reading audio file in c

http://www.mega-nerd.com/libsndfile/

thanks..

I got the program to read audio (.WAV)- courtesy: NAUFAL, CET

#include <stdio.h>
#include "wav.h"

main()
{
    int16_t *samples = NULL;

    wavread("track.wav", &samples);

    printf("No. of channels: %d\n",     header->num_channels);
    printf("Sample rate:     %d\n",     header->sample_rate);
    printf("Bit rate:        %dkbps\n", header->byte_rate*8 / 1000);
    printf("Bits per sample: %d\n\n",     header->bps);

    printf("Sample 0:        %d\n", samples[0]);
    printf("Sample 1:        %d\n", samples[1]);

    // Modify the header values & samples before writing the new file
    wavwrite("track2.wav", samples);

    free(header);
    free(samples);
}

wav.h

#include <inttypes.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <err.h>

typedef struct {
    char     chunk_id[4];
    uint32_t chunk_size;
    char     format[4];

    char     fmtchunk_id[4];
    uint32_t fmtchunk_size;
    uint16_t audio_format;
    uint16_t num_channels;
    uint32_t sample_rate;
    uint32_t byte_rate;
    uint16_t block_align;
    uint16_t bps;

    char     datachunk_id[4];
    uint32_t datachunk_size;
}WavHeader;

WavHeader *header;

void wavread(char *file_name, int16_t **samples)
{
    int fd;

    if (!file_name)
        errx(1, "Filename not specified");

    if ((fd = open(file_name, O_RDONLY)) < 1)
        errx(1, "Error opening file");

    if (!header)
        header = (WavHeader*)malloc(sizeof(WavHeader));

    if (read(fd, header, sizeof(WavHeader)) < sizeof(WavHeader))
        errx(1, "File broken: header");

    if (strncmp(header->chunk_id, "RIFF", 4) ||
        strncmp(header->format, "WAVE", 4))
        errx(1, "Not a wav file");

    if (header->audio_format != 1)
        errx(1, "Only PCM encoding supported");

    if (*samples) free(*samples);
    *samples = (int16_t*)malloc(header->datachunk_size);
    if (!*samples)
        errx(1, "Error allocating memory");

    if (read(fd, *samples, header->datachunk_size) < header->datachunk_size)
        errx(1, "File broken: samples");

    close(fd);
}

void wavwrite(char *file_name, int16_t *samples)
{
    int fd;

    if (!file_name)
        errx(1, "Filename not specified");

    if (!samples)
        errx(1, "Samples buffer not specified");

    if ((fd = creat(file_name, 0666)) < 1)
        errx(1, "Error creating file");

    if (write(fd, header, sizeof(WavHeader)) < sizeof(WavHeader))
        errx(1, "Error writing header");

    if (write(fd, samples, header->datachunk_size) < header->datachunk_size)
        errx(1, "Error writing samples");

    close(fd);
}

audio file is here at http://rapidshare.com/files/456227826/track.wav
Thanks for all helps from Daniweb. Our project is complete. will be in touch...

thanks

May I know what does read/write function do?