main.c

Video4Linux_test.rar 接視訊的範例程式

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "ccvt.h"
#include "v4l/v4l.h"
#include <jpeglib.h>
#include <jerror.h>
#include <jconfig.h>
#define DEFAULT_PALETTE VIDEO_PALETTE_YUV420P
//#define DEFAULT_PALETTE VIDEO_PALETTE_RGB24

//if need to debug, please open it
//#define DEBUG 0

#define PUSH_RGB24	1
#define PUSH_BGR24	2
#define PUSH_RGB32	3
#define PUSH_BGR32	4
#define IMAGE_WIDTH 320
#define IMAGE_HEIGHT 240
v4l_device vd;

int device_init(char *dev,int norm)
{
	int i;
	
	if(dev == NULL)
	{
		dev = "/dev/v4l/video0"; //set to default device
	}

	if(v4l_open(dev,&vd)) return -1;
	if(v4l_get_channels(&vd)) return -1;
	if(v4l_set_norm(&vd,norm)) return -1;
	if(v4l_mmap_init(&vd)) return -1;

#ifdef DEBUG
	printf("%s: initialization Ok... %s\n %d channels \n %d audios \n"
					,dev,vd.capability.name,vd.capability.channels
					,vd.capability.audios);

	for(i=0;i<vd.capability.channels;i++)
	{
		printf("Channel %d: %s \n",i,vd.channel[i].name);
	}
	
	printf("v4l:mmap's address = %p\n",vd.map);
	printf("v4l:mmap's buffer size = 0x%x\n",vd.mbuf.size);
	printf("v4l:mmap's frames = %d(%d max)\n",vd.mbuf.frames,VIDEO_MAX_FRAME);
	

	for(i=0; i< vd.mbuf.frames;i++)
	{
		printf("v4l: frames %d's offset = 0x%x\n",i,vd.mbuf.offsets[i]);
	}
#endif

	//start initialize grab
	if(v4l_get_picture(&vd)) return -1;
	if(v4l_set_palette(&vd,DEFAULT_PALETTE)) return -1;

#ifdef DEBUG
	printf("test open 3\n");
#endif

	if(v4l_grab_init(&vd,IMAGE_WIDTH,IMAGE_HEIGHT)) return -1;
	if(v4l_grab_sync(&vd)) return -1;

#ifdef DEBUG
	printf("test open 4\n");
#endif

	return 0;
}

int device_grab_frame()
{
	vd.frame_current = 0;
	if(v4l_grab_frame(&vd,0) < 0)	return -1;

	return 0;
}

int device_next_frame()
{
	vd.frame_current ^= 1;
	if(v4l_grab_frame(&vd,vd.frame_current) < 0) return -1;

	return 0;
}



/* This is a simplistic approach. */
static void ccvt_420p(int width, int height, const unsigned char *src, unsigned char *dst, int push)
{
	int line, col, linewidth;
	int y, u, v, yy, vr, ug, vg, ub;
	int r, g, b;
	const unsigned char *py, *pu, *pv;

	linewidth = width >> 1;
	py = src;
	pu = py + (width * height);
	pv = pu + (width * height) / 4;

	y = *py++;
	yy = y << 8;
	u = *pu - 128;
	ug =   88 * u;
	ub =  454 * u;
	v = *pv - 128;
	vg =  183 * v;
	vr =  359 * v;

	for (line = 0; line < height; line++) {
		for (col = 0; col < width; col++) {
			r = (yy +      vr) >> 8;
			g = (yy - ug - vg) >> 8;
			b = (yy + ub     ) >> 8;

			if (r < 0)   r = 0;
			if (r > 255) r = 255;
			if (g < 0)   g = 0;
			if (g > 255) g = 255;
			if (b < 0)   b = 0;
			if (b > 255) b = 255;

			switch(push) {
			case PUSH_RGB24:
				*dst++ = r;
				*dst++ = g;
				*dst++ = b;
				break;

			case PUSH_BGR24:
				*dst++ = b;
				*dst++ = g;
				*dst++ = r;
				break;
			
			case PUSH_RGB32:
				*dst++ = r;
				*dst++ = g;
				*dst++ = b;
				*dst++ = 0;
				break;

			case PUSH_BGR32:
				*dst++ = b;
				*dst++ = g;
				*dst++ = r;
				*dst++ = 0;
				break;
			}
			
