Memory Allocation Problems

**amac** · 12-09-2009

Hi everybody,

I'm writing a program that generates a music score for a program called CSound. My code reads in a 24 bit bitmap, converts pixels from RGB to HSI color space, and then translates the resultant data into
a score. I get runtime errors related to memory allocation.

If I include free() statements to de-allocate malloc'd memory, I get segmentation faults at run-time. The version of code I have attached includes these free() statements. If I remove the free() statements, then
I get the following runtime error message when I input images larger than some threshold (for example, I get errors for a 30x50 pixel image but not a10x4):

Code:

alex@laptop:~/Music/MUS88/final$ ./bmpscore instr1v2.bmp instr1.txt 1 5 0 20
bmpscore: malloc.c:3074: sYSMALLOc: Assertion `(old_top == (((mbinptr) (((char *)
 &((av)->bins[((1) - 1) * 2])) - __builtin_offsetof (struct malloc_chunk, fd)))) && old_size == 0) || 
((unsigned long) (old_size) >= (unsigned long)((((__builtin_offsetof (struct malloc_chunk, 
fd_nextsize))+((2 * (sizeof(size_t))) - 1)) & ~((2 * (sizeof(size_t))) - 1))) && ((old_top)->size & 0x1) 
&& ((unsigned long)old_end & pagemask) == 0)' failed.

Aborted

Here's the code. I'm running Ubuntu and compiled the program with GCC. Can someone please help me figure out why it's not working?

Code:

/* file for Comp. Mus. Final Project */
/* Alex McAuley 2009 */
/* transforms input 24-bit .bmp into Csound score */

/* input: <.bmp in> <.txt out> <instr #> <sec/pixel> <start time> <%overlap>
   example output line: i<instr #> <time> <duration> <volume (0-1)> <pitch parameter (0-1)> <timbral parameter (0-1)> */

/* return states:
	0: successful
	1: error
*/

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>

/* define structures */
typedef struct{				//file header
	unsigned short type;		
	unsigned long size;			
	unsigned short reserved1;	
	unsigned short reserved2;	
	unsigned long offset;		
} FILE_HEADER;

typedef struct{				//info header
	unsigned long headersize;
	unsigned long width;
	unsigned long height;
	unsigned short colorplanes;
	unsigned short bitsperpixel;
	unsigned long compression;
	unsigned long bmpsize;
	unsigned long horizontalres;
	unsigned long verticalres;
	unsigned long colors;
	unsigned long importantcolors;
} INFO_HEADER;

typedef struct{				//RGB values
	unsigned char blue;
	unsigned char green;
	unsigned char red;
} PIXEL;


/* function prototypes */
int rgbhsi(unsigned char *rav, unsigned char *gav, unsigned char *bav, float *huepix, float *satpix,
			float *intenspix, unsigned long pixlength);
float	minrgb(float r, float g, float b);
int	avrgb(unsigned char *rpixels, unsigned char *gpixels, unsigned char *bpixels, unsigned char *rav,
                    unsigned char *gav, unsigned char *bav, unsigned 	long width, unsigned long height);



int main(int argc,char* argv[])
{
	/* Declare variables */
	int i,n;
	float dur, time, volume, pitch, timbre, start, overlap; 
	PIXEL pixel;
	FILE_HEADER header;
	INFO_HEADER info;
	unsigned char *rpixels, *gpixels, *bpixels, *rav, *gav, *bav;	//vectors of pixels
	float	*huepix, *satpix, *intenspix;	; //hue, saturation, intenspixity of pixels 
	FILE *fpin, *fpout;		//input and output file pointers

	if (argc != 7){
		printf("\nbmpscore: 'bmpscore <.bmp in> <.txt out> <instr #> <sec/pixel> <start time> <%%overlap>'\n\n"); 
		return 1;
	}

	/* Open files */
	if ( (fpin = fopen(argv[1], "rb")) == NULL ){
		printf("\nERROR: Cannot open input file.\n\n");
		return 1;
	}

	if ( (fpout = fopen(argv[2], "w")) == NULL ){
		printf("\nERROR: Cannot open/create output file.\n\n");
		return 1;
	}

