Something about C

What the hell? How long since I touch with C?

What a pity, I have to work with it now.

Global variable

Better define a global.h, define variable as

extern int i;

And when U use it in another C, do as

unsigned char SysEventCounter = 0;

U can do it in one C file, if U do it in another C file, it will broadcast error.

Operator

Sometimes U encounter & and &&, what’s difference between them? & is bit operator for instance: 5 & 3 = 3; As for &&, a logical operator, 1 && 3 = 1.

Pointer

To allocation two dimension dynamic array:

#include <malloc.h>
reconstructedMVField**MVField;
MVField=(reconstructedMVField**)malloc((picSizeY>>2) * sizeof(reconstructedMVField *));
for(j = 0; j < (picSizeY >> 2); j++)
{
MVField[j]=(reconstructedMVField*)malloc((picSizeX>>2) * sizeof(reconstructedMVField));
}
for(j = 0; j < (picSizeY >> 2); j++)
free(MVField[j]);
free(MVField);

This guy’s blog is not bad.

http://www.cnblogs.com/chenwenbiao/archive/2011/11/04/2236679.html

http://blog.sina.com.cn/s/blog_5d6189e50100bbnd.html

http://blog.sina.com.cn/s/blog_67299aec0100mqek.html

http://zhidao.baidu.com/link?url=4pICOIhwQAtDmMO3LYT-rKMCY-OQWsQJ2TjKGQM56I_wCit92g_s1IaXoMODJOEzpXUol_CItlPVv6AnXBOCbq

MVField **a;
MVField *temp;
a = (MVField**)malloc(10*sizeof(MVField*));

for (int i = 0; i < 10; i++)
a[i] = (MVField*)malloc(9*sizeof(MVField));

for (int i = 0; i < 10; i++)
{
temp = a[i];
for (int j = 0; j < 9; j++)
{
(*temp).priority = i + j;
(*temp).MVdistance = 0;
(*temp).location.X = j;
(*temp).location.Y = i;
*temp++;
}
}

http://blog.csdn.net/happen23/article/details/4710368

Type Transition

double temp_mvX = 0;
double temp_mvY = 0;
int mvX;
int mvY;
int index_X = 0;
int index_Y = 0;
int region_cover_X = 0;
int region_cover_Y = 0;
temp_mvX = round( (refPic->mv_info[i_row][j_column]).mv[0].mv_x/4.0 );  // X MV in pixel
temp_mvY = round( (refPic->mv_info[i_row][j_column]).mv[0].mv_y/4.0 );  // Y MV in pixel
// to get which region the 4x4 block has covered
mvX = temp_mvX;
mvY = temp_mvY;
region_cover_X = (mvX >= 0) ? (mvX % 4) : ((4 - abs(mvX) % 4)%4);
region_cover_Y = (mvY >= 0) ? (mvY % 4) : ((4 - abs(mvY) % 4)%4);
index_X = j_column + mvX / 4;  // to index block position
index_Y = i_row + mvY / 4;

-> and .

If pointer, “->”

else “.”

But it doesn’t matter, as compiler will tell U.

Multiple Dimension

Be careful of X and Y. Hehe!

Defines like Taps

#ifdef  ERC_BYCOPY_YUV
#undef  ERC_BYCOPY_YUV
#endif

#define IntraMBinSliceAndMBNumInSlice   "D:/CY/JM18_6_RC/scene_change_p_slice.txt"