			y = *py++;
			yy = y << 8;
			if (col & 1) {
				pu++;
				pv++;

				u = *pu - 128;
				ug =   88 * u;
				ub =  454 * u;
				v = *pv - 128;
				vg =  183 * v;
				vr =  359 * v;
			}
		} /* ..for col */
		if ((line & 1) == 0) { // even line: rewind
			pu -= linewidth;
			pv -= linewidth;
		}
	} /* ..for line */
}

void ccvt_420p_rgb24(int width, int height, const void *src, void *dst)
{
	ccvt_420p(width, height, (const unsigned char *)src, (unsigned char *)dst, PUSH_RGB24);
}

void ccvt_420p_bgr24(int width, int height, const void *src, void *dst)
{
	ccvt_420p(width, height, (const unsigned char *)src, (unsigned char *)dst, PUSH_BGR24);
}

void ccvt_420p_rgb32(int width, int height, const void *src, void *dst)
{
	ccvt_420p(width, height, (const unsigned char *)src, (unsigned char *)dst, PUSH_RGB32);
}

void ccvt_420p_bgr32(int width, int height, const void *src, void *dst)
{
	ccvt_420p(width, height, (const unsigned char *)src, (unsigned char *)dst, PUSH_BGR32);
}


int write_jpeg(char *filename, unsigned char *img,int quality,int gray)
{
	FILE *fp;
	struct jpeg_compress_struct cinfo;
	struct jpeg_error_mgr jerr;
	unsigned int i;
	unsigned char *line;
	int line_length;
	
	if(NULL == (fp = fopen(filename,"w")))
	{
		fprintf(stderr,"grab: can't open %s\n",filename);
		return -1;
	}

	cinfo.err = jpeg_std_error(&jerr);
	jpeg_create_compress(&cinfo);
	jpeg_stdio_dest(&cinfo, fp);
	cinfo.image_width = IMAGE_WIDTH;
	cinfo.image_height = IMAGE_HEIGHT;
	cinfo.input_components = gray ? 1 : 3 ;
	cinfo.in_color_space = gray ? JCS_GRAYSCALE : JCS_RGB;

#ifdef DEBUG
	printf("test jpeg stage 1 ok\n");
#endif

	jpeg_set_defaults(&cinfo);
	
	jpeg_set_quality(&cinfo,quality,TRUE);
	jpeg_start_compress(&cinfo,TRUE);

#ifdef DEBUG
	printf("test jpeg stage 2 ok\n");
#endif

	line_length = gray ? IMAGE_WIDTH : IMAGE_WIDTH*3;
	
	for(i=0,line=img;i<IMAGE_HEIGHT;i++,line+=line_length)
		jpeg_write_scanlines(&cinfo,&line,1);		

	jpeg_finish_compress(&(cinfo));
	jpeg_destroy_compress(&(cinfo));
	fclose(fp);

#ifdef DEBUG
	printf("test jpeg stage 3 ok\n");
#endif
	return 0;
}



int main()
{
	unsigned char *img;
	unsigned char *img_out = malloc(IMAGE_WIDTH*IMAGE_HEIGHT*3);
	FILE *fp;
  memset(img_out,0,sizeof(img_out));		
	
	if(device_init("/dev/v4l/video0",3) == -1)
	{
		perror("device_init:failed...\n");
		exit(1);
	}
	else
	{
		
#ifdef DEBUG
		printf("OK!\n");
#endif

		//device_next_frame();
		//device_grab_frame();
		img = device_get_address(&vd);
#ifdef DEBUG
		printf("img address is: %p \n",img);
		printf("img_out address is: %p \n",img_out);
#endif
		
		ccvt_420p_rgb24(IMAGE_WIDTH,IMAGE_HEIGHT,img,img_out);

#ifdef DEBUG
		printf("ccvt_420p_rgb24_ok\n");	
		fp = fopen("test.ppm","w");
		fprintf(fp,"P6\n%d %d\n255\n",IMAGE_WIDTH,IMAGE_HEIGHT);
		fwrite(img_out,IMAGE_WIDTH*3,IMAGE_HEIGHT,fp);
		fclose(fp);
#endif		
		
		write_jpeg("test.jpeg", img_out , 75, 0);
		
#ifdef DEBUG
		printf("write_jpeg_ok\n");
#endif
	}

	exit(0);	
}