static int decode_hextile(VmncContext *c, uint8_t* dst, GetByteContext *gb,
                          int w, int h, int stride)
{
    int i, j, k;
    int bg = 0, fg = 0, rects, color, flags, xy, wh;
    const int bpp = c->bpp2;
    uint8_t *dst2;
    int bw = 16, bh = 16;

    for (j = 0; j < h; j += 16) {
        dst2 = dst;
        bw   = 16;
        if (j + 16 > h)
            bh = h - j;
        for (i = 0; i < w; i += 16, dst2 += 16 * bpp) {
            if (bytestream2_get_bytes_left(gb) <= 0) {
                av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
                return AVERROR_INVALIDDATA;
            }
            if (i + 16 > w)
                bw = w - i;
            flags = bytestream2_get_byte(gb);
            if (flags & HT_RAW) {
                if (bytestream2_get_bytes_left(gb) < bw * bh * bpp) {
                    av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
                    return AVERROR_INVALIDDATA;
                }
                paint_raw(dst2, bw, bh, gb, bpp, c->bigendian, stride);
            } else {
                if (flags & HT_BKG)
                    bg = vmnc_get_pixel(gb, bpp, c->bigendian);
                if (flags & HT_FG)
                    fg = vmnc_get_pixel(gb, bpp, c->bigendian);
                rects = 0;
                if (flags & HT_SUB)
                    rects = bytestream2_get_byte(gb);
                color = !!(flags & HT_CLR);

                paint_rect(dst2, 0, 0, bw, bh, bg, bpp, stride);

                if (bytestream2_get_bytes_left(gb) < rects * (color * bpp + 2)) {
                    av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
                    return AVERROR_INVALIDDATA;
                }
                for (k = 0; k < rects; k++) {
                    if (color)
                        fg = vmnc_get_pixel(gb, bpp, c->bigendian);
                    xy = bytestream2_get_byte(gb);
                    wh = bytestream2_get_byte(gb);
                    paint_rect(dst2, xy >> 4, xy & 0xF,
                               (wh>>4)+1, (wh & 0xF)+1, fg, bpp, stride);
                }
            }
        }
        dst += stride * 16;
    }
    return 0;
}
Unknown