static void kempf_restore_buf(const uint8_t *src, int len,
                              uint8_t *dst, int stride,
                              const uint8_t *jpeg_tile, int tile_stride,
                              int width, int height,
                              const uint8_t *pal, int npal, int tidx)
{
    GetBitContext gb;
    int i, j, nb, col;

    init_get_bits(&gb, src, len * 8);

    if (npal <= 2)       nb = 1;
    else if (npal <= 4)  nb = 2;
    else if (npal <= 16) nb = 4;
    else                 nb = 8;

    for (j = 0; j < height; j++, dst += stride, jpeg_tile += tile_stride) {
        if (get_bits(&gb, 8))
            continue;
        for (i = 0; i < width; i++) {
            col = get_bits(&gb, nb);
            if (col != tidx)
                memcpy(dst + i * 3, pal + col * 3, 3);
            else
                memcpy(dst + i * 3, jpeg_tile + i * 3, 3);
        }
    }
}
static void kempf_restore_buf(const uint8_t *src, int len,
                              uint8_t *dst, int stride,
                              const uint8_t *jpeg_tile, int tile_stride,
                              int width, int height,
                              const uint8_t *pal, int npal, int tidx)
{
    GetBitContext gb;
    int i, j, nb, col;

    init_get_bits(&gb, src, len * 8);

    if (npal <= 2)       nb = 1;
    else if (npal <= 4)  nb = 2;
    else if (npal <= 16) nb = 4;
    else                 nb = 8;

    for (j = 0; j < height; j++, dst += stride, jpeg_tile += tile_stride) {
        if (get_bits(&gb, 8))
            continue;
        for (i = 0; i < width; i++) {
            col = get_bits(&gb, nb);
            if (col != tidx)
                memcpy(dst + i * 3, pal + col * 3, 3);
            else
                memcpy(dst + i * 3, jpeg_tile + i * 3, 3);
        }
    }
}