? img-&current_mb_nr%2 ? 4 : 2 : 0;
int imgblock_y= ((img-&MbaffFrameFlag)&&(currMB-&mb_field))? (img-&current_mb_nr%2) ? (img-&block_y-4)/2 : img-&block_y/2 : img-&block_y;
int refList = co_located_ref_idx[LIST_0 ][img-&block_x+k][imgblock_y+j]== -1 ? LIST_1 : LIST_0;
int ref_idx = co_located_ref_idx[refList][img-&block_x + k][imgblock_y + j];
int mapped_idx=-1,
if (ref_idx == -1)
dec_picture-&ref_idx [LIST_0][img-&block_x + k][img-&block_y + j] = 0;
dec_picture-&ref_idx [LIST_1][img-&block_x + k][img-&block_y + j] = 0;
for (iref=0;iref&min(img-&num_ref_idx_l0_active,listXsize[LIST_0 + list_offset]);iref++)
if (dec_picture-&ref_pic_num[img-&current_slice_nr][LIST_0 + list_offset][iref]==co_located_ref_id[refList][img-&block_x + k][imgblock_y + j])
mapped_idx=
else //! invalid index. Default to zero even though this case should not happen
mapped_idx=INVALIDINDEX;
if (INVALIDINDEX == mapped_idx)
error(&temporal direct error\ncolocated block has ref that is unavailable&,-1111);
dec_picture-&ref_idx [LIST_0][img-&block_x + k][img-&block_y + j] = mapped_
dec_picture-&ref_idx [LIST_1][img-&block_x + k][img-&block_y + j] = 0;
If multiple ref. frames, read reference frame for the MB *********************************
if(img-&num_ref_idx_l0_active&1)
flag_mode = ( img-&num_ref_idx_l0_active == 2 ? 1 : 0);
currSE.type = SE_REFFRAME;
dP = &(currSlice-&partArr[partMap[SE_REFFRAME]]);
if (active_pps-&entropy_coding_mode_flag == UVLC || dP-&bitstream-&ei_flag)
currSE.mapping = linfo_
currSE.reading = readRefFrame_CABAC;
for (j0=0; j0&4; j0+=step_v0)
for (i0=0; i0&4; i0+=step_h0)
k=2*(j0/2)+(i0/2);
if ((currMB-&b8pdir[k]==0 || currMB-&b8pdir[k]==2) && currMB-&b8mode[k]!=0)
TRACE_STRING(&ref_idx_l0&);
img-&subblock_x = i0;
img-&subblock_y = j0;
if (!IS_P8x8 (currMB) || bframe || (!bframe && !img-&allrefzero))
currSE.context = BType2CtxRef (currMB-&b8mode[k]);
if( (active_pps-&entropy_coding_mode_flag == UVLC || dP-&bitstream-&ei_flag) && flag_mode )
currSE.len = 1;
readSyntaxElement_FLC(&currSE, dP-&bitstream);
currSE.value1 = 1 - currSE.value1;
currSE.value2 = LIST_0;
dP-&readSyntaxElement (&currSE,img,inp,dP);
refframe = currSE.value1;
refframe = 0;
if (bframe && refframe&img-&buf_cycle)
// img-&buf_cycle should be correct for field MBs now
set_ec_flag(SE_REFFRAME);
refframe = 1;
for (j=j0; j&j0+step_v0;j++)
for (i=i0; i&i0+step_h0;i++)
dec_picture-&ref_idx[LIST_0][img-&block_x + i][img-&block_y + j] =
for (j0=0; j0&4; j0+=step_v0)
for (i0=0; i0&4; i0+=step_h0)
k=2*(j0/2)+(i0/2);
if ((currMB-&b8pdir[k]==0 || currMB-&b8pdir[k]==2) && currMB-&b8mode[k]!=0)
for (j=j0; j&j0+step_v0;j++)
for (i=i0; i&i0+step_h0;i++)
dec_picture-&ref_idx[LIST_0][img-&block_x + i][img-&block_y + j] = 0;
If backward multiple ref. frames, read backward reference frame for the MB *********************************
if(img-&num_ref_idx_l1_active&1)
flag_mode = ( img-&num_ref_idx_l1_active == 2 ? 1 : 0);
currSE.type = SE_REFFRAME;
dP = &(currSlice-&partArr[partMap[SE_REFFRAME]]);
if (active_pps-&entropy_coding_mode_flag == UVLC || dP-&bitstream-&ei_flag)
currSE.mapping = linfo_
currSE.reading = readRefFrame_CABAC;
for (j0=0; j0&4; j0+=step_v0)
for (i0=0; i0&4; i0+=step_h0)
k=2*(j0/2)+(i0/2);
if ((currMB-&b8pdir[k]==1 || currMB-&b8pdir[k]==2) && currMB-&b8mode[k]!=0)
TRACE_STRING(&ref_idx_l1&);
