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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h> /* low-level i/o */
#include <unistd.h>
#include <signal.h>
#include <errno.h>
#include <malloc.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <linux/videodev2.h>
#include <pthread.h>
#include <semaphore.h>
static char *v4l2dev = "/dev/video1";
static int v4l2sink = -1;
static int width = 80; //640; // Default for Flash
static int height = 60; //480; // Default for Flash
static char *vidsendbuf = NULL;
static int vidsendsiz = 0;
static void init_device() {
}
static void grab_frame() {
struct timespec ts;
clock_gettime(CLOCK_REALTIME, &ts);
memset( vidsendbuf, 0, 3);
switch( ts.tv_sec & 3 ) {
case 0:
vidsendbuf[0] = 255;
break;
case 1:
vidsendbuf[0] = 255;
vidsendbuf[1] = 255;
break;
case 2:
vidsendbuf[1] = 255;
break;
case 3:
vidsendbuf[2] = 255;
break;
}
memcpy( vidsendbuf+3, vidsendbuf, vidsendsiz-3 );
}
static void stop_device() {
}
static void open_vpipe()
{
v4l2sink = open(v4l2dev, O_WRONLY);
if (v4l2sink < 0) {
fprintf(stderr, "Failed to open v4l2sink device. (%s)\n", strerror(errno));
exit(-2);
}
// setup video for proper format
struct v4l2_format v;
int t;
v.type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
t = ioctl(v4l2sink, VIDIOC_G_FMT, &v);
if( t < 0 )
exit(t);
v.fmt.pix.width = width;
v.fmt.pix.height = height;
v.fmt.pix.pixelformat = V4L2_PIX_FMT_RGB24;
vidsendsiz = width * height * 3;
v.fmt.pix.sizeimage = vidsendsiz;
t = ioctl(v4l2sink, VIDIOC_S_FMT, &v);
if( t < 0 )
exit(t);
vidsendbuf = malloc( vidsendsiz );
}
static pthread_t sender;
static sem_t lock1,lock2;
static void *sendvid(void *v)
{
for (;;) {
sem_wait(&lock1);
if (vidsendsiz != write(v4l2sink, vidsendbuf, vidsendsiz))
exit(-1);
sem_post(&lock2);
}
}
int main(int argc, char **argv)
{
struct timespec ts;
if( argc == 2 )
v4l2dev = argv[1];
open_vpipe();
// open and lock response
if (sem_init(&lock2, 0, 1) == -1)
exit(-1);
sem_wait(&lock2);
if (sem_init(&lock1, 0, 1) == -1)
exit(-1);
pthread_create(&sender, NULL, sendvid, NULL);
for (;;) {
// wait until a frame can be written
fprintf( stderr, "Waiting for sink\n" );
sem_wait(&lock2);
// setup source
init_device(); // open and setup SPI
for (;;) {
grab_frame();
// push it out
sem_post(&lock1);
clock_gettime(CLOCK_REALTIME, &ts);
ts.tv_sec += 2;
// wait for it to get written (or is blocking)
if (sem_timedwait(&lock2, &ts))
break;
}
stop_device(); // close SPI
}
close(v4l2sink);
return 0;
}
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