Docker on LFS - The hard way

Capture a frame from webcam with opencv

#include
#include
#include
#include
// OpenCV Webcam Start
#include
#include


// Needed only in C
enum boolean {
true = 1, false = 0
};
typedef enum boolean bool;


FILE * logfile = NULL;
/*
char *timetochar(const struct tm *timeptr)
{
static char wday_name[7][3] = {
"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
};
static char mon_name[12][3] = {
"Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
};
static char result[26];


sprintf(result, "%.3s %.3s%3d %.2d:%.2d:%.2d %d\n",
wday_name[timeptr->tm_wday],
mon_name[timeptr->tm_mon],
timeptr->tm_mday, timeptr->tm_hour,
timeptr->tm_min, timeptr->tm_sec,
1900 + timeptr->tm_year);
return result;
}*/

char *replace(char *st, char *orig, char *repl) {
static char buffer[4096];
char *ch;
if (!(ch = strstr(st, orig)))
return st;
strncpy(buffer, st, ch-st);
buffer[ch-st] = 0;
sprintf(buffer+(ch-st), "%s%s", repl, ch+strlen(orig));
return buffer;
}

void write_log(char * str)
{
if ( logfile != NULL ) {
char * text;
struct tm *ptr;
time_t tm;
tm = time(NULL);
ptr = localtime(&tm);
fprintf( logfile, "[%s] [PID: %i] %s\n", replace(asctime(ptr),"\n",""), getpid(), str );
fflush( logfile );
}
}

void open_log()
{
char * logfilename = "civacam.log\0";
logfile = fopen (logfilename, "a");
}

void close_log()
{
if ( logfile != NULL ) fclose( logfile );
}

char msglog[1000];
bool debugging = false;
bool black_image_detector(IplImage* inputImage)
{
if ( inputImage == 0 ) return true;
// Go over all pixels in the detector
int x = 0;
for( x = 0 ; x < inputImage->width; x++) {
int y = 0;
for( y = 0; y < inputImage->height; y++) {
// Get pixel value from the input image
int inputVal = (int)(cvGet2D(inputImage,y,x).val[0]);
if ( inputVal > 5 ) {
if (debugging) sprintf( msglog, "[DEBUG] dentro do black_image_detector vou retornou false" );
if (debugging) write_log(&msglog[0]);
return false;
}
}
}
return true;
}

int main(int argc, char *argv[])
{
open_log();
if ( argc == 1 ) {
write_log("[FATAL] PROCESSO INTERROMPIDO! Motivo: Processo civacam chamado sem argumentos, Obrigatoria a informacao do endereco de destino do arquivo.");
return 1;
}
char * outfilename = argv[1];
sprintf( msglog, "[INFO] Processo civacam iniciado para capturar foto com nome de arquivo: [%s]...", outfilename );
write_log(&msglog[0]);

/*
// A way to set directshow input to composite - Only C++
videoInput VI;
VI.setupDevice(0, VI_COMPOSITE);
VI.setFormat(0, VI_NTSC_M);
VI.stopDevice(0);
sprintf( msglog, "[DEBUG] Terminou de configurar e fechar a camera 0 " );
write_log(&msglog[0]);
*/
CvCapture* capture = cvCaptureFromCAM(0); // open the default camera id == 0
// Exit if fail to open a Webcam
if( capture == NULL ) {
sprintf( msglog, "[FATAL] PROCESSO INTERROMPIDO! Motivo: Impossivel acessar a camera. Arquivo solicitado: [%s]...", outfilename );
write_log(&msglog[0]);
exit(1);
}
if (debugging) write_log("[DEBUG] Camera aberta");
IplImage* img = 0;
while ( black_image_detector(img) ) {
if (debugging) sprintf( msglog, "[DEBUG] black_image_detector retornou true... continua loop..." );
if (debugging) write_log(&msglog[0]);
if(!cvGrabFrame(capture)){ // capture a frame
sprintf( msglog, "[FATAL] PROCESSO INTERROMPIDO! Motivo: Impossivel captura um frame da camera. Arquivo solicitado: [%s]...", outfilename );
write_log(&msglog[0]);
exit(1);
}
if (debugging) sprintf( msglog, "[DEBUG] passou do cvGrabFrame ok ..." );
if (debugging) write_log(&msglog[0]);
img=cvRetrieveFrame(capture,0); // retrieve the captured frame
if (debugging) sprintf( msglog, "[DEBUG] passou do cvRetrieveFrame..." );
if (debugging) write_log(&msglog[0]);
if ( img == NULL || img == 0 ) cvWaitKey(100);
}
if (debugging) sprintf( msglog, "[DEBUG] black_image_detector retornou false" );
if (debugging) write_log(&msglog[0]);
cvSaveImage(outfilename, img, 0);
// FECHANDO...
sprintf( msglog, "[INFO] OK ! Processo terminado normalmente. Arquivo capturado: [%s]...", outfilename );
write_log(&msglog[0]);
close_log();
cvReleaseCapture(&capture);
return 0;
}