PSNR calclator of 2 YUV files using c++ segmentation fault - c++

Question

Iam trying to write a code in c++ to calculate PSNR of two yuv video files however everything should work but i get a segmentation fault error ..
any help here is highly appreciated
here is my code
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "base.h"
void makeAFrame( YuvFrame* f, int width, int height )
{
f->lum.width = width; f->lum.height = height;
f->cb .width = width/2; f->cb .height = height/2;
f->cr .width = width/2; f->cr .height = height/2;
}
void readColorComponent( ColorComponent* cc, FILE* file )
{
unsigned int size = cc->width*cc->height;
unsigned int rsize;
rsize = fread( cc->data, sizeof(unsigned char), size, file );
}
double psnr( ColorComponent& rec, ColorComponent& org)
{
unsigned char* pOrg = org.data;
unsigned char* pRec = rec.data;
double ssd = 0;
int diff;
for ( int r = 0; r < rec.height; r++ )
{
for( int c = 0; c < rec.width; c++ )
{
diff = pRec[c] - pOrg[c];
ssd += (double)( diff * diff );
}
pRec += rec.width;
pOrg += org.width;
}
if( ssd == 0.0 )
{
return 99.99;
}
return ( 10.0 * log10( (double)rec.width * (double)rec.height * 65025.0 / ssd ) );
}
void getPSNR( double& psnrY, double& psnrU, double& psnrV, YuvFrame& rcFrameOrg, YuvFrame& rcFrameRec )
{
psnrY = psnr( rcFrameRec.lum, rcFrameOrg.lum );
psnrU = psnr( rcFrameRec.cb, rcFrameOrg.cb );
psnrV = psnr( rcFrameRec.cr, rcFrameOrg.cr );
}
void readFrame( YuvFrame* f, FILE* file )
{
readColorComponent( &f->lum, file );
readColorComponent( &f->cb, file );
readColorComponent( &f->cr, file );
}
int main(int argc, char *argv[])
{
int acc = 10000;
#define OUT "%d,%04d"
int stream = 0;
unsigned int width = 0;
unsigned int height = 0;
unsigned int temporal_stages = 0;
unsigned int skip_at_start = 0;
double fps = 0.0;
FILE* org_file = 0;
FILE* rec_file = 0;
FILE* str_file = 0;
char* prefix_string = 0;
unsigned int index, skip, skip_between, sequence_length;
int py, pu, pv, br;
double bitrate = 0.0;
double psnrY, psnrU, psnrV;
YuvFrame cOrgFrame, cRecFrame;
double AveragePSNR_Y = 0.0;
double AveragePSNR_U = 0.0;
double AveragePSNR_V = 0.0;
int currarg = 5;
int rpsnr = 0;
width = 300;
height = 240;
org_file = fopen("foreman_qcif.yuv","rb");
rec_file = fopen("foreman_qcif2.yuv","rb");
temporal_stages=2;
fseek( rec_file, 0, SEEK_END );
fseek( org_file, 0, SEEK_END );
size_t rsize = ftell( rec_file );
size_t osize = ftell( org_file );
fseek( rec_file, 0, SEEK_SET );
fseek( org_file, 0, SEEK_SET );
if (rsize < osize)
{
sequence_length = (unsigned int)((double)rsize/(double)((width*height*3)/2));
}
else
{
sequence_length = (unsigned int)((double)osize/(double)((width*height*3)/2));
skip_between = ( 1 << temporal_stages ) - 1;
}
//here we try to make frames out of images
makeAFrame( &cOrgFrame, width, height );
makeAFrame( &cRecFrame, width, height );
//looping over all frames
for( skip = skip_at_start, index = 0; index < sequence_length; index++, skip = skip_between )
{
fseek( org_file, skip*width*height*3/2, SEEK_CUR);
readFrame ( &cOrgFrame, org_file );
readFrame ( &cRecFrame, rec_file );
getPSNR ( psnrY, psnrU, psnrV, cOrgFrame, cRecFrame);
AveragePSNR_Y += psnrY;
AveragePSNR_U += psnrU;
AveragePSNR_V += psnrV;
py = (int)floor( acc * psnrY + 0.5 );
pu = (int)floor( acc * psnrU + 0.5 );
pv = (int)floor( acc * psnrV + 0.5 );
fprintf(stdout,"%d\t"OUT"\t"OUT"\t"OUT"\n",index,py/acc,py%acc,pu/acc,pu%acc,pv/acc,pv%acc);
}
fprintf(stdout,"\n");
py = (int)floor( acc * AveragePSNR_Y / (double)sequence_length + 0.5 );
pu = (int)floor( acc * AveragePSNR_U / (double)sequence_length + 0.5 );
pv = (int)floor( acc * AveragePSNR_V / (double)sequence_length + 0.5 );
br = (int)floor( acc * bitrate + 0.5 );
if( stream )
{
if( prefix_string )
{
fprintf(stderr,"%s\t"OUT"\t"OUT"\t"OUT"\t"OUT"\n",prefix_string,br/acc,br%acc,py/acc,py%acc,pu/acc,pu%acc,pv/acc,pv%acc);
fprintf(stdout,"%s\t"OUT"\t"OUT"\t"OUT"\t"OUT"\n",prefix_string,br/acc,br%acc,py/acc,py%acc,pu/acc,pu%acc,pv/acc,pv%acc);
}
else
{
fprintf(stderr,OUT"\t"OUT"\t"OUT"\t"OUT"\n",br/acc,br%acc,py/acc,py%acc,pu/acc,pu%acc,pv/acc,pv%acc);
fprintf(stdout,OUT"\t"OUT"\t"OUT"\t"OUT"\n",br/acc,br%acc,py/acc,py%acc,pu/acc,pu%acc,pv/acc,pv%acc);
}
}
else
{
fprintf(stderr,"total\t"OUT"\t"OUT"\t"OUT"\n",py/acc,py%acc,pu/acc,pu%acc,pv/acc,pv%acc);
fprintf(stdout,"total\t"OUT"\t"OUT"\t"OUT"\n",py/acc,py%acc,pu/acc,pu%acc,pv/acc,pv%acc);
}
fprintf(stdout, "\n");
fclose ( org_file );
fclose ( rec_file );
if( stream )
{
fclose ( str_file );
}
return (rpsnr*py);
}
and base.h contains structures
typedef struct
{
int width;
int height;
unsigned char* data;
} ColorComponent;
typedef struct
{
ColorComponent lum;
ColorComponent cb;
ColorComponent cr;
} YuvFrame;

Answer 1

well, segmentation error arises from you trying to access memory addresses not assigned to you ... as w hot-fix to avoid the error add this function to your code
void foo( ColorComponent* cc )
{
if( ! ( cc->data = new unsigned char[cc->width * cc->height]))
{
fprintf(stderr, "\nERROR: memory allocation failed!\n\n");
exit(-1);
}
}
and change these lines
void makeAFrame( YuvFrame* f, int width, int height )
{
f->lum.width = width; f->lum.height = height;
f->cb .width = width/2; f->cb .height = height/2;
f->cr .width = width/2; f->cr .height = height/2;
}
to
void makeAFrame( YuvFrame* f, int width, int height )
{
f->lum.width = width; f->lum.height = height;
foo( &f->lum );
f->cb .width = width/2; f->cb .height = height/2;
foo( &f->cb );
f->cr .width = width/2; f->cr .height = height/2;
foo( &f->cr );
}
things should work now