#if (DEBUG_OPEN == 1)
FILE *erc_dec_mv_info = NULL;
recfr.p_Vid = p_Vid;
VideoParameters *p_Vid1 = recfr.p_Vid;
StorablePicture* refPic = p_Vid1->ppSliceList[0]->listX[0][0];//p_Vid->ppSliceList[0]->listX[0][0];
#if(DEBUG_INFO_FOR_MV == 1)
erc_dec_mv_info = fopen(DEBUG_INFO_FOR_MV_TXT, "a+");
if(p_Vid->dec_picture->frame_num == 3)  // Just look the second frame's mv information and be attention to the start frame and end frame in Concealment_CY.h
{
for(i_row = 0;i_row < ((*dec_picture)->size_y) /4 ;i_row++)
{
for(j_column = 0;j_column < ((*dec_picture)->size_x) / 4;j_column++)
{
fprintf(erc_dec_mv_info, "(%d,%d) -> (%d,%d)->(%d,%d)  ,",i_row,j_column,(refPic->mv_info[i_row][j_column]).mv[0].mv_x,(refPic->mv_info[i_row][j_column]).mv[0].mv_y,(refPic->mv_info[i_row][j_column]).ref_idx[0],(refPic->mv_info[i_row][j_column]).ref_idx[1]);
}
fprintf(erc_dec_mv_info,"\n");
}
fclose(erc_dec_mv_info);
}
#endif
#endif

Bad Code

#define  _CRT_SECURE_NO_WARNINGS

#include <stdio.h>
#include <math.h>
#include <malloc.h>

#define LENCorrupetedBLKMVList sizeof(CorrupetedBLKMVList)
#define AddrNull  0

typedef struct motion_vector
{
int mvX;
int mvY;
} ercMV;

// This struct means that the reconstructed MV of each 4x4 block
typedef struct important_POS
{
int Block_X;  // Here is just for P frame.
int Block_Y;            // 1 means the best suit, next 2, then 3, then 4, then 5 and other number means this mv is empty.
}Position;

void simpletest(ercMV Cst_mv){
printf("%d  %d\n",Cst_mv.mvX,Cst_mv.mvY);
}

typedef struct Corrupted_Per_Block_Ref_MV_Field_Information
{
Position PPixle;
ercMV   estiMV;
int *  pixel;   // With chroma and luma
}RefBLKMVInfor;

// This struct is used for every corrupted block
typedef struct Corrupted_Block_MV_List
{
RefBLKMVInfor  blkInfor;
struct Corrupted_Block_MV_List* next;
}CorrupetedBLKMVList;

/*!
************************************************************************
* \brief
*      To create MV list for block in corrupted frameMV field.
* \return
*      Pointer of struct CorrupetedBLKMVList.
* \param NONE
* \2015/10/9 14:56:30
************************************************************************
*/
CorrupetedBLKMVList* CreateMVFieldPerBlockMVListHead(void)
{
CorrupetedBLKMVList* head;
head = (CorrupetedBLKMVList*)malloc(LENCorrupetedBLKMVList);
head -> next = AddrNull;

return head;
}

/*!
************************************************************************
* \brief
*      To insert MV block node  for block in corrupted frameMV field.
* \return
*      Pointer head of struct CorrupetedBLKMVList.
* \param NONE
* \2015/10/9 14:56:30
************************************************************************
*/
void InsertMVNodeIntoBlockList(CorrupetedBLKMVList* head, RefBLKMVInfor  insertData, int blockSize)
{
CorrupetedBLKMVList*temp;
int i;
temp = AddrNull;
temp = (CorrupetedBLKMVList*)malloc(LENCorrupetedBLKMVList);
if(temp == AddrNull)
{
printf("Error:In malloc memory for CorrupetedBLKMVList\n");
return;
}

temp -> next = AddrNull;
temp -> blkInfor.PPixle.Block_X =  insertData.PPixle.Block_X;
temp -> blkInfor.PPixle.Block_Y =  insertData.PPixle.Block_Y;
temp -> blkInfor.estiMV.mvX =  insertData.estiMV.mvX;
temp -> blkInfor.estiMV.mvY = insertData.estiMV.mvY;
temp -> blkInfor.pixel = (int*)malloc(blockSize*sizeof(int));

for(i = 0; i < blockSize; i++)
{
temp -> blkInfor.pixel[i] = insertData.pixel[i];
}

head -> next = temp;
}

int main()
{
int i = 0;
const int blockSize = 16;

RefBLKMVInfor  testInsertData;
RefBLKMVInfor  testInsertData2;

