image-match/python/opencv/modules/videoio/test/test_ffmpeg.cpp

// This file is part of OpenCV project.
// It is subject to the license terms in the LICENSE file found in the top-level directory
// of this distribution and at http://opencv.org/license.html.

#include "test_precomp.hpp"

using namespace std;

namespace opencv_test { namespace {

static inline long long getFileSize(const string &filename)
{
    ifstream f(filename, ios_base::in | ios_base::binary);
    f.seekg(0, ios_base::end);
    return f.tellg();
}

typedef tuple<string, string, Size> FourCC_Ext_Size;
typedef testing::TestWithParam< FourCC_Ext_Size > videoio_ffmpeg;

TEST_P(videoio_ffmpeg, write_big)
{
    if (!videoio_registry::hasBackend(CAP_FFMPEG))
        throw SkipTestException("FFmpeg backend was not found");

    const string fourcc = get<0>(GetParam());
    const string ext = get<1>(GetParam());
    const Size sz = get<2>(GetParam());
    const double time_sec = 1;
    const double fps = 25;

    ostringstream buf;
    buf << "write_big_" << fourcc << "." << ext;
    const string filename = tempfile(buf.str().c_str());

    VideoWriter writer(filename, CAP_FFMPEG, fourccFromString(fourcc), fps, sz);
    if (ext == "mp4" && fourcc == "H264" && !writer.isOpened())
    {
        throw cvtest::SkipTestException("H264/mp4 codec is not supported - SKIP");
    }
    ASSERT_TRUE(writer.isOpened());
    Mat img(sz, CV_8UC3, Scalar::all(0));
    const int coeff = cvRound(min(sz.width, sz.height)/(fps * time_sec));
    for (int i = 0 ; i < static_cast<int>(fps * time_sec); i++ )
    {
        rectangle(img,
                  Point2i(coeff * i, coeff * i),
                  Point2i(coeff * (i + 1), coeff * (i + 1)),
                  Scalar::all(255 * (1.0 - static_cast<double>(i) / (fps * time_sec * 2))),
                  -1);
        writer << img;
    }
    writer.release();
    EXPECT_GT(getFileSize(filename), 8192);
    remove(filename.c_str());
}

#if defined(OPENCV_32BIT_CONFIGURATION)
static const Size bigSize(1920, 1080);
#else
static const Size bigSize(4096, 4096);
#endif

const FourCC_Ext_Size entries[] =
{
    make_tuple("", "avi", bigSize),
    make_tuple("DX50", "avi", bigSize),
    make_tuple("FLV1", "avi", bigSize),
    make_tuple("H261", "avi", Size(352, 288)),
    make_tuple("H263", "avi", Size(704, 576)),
    make_tuple("I420", "avi", bigSize),
    make_tuple("MJPG", "avi", bigSize),
    make_tuple("mp4v", "avi", bigSize),
    make_tuple("MPEG", "avi", Size(720, 576)),
    make_tuple("XVID", "avi", bigSize),
    make_tuple("H264", "mp4", Size(4096, 2160)),
    make_tuple("FFV1", "avi", bigSize),
    make_tuple("FFV1", "mkv", bigSize)
};

inline static std::string videoio_ffmpeg_name_printer(const testing::TestParamInfo<videoio_ffmpeg::ParamType>& info)
{
    std::ostringstream os;
    const string & fourcc = get<0>(info.param);
    const Size sz = get<2>(info.param);
    os << (fourcc.size() == 0 ? "NONE" : fourcc) << "_" << get<1>(info.param) << "_" << sz.height << "p";
    return os.str();
}

INSTANTIATE_TEST_CASE_P(videoio, videoio_ffmpeg, testing::ValuesIn(entries), videoio_ffmpeg_name_printer);

//==========================================================================

TEST(videoio_ffmpeg, image)
{
    if (!videoio_registry::hasBackend(CAP_FFMPEG))
        throw SkipTestException("FFmpeg backend was not found");

    const string filename = findDataFile("readwrite/ordinary.bmp");
    Mat image = imread(filename, IMREAD_COLOR);
    ASSERT_FALSE(image.empty());
    VideoCapture cap(filename, CAP_FFMPEG);
    ASSERT_TRUE(cap.isOpened());
    Mat frame1, frame2;
    cap >> frame1 >> frame2;
    ASSERT_FALSE(frame1.empty());
    ASSERT_TRUE(frame2.empty());
    ASSERT_EQ(0, cvtest::norm(image, frame1, NORM_INF));
}

//==========================================================================

typedef tuple<string, int, bool> videoio_read_params_t;
typedef testing::TestWithParam< testing::tuple<videoio_read_params_t, int, bool>> videoio_read;

TEST_P(videoio_read, threads)
{
    const VideoCaptureAPIs api = CAP_FFMPEG;
    if (!videoio_registry::hasBackend(api))
        throw SkipTestException("Backend was not found");
    const string fileName = get<0>(get<0>(GetParam()));
    const int nFrames = get<1>(get<0>(GetParam()));
    const bool fixedThreadCount = get<2>(get<0>(GetParam()));
    const int nThreads = get<1>(GetParam());
    const bool rawRead = get<2>(GetParam());
    VideoCapture cap(findDataFile(fileName), api, { CAP_PROP_N_THREADS, nThreads });
    if (!cap.isOpened())
        throw SkipTestException("Video stream is not supported");
    if (nThreads == 0 || fixedThreadCount)
        EXPECT_EQ(cap.get(CAP_PROP_N_THREADS), VideoCapture(findDataFile(fileName), api).get(CAP_PROP_N_THREADS));
    else
        EXPECT_EQ(cap.get(CAP_PROP_N_THREADS), nThreads);
    if (rawRead && !cap.set(CAP_PROP_FORMAT, -1))  // turn off video decoder (extract stream)
        throw SkipTestException("Fetching of RAW video streams is not supported");
    Mat frame;
    int n = 0;
    while (cap.read(frame)) {
        ASSERT_FALSE(frame.empty());
        n++;
    }
    ASSERT_EQ(n, nFrames);
}

const videoio_read_params_t videoio_read_params[] =
{
    videoio_read_params_t("video/big_buck_bunny.h264", 125, false),
    //videoio_read_params_t("video/big_buck_bunny.h265", 125, false),
    videoio_read_params_t("video/big_buck_bunny.mjpg.avi", 125, true),
    //videoio_read_params_t("video/big_buck_bunny.mov", 125, false),
    //videoio_read_params_t("video/big_buck_bunny.mp4", 125, false),
    //videoio_read_params_t("video/big_buck_bunny.mpg", 125, false),
    //videoio_read_params_t("video/big_buck_bunny.wmv", 125, true),
};

inline static std::string videoio_read_name_printer(const testing::TestParamInfo<videoio_read::ParamType>& info)
{
    std::ostringstream out;
    out << getExtensionSafe(get<0>(get<0>(info.param))) << "_"
        << get<1>(info.param) << "_"
        << (get<2>(info.param) ? "RAW" : "ENC");
    return out.str();
}