	/* Read headers */
	/* NOTE: Since some compilers force FILE_HEADER struct to be 16 bits when it
	should really be 14 bits (not a multiple of 4 bytes), read data into
	each FILE_HEADER element individually */

	fread(&header.type, sizeof(header.type), 1, fpin);
	fread(&header.size, sizeof(header.size), 1, fpin);
	fread(&header.reserved1, sizeof(header.reserved1), 1, fpin);
	fread(&header.reserved2, sizeof(header.reserved2), 1, fpin);
	fread(&header.offset, sizeof(header.offset), 1, fpin);
	fread(&info, sizeof(INFO_HEADER), 1, fpin);

	/* Make sure file is a 24-bit bitmap */
	if((header.type != 19778) || (info.bitsperpixel != 24))	//not a 24-bit bitmap
	{
		printf("\nERROR. File is not a 24-bit bitmap.\n\n");
		return 1;
	}


	fseek(fpin, header.offset, SEEK_SET);

	rpixels = malloc(info.width*info.height*sizeof(unsigned char));
	memset(rpixels, 0, info.width*info.height*sizeof(unsigned char));

	gpixels = malloc(info.width*info.height*sizeof(unsigned char));
	memset(gpixels, 0, info.width*info.height*sizeof(unsigned char));

	bpixels = malloc(info.width*info.height*sizeof(unsigned char));
	memset(bpixels, 0, info.width*info.height*sizeof(unsigned char));


	/* read in pixel data */
	for(i=0; i<info.height; i++){					//iterate through rows
		for(n=0; n<info.width; n++){				//iterate through columns
			fread(&pixel,3,1,fpin);					//read pixel into pixels array
			*(rpixels+i*info.width+n) = pixel.red;
			*(gpixels+i*info.width+n) = pixel.green;
			*(bpixels+i*info.width+n) = pixel.blue;
		}
		if((info.width*3)%4 != 0){						//handle padding
			fseek(fpin, 4-(info.width*3)%4, SEEK_CUR);	//skip padding bytes
		}
	}


	/* average pix values */
	rav = malloc(info.width*sizeof(unsigned char));
	memset(rav, 0, info.width*sizeof(unsigned char));

	gav = malloc(info.width*sizeof(unsigned char));
	memset(gav, 0, info.width*sizeof(unsigned char));

	bav = malloc(info.width*sizeof(unsigned char));
	memset(bav, 0, info.width*sizeof(unsigned char));


	avrgb(rpixels,gpixels,bpixels,rav,gav,bav, info.width, info.height);
	/* */

	/* free r,g,b pixels */
	free(rpixels);
	free(gpixels);
	free(bpixels);

	huepix = malloc(info.width*sizeof(float));
	memset(huepix, 0, info.width*sizeof(float));

	satpix = malloc(info.width*sizeof(float));
	memset(satpix, 0, info.width*sizeof(float));

	intenspix = malloc(info.width*sizeof(float));
	memset(intenspix, 0, info.width*sizeof(float));


	/* convert RGB to HSI */
	rgbhsi(rav, gav, bav, huepix, satpix, intenspix, info.width);
	/* */

	/* free rav,gav,bav */
	free(rav);
	free(gav);
	free(bav);

	/* compute parameters, write output */
	dur = atof(argv[4]);
	time = atof(argv[5]);
	overlap	= atof(argv[6]);

	fprintf(fpout, ";instr	time	dur	vol	pitch	timbre\n");

	for(i=0; i<info.width; i++){
		volume = *(intenspix+i)/255;	//all values are between 0 and 1
		pitch = *(huepix+i)/360;
		timbre = *(satpix+i);
		//i<instr #> <duration> <time> <volume (0-1)> <pitch parameter (0-1)> <timbral parameter (0-1)>

		fprintf(fpout, "i%d	%5.4f	%5.4f	%5.4f	%5.4f	%5.4f\n",atoi(argv[3]),time,dur,volume,pitch,timbre);

		time += dur*(1-overlap/100);
	}


	/* free remaining memory */
	free(huepix);
	free(satpix);
	free(intenspix);

	/* close files */
	fclose(fpin);
	fclose(fpout);

	return 0;
}



int rgbhsi(unsigned char *rav, unsigned char *gav, unsigned char *bav, float *huepix, float *satpix,
                  float *intenspix, unsigned long pixlength){