// Create node
CorrupetedBLKMVList* test_create = AddrNull;
CorrupetedBLKMVList* search = AddrNull;
test_create = CreateMVFieldPerBlockMVListHead();
if (test_create->next == AddrNull)
printf("Good!\n");
if(test_create != AddrNull)
printf("Create OK:%d \n",test_create);

//  Insert node
testInsertData.pixel = (int*)malloc(blockSize*sizeof(int));

for(i = 0; i < blockSize; i++)
{
testInsertData.pixel[i] = i;
}
testInsertData.PPixle.Block_X = 1;
testInsertData.PPixle.Block_Y = 2;
testInsertData.estiMV.mvX = 3;
testInsertData.estiMV.mvY = 5;

testInsertData2.pixel = (int*)malloc(blockSize*sizeof(int));

for (i = 0; i < blockSize; i++)
{
testInsertData2.pixel[i] = i+1;
}
testInsertData2.PPixle.Block_X = 100;
testInsertData2.PPixle.Block_Y = 21;
testInsertData2.estiMV.mvX = 23;
testInsertData2.estiMV.mvY = 15;

InsertMVNodeIntoBlockList(test_create, testInsertData, blockSize);
InsertMVNodeIntoBlockList(test_create, testInsertData2, blockSize);
InsertMVNodeIntoBlockList(test_create, testInsertData, blockSize);
search = test_create;

while (search != AddrNull)
{
printf("%d\n", search);
printf("%d\n", search->blkInfor.PPixle.Block_X);
printf("%d\n", search->blkInfor.PPixle.Block_Y);
printf("%d\n", search->blkInfor.estiMV.mvX);
printf("%d\n", search->blkInfor.estiMV.mvY);
//      printf("%d\n", search->blkInfor.pixel[5]);
search = search->next;
}

search = test_create;

while (search->next != AddrNull)
{
//  free(search->blkInfor.pixel);
search = search->next;
}

free(testInsertData.pixel);
free(testInsertData2.pixel);
system("pause");
return 0;
}

Good List

#define  _CRT_SECURE_NO_WARNINGS

#include <stdio.h>
#include <math.h>
#include <malloc.h>

#define LENCorrupetedBLKMVList sizeof(CorrupetedBLKMVList)
#define AddrNull  0

typedef struct motion_vector
{
int mvX;
int mvY;
} ercMV;

// This struct means that the reconstructed MV of each 4x4 block
typedef struct important_POS
{
int Block_X;  // Here is just for P frame.
int Block_Y;            // 1 means the best suit, next 2, then 3, then 4, then 5 and other number means this mv is empty.
}Position;

void simpletest(ercMV Cst_mv){
printf("%d  %d\n",Cst_mv.mvX,Cst_mv.mvY);
}

typedef struct Corrupted_Per_Block_Ref_MV_Field_Information
{
Position PPixle;
ercMV   estiMV;
int *  pixel;   // With chroma and luma
}RefBLKMVInfor;

// This struct is used for every corrupted block
typedef struct Corrupted_Block_MV_List
{
RefBLKMVInfor  blkInfor;
struct Corrupted_Block_MV_List* next;
}CorrupetedBLKMVList;

/*!
************************************************************************
* \brief
*      To create MV list for block in corrupted frameMV field.
* \return
*      Pointer of struct CorrupetedBLKMVList.
* \param NONE
* \2015/10/9 14:56:30
************************************************************************
*/
CorrupetedBLKMVList* CreateMVFieldPerBlockMVListHead(void)
{
CorrupetedBLKMVList* head;
head = (CorrupetedBLKMVList*)malloc(LENCorrupetedBLKMVList);
head -> next = AddrNull;

return head;
}

/*!
************************************************************************
* \brief
*      To insert MV block node  for block in corrupted frameMV field.
* \return
*      Pointer head of struct CorrupetedBLKMVList.
* \param NONE
* \2015/10/9 14:56:30
************************************************************************
*/
CorrupetedBLKMVList* InsertMVNodeIntoBlockList(CorrupetedBLKMVList* head, RefBLKMVInfor  insertData, int blockSize)
{
CorrupetedBLKMVList*temp = AddrNull;
int i;