INSTANTIATE_TEST_CASE_P(/**/, videoio_read, testing::Combine(testing::ValuesIn(videoio_read_params),
                                                             testing::Values(0, 1, 2, 50),
                                                             testing::Values(true, false)),
                        videoio_read_name_printer);

//==========================================================================

typedef tuple<VideoCaptureAPIs, string, string, string, string, string> videoio_container_params_t;
typedef testing::TestWithParam< videoio_container_params_t > videoio_container;

TEST_P(videoio_container, read)
{
    const VideoCaptureAPIs api = get<0>(GetParam());

    if (!videoio_registry::hasBackend(api))
        throw SkipTestException("Backend was not found");

    const string path = get<1>(GetParam());
    const string ext = get<2>(GetParam());
    const string ext_raw = get<3>(GetParam());
    const string codec = get<4>(GetParam());
    const string pixelFormat = get<5>(GetParam());
    const string fileName = path + "." + ext;
    const string fileNameOut = tempfile(cv::format("test_container_stream.%s", ext_raw.c_str()).c_str());

    // Write encoded video read using VideoContainer to tmp file
    size_t totalBytes = 0;
    {
        VideoCapture container(findDataFile(fileName), api);
        if (!container.isOpened())
            throw SkipTestException("Video stream is not supported");
        if (!container.set(CAP_PROP_FORMAT, -1))  // turn off video decoder (extract stream)
            throw SkipTestException("Fetching of RAW video streams is not supported");
        ASSERT_EQ(-1.f, container.get(CAP_PROP_FORMAT));  // check
        EXPECT_EQ(codec, fourccToString((int)container.get(CAP_PROP_FOURCC)));
        EXPECT_EQ(pixelFormat, fourccToString((int)container.get(CAP_PROP_CODEC_PIXEL_FORMAT)));

        std::ofstream file(fileNameOut.c_str(), ios::out | ios::trunc | std::ios::binary);
        Mat raw_data;
        while (true)
        {
            container >> raw_data;
            size_t size = raw_data.total();
            if (raw_data.empty())
                break;
            ASSERT_EQ(CV_8UC1, raw_data.type());
            ASSERT_LE(raw_data.dims, 2);
            ASSERT_EQ(raw_data.rows, 1);
            ASSERT_EQ((size_t)raw_data.cols, raw_data.total());
            ASSERT_TRUE(raw_data.isContinuous());
            totalBytes += size;
            file.write(reinterpret_cast<char*>(raw_data.data), size);
            ASSERT_FALSE(file.fail());
        }
        ASSERT_GE(totalBytes, (size_t)39775) << "Encoded stream is too small";
    }

    std::cout << "Checking extracted video stream: " << fileNameOut << " (size: " << totalBytes << " bytes)" << std::endl;

    // Check decoded frames read from original media are equal to frames decoded from tmp file
    {
        VideoCapture capReference(findDataFile(fileName), api);
        ASSERT_TRUE(capReference.isOpened());
        VideoCapture capActual(fileNameOut.c_str(), api);
        ASSERT_TRUE(capActual.isOpened());
        Mat reference, actual;
        int nframes = 0, n_err = 0;
        while (capReference.read(reference) && n_err < 3)
        {
            nframes++;
            ASSERT_TRUE(capActual.read(actual)) << nframes;
            EXPECT_EQ(0, cvtest::norm(actual, reference, NORM_INF)) << "frame=" << nframes << " err=" << ++n_err;
        }
        ASSERT_GT(nframes, 0);
    }

    ASSERT_EQ(0, remove(fileNameOut.c_str()));
}

const videoio_container_params_t videoio_container_params[] =
{
    videoio_container_params_t(CAP_FFMPEG, "video/big_buck_bunny", "h264", "h264", "h264", "I420"),
    videoio_container_params_t(CAP_FFMPEG, "video/big_buck_bunny", "h265", "h265", "hevc", "I420"),
    videoio_container_params_t(CAP_FFMPEG, "video/big_buck_bunny", "mjpg.avi", "mjpg", "MJPG", "I420"),
    videoio_container_params_t(CAP_FFMPEG, "video/sample_322x242_15frames.yuv420p.libx264", "mp4", "h264", "h264", "I420")
    //videoio_container_params_t(CAP_FFMPEG, "video/big_buck_bunny", "h264.mkv", "mkv.h264", "h264", "I420"),
    //videoio_container_params_t(CAP_FFMPEG, "video/big_buck_bunny", "h265.mkv", "mkv.h265", "hevc", "I420"),
    //videoio_container_params_t(CAP_FFMPEG, "video/big_buck_bunny", "h264.mp4", "mp4.avc1", "avc1", "I420"),
    //videoio_container_params_t(CAP_FFMPEG, "video/big_buck_bunny", "h265.mp4", "mp4.hev1", "hev1", "I420"),
};

INSTANTIATE_TEST_CASE_P(/**/, videoio_container, testing::ValuesIn(videoio_container_params));

typedef tuple<VideoCaptureAPIs, string, int, int, int, int, int> videoio_container_get_params_t;
typedef testing::TestWithParam<videoio_container_get_params_t > videoio_container_get;

TEST_P(videoio_container_get, read)
{
    const VideoCaptureAPIs api = get<0>(GetParam());

    if (!videoio_registry::hasBackend(api))
        throw SkipTestException("Backend was not found");

    const string fileName = get<1>(GetParam());
    const int height = get<2>(GetParam());
    const int width = get<3>(GetParam());
    const int nFrames = get<4>(GetParam());
    const int bitrate = get<5>(GetParam());
    const int fps = get<6>(GetParam());