	/* conversion algorithm based on http://fourier.eng.hmc.edu/e161/lectures/color_processing/node3.html (Prof. Wang)*/
	long i;
	unsigned char R,G,B;
	float r,g,b,H,S,I;

	for(i=0; i<pixlength; i++){
		R = *(rav + i);
		G = *(gav + i);
		B = *(bav + i);

		I = (R+G+B)/3.0;

		r = R/(3*I);
		g = G/(3*I);
		b = B/(3*I);

		if(I ==0){
			r = 1;
			g = 1;
			b = 1;
		}

		H = acos((2*R - G - B)/(2*sqrt(pow((R-G),2) + (R-B)*(G-B))))*180/3.14159265; //in DEGREES

		if(isnan(H)){	//deal with nan problem */
			H = 360;
		}

		if(B>G){
			H = 360 - H;
		}

	S = 1-3*minrgb(r,g,b);

	*(huepix+i) = H;
	*(satpix+i) = S;
	*(intenspix+i) = I;
	}

	return 0;
}


float	minrgb(float r, float g, float b){
	/* returns the lowest value of r, g, b */
	
        if((r<=g)&&(g<=b))
		return r;
	else if((r<=b)&&(b<=g))
		return r;
	else if((b<=r)&&(r<=g))
		return b;
	else if((b<=g)&&(g<=r))
		return b;
	else if((g<=r)&&(r<=b))
		return g;
	else //((g<=b)&&(b<=r))
		return g;
}



int	avrgb(unsigned char *rpixels, unsigned char *gpixels, unsigned char *bpixels, unsigned char *rav,
                   unsigned char *gav, unsigned char *bav, unsigned 	long width, unsigned long height){

	int i, n;
	unsigned long r, g, b;

	for(n=0;n<width;n++){	//iterate through columns
		r=0;
		g=0;
		b=0;

		for(i=0;i<height;i++){
			r += *(rpixels + i*width+n);
			g += *(gpixels + i*width+n);
			b += *(bpixels + i*width+n);			
			*(rav+i*width+n) = r/(width*height);
			*(gav+i*width+n) = g/(width*height);
			*(bav+i*width+n) = b/(width*height);
		}
	}

	return 0;
}

**itsme86** · 12-09-2009

No one's going to take the time to read that double-spaced pile of fantastically ugly crap. Condense it to save us time.

**Adak** · 12-09-2009

Aren't you playing fast and loose with malloc? No sizeof(YourDataType) * NumberYouWant.

I'm not sure, but I don't believe malloc() knows or looks up your data type for you. You tell it the size of your data type, or you're just taking a chance the default will be OK for your use.

Itsme86:

You've got to quit holding back how you feel, about posts.

I believe that's the interaction of his editor and the forum's software. My program posts used to do that, also. Since I switched to all char's, instead of tabs, it has cured the problem. Not sure just why,

**amac** · 12-09-2009

Originally Posted by Adak

Aren't you playing fast and loose with malloc? No sizeof(YourDataType) * NumberYouWant.

I'm not sure, but I don't believe malloc() knows or looks up your data type for you. You tell it the size of your data type, or you're just taking a chance the default will be OK for your use.

Itsme86:

You've got to quit holding back how you feel, about posts.

I believe that's the interaction of his editor and the forum's software. My program posts used to do that, also. Since I switched to all char's, instead of tabs, it has cured the problem. Not sure just why,

Since sizeof(unsigned char) = 1 (at least on my coumputer/compiler/whatever), I left off the sizeof(unsigned char) part in malloc(). Haha, yeah, the code looks fine in the post editing window but comes out double-spaced when I submit it. I'll probably go back and try to fix it when I have time later tonight.

**Adak** · 12-09-2009

Oh you wish!

I thought info.width and info.height referred to these:

unsigned long width;
unsigned long height;

from your info_header, used to make your info struct.

and these look suspiciously like what you're malloc'ing, here:

Code:

	rpixels = malloc(info.width*info.height);	//sizeof(unsigned char) = 1
        gpixels = malloc(info.width*info.height);
	bpixels = malloc(info.width*info.height);

You comment about unsigned char = 1, but they appear to be unsigned long's.

**amac** · 12-10-2009

Originally Posted by Adak

...
You comment about unsigned char = 1, but they appear to be unsigned long's.

