讀取bmp格式文件頭信息的問題

bmp格式文件頭信息的問題bmp格式文件頭信息的問題簡單的方法如（如果不是很了解bmp文件的格式可以看我在這個專欄的一篇文章）： Thisisthebasicdatastructforbitmap#ifndefHAVE_BMP_STRUCT_H#defineHAVE_BMP_STRUCT_H #ifdefcplusplususingnamespacestd;extern"C"{struct unsignedint //needtobe //needtobe //offsettobitmap structunsignedintbiSize; structsize //widthof //heightof //needtobe0,numberofnesofthedeviceunsignedshortbiBitCount; per //typeofcompressionset0ifunsignedint nocompressionset0orthesizeoftheimagedataunsignedint horizonalpixelspermeteronthedesignateddevice,usallyset0;unsignedint unsignedintbiClrUsed; numberofcolorsusedinthebitmap,ifset0,caculateitfrombiCountunsignedintbiClrImportant; nubmerofcolorswhichareimportant,ifset0all structunsignedcharrgbBlue;unsignedcharrgbGreen;unsignedcharrgbRed;unsignedcharrgb structstructcBmpFileHeaderstructcBmpInfoHeader #ifdef //extern"C"{ #include<stdio.h>#include<stdlib.h>#include"../include/macros.h"#include"../include/bmpstruct.h"http://#defineBMP_FILE_PATH//usingnamespacestd;usingnamespacestd;{charfscanf(stdin,"%s",path);DEBUG("pathis%s\n",path);FILE*bmp_fp=fopen(path,"r");if(bmp_fp==NULL){DEBUG("fopen%sfailed\n",path);return-1;}structcBmpFileHeaderfile_header;structcBmpInfoHeaderinfo_header;structcBmpHeaderbmp_header;memset(&file_header,0,memset(&info_header,0,memset(&bmp_header,0, bmp_fp)!=sizeof(bmp_header)){DEBUG("freaderror!\n");}DEBUG("filetypeis%d%p\nfilesizeis%d%p\n is%d%p%d%p\nfileoffsettothe }注意的問題）GNUC++默認(rèn)情況下會主動進(jìn)行必要的優(yōu)化動作，這種情況。在此，需要在定義structcBmpFileHeaderstruct等數(shù)據(jù)結(jié)構(gòu)的時候明確告訴編譯器你不需要它進(jìn)行對其操作也就是必須進(jìn)行paed的操作（對于嵌入式程序最好進(jìn)行align操作，這樣可以節(jié)約CPU時間，盡管浪費一點空降）方法