img-&subblock_x = i0;
img-&subblock_y = j0;
currSE.context = BType2CtxRef (currMB-&b8mode[k]);
if( (active_pps-&entropy_coding_mode_flag == UVLC || dP-&bitstream-&ei_flag) && flag_mode )
currSE.len = 1;
readSyntaxElement_FLC(&currSE, dP-&bitstream);
currSE.value1 = 1-currSE.value1;
currSE.value2 = LIST_1;
dP-&readSyntaxElement (&currSE,img,inp,dP);
refframe = currSE.value1;
for (j=j0; j&j0+step_v0;j++)
for (i=i0; i&i0+step_h0;i++)
dec_picture-&ref_idx[LIST_1][img-&block_x + i][img-&block_y + j] =
for (j0=0; j0&4; j0+=step_v0)
for (i0=0; i0&4; i0+=step_h0)
k=2*(j0/2)+(i0/2);
if ((currMB-&b8pdir[k]==1 || currMB-&b8pdir[k]==2) && currMB-&b8mode[k]!=0)
for (j=j0; j&j0+step_v0;j++)
for (i=i0; i&i0+step_h0;i++)
dec_picture-&ref_idx[LIST_1][img-&block_x + i][img-&block_y + j] = 0;
READ FORWARD MOTION VECTORS =====
currSE.type = SE_MVD;
dP = &(currSlice-&partArr[partMap[SE_MVD]]);
if (active_pps-&entropy_coding_mode_flag == UVLC || dP-&bitstream-&ei_flag) currSE.mapping = linfo_
currSE.reading = readMVD_CABAC;
for (j0=0; j0&4; j0+=step_v0)
for (i0=0; i0&4; i0+=step_h0)
k=2*(j0/2)+(i0/2);
if ((currMB-&b8pdir[k]==0 || currMB-&b8pdir[k]==2) && (currMB-&b8mode[k] !=0))//has forward vector
= currMB-&b8mode[k];
= BLOCK_STEP [mv_mode][0];
= BLOCK_STEP [mv_mode][1];
refframe = dec_picture-&ref_idx[LIST_0][img-&block_x+i0][img-&block_y+j0];
for (j=j0; j&j0+step_v0; j+=step_v)
for (i=i0; i&i0+step_h0; i+=step_h)
j4 = img-&block_y+j;
i4 = img-&block_x+i;
// first make mv-prediction
SetMotionVectorPredictor (img, pmv, pmv+1, refframe, LIST_0, dec_picture-&ref_idx, dec_picture-&mv, i, j, 4*step_h, 4*step_v);
for (k=0; k & 2; k++)
TRACE_STRING(&mvd_l0&);
img-&subblock_x = // position used for context determination
img-&subblock_y = // position used for context determination
currSE.value2 = k&&1; // iden only used for context determination
dP-&readSyntaxElement(&currSE,img,inp,dP);
curr_mvd = currSE.value1;
// 运动矢量就在此
vec=curr_mvd+pmv[k];
/* find motion vector */
// 取每个宏块的最左上角的那个4 * 4块的运动矢量
// 故用controlFlag &= 2 来限制x分量和y分量
// 由于B宏块也会进入到这里，所以要用P_SLICE限制
// skip形式的P宏块不会进入到这里来，所以不用担心
controlFlag++;
if(controlFlag &= 2 && img-&type == P_SLICE)
//another++;
//printf(&********%d another\n&, another);
fprintf(myMV, &%-4d &, vec);
for(ii=0;ii&step_h;ii++)
for(jj=0;jj&step_v;jj++)
dec_picture-&mv
[LIST_0][i4+ii][j4+jj][k] =
currMB-&mvd
[LIST_0][j+jj] [i+ii] [k] = curr_
else if (currMB-&b8mode[k=2*(j0/2)+(i0/2)]==0)
if (!img-&direct_type)
int list_offset = ((img-&MbaffFrameFlag)&&(currMB-&mb_field))? img-&current_mb_nr%2 ? 4 : 2 : 0;
int imgblock_y= ((img-&MbaffFrameFlag)&&(currMB-&mb_field))? (img-&current_mb_nr%2) ? (img-&block_y-4)/2:img-&block_y/2 : img-&block_y;
int refList = (co_located_ref_idx[LIST_0][img-&block_x+i0][imgblock_y+j0]== -1 ? LIST_1 : LIST_0);
int ref_idx =
co_located_ref_idx[refList][img-&block_x+i0][imgblock_y+j0];
if (ref_idx==-1)
for (j=j0; j&j0+step_v0; j++)
for (i=i0; i&i0+step_h0; i++)
dec_picture-&ref_idx [LIST_1][img-&block_x+i][img-&block_y+j]=0;
dec_picture-&ref_idx [LIST_0][img-&block_x+i][img-&block_y+j]=0;
j4 = img-&block_y+j;
i4 = img-&block_x+i;
for (ii=0; ii & 2; ii++)
dec_picture-&mv [LIST_0][i4][j4][ii]=0;
dec_picture-&mv [LIST_1][i4][j4][ii]=0;
int mapped_idx=-1,
for (iref=0;iref&min(img-&num_ref_idx_l0_active,listXsize[LIST_0 + list_offset]);iref++)
