typedef testing::TestWithParam<int> Imgcodecs_Gif_GIF_LOOP;
TEST_P(Imgcodecs_Gif_GIF_LOOP, imencode)
{
    int loopCount = GetParam();

    vector<int> param;
    param.push_back(cv::IMWRITE_GIF_LOOP);
    param.push_back(loopCount);

    vector<cv::Mat> src;
    for(int n = 1; n <= 5 ; n ++ )
    {
        cv::Mat frame(64, 64, CV_8UC3, cv::Scalar::all(0));
        cv::putText(frame, cv::format("%d", n), cv::Point(0,64), cv::FONT_HERSHEY_PLAIN, 4.0, cv::Scalar::all(255));
        src.push_back(frame);
    }

    bool ret = false;
    vector<uint8_t> buf;
#if 0
    // To output gif image for test.
    EXPECT_NO_THROW(ret = imwrite(cv::format("gif_loop-%d.gif", loopCount), src, param));
    EXPECT_TRUE(ret);
#endif
    EXPECT_NO_THROW(ret = imencode(".gif", src, buf, param));
    EXPECT_TRUE(ret);

    std::vector<uint8_t> netscape = {'N','E','T','S','C','A','P','E'};
    auto pos = std::search(buf.begin(), buf.end(), netscape.begin(), netscape.end());
    if(loopCount < 0) {
        EXPECT_EQ(pos, buf.end()) << "Netscape Applicatioin Block should not be included if IMWRITE_GIF_LOOP < 0";
    } else {
        EXPECT_NE(pos, buf.end()) << "Netscape Applicatioin Block should be included if IMWRITE_GIF_LOOP >= 0";
    }
}

INSTANTIATE_TEST_CASE_P(/*nothing*/,
    Imgcodecs_Gif_GIF_LOOP,
    testing::Values(
        -2,
        -1, // Minimum Limit, no-loop
         0, // Default, loop-forever
         1, // Positive minimum value
         2,
     65534,
     65535, // Maximum Limit
     65536
    )
);