    VideoCapture container(findDataFile(fileName), api, { CAP_PROP_FORMAT, -1 });
    if (!container.isOpened())
        throw SkipTestException("Video stream is not supported");

    const int heightProp = static_cast<int>(container.get(CAP_PROP_FRAME_HEIGHT));
    ASSERT_EQ(height, heightProp);
    const int widthProp = static_cast<int>(container.get(CAP_PROP_FRAME_WIDTH));
    ASSERT_EQ(width, widthProp);
    const int nFramesProp = static_cast<int>(container.get(CAP_PROP_FRAME_COUNT));
    ASSERT_EQ(nFrames, nFramesProp);
    const int bitrateProp = static_cast<int>(container.get(CAP_PROP_BITRATE));
    ASSERT_EQ(bitrate, bitrateProp);
    const double fpsProp = container.get(CAP_PROP_FPS);
    ASSERT_EQ(fps, fpsProp);

    vector<int> displayTimeMs;
    int iFrame = 1;
    while (container.grab()) {
        displayTimeMs.push_back(static_cast<int>(container.get(CAP_PROP_POS_MSEC)));
        const int iFrameProp = static_cast<int>(container.get(CAP_PROP_POS_FRAMES));
        ASSERT_EQ(iFrame++, iFrameProp);
    }
    sort(displayTimeMs.begin(), displayTimeMs.end());
    vector<int> displayTimeDiffMs(displayTimeMs.size());
    std::adjacent_difference(displayTimeMs.begin(), displayTimeMs.end(), displayTimeDiffMs.begin());
    auto minTimeMsIt = min_element(displayTimeDiffMs.begin() + 1, displayTimeDiffMs.end());
    auto maxTimeMsIt = max_element(displayTimeDiffMs.begin() + 1, displayTimeDiffMs.end());
    const int frameTimeMs = static_cast<int>(1000.0 / fps);
    ASSERT_NEAR(frameTimeMs, *minTimeMsIt, 1);
    ASSERT_NEAR(frameTimeMs, *maxTimeMsIt, 1);
}

const videoio_container_get_params_t videoio_container_get_params[] =
{
    videoio_container_get_params_t(CAP_FFMPEG, "video/big_buck_bunny.mp4", 384, 672, 125, 483, 24),
    videoio_container_get_params_t(CAP_FFMPEG, "video/big_buck_bunny.mjpg.avi", 384, 672, 125, 2713, 24),
    videoio_container_get_params_t(CAP_FFMPEG, "video/sample_322x242_15frames.yuv420p.libx264.mp4", 242, 322, 15, 542, 25)
};

INSTANTIATE_TEST_CASE_P(/**/, videoio_container_get, testing::ValuesIn(videoio_container_get_params));

typedef tuple<string, string, int, int, bool, bool> videoio_encapsulate_params_t;
typedef testing::TestWithParam< videoio_encapsulate_params_t > videoio_encapsulate;

TEST_P(videoio_encapsulate, write)
{
    const VideoCaptureAPIs api = CAP_FFMPEG;
    if (!videoio_registry::hasBackend(api))
        throw SkipTestException("FFmpeg backend was not found");

    const string fileName = findDataFile(get<0>(GetParam()));
    const string ext = get<1>(GetParam());
    const int idrPeriod = get<2>(GetParam());
    const int nFrames = get<3>(GetParam());
    const string fileNameOut = tempfile(cv::format("test_encapsulated_stream.%s", ext.c_str()).c_str());
    const bool setPts = get<4>(GetParam());
    const bool tsWorking = get<5>(GetParam());

    // Use VideoWriter to encapsulate encoded video read with VideoReader
    {
        VideoCapture capRaw(fileName, api, { CAP_PROP_FORMAT, -1 });
        ASSERT_TRUE(capRaw.isOpened());
        const int width = static_cast<int>(capRaw.get(CAP_PROP_FRAME_WIDTH));
        const int height = static_cast<int>(capRaw.get(CAP_PROP_FRAME_HEIGHT));
        const double fps = capRaw.get(CAP_PROP_FPS);
        const int codecExtradataIndex = static_cast<int>(capRaw.get(CAP_PROP_CODEC_EXTRADATA_INDEX));
        Mat extraData;
        capRaw.retrieve(extraData, codecExtradataIndex);
        const int fourcc = static_cast<int>(capRaw.get(CAP_PROP_FOURCC));
        const bool mpeg4 = (fourcc == fourccFromString("FMP4"));
        VideoWriter container(fileNameOut, api, fourcc, fps, { width, height }, { VideoWriterProperties::VIDEOWRITER_PROP_RAW_VIDEO, 1, VideoWriterProperties::VIDEOWRITER_PROP_KEY_INTERVAL, idrPeriod });
        ASSERT_TRUE(container.isOpened());
        Mat rawFrame;
        for (int i = 0; i < nFrames; i++) {
            ASSERT_TRUE(capRaw.read(rawFrame));
            if (setPts && i == 0) {
                double dts = capRaw.get(CAP_PROP_DTS_DELAY);
                ASSERT_TRUE(container.set(VIDEOWRITER_PROP_DTS_DELAY, dts)) << "dts=" << dts;
            }
            ASSERT_FALSE(rawFrame.empty());
            if (i == 0 && mpeg4) {
                Mat tmp = rawFrame.clone();
                const size_t newSzt = tmp.total() + extraData.total();
                const int newSz = static_cast<int>(newSzt);
                ASSERT_TRUE(newSzt == static_cast<size_t>(newSz));
                rawFrame = Mat(1, newSz, CV_8UC1);
                memcpy(rawFrame.data, extraData.data, extraData.total());
                memcpy(rawFrame.data + extraData.total(), tmp.data, tmp.total());
            }
            if (setPts) {
                double pts = capRaw.get(CAP_PROP_PTS);
                ASSERT_TRUE(container.set(VIDEOWRITER_PROP_PTS, pts)) << "pts=" << pts;
            }
            container.write(rawFrame);
        }
        container.release();
    }

    std::cout << "Checking encapsulated video container: " << fileNameOut << std::endl;