if (dec_picture-&ref_pic_num[img-&current_slice_nr][LIST_0 + list_offset][iref]==co_located_ref_id[refList][img-&block_x+i0][imgblock_y+j0])
mapped_idx=
else //! invalid index. Default to zero even though this case should not happen
mapped_idx=INVALIDINDEX;
if (INVALIDINDEX == mapped_idx)
error(&temporal direct error\ncolocated block has ref that is unavailable&,-1111);
for (j=j0; j&j0+step_v0; j++)
for (i=i0; i&i0+step_h0; i++)
mv_scale = img-&mvscale[LIST_0 + list_offset][mapped_idx];
dec_picture-&ref_idx [LIST_0][img-&block_x+i][img-&block_y+j] = mapped_
dec_picture-&ref_idx [LIST_1][img-&block_x+i][img-&block_y+j] = 0;
j4 = img-&block_y+j;
j6 = imgblock_y+j;
i4 = img-&block_x+i;
for (ii=0; ii & 2; ii++)
//if (iTRp==0)
if (mv_scale == 9999 || listX[LIST_0+list_offset][mapped_idx]-&is_long_term)
if (mv_scale==9999 || Co_located-&is_long_term)
dec_picture-&mv
[LIST_0][i4][j4][ii]=co_located_mv[refList][i4][j6][ii];
dec_picture-&mv
[LIST_1][i4][j4][ii]=0;
dec_picture-&mv
[LIST_0][i4][j4][ii]=(mv_scale * co_located_mv[refList][i4][j6][ii] + 128 ) && 8;
dec_picture-&mv
[LIST_1][i4][j4][ii]=dec_picture-&mv[LIST_0][i4][j4][ii] - co_located_mv[refList][i4][j6][ii];
READ BACKWARD MOTION VECTORS =====
currSE.type = SE_MVD;
= &(currSlice-&partArr[partMap[SE_MVD]]);
if (active_pps-&entropy_coding_mode_flag == UVLC || dP-&bitstream-&ei_flag) currSE.mapping = linfo_
currSE.reading = readMVD_CABAC;
for (j0=0; j0&4; j0+=step_v0)
for (i0=0; i0&4; i0+=step_h0)
k=2*(j0/2)+(i0/2);
if ((currMB-&b8pdir[k]==1 || currMB-&b8pdir[k]==2) && (currMB-&b8mode[k]!=0))//has backward vector
= currMB-&b8mode[k];
= BLOCK_STEP [mv_mode][0];
= BLOCK_STEP [mv_mode][1];
refframe = dec_picture-&ref_idx[LIST_1][img-&block_x+i0][img-&block_y+j0];
for (j=j0; j&j0+step_v0; j+=step_v)
for (i=i0; i&i0+step_h0; i+=step_h)
j4 = img-&block_y+j;
i4 = img-&block_x+i;
// first make mv-prediction
SetMotionVectorPredictor (img, pmv, pmv+1, refframe, LIST_1, dec_picture-&ref_idx, dec_picture-&mv, i, j, 4*step_h, 4*step_v);
for (k=0; k & 2; k++)
TRACE_STRING(&mvd_l1&);
img-&subblock_x = // position used for context determination
img-&subblock_y = // position used for context determination
currSE.value2
= (k&&1) +1; // iden only used for context determination
dP-&readSyntaxElement(&currSE,img,inp,dP);
curr_mvd = currSE.value1;
vec=curr_mvd+pmv[k];
/* find motion vector */
for(ii=0;ii&step_h;ii++)
for(jj=0;jj&step_v;jj++)
dec_picture-&mv
[LIST_1][i4+ii][j4+jj][k] =
currMB-&mvd
[LIST_1][j+jj] [i+ii] [k] = curr_
// record reference picture Ids for deblocking decisions
for(i4=img-&block_x;i4&(img-&block_x+4);i4++)
for(j4=img-&block_y;j4&(img-&block_y+4);j4++)
if(dec_picture-&ref_idx[LIST_0][i4][j4]&=0)
dec_picture-&ref_pic_id[LIST_0][i4][j4] = dec_picture-&ref_pic_num[img-&current_slice_nr][LIST_0 + list_offset][dec_picture-&ref_idx[LIST_0][i4][j4]];
dec_picture-&ref_pic_id[LIST_0][i4][j4] = INT64_MIN;
if(dec_picture-&ref_idx[LIST_1][i4][j4]&=0)
dec_picture-&ref_pic_id[LIST_1][i4][j4] = dec_picture-&ref_pic_num[img-&current_slice_nr][LIST_1 + list_offset][dec_picture-&ref_idx[LIST_1][i4][j4]];
dec_picture-&ref_pic_id[LIST_1][i4][j4] = INT64_MIN;
&&&&&&&经验证，上面提取的运动矢量的结果和H.264visa提取的运动矢量的结果完全一致. OK, 这样就实现了对码流中P帧运动矢量的提取. 最后强调一句：实际运动矢量是上述运动矢量除以4.
&&相关文章推荐
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