OpenCV Segfaulting

Member Posts : 4 Join date : 2011-05-20

Hi,

I've just got cracking with OpenCV- I got basic single frame capture and image writing to work no problem. What I'm trying to do now is sort of like a logger- capture frame by frame and record in files. My code segfaults with the saving line in, but seems to run with it commented..

Here's the code:

Code:: #include <stdio.h>
#include <iostream>
#include <time.h>
//OpenCV
#include <cv.h>
#include <cvaux.h>
#include <highgui.h>
#include <cxcore.h>

char* image_name (const int cam_number) {
   char* filestamp;
   struct tm *current;
   time_t now;
   time(&now);
   current = localtime(&now);
   sprintf(filestamp, "images/%i-%i-%i-%i-Cam%i.png", current->tm_yday, current->tm_hour, current->tm_min, current->tm_sec, cam_number);
   return filestamp;
}

class camera {
public:
   int cam_number; //x where /dev/videox is camera
   CvCapture *capture;
   IplImage *image;

   CvCapture* init();
   IplImage* image_grab();
}camera1;

CvCapture* camera::init(){
capture = cvCaptureFromCAM(cam_number);
return capture;
}

IplImage* camera::image_grab(){
image = cvQueryFrame(capture);
cvSaveImage(image_name(cam_number), image);
return image;
}
int main (int argc, char *argv[]) {
bool run = true;
char input;
camera1.cam_number = 3;

camera1.init();
while(run){
   camera1.image_grab();
   printf("Iteration \n");
}
return 0;
}

Thanks for any ideas.

Member Posts : 17 Join date : 2011-06-05

In your image_name function you never allocate any memory for filestamp. That is why it is crashing.

Member Posts : 4 Join date : 2011-05-20

Oh great, thanks a lot All working now. :D