if (head == AddrNull)  // first node
{
head = (CorrupetedBLKMVList*)malloc(LENCorrupetedBLKMVList);
head->next = AddrNull;
head->blkInfor.PPixle.Block_X = insertData.PPixle.Block_X;
head->blkInfor.PPixle.Block_Y = insertData.PPixle.Block_Y;
head->blkInfor.estiMV.mvX = insertData.estiMV.mvX;
head->blkInfor.estiMV.mvY = insertData.estiMV.mvY;
head->blkInfor.pixel = (int*)malloc(blockSize*sizeof(int));

for (i = 0; i < blockSize; i++)
{
head->blkInfor.pixel[i] = insertData.pixel[i];
}
}
else
{
temp = (CorrupetedBLKMVList*)malloc(LENCorrupetedBLKMVList);

if (temp == AddrNull)
{
printf("Error:In malloc memory for CorrupetedBLKMVList\n");
return;
}

temp->blkInfor.PPixle.Block_X = insertData.PPixle.Block_X;
temp->blkInfor.PPixle.Block_Y = insertData.PPixle.Block_Y;
temp->blkInfor.estiMV.mvX = insertData.estiMV.mvX;
temp->blkInfor.estiMV.mvY = insertData.estiMV.mvY;
temp->blkInfor.pixel = (int*)malloc(blockSize*sizeof(int));

for (i = 0; i < blockSize; i++)
{
temp->blkInfor.pixel[i] = insertData.pixel[i];
}

temp->next = head;
head = temp;
}
return head;
}

int main()
{
int i = 0;
const int blockSize = 16;

RefBLKMVInfor  testInsertData;
RefBLKMVInfor  testInsertData2;

// Create node
CorrupetedBLKMVList* test_create = AddrNull;
CorrupetedBLKMVList* search = AddrNull;

if(test_create != AddrNull)
printf("Create OK:%d \n",test_create);

//  Insert node
testInsertData.pixel = (int*)malloc(blockSize*sizeof(int));

for(i = 0; i < blockSize; i++)
{
testInsertData.pixel[i] = i;
}
testInsertData.PPixle.Block_X = 1;
testInsertData.PPixle.Block_Y = 2;
testInsertData.estiMV.mvX = 3;
testInsertData.estiMV.mvY = 5;

testInsertData2.pixel = (int*)malloc(blockSize*sizeof(int));

for (i = 0; i < blockSize; i++)
{
testInsertData2.pixel[i] = i+1;
}
testInsertData2.PPixle.Block_X = 100;
testInsertData2.PPixle.Block_Y = 21;
testInsertData2.estiMV.mvX = 23;
testInsertData2.estiMV.mvY = 15;

test_create = InsertMVNodeIntoBlockList(test_create, testInsertData, blockSize);
test_create = InsertMVNodeIntoBlockList(test_create, testInsertData2, blockSize);
test_create = InsertMVNodeIntoBlockList(test_create, testInsertData, blockSize);
search = test_create;

while (search != AddrNull)
{
printf("%d\n", search);
printf("%d\n", search->blkInfor.PPixle.Block_X);
printf("%d\n", search->blkInfor.PPixle.Block_Y);
printf("%d\n", search->blkInfor.estiMV.mvX);
printf("%d\n", search->blkInfor.estiMV.mvY);
//      printf("%d\n", search->blkInfor.pixel[5]);
search = search->next;
}

search = test_create;

while (search->next != AddrNull)
{
//  free(search->blkInfor.pixel);
search = search->next;
}

free(testInsertData.pixel);
free(testInsertData2.pixel);
system("pause");
return 0;
}

Malloc Two Dimension Pointer

I think the code I write is so beautiful!