    // Check encapsulated video container is "identical" to the original
    {
        VideoCapture capReference(fileName), capActual(fileNameOut), capActualRaw(fileNameOut, api, { CAP_PROP_FORMAT, -1 });
        ASSERT_TRUE(capReference.isOpened());
        ASSERT_TRUE(capActual.isOpened());
        ASSERT_TRUE(capActualRaw.isOpened());
        const double fpsReference = capReference.get(CAP_PROP_FPS);
        const double fpsActual = capActual.get(CAP_PROP_FPS);
        ASSERT_NEAR(fpsReference, fpsActual, 1e-2);
        const int nFramesActual = static_cast<int>(capActual.get(CAP_PROP_FRAME_COUNT));
        ASSERT_EQ(nFrames, nFramesActual);

        Mat reference, actual;
        for (int i = 0; i < nFrames; i++) {
            ASSERT_TRUE(capReference.read(reference));
            ASSERT_FALSE(reference.empty());
            ASSERT_TRUE(capActual.read(actual));
            ASSERT_FALSE(actual.empty());
            ASSERT_EQ(0, cvtest::norm(reference, actual, NORM_INF));
            ASSERT_TRUE(capActualRaw.grab());
            const bool keyFrameActual = capActualRaw.get(CAP_PROP_LRF_HAS_KEY_FRAME) == 1.;
            const bool keyFrameReference = idrPeriod ? i % idrPeriod == 0 : 1;
            ASSERT_EQ(keyFrameReference, keyFrameActual);
            if (tsWorking) {
                ASSERT_EQ(round(capReference.get(CAP_PROP_POS_MSEC)), round(capActual.get(CAP_PROP_POS_MSEC)));
            }
        }
    }

    ASSERT_EQ(0, remove(fileNameOut.c_str()));
}

const videoio_encapsulate_params_t videoio_encapsulate_params[] =
{
    videoio_encapsulate_params_t("video/big_buck_bunny.h264", "avi", 125, 125, false, false), // tsWorking = false: no timestamp information
    videoio_encapsulate_params_t("video/big_buck_bunny.h265", "mp4", 125, 125, false, false), // tsWorking = false: no timestamp information
    videoio_encapsulate_params_t("video/big_buck_bunny.wmv", "wmv", 12, 13, false, true),
    videoio_encapsulate_params_t("video/big_buck_bunny.mp4", "mp4", 12, 13, false, true),
    videoio_encapsulate_params_t("video/big_buck_bunny.mjpg.avi", "mp4", 0, 4, false, true),
    videoio_encapsulate_params_t("video/big_buck_bunny.mov", "mp4", 12, 13, false, true),
    videoio_encapsulate_params_t("video/big_buck_bunny.avi", "mp4", 125, 125, false, false), // tsWorking = false: PTS not available for all frames
    videoio_encapsulate_params_t("video/big_buck_bunny.mpg", "mp4", 12, 13, true, true),
    videoio_encapsulate_params_t("video/VID00003-20100701-2204.wmv", "wmv", 12, 13, false, true),
    videoio_encapsulate_params_t("video/VID00003-20100701-2204.mpg", "mp4", 12, 13, false, false), // tsWorking = false: PTS not available for all frames
    videoio_encapsulate_params_t("video/VID00003-20100701-2204.avi", "mp4", 12, 13, false, false), // tsWorking = false: Unable to correctly set PTS when writing
    videoio_encapsulate_params_t("video/VID00003-20100701-2204.3GP", "mp4", 51, 52, false, false), // tsWorking = false: Source with variable fps
    videoio_encapsulate_params_t("video/sample_sorenson.avi", "mp4", 12, 13, false, true),
    videoio_encapsulate_params_t("video/sample_322x242_15frames.yuv420p.libxvid.mp4", "mp4", 3, 4, false, true),
    videoio_encapsulate_params_t("video/sample_322x242_15frames.yuv420p.mpeg2video.mp4", "mpg", 12, 13, false, true),
    videoio_encapsulate_params_t("video/sample_322x242_15frames.yuv420p.mjpeg.mp4", "mp4", 0, 5, false, true),
    videoio_encapsulate_params_t("video/sample_322x242_15frames.yuv420p.libx264.mp4", "ts", 15, 15, true, true),
    videoio_encapsulate_params_t("../cv/tracking/faceocc2/data/faceocc2.webm", "webm", 128, 129, false, true),
    videoio_encapsulate_params_t("../cv/video/1920x1080.avi", "mp4", 12, 13, false, true),
    videoio_encapsulate_params_t("../cv/video/768x576.avi", "avi", 15, 16, false, true),
    // Not supported by with FFmpeg:
    //videoio_encapsulate_params_t("video/sample_322x242_15frames.yuv420p.libx265.mp4", "mp4", 15, 15, true, true),
    //videoio_encapsulate_params_t("video/sample_322x242_15frames.yuv420p.libvpx-vp9.mp4", "mp4", 15, 15, false, true),
};

INSTANTIATE_TEST_CASE_P(/**/, videoio_encapsulate, testing::ValuesIn(videoio_encapsulate_params));

TEST(videoio_encapsulate_set_idr, write)
{
    const VideoCaptureAPIs api = CAP_FFMPEG;
    if (!videoio_registry::hasBackend(api))
        throw SkipTestException("FFmpeg backend was not found");

    const string fileName = findDataFile("video/big_buck_bunny.mp4");
    const string ext = "mp4";
    const string fileNameOut = tempfile(cv::format("test_encapsulated_stream_set_idr.%s", ext.c_str()).c_str());

    // Use VideoWriter to encapsulate encoded video read with VideoReader
    {
        VideoCapture capRaw(fileName, api, { CAP_PROP_FORMAT, -1 });
        ASSERT_TRUE(capRaw.isOpened());
        const int width = static_cast<int>(capRaw.get(CAP_PROP_FRAME_WIDTH));
        const int height = static_cast<int>(capRaw.get(CAP_PROP_FRAME_HEIGHT));
        const double fps = capRaw.get(CAP_PROP_FPS);
        const int codecExtradataIndex = static_cast<int>(capRaw.get(CAP_PROP_CODEC_EXTRADATA_INDEX));
        Mat extraData;
        capRaw.retrieve(extraData, codecExtradataIndex);
        const int fourcc = static_cast<int>(capRaw.get(CAP_PROP_FOURCC));
        const bool mpeg4 = (fourcc == fourccFromString("FMP4"));

