QB64-PE/internal/c/parts/video/image/decode/jpg/src.c

#ifdef QB64_BACKSLASH_FILESYSTEM
#    include "src\\nanojpeg.c"
#else
#    include "src/nanojpeg.c"
#endif

uint8 *image_decode_jpg(uint8 *content, int32 bytes, int32 *result, int32 *x, int32 *y) {
    // Result:bit 1=Success,bit 2=32bit[BGRA]
    *result = 0;
    static int32 init = 0;
    if (!init) {
        init = 1;
        njInit();
    }
    if (njDecode(content, bytes))
        return NULL;

    static uint8 *si;
    si = (uint8 *)njGetImage();
    static int32 w, h;
    w = njGetWidth();
    h = njGetHeight();
    static uint8 *di;

    if (njIsColor) { // RGB

        // Create a buffer large enough to store image
        if (w * h * 3 != njGetImageSize())
            return NULL;
        di = (uint8 *)malloc(w * h * 4);

        // RGB->BGRA
        static int32 c;
        c = w * h;
        while (c--) {
            di[c * 4 + 2] = si[c * 3];     // red
            di[c * 4 + 1] = si[c * 3 + 1]; // green
            di[c * 4] = si[c * 3 + 2];     // blue
            di[c * 4 + 3] = 255;           // alpha
        }

    } else { // Greyscale

        // Create a buffer large enough to store image
        if (w * h != njGetImageSize())
            return NULL;
        di = (uint8 *)malloc(w * h * 4);

        // Greyscale->BGRA
        static int32 c;
        c = w * h;
        while (c--) {
            di[c * 4 + 2] = si[c]; // red
            di[c * 4 + 1] = si[c]; // green
            di[c * 4] = si[c];     // blue
            di[c * 4 + 3] = 255;   // alpha
        }
    }

    *result = 1 + 2;
    *x = w;
    *y = h;
    return di;
}