CorrupetedBLKMVList*** Pic;
Pic = (CorrupetedBLKMVList***)malloc(height*sizeof(CorrupetedBLKMVList**));

for(j = 0; j < height;j++)
{
Pic[j] = (CorrupetedBLKMVList**)malloc(width*sizeof(CorrupetedBLKMVList*));
}
for(j = 0; j < height;j++)
{
free(Pic[j]);
}
free(Pic);

Flexible Pointer Using

static void GetLumaBlock10(imgpel **block, imgpel **imgY, int blockSizeX, int blockSizeY, int XPosPixel, int YPosPixel, int maxImgpelValue)
{
imgpel *p0, *p1, *p2, *p3, *p4, *p5;
imgpel *orig_line, *cur_line;
int i, j;
int result;

for (j = 0; j < blockSizeY; j++)
{
cur_line = &(cur_imgY[j][XPosPixel]);
p0 = &cur_imgY[j][XPosPixel - 2];
p1 = p0 + 1;
p2 = p1 + 1;
p3 = p2 + 1;
p4 = p3 + 1;
p5 = p4 + 1;
orig_line = block[j];

for (i = 0; i < blockSizeX; i++)
{
result  = (*(p0++) + *(p5++)) - 5 * (*(p1++) + *(p4++)) + 20 * (*(p2++) + *(p3++));
*orig_line = (imgpel) iClip1(maxImgpelValue, ((result + 16)>>5));
*orig_line = (imgpel) ((*orig_line + *(cur_line++) + 1 ) >> 1);
orig_line++;
}
}
}

Divide

‘&’ is a excellent operation. Just think that (-5) & 3 = 3, you will get the right result of U want.

‘%’ is another operation that (-5) % 4 = -1

‘a & b’ can be get by ‘b < 0? (b - abs(a%b)) : (a%b)’

I found that the operation is excellent.

(-3) >> 2 = -1 <=> (int)floor((-3.0)/4.0)

(-3)/4 = 0 <=> (int)ceil((-3.0)/4.0)

Create Files and Copy String

const char* s = "../../new3";

is the same as

#define s "../../new3"

#include <stdio.h>
#include <math.h>
#include <malloc.h>
#include <process.h>
#include <direct.h>
#include <sys/stat.h>
#include <string.h>

static void try_create_dir(const char* dest_dir)
{
if (_access(dest_dir, 0) != 0)
{
_mkdir(dest_dir);
}
}

int main()
{
const char* s = "../../new3";char s1[100];
FILE *f1 = NULL;

try_create_dir(s);

strcpy(s1, s);
strcat(s1,"/file1.txt" );

if ((f1 = fopen(s1, "w+")) == NULL)
{
printf("Error in create log file of reconstructed MV field.\n");
}

fprintf(f1, "----------------------Successful-------------------------------------\n");

fclose(f1);

system("pause");
return 0;
}

VS Skills

1、improve Ur VS running speed:

http://www.jb51.net/os/windows/73851.html

2、Condition Breakpoint：

Double click then tight click on the breakpoint and set condition:

for instance:

pxlLocation.Y == 0x110

MEMCPY

For two dynamic arrays copy by memcpy, be careful of data type.

// Y component assignment.
frame_ref->imgY_ref = (imgPel**)malloc(tempHeight * sizeof(imgPel*));

for(i = 0; i < tempHeight; i++)
{
frame_ref->imgY_ref[i]=(imgPel*)malloc(tempWidth * sizeof(imgPel));
if(refPic->imgY[i] != NULL)
{
memcpy(frame_ref->imgY_ref[i], refPic->imgY[i], tempWidth * sizeof(imgPel));
}
}

C-free using and debug skills

http://www.programarts.com/cfree_ch/doc/help/UsingCF/Debug.htm

http://www.cnblogs.com/lidabo/p/3631224.html

C File Operetion

http://blog.csdn.net/gneveek/article/details/6848473

http://www.cppblog.com/Tongy0/archive/2014/03/23/206305.html

C Using Skill As 默认参数

http://blog.sina.com.cn/s/blog_933d4eec0100vdk0.html

Stack Overflow

http://www.cnblogs.com/fanzhidongyzby/archive/2013/08/10/3250405.html