        VideoWriter container(fileNameOut, api, fourcc, fps, { width, height }, { VideoWriterProperties::VIDEOWRITER_PROP_RAW_VIDEO, 1 });
        ASSERT_TRUE(container.isOpened());
        Mat rawFrame;
        int i = 0;
        while (capRaw.read(rawFrame)) {
            ASSERT_FALSE(rawFrame.empty());
            if (i == 0 && mpeg4) {
                Mat tmp = rawFrame.clone();
                const size_t newSzt = tmp.total() + extraData.total();
                const int newSz = static_cast<int>(newSzt);
                ASSERT_TRUE(newSzt == static_cast<size_t>(newSz));
                rawFrame = Mat(1, newSz, CV_8UC1);
                memcpy(rawFrame.data, extraData.data, extraData.total());
                memcpy(rawFrame.data + extraData.total(), tmp.data, tmp.total());
            }
            if (capRaw.get(CAP_PROP_LRF_HAS_KEY_FRAME) != 0)
                container.set(VideoWriterProperties::VIDEOWRITER_PROP_KEY_FLAG, 1);
            else
                container.set(VideoWriterProperties::VIDEOWRITER_PROP_KEY_FLAG, 0);
            container.write(rawFrame);
            i++;
        }
        container.release();
    }

    std::cout << "Checking encapsulated video container: " << fileNameOut << std::endl;

    // Check encapsulated video container is "identical" to the original
    {
        VideoCapture capReference(fileName), capReferenceRaw(fileName, api, { CAP_PROP_FORMAT, -1 }), capActual(fileNameOut), capActualRaw(fileNameOut, api, { CAP_PROP_FORMAT, -1 });
        ASSERT_TRUE(capReference.isOpened());
        ASSERT_TRUE(capActual.isOpened());
        ASSERT_TRUE(capReferenceRaw.isOpened());
        ASSERT_TRUE(capActualRaw.isOpened());
        const double fpsReference = capReference.get(CAP_PROP_FPS);
        const double fpsActual = capActual.get(CAP_PROP_FPS);
        ASSERT_EQ(fpsReference, fpsActual);
        const int nFramesReference = static_cast<int>(capReference.get(CAP_PROP_FRAME_COUNT));
        const int nFramesActual = static_cast<int>(capActual.get(CAP_PROP_FRAME_COUNT));
        ASSERT_EQ(nFramesReference, nFramesActual);

        Mat reference, actual;
        for (int i = 0; i < nFramesReference; i++) {
            ASSERT_TRUE(capReference.read(reference));
            ASSERT_FALSE(reference.empty());
            ASSERT_TRUE(capActual.read(actual));
            ASSERT_FALSE(actual.empty());
            ASSERT_EQ(0, cvtest::norm(reference, actual, NORM_INF));
            ASSERT_TRUE(capReferenceRaw.grab());
            ASSERT_TRUE(capActualRaw.grab());
            const bool keyFrameReference = capActualRaw.get(CAP_PROP_LRF_HAS_KEY_FRAME) == 1.;
            const bool keyFrameActual = capActualRaw.get(CAP_PROP_LRF_HAS_KEY_FRAME) == 1.;
            ASSERT_EQ(keyFrameReference, keyFrameActual);
        }
    }

    ASSERT_EQ(0, remove(fileNameOut.c_str()));
}

typedef tuple<string, string, int> videoio_skip_params_t;
typedef testing::TestWithParam< videoio_skip_params_t > videoio_skip;

TEST_P(videoio_skip, DISABLED_read)  // optional test, may fail in some configurations
{
#if CV_VERSION_MAJOR >= 4
    if (!videoio_registry::hasBackend(CAP_FFMPEG))
        throw SkipTestException("Backend was not found");
#endif

    const string path = get<0>(GetParam());
    const string env = get<1>(GetParam());
    const int expectedFrameNumber = get<2>(GetParam());

    #ifdef _WIN32
        _putenv_s("OPENCV_FFMPEG_CAPTURE_OPTIONS", env.c_str());
    #else
        setenv("OPENCV_FFMPEG_CAPTURE_OPTIONS", env.c_str(), 1);
    #endif
    VideoCapture container(findDataFile(path), CAP_FFMPEG);
    #ifdef _WIN32
        _putenv_s("OPENCV_FFMPEG_CAPTURE_OPTIONS", "");
    #else
        setenv("OPENCV_FFMPEG_CAPTURE_OPTIONS", "", 1);
    #endif

    ASSERT_TRUE(container.isOpened());

    Mat reference;
    int nframes = 0, n_err = 0;
    while (container.isOpened())
    {
        if (container.read(reference))
            nframes++;
        else if (++n_err > 3)
            break;
    }
    EXPECT_EQ(expectedFrameNumber, nframes);
}

const videoio_skip_params_t videoio_skip_params[] =
{
    videoio_skip_params_t("video/big_buck_bunny.mp4", "", 125),
    videoio_skip_params_t("video/big_buck_bunny.mp4", "avdiscard;nonkey", 11)
};

INSTANTIATE_TEST_CASE_P(/**/, videoio_skip, testing::ValuesIn(videoio_skip_params));

//==========================================================================

static void generateFrame(Mat &frame, unsigned int i, const Point &center, const Scalar &color)
{
    frame = Scalar::all(i % 255);
    stringstream buf(ios::out);
    buf << "frame #" << i;
    putText(frame, buf.str(), Point(50, center.y), FONT_HERSHEY_SIMPLEX, 5.0, color, 5, LINE_AA);
    circle(frame, center, i + 2, color, 2, LINE_AA);
}

TEST(videoio_ffmpeg, parallel)
{
    if (!videoio_registry::hasBackend(CAP_FFMPEG))
        throw SkipTestException("FFmpeg backend was not found");

    const int NUM = 4;
    const int GRAN = 4;
    const Range R(0, NUM);
    const Size sz(1020, 900);
    const int frameNum = 300;
    const Scalar color(Scalar::all(0));
    const Point center(sz.height / 2, sz.width / 2);

