我正在尝试处理 bmp 文件。首先，我尝试从 bmp 文件中读取标题和数据并将其写入新文件：
#pragma pack(push,1)
/* Windows 3.x bitmap file header */
typedef struct {
char filetype[2]; /* magic - always 'B' 'M' */
unsigned int filesize;
short reserved1;
short reserved2;
unsigned int dataoffset; /* offset in bytes to actual bitmap data */
} file_header;
/* Windows 3.x bitmap full header, including file header */
typedef struct {
file_header fileheader;
unsigned int headersize;
int width;
int height;
short planes;
short bitsperpixel; /* we only support the value 24 here */
unsigned int compression; /* we do not support compression */
unsigned int bitmapsize;
int horizontalres;
int verticalres;
unsigned int numcolors;
unsigned int importantcolors;
} bitmap_header;
#pragma pack(pop)
int foo(char* input, char *output) {
//variable dec:
FILE *fp,*out;
bitmap_header* hp;
int n;
char *data;
//Open input file:
fp = fopen(input, "r");
if(fp==NULL){
//cleanup
}
//Read the input file headers:
hp=(bitmap_header*)malloc(sizeof(bitmap_header));
if(hp==NULL)
return 3;
n=fread(hp, sizeof(bitmap_header), 1, fp);
if(n<1){
//cleanup
}
//Read the data of the image:
data = (char*)malloc(sizeof(char)*hp->bitmapsize);
if(data==NULL){
//cleanup
}
fseek(fp,sizeof(char)*hp->fileheader.dataoffset,SEEK_SET);
n=fread(data,sizeof(char),hp->bitmapsize, fp);
if(n<1){
//cleanup
}
//Open output file:
out = fopen(output, "w");
if(out==NULL){
//cleanup
}
n=fwrite(hp,sizeof(char),sizeof(bitmap_header),out);
if(n<1){
//cleanup
}
fseek(out,sizeof(char)*hp->fileheader.dataoffset,SEEK_SET);
n=fwrite(data,sizeof(char),hp->bitmapsize,out);
if(n<1){
//cleanup
}
fclose(fp);
fclose(out);
free(hp);
free(data);
return 0;
}
这是输入文件：
这是输出：
它们的大小相同，并且似乎具有相同的标题。有什么问题？谢谢。