Accessing binary MP3 Header in C via fopen

Question

I am trying to extract the mp3 header from a file. This is different then the ID3 tags -- the mp3 header is where information about the MPEG version, bit rate, frequency, etc is held.

You can see an overview of the mp3 header structure here: http://upload.wikimedia.org/wikipedia/commons/0/01/Mp3filestructure.svg

My problem is, despite loading the file and now receiving valid (as far as I know) binary output, I am not seeing the expected values. The first 12 bits of the mp3 file should be all ones, for the mp3 sync word. However, I am receiving something different for the first 8 bits alone. This would suggest a problem to me.

As a side note, I have a valid mp3 file being attached via fopen

// Main function
int main (void)
{
    // Declare variables
    FILE *mp3file;
    char requestedFile[255] = "";
    unsigned long fileLength;

    // Counters
    int i;

    // Tryout
    unsigned char byte; // Read from file
    unsigned char mask = 1; // Bit mask
    unsigned char bits[8];

    // Memory allocation with malloc
    // Ignore this at the moment! Will be used in the future
    //mp3syncword=(unsigned int *)malloc(20000);

    // Let's get the name of the file thats requested
    strcpy(requestedFile,"testmp3.mp3"); // lets hardcode this into here for now

    // Open the file
    mp3file = fopen(requestedFile, "rb"); // open the requested file with mode read, binary
    if (!mp3file){
        printf("Not found!"); // if we can't find the file, notify the user of the problem
    }

    // Let's get some header data from the file
    fseek(mp3file,0,SEEK_SET);
    fread(&byte,sizeof(byte),1,mp3file);

    // Extract the bits
    for (int i = 0; i < sizeof(bits); i++) {
        bits[i] = (byte >> i) & mask;
    }

    // For debug purposes, lets print the received data
    for (int i = 0; i < sizeof(bits); i++) {
        printf("Bit: %d\n",bits[i]);
    }

Answer 1

The ID3 info may come first. Are the first 3 characters ID3?