    // Generate filenames
    vector<string> files;
    for (int i = 0; i < NUM; ++i)
    {
        ostringstream stream;
        stream << i << ".avi";
        files.push_back(tempfile(stream.str().c_str()));
    }
    // Write videos
    {
        vector< Ptr<VideoWriter> > writers(NUM);
        auto makeWriters = [&](const Range &r)
        {
            for (int i = r.start; i != r.end; ++i)
                writers[i] = makePtr<VideoWriter>(files[i],
                                                  CAP_FFMPEG,
                                                  VideoWriter::fourcc('X','V','I','D'),
                                                  25.0f,
                                                  sz);
        };
        parallel_for_(R, makeWriters, GRAN);
        for(int i = 0; i < NUM; ++i)
        {
            ASSERT_TRUE(writers[i]);
            ASSERT_TRUE(writers[i]->isOpened());
        }
        auto writeFrames = [&](const Range &r)
        {
            for (int j = r.start; j < r.end; ++j)
            {
                Mat frame(sz, CV_8UC3);
                for (int i = 0; i < frameNum; ++i)
                {
                    generateFrame(frame, i, center, color);
                    writers[j]->write(frame);
                }
            }
        };
        parallel_for_(R, writeFrames, GRAN);
    }
    // Read videos
    {
        vector< Ptr<VideoCapture> > readers(NUM);
        auto makeCaptures = [&](const Range &r)
        {
            for (int i = r.start; i != r.end; ++i)
                readers[i] = makePtr<VideoCapture>(files[i], CAP_FFMPEG);
        };
        parallel_for_(R, makeCaptures, GRAN);
        for(int i = 0; i < NUM; ++i)
        {
            ASSERT_TRUE(readers[i]);
            ASSERT_TRUE(readers[i]->isOpened());
        }
        auto readFrames = [&](const Range &r)
        {
            for (int j = r.start; j < r.end; ++j)
            {
                Mat reference(sz, CV_8UC3);
                for (int i = 0; i < frameNum; ++i)
                {
                    Mat actual;
                    EXPECT_TRUE(readers[j]->read(actual));
                    EXPECT_FALSE(actual.empty());
                    generateFrame(reference, i, center, color);
                    EXPECT_EQ(reference.size(), actual.size());
                    EXPECT_EQ(reference.depth(), actual.depth());
                    EXPECT_EQ(reference.channels(), actual.channels());
                    EXPECT_GE(cvtest::PSNR(actual, reference), 35.0) << "cap" << j << ", frame " << i;
                }
            }
        };
        parallel_for_(R, readFrames, GRAN);
    }
    // Remove files
    for(int i = 0; i < NUM; ++i)
    {
        remove(files[i].c_str());
    }
}

typedef std::pair<VideoCaptureProperties, double> cap_property_t;
typedef std::vector<cap_property_t> cap_properties_t;
typedef std::pair<std::string, cap_properties_t> ffmpeg_cap_properties_param_t;
typedef testing::TestWithParam<ffmpeg_cap_properties_param_t> ffmpeg_cap_properties;

TEST_P(ffmpeg_cap_properties, can_read_property)
{
    if (!videoio_registry::hasBackend(CAP_FFMPEG))
        throw SkipTestException("FFmpeg backend was not found");

    ffmpeg_cap_properties_param_t parameters = GetParam();
    const std::string path = parameters.first;
    const cap_properties_t properties = parameters.second;

    VideoCapture cap(findDataFile(path), CAP_FFMPEG);
    ASSERT_TRUE(cap.isOpened()) << "Can not open " << findDataFile(path);

    for (std::size_t i = 0; i < properties.size(); ++i)
    {
        const cap_property_t& prop = properties[i];
        const double actualValue = cap.get(static_cast<int>(prop.first));
        EXPECT_DOUBLE_EQ(actualValue, prop.second)
            << "Property " << static_cast<int>(prop.first) << " has wrong value";
    }
}

cap_properties_t loadBigBuckBunnyFFProbeResults() {
    cap_property_t properties[] = { cap_property_t(CAP_PROP_BITRATE, 5851.),
                                    cap_property_t(CAP_PROP_FPS, 24.),
                                    cap_property_t(CAP_PROP_FRAME_HEIGHT, 384.),
                                    cap_property_t(CAP_PROP_FRAME_WIDTH, 672.) };
    return cap_properties_t(properties, properties + sizeof(properties) / sizeof(cap_property_t));
}

const ffmpeg_cap_properties_param_t videoio_ffmpeg_properties[] = {
    ffmpeg_cap_properties_param_t("video/big_buck_bunny.avi", loadBigBuckBunnyFFProbeResults())
};

INSTANTIATE_TEST_CASE_P(videoio, ffmpeg_cap_properties, testing::ValuesIn(videoio_ffmpeg_properties));

typedef tuple<string, string> ffmpeg_get_fourcc_param_t;
typedef testing::TestWithParam<ffmpeg_get_fourcc_param_t> ffmpeg_get_fourcc;

TEST_P(ffmpeg_get_fourcc, check_short_codecs)
{
    const VideoCaptureAPIs api = CAP_FFMPEG;
    if (!videoio_registry::hasBackend(api))
        throw SkipTestException("Backend was not found");
    const string fileName = get<0>(GetParam());
    const string fourcc_string = get<1>(GetParam());
    VideoCapture cap(findDataFile(fileName), api);
    if (!cap.isOpened())
        throw SkipTestException("Video stream is not supported");
    const double fourcc = cap.get(CAP_PROP_FOURCC);
    ASSERT_EQ(fourcc_string, fourccToString((int)fourcc));
}

const ffmpeg_get_fourcc_param_t ffmpeg_get_fourcc_param[] =
{
    ffmpeg_get_fourcc_param_t("../cv/tracking/faceocc2/data/faceocc2.webm", "VP80"),
    ffmpeg_get_fourcc_param_t("video/big_buck_bunny.h265", "hevc"),
    ffmpeg_get_fourcc_param_t("video/big_buck_bunny.h264", "h264"),
    ffmpeg_get_fourcc_param_t("video/sample_322x242_15frames.yuv420p.libvpx-vp9.mp4", "VP90"),
    ffmpeg_get_fourcc_param_t("video/sample_322x242_15frames.yuv420p.libaom-av1.mp4", "AV01"),
    ffmpeg_get_fourcc_param_t("video/big_buck_bunny.mp4", "FMP4"),
    ffmpeg_get_fourcc_param_t("video/sample_322x242_15frames.yuv420p.mpeg2video.mp4", "mpg2"),
    ffmpeg_get_fourcc_param_t("video/sample_322x242_15frames.yuv420p.mjpeg.mp4", "MJPG"),
    ffmpeg_get_fourcc_param_t("video/sample_322x242_15frames.yuv420p.libxvid.mp4", "FMP4"),
    ffmpeg_get_fourcc_param_t("video/sample_322x242_15frames.yuv420p.libx265.mp4", "hevc"),
    ffmpeg_get_fourcc_param_t("video/sample_322x242_15frames.yuv420p.libx264.mp4", "h264")
};

inline static std::string ffmpeg_get_fourcc_name_printer(const testing::TestParamInfo<ffmpeg_get_fourcc::ParamType>& info)
{
    std::ostringstream os;
    const string & fourcc = get<1>(info.param);
    os << info.index << "_" << (fourcc.size() == 0 ? "NONE" : fourcc);
    return os.str();
}

