pset4 resize.c unsupported format or file size exceeded

Question

so every time I run my program I get the error message: "unsupported file format". What's more, even if I delete the line handling the file format, the program still fails due to "File size limit exceeded". Any tips please?

Hopefully the code isn't too messy, I tried to keep it commented.

int main(int argc, char* argv[])
{
    if (argc != 4)
    {
        printf("Proper usage: n, infile, outfile\n");
        return 1;
    }
    char* infile = argv[2];
    char* outfile = argv[3];
    int n = atoi(argv[1]);

    //open infile
    FILE* inptr = fopen(infile, "r");
    if (inptr == NULL)
    {
        printf("Could not open %s.\n", infile);
        return 2;
    }

    //open outfile
    FILE* outptr = fopen(outfile, "w");
    if (outptr == NULL)
    {
        fclose(inptr);
        fprintf(stderr, "Could not create %s.\n", outfile);
        return 3;
    }

    //read infile BFHEADER
    BITMAPFILEHEADER bf;
    fread(&bf, sizeof(BITMAPFILEHEADER), 1, inptr);
    //read outfile BIHEADER
    BITMAPINFOHEADER bi;
    fread(&bi, sizeof(BITMAPINFOHEADER), 1, outptr);

    // ensure infile is (likely) a 24-bit uncompressed BMP 4.0
    if (bf.bfType != 0x4d42 || bf.bfOffBits != 54 || bi.biSize != 40 || 
        bi.biBitCount != 24 || bi.biCompression != 0)
    {
        fclose(outptr);
        fclose(inptr);
        fprintf(stderr, "Unsupported file format.\n");
        return 4;
    }

    //save for future purpose
    int width = bi.biWidth;
    int height = bi.biHeight;

    //edit the headers
    bf.bfSize = 54 + bi.biSizeImage * n;
    bi.biSizeImage = bi.biSizeImage * n;
    bi.biWidth = bi.biWidth * n;
    bi.biHeight = bi.biHeight * n;

    //write in the updated BFHEADER
    fwrite(&bf, sizeof(BITMAPFILEHEADER), 1, outptr);
    //write in the updated BIHEADER
    fwrite(&bi, sizeof(BITMAPINFOHEADER), 1, outptr);

    //determine padding
    int padding = (4 - (width * sizeof(RGBTRIPLE) % 4));
    int paddingNew = (4 - (bi.biWidth * sizeof(RGBTRIPLE) % 4));

    //iterate each scanline
    RGBTRIPLE triple;
    for (int i = 0, l = abs(height); i < l; i++)
    {
        for (int h = 0; h < n; h++)
        {
            for (int j = 0; j < width; j++)
            {
                fread(&triple, sizeof(RGBTRIPLE), 1, inptr);

                fwrite(&triple, sizeof(RGBTRIPLE), n, outptr);
            }

            //skip the padding
            fseek(inptr, padding, SEEK_CUR);
            //write in the new padding
            for (int o = 0; i < paddingNew; o++)
                fputc(0x00, outptr);
        }
    }

    fclose(inptr);
    fclose(outptr);
}

Answer 1

See any problems here?

//read infile BFHEADER
BITMAPFILEHEADER bf;
fread(&bf, sizeof(BITMAPFILEHEADER), 1, inptr);
//read outfile BIHEADER
BITMAPINFOHEADER bi;
fread(&bi, sizeof(BITMAPINFOHEADER), 1, outptr);

SPOILER: Which file are you reading from? If you can't see it, leave a comment.

This fixes the problem in your question, but there are other issues that follow, perhaps an infinite loop. But that would be a new question. Wouldn't want to deprive you of the fun of debugging them. ;-)

If this answers your question, please click on the check mark to accept. Let's keep up on forum maintenance. ;-)

Answer 2

So Cliff, even though you adviced me not to continue and even though I agree that was probably the best solution, I continued nevertheless because I was just going mad from not coming up with proper solution.

3 hours later I solved this madness!!!

Turned out I had to edit a lot of the code and after I got the resize thing correct and working, few problems regarding the header came up, but I dealt with those as well and now it is fully functional and has passed check50 control!

HELL YEAH! NEVER GIVE UP, YAAAAA! 8 fruiting hours spent on this but I GOT IT!!