int read_frame(void) {
struct v4l2_buffer buf;
memset(&buf, 0, sizeof(buf));
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
if (ioctl(fd_camera, VIDIOC_DQBUF, &buf) != 0) {
if (errno != EAGAIN && errno != EIO) {
perror("red_frame: VIDIOC_DQBUF");
exit(EXIT_FAILURE);
} else {
return 0;
}
}
if (buf.index > n_buffers) {
fprintf(stderr, "Wrong buffer size\n");
exit(EXIT_FAILURE);
}
make_ppm(buffers[buf.index].start, "image.ppm", width, height);
if (ioctl(fd_camera, VIDIOC_QBUF, &buf) != 0) {
perror("read_frame: VIDIOC_QBUF");
exit(EXIT_FAILURE);
}
return 1;
}
int makeImage(double m1, double b1, double m2, double b2, int count, int w, int h) {
double m[2] = {2,-2}, b[2] = {0,200};
int add_noise = 0;
m[0] = m1; m[1] = m2;
b[0] = b1; b[1] = b2;
add_noise = 0;
printf("Producing frame %d with m = %f b = %f add_noise = %d\n", count, m[0], b[0], add_noise);
unsigned char *img = (unsigned char *)malloc(w*h*3);
for (int i=0; i< w*h; i++) // set it to blue;
{
img[3*(i) + 0] = 40; // B?
img[3*(i) + 1] = 0; // G
img[3*(i) + 2] = 0; // R
}
int max_r_c= (h>w) ? h : w;
double y=0, x=0, this_b, this_m;
int row, col, r_err=0, c_err=0;
for (int l=0; l<2; l++)
{
this_b=b[l];
this_m=m[l];
for(int i=0; i< max_r_c; i++)
{
if (fabs(this_m) < 1)
{
y=this_m*i+this_b;
col = i;
row = (int)(y+.5);
}
else
{
x=(i-this_b)/this_m;
row = i;
col = (int)(x+.5);
}
if (add_noise)
{
col = col+(c_err=rand_err());
row = row+(r_err=rand_err());
}
if ((col>=0)&&(row>=0)&&(col<w)&&(row<h))
{
img[3*(col+row*w)+0]=0;
img[3*(col+row*w)+1]=0;
img[3*(col+row*w)+2]=125;
}
}
}
make_ppm("test.ppm", img, w, h);
char msg[100];
/*sprintf(msg, "ppmtobmp test.ppm > %d.bmp", count);
system(msg);
sprintf(msg, "pnmtojpeg test.ppm -quality 95 > %d.jpg", count);
system(msg);*/
sprintf(msg, "pnmtotiff test.ppm > %d.tiff", count);
system(msg);
return 0;
}