INSTANTIATE_TEST_CASE_P(videoio, ffmpeg_get_fourcc, testing::ValuesIn(ffmpeg_get_fourcc_param), ffmpeg_get_fourcc_name_printer);

static void ffmpeg_check_read_raw(VideoCapture& cap)
{
    ASSERT_TRUE(cap.isOpened()) << "Can't open the video";

    Mat data;
    cap >> data;
    EXPECT_EQ(CV_8UC1, data.type()) << "CV_8UC1 != " << typeToString(data.type());
    EXPECT_TRUE(data.rows == 1 || data.cols == 1) << data.size;
    EXPECT_EQ((size_t)29729, data.total());

    cap >> data;
    EXPECT_EQ(CV_8UC1, data.type()) << "CV_8UC1 != " << typeToString(data.type());
    EXPECT_TRUE(data.rows == 1 || data.cols == 1) << data.size;
    EXPECT_EQ((size_t)37118, data.total());

    // 12 is the nearset key frame to frame 18
    EXPECT_TRUE(cap.set(CAP_PROP_POS_FRAMES, 18.));
    EXPECT_EQ(cap.get(CAP_PROP_POS_FRAMES), 12.);
    cap >> data;
    EXPECT_EQ(CV_8UC1, data.type()) << "CV_8UC1 != " << typeToString(data.type());
    EXPECT_TRUE(data.rows == 1 || data.cols == 1) << data.size;
    EXPECT_EQ((size_t)8726, data.total());
}

TEST(videoio_ffmpeg, ffmpeg_check_extra_data)
{
    if (!videoio_registry::hasBackend(CAP_FFMPEG))
        throw SkipTestException("FFmpeg backend was not found");

    string video_file = findDataFile("video/big_buck_bunny.mp4");
    VideoCapture cap;
    EXPECT_NO_THROW(cap.open(video_file, CAP_FFMPEG));
    ASSERT_TRUE(cap.isOpened()) << "Can't open the video";
    const int codecExtradataIdx = (int)cap.get(CAP_PROP_CODEC_EXTRADATA_INDEX);
    Mat data;
    ASSERT_TRUE(cap.retrieve(data, codecExtradataIdx));
    EXPECT_EQ(CV_8UC1, data.type()) << "CV_8UC1 != " << typeToString(data.type());
    EXPECT_TRUE(data.rows == 1 || data.cols == 1) << data.size;
    EXPECT_EQ((size_t)45, data.total());
}

TEST(videoio_ffmpeg, open_with_property)
{
    if (!videoio_registry::hasBackend(CAP_FFMPEG))
        throw SkipTestException("FFmpeg backend was not found");

    string video_file = findDataFile("video/big_buck_bunny.mp4");
    VideoCapture cap;
    EXPECT_NO_THROW(cap.open(video_file, CAP_FFMPEG, {
        CAP_PROP_FORMAT, -1  // demux only
    }));

    // confirm properties are returned without initializing AVCodecContext
    EXPECT_EQ(cap.get(CAP_PROP_FORMAT), -1);
    EXPECT_EQ(static_cast<int>(cap.get(CAP_PROP_FOURCC)), fourccFromString("FMP4"));
    EXPECT_EQ(cap.get(CAP_PROP_N_THREADS), 0.0);
    EXPECT_EQ(cap.get(CAP_PROP_FRAME_HEIGHT), 384.0);
    EXPECT_EQ(cap.get(CAP_PROP_FRAME_WIDTH), 672.0);
    EXPECT_EQ(cap.get(CAP_PROP_FRAME_COUNT), 125);
    EXPECT_EQ(cap.get(CAP_PROP_FPS), 24.0);
    ffmpeg_check_read_raw(cap);
}

TEST(videoio_ffmpeg, create_with_property)
{
    if (!videoio_registry::hasBackend(CAP_FFMPEG))
        throw SkipTestException("FFmpeg backend was not found");

    string video_file = findDataFile("video/big_buck_bunny.mp4");
    VideoCapture cap(video_file, CAP_FFMPEG, {
        CAP_PROP_FORMAT, -1  // demux only
    });

    // confirm properties are returned without initializing AVCodecContext
    EXPECT_TRUE(cap.get(CAP_PROP_FORMAT) == -1);
    EXPECT_EQ(static_cast<int>(cap.get(CAP_PROP_FOURCC)), fourccFromString("FMP4"));
    EXPECT_EQ(cap.get(CAP_PROP_N_THREADS), 0.0);
    EXPECT_EQ(cap.get(CAP_PROP_FRAME_HEIGHT), 384.0);
    EXPECT_EQ(cap.get(CAP_PROP_FRAME_WIDTH), 672.0);
    EXPECT_EQ(cap.get(CAP_PROP_FRAME_COUNT), 125);
    EXPECT_EQ(cap.get(CAP_PROP_FPS), 24.0);
    ffmpeg_check_read_raw(cap);
}

TEST(videoio_ffmpeg, create_with_property_badarg)
{
    if (!videoio_registry::hasBackend(CAP_FFMPEG))
        throw SkipTestException("FFmpeg backend was not found");

    string video_file = findDataFile("video/big_buck_bunny.mp4");
    VideoCapture cap(video_file, CAP_FFMPEG, {
        CAP_PROP_FORMAT, -2  // invalid
    });
    EXPECT_FALSE(cap.isOpened());
}

// related issue: https://github.com/opencv/opencv/issues/16821
TEST(videoio_ffmpeg, DISABLED_open_from_web)
{
    if (!videoio_registry::hasBackend(CAP_FFMPEG))
        throw SkipTestException("FFmpeg backend was not found");

    string video_file = "http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4";
    VideoCapture cap(video_file, CAP_FFMPEG);
    int n_frames = -1;
    EXPECT_NO_THROW(n_frames = (int)cap.get(CAP_PROP_FRAME_COUNT));
    EXPECT_EQ((int)14315, n_frames);
}


typedef tuple<string, string, bool, bool> FourCC_Ext_Color_Support;
typedef testing::TestWithParam< FourCC_Ext_Color_Support > videoio_ffmpeg_16bit;

