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Given below is my solution to CS50's Week 4: Volume. The problem I was trying to solve was to read a .wav file and change its volume based on a comandline argument 'factor'.
CS50's Week 4: Volume
Problem:
When I was testing this code I initially used
fread(header, HEADER_SIZE, 1, input);
My code would compile without error and an output file would be produced for the following:
./volume input.wav output.wav 1.0
Problem:
fread(header, HEADER_SIZE, 1, input);
./volume input.wav output.wav 1.0
But a currupted output file would be produced if I changed the volume factor to anything else other than 1.0.
// Modifies the volume of an audio file

#include stdint.h
#include stdio.h
#include stdlib.h

// Number of bytes in .wav header
const int HEADER_SIZE = 44;

void copy_header(FILE *input, FILE *output);
void copy_samples(FILE *input, FILE *output, float factor);

int main(int argc, char *argv[])
{
// Check command-line arguments
if (argc != 4)
{
printf("Usage: ./volume input.wav output.wav factor\n");
return 1;
}

// Open files and determine scaling factor
FILE *input = fopen(argv[1], "r");
if (input == NULL)
{
printf("Could not open file.\n");
return 1;
}

FILE *output = fopen(argv[2], "w");
if (output == NULL)
{
printf("Could not open file.\n");
return 1;
}

float factor = atof(argv[3]);

copy_header(input, output);
copy_samples(input, output, factor);

// Close files
fclose(input);
fclose(output);
}

void copy_header(FILE *input, FILE *output)
{
uint8_t header[HEADER_SIZE];

fread(header, sizeof(HEADER_SIZE), 1, input);
fwrite(header, sizeof(HEADER_SIZE), 1, output);
printf("header: %s; header_size: %lu; HEADER_s: %lu\n", header, sizeof(header), sizeof(HEADER_SIZE));
}

void copy_samples(FILE *input, FILE *output, float factor)
{
int16_t buffer;

while (fread(&buffer, sizeof(int16_t), 1, input) != 0)
{
buffer = buffer * factor;
fwrite(&buffer, sizeof(int16_t), 1, output);
}
}

// Modifies the volume of an audio file

#include stdint.h
#include stdio.h
#include stdlib.h

// Number of bytes in .wav header
const int HEADER_SIZE = 44;

void copy_header(FILE *input, FILE *output);
void copy_samples(FILE *input, FILE *output, float factor);

int main(int argc, char *argv[])
{
// Check command-line arguments
if (argc != 4)
{
printf("Usage: ./volume input.wav output.wav factor\n");
return 1;
}

// Open files and determine scaling factor
FILE *input = fopen(argv[1], "r");
if (input == NULL)
{
printf("Could not open file.\n");
return 1;
}

FILE *output = fopen(argv[2], "w");
if (output == NULL)
{
printf("Could not open file.\n");
return 1;
}

float factor = atof(argv[3]);

copy_header(input, output);
copy_samples(input, output, factor);

// Close files
fclose(input);
fclose(output);
}

void copy_header(FILE *input, FILE *output)
{
uint8_t header[HEADER_SIZE];

fread(header, sizeof(HEADER_SIZE), 1, input);
fwrite(header, sizeof(HEADER_SIZE), 1, output);
printf("header: %s; header_size: %lu; HEADER_s: %lu\n", header, sizeof(header), sizeof(HEADER_SIZE));
}

void copy_samples(FILE *input, FILE *output, float factoSource of the question:
https://stackoverflow.com/questions/79033153

Question and source license information:
https://meta.stackexchange.com/help/licensing
https://stackoverflow.com/