I'm not sure I see the problem here. They are unsigned longs, but their product is just a number I pass to malloc(), specifically the number of bytes I want allocated. I tried replacing the

Code:

 malloc(info.width*info.height)

statements with

Code:

 malloc(info.width*info.height*sizeof(unsigned char))

statements, but there are still seg faults when I try to run the code (which I have edited in the first post to eliminate annoying double-spaces.).

**zacs7** · 12-10-2009

sizeof(char) or sizeof(unsigned char) is ALWAYS 1. So you've done nothing.

As the first poster said, condense it down.

Code:

	huepix = malloc(info.width*sizeof(float));
	memset(huepix, 0, info.width*sizeof(float));

	satpix = malloc(info.width*sizeof(float));
	memset(satpix, 0, info.width*sizeof(float));

	intenspix = malloc(info.width*sizeof(float));
	memset(intenspix, 0, info.width*sizeof(float));

Are you wanting to store the hue, saturation and intensity of each row of pixels, or per pixel?

**amac** · 12-10-2009

Originally Posted by zacs7

Are you wanting to store the hue, saturation and intensity of each row of pixels, or per pixel?

I want to store the average hue, saturation, and intensity of each column. There are info.width columns of pixels in an image.

*EDIT*

I think I solved the problem. My avrgb function was not taking the average properly. I fixed it and now there are no more errors.

Code:

	for(n=0;n<width;n++){	//iterate through columns
		r=0;
		g=0;
		b=0;
		for(i=0;i<height;i++){
			r += *(rpixels + i*width+n);
			g += *(gpixels + i*width+n);
			b += *(bpixels + i*width+n);			
		}
		*(rav+n) = r/height;
		*(gav+n) = g/height;
		*(bav+n) = b/height;
	}

Thanks for trying to help, guys. I'm impressed by the response-to-views ratio on this forum -- helpful bunch.

**arpsmack** · 12-10-2009

This looks completely wrong:

Code:

int	avrgb(unsigned char *rpixels, unsigned char *gpixels, unsigned char *bpixels, unsigned char *rav,
                   unsigned char *gav, unsigned char *bav, unsigned 	long width, unsigned long height){

	int i, n;
	unsigned long r, g, b;

	for(n=0;n<width;n++){	//iterate through columns
		r=0;
		g=0;
		b=0;

		for(i=0;i<height;i++){
			r += *(rpixels + i*width+n);
			g += *(gpixels + i*width+n);
			b += *(bpixels + i*width+n);			
			*(rav+i*width+n) = r/(width*height);
			*(gav+i*width+n) = g/(width*height);
			*(bav+i*width+n) = b/(width*height);
		}
	}

	return 0;
}

I'm pretty sure you meant for those three red lines to be OUTSIDE of that inner i loop. This makes me feel much better:

Code:

int	avrgb(unsigned char *rpixels, unsigned char *gpixels, unsigned char *bpixels, unsigned char *rav,
                   unsigned char *gav, unsigned char *bav, unsigned 	long width, unsigned long height){

	int i, n;
	unsigned long r, g, b;

	for(n=0;n<width;n++){	//iterate through columns
		r=0;
		g=0;
		b=0;

		for(i=0;i<height;i++){
			r += *(rpixels + i*width+n);
			g += *(gpixels + i*width+n);
			b += *(bpixels + i*width+n);
		}

		rav[n] = r/height;
		gav[n] = g/height;
		bav[n] = b/height;
	}

	return 0;
}

Of course, I'm assuming that the wonderfully named avrgb() is supposed to calculate the average RGB values for the pixels in each column.

[edit]
ROFL, looks like I posted a couple seconds too late!

[/edit]

**Epy** · 12-10-2009

Code:

	huepix = malloc(info.width*sizeof(float));
	memset(huepix, 0, info.width*sizeof(float));

	satpix = malloc(info.width*sizeof(float));
	memset(satpix, 0, info.width*sizeof(float));

	intenspix = malloc(info.width*sizeof(float));
	memset(intenspix, 0, info.width*sizeof(float));

You could use calloc here, calloc does the same thing as malloc except it sets the allocated memory to 0s...calloc - C++ Reference
i.e.
intenspix = calloc(info.width, sizeof(float));

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