CImgList<uint8_t>* ph_getKeyFramesFromVideo(const char *filename){
long N = GetNumberVideoFrames(filename);
if (N < 0){
return NULL;
}
float frames_per_sec = 0.5*fps(filename);
if (frames_per_sec < 0){
return NULL;
}
int step = (int)(frames_per_sec + ROUNDING_FACTOR(frames_per_sec));
long nbframes = (long)(N/step);
float *dist = (float*)malloc((nbframes)*sizeof(float));
if (!dist){
return NULL;
}
CImg<float> prev(64,1,1,1,0);
VFInfo st_info;
st_info.filename = filename;
st_info.nb_retrieval = 100;
st_info.step = step;
st_info.pixelformat = 0;
st_info.pFormatCtx = NULL;
st_info.width = -1;
st_info.height = -1;
CImgList<uint8_t> *pframelist = new CImgList<uint8_t>();
if (!pframelist){
return NULL;
}
int nbread = 0;
int k=0;
do {
nbread = NextFrames(&st_info, pframelist);
if (nbread < 0){
delete pframelist;
free(dist);
return NULL;
}
unsigned int i = 0;
while ((i < pframelist->size()) && (k < nbframes)){
CImg<uint8_t> current = pframelist->at(i++);
CImg<float> hist = current.get_histogram(64,0,255);
float d = 0.0;
dist[k] = 0.0;
cimg_forX(hist,X){
d = hist(X) - prev(X);
d = (d>=0) ? d : -d;
dist[k] += d;
prev(X) = hist(X);
}
k++;
}
pframelist->clear();
} while ((nbread >= st_info.nb_retrieval)&&(k < nbframes));
