linux下bmp转化为jpeg程序源代码

// http://blog.youkuaiyun.com/npy_lp/article/details/6991664
// 常用库之一：libjpeg的交叉编译

// http://www.oschina.net/code/snippet_4873_3518

/****************************************************************************
名称：   jpeg.c
功能：   linux下bmp转化为jpeg程序源代码
日期：   2010.01.26
注意：   编译时加“-ljpeg”(gcc -o bmp2jpg jpeg.c -ljpeg)
*****************************************************************************/
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <linux/videodev.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <signal.h>
#include <sys/timeb.h>
// #include <jpeglib.h>
// Wrong JPEG library version: library is 62, caller expects 80
#include "jpeglib.h"

#define JPEG_QUALITY 95 //图片质量

int Bmp2Jpg(const char *bmp_file, const char *jeg_file, const int width, const int height)
{
	struct timeval tp1;
	struct timeval tp2;
	
	
	
	
	FILE *fd;
	int ret;
	unsigned char *data;
	long sizeImage;
	int depth = 3;
	JSAMPROW * row_pointer;
	long rgb_index = 0;
	int i=0;
	struct jpeg_compress_struct cinfo;
	struct jpeg_error_mgr jerr;
	FILE *outfile;                       
	;
	
	// Read bmp image data
	sizeImage = width*height*3;
	data = (unsigned char*)malloc(sizeImage);
	fd = fopen(bmp_file, "rb");
	
	if(!fd)
	{
		printf("ERROR1: Can not open the image.\n");
		free(data);
		
		return -1;
	}

	fseek(fd, 54, SEEK_SET); 
	ret = fread(data, sizeof(unsigned char)*sizeImage, 1, fd);
	
	if(ret == 0)
	{
		if(ferror(fd))
		{
			printf("\nERROR2: Can not read the pixel data.\n");
			free(data);
			fclose(fd);
			
			return -1;
		}
	}

	//Convert BMP to JPG
	cinfo.err = jpeg_std_error(&jerr);
	//* Now we can initialize the JPEG compression object.
	jpeg_create_compress(&cinfo);

	if ((outfile = fopen(jeg_file, "wb")) == NULL)
	{
		fprintf(stderr, "can't open %s\n", jeg_file);
		
		return -1;
	}
	
	jpeg_stdio_dest(&cinfo, outfile);

	cinfo.image_width = width;             //* image width and height, in pixels
	cinfo.image_height = height;
	cinfo.input_components = depth;    //* # of color components per pixel
	cinfo.in_color_space = JCS_RGB;     //* colorspace of input image
	jpeg_set_defaults(&cinfo);

	//Now you can set any non-default parameters you wish to.
	//Here we just illustrate the use of quality (quantization table) scaling:

	jpeg_set_quality(&cinfo, JPEG_QUALITY, TRUE ); //* limit to baseline-JPEG values
	jpeg_start_compress(&cinfo, TRUE);
	
	
	
	
	gettimeofday(&tp1, NULL);
	//一次写入
	int j=0;
	row_pointer = malloc(height*width*3);
	// char * line[300];
	// 2012-11-28 01:42下午 在VGA分辨率640*480下溢出。单步调试发现 i 的值变得很大（溢出）！
	char * line[1000];

	for(i=0;i<height;i++)
	{    
		unsigned char * lineData = NULL;
		
		lineData = malloc(width*3);
		line[i]=lineData;
		
		for(j=0;j<width;j++)
		{
			lineData[j*3+2] = data[rgb_index];
			rgb_index ++;
			lineData[j*3+1] = data[rgb_index];
			rgb_index ++;
			lineData[j*3+0] = data[rgb_index];
			rgb_index ++;
		}
		
		row_pointer[height-i-1] = lineData;      
	}
	
	jpeg_write_scanlines(&cinfo, row_pointer, height);
	
	
	
	jpeg_finish_compress(&cinfo);
	
	gettimeofday(&tp2, NULL);
	printf("1 cost time=%ld us\n", (tp2.tv_sec - tp1.tv_sec)*1000000 + tp2.tv_usec - tp1.tv_usec) ;
	
	jpeg_destroy_compress(&cinfo);
	
	for (i=0; i<height; i++)
	{
		free(line[i]);
	}
	
	free(row_pointer);
	free(data); 
	fclose(fd);
	fclose(outfile);

	return 0;
} 




// 函数名称：main
// 函数功能：
// 参数列表：
// 返回值  ：
int main(int argc, char **argv)
{
	struct timeval tp1;
	struct timeval tp2;
	
	gettimeofday(&tp1, NULL);
	
	// Bmp2Jpg( "/tmp/yuyv001.bmp", "/tmp/yuyv001.jpg", 640, 480 );
	Bmp2Jpg( "yuyv001.bmp", "yuyv001.jpg", 640, 480 );
	
	gettimeofday(&tp2, NULL);
	
	// printf("cost time=%u us\n", (tp2.tv_sec - tp1.tv_sec*1000000) + tp2.tv_usec - tp1.tv_usec) ;
	// printf("cost time=%d us\n", (tp2.tv_sec - tp1.tv_sec*1000000) + tp2.tv_usec - tp1.tv_usec) ;
	// cost time=38603 us
	printf("cost time=%ld us\n", (tp2.tv_sec - tp1.tv_sec)*1000000 + tp2.tv_usec - tp1.tv_usec) ;
	
	return 0;
}