TEST_P(videoio_ffmpeg_16bit, basic)
{
    if (!videoio_registry::hasBackend(CAP_FFMPEG))
        throw SkipTestException("FFmpeg backend was not found");

    const int fourcc = fourccFromString(get<0>(GetParam()));
    const string ext = string(".") + get<1>(GetParam());
    const bool isColor = get<2>(GetParam());
    const bool isSupported = get<3>(GetParam());
    const int cn = isColor ? 3 : 1;
    const int dataType = CV_16UC(cn);

    const string filename = tempfile(ext.c_str());
    const Size sz(640, 480);
    const double fps = 30.0;
    const double time_sec = 1;
    const int numFrames = static_cast<int>(fps * time_sec);

    {
        VideoWriter writer;
        writer.open(filename, CAP_FFMPEG, fourcc, fps, sz,
                             {
                                 VIDEOWRITER_PROP_DEPTH, CV_16U,
                                 VIDEOWRITER_PROP_IS_COLOR, isColor
                             });

        ASSERT_EQ(isSupported, writer.isOpened());
        if (isSupported)
        {
            Mat img(sz, dataType, Scalar::all(0));
            const int coeff = cvRound(min(sz.width, sz.height)/(fps * time_sec));
            for (int i = 0 ; i < numFrames; i++ )
            {
                rectangle(img,
                          Point2i(coeff * i, coeff * i),
                          Point2i(coeff * (i + 1), coeff * (i + 1)),
                          Scalar::all(255 * (1.0 - static_cast<double>(i) / (fps * time_sec * 2))),
                          -1);
                writer << img;
            }
            writer.release();
            EXPECT_GT(getFileSize(filename), 8192);
        }
    }

    if (isSupported)
    {
        VideoCapture cap;
        ASSERT_TRUE(cap.open(filename, CAP_FFMPEG, {CAP_PROP_CONVERT_RGB, false}));
        ASSERT_TRUE(cap.isOpened());
        Mat img;
        bool res = true;
        int numRead = 0;
        while(res)
        {
            res = cap.read(img);
            if (res)
            {
                ++numRead;
                ASSERT_EQ(img.type(), dataType);
                ASSERT_EQ(img.size(), sz);
            }
        }
        ASSERT_EQ(numRead, numFrames);
        remove(filename.c_str());
    }
}

const FourCC_Ext_Color_Support sixteen_bit_modes[] =
{
    // 16-bit grayscale is supported
    make_tuple("FFV1", "avi", false, true),
    make_tuple("FFV1", "mkv", false, true),
    // 16-bit color formats are NOT supported
    make_tuple("FFV1", "avi", true, false),
    make_tuple("FFV1", "mkv", true, false),

};

inline static std::string videoio_ffmpeg_16bit_name_printer(const testing::TestParamInfo<videoio_ffmpeg_16bit::ParamType>& info)
{
    std::ostringstream os;
    os << get<0>(info.param) << "_"
        << get<1>(info.param) << "_"
        << (get<2>(info.param) ? "COLOR" : "GRAY") << "_"
        << (get<3>(info.param) ? "SUP" : "NOT");
    return os.str();
}

INSTANTIATE_TEST_CASE_P(/**/, videoio_ffmpeg_16bit, testing::ValuesIn(sixteen_bit_modes), videoio_ffmpeg_16bit_name_printer);

typedef tuple<int /*inputType*/, int /*Depth*/, bool /*isColor*/, bool /*isValid*/, string /*description*/> ChannelMismatchTestParams;
typedef testing::TestWithParam< ChannelMismatchTestParams > videoio_ffmpeg_channel_mismatch;

TEST_P(videoio_ffmpeg_channel_mismatch, basic)
{
    if (!videoio_registry::hasBackend(CAP_FFMPEG))
        throw SkipTestException("FFmpeg backend was not found");

    const string filename = "mismatch_video.mp4";
    int input_type = get<0>(GetParam());
    int depth = get<1>(GetParam());
    bool is_Color = get<2>(GetParam());
    bool is_valid = get<3>(GetParam());
    const string description = get<4>(GetParam());

    const double fps = 15.0;
    const int fourcc = VideoWriter::fourcc('m', 'p', '4', 'v');
    const Mat frame(480, 640, input_type, Scalar::all(0));

    VideoWriter writer(filename, fourcc, fps, frame.size(),
                                {
                                    cv::VIDEOWRITER_PROP_DEPTH, depth,
                                    VIDEOWRITER_PROP_IS_COLOR, is_Color
                                });

    if (!writer.isOpened())
        throw SkipTestException("Failed to open video writer");

    for (int i = 1; i <= 15; i++)
    {
        // In case of mismatch between input frame channels and
        // expected depth/isColor configuration a warning  should be printed communicating it
        writer.write(frame);
    }

    writer.release();

    VideoCapture cap(filename, CAP_FFMPEG);

    if (is_valid) {
        ASSERT_TRUE(cap.isOpened()) << "Can't open video for " << description;
        EXPECT_EQ(cap.get(CAP_PROP_FRAME_COUNT), 15) << "All frames should be written for: " << description;
    } else {
        ASSERT_FALSE(cap.isOpened()) << "Video capture should fail to open for: " << description;
    }

    std::remove(filename.c_str());
}

const ChannelMismatchTestParams mismatch_cases[] =
{
    // Testing input frame channels and expected depth/isColor combinations

    // Open VideoWriter depth/isColor combination: CV_8U/true, everything with 3 channels should be valid
    make_tuple(CV_16UC1, CV_8U, true, false, "input_CV_16UC1_expected_CV_8U_isColor_true"),
    make_tuple(CV_8UC1, CV_8U, true, false, "input_CV_8UC1_expected_CV_8U_isColor_true"),
    make_tuple(CV_8UC3, CV_8U, true, true, "input_CV_8UC3_expected_CV_8U_isColor_true_valid"),
    make_tuple(CV_16UC3, CV_8U, true, true, "input_CV_16UC3_expected_CV_8U_isColor_true_valid"),

    // Open VideoWriter depth/isColor combination: 16U,8U/false, everything with 1 channel should be valid
    make_tuple(CV_8UC3, CV_8U, false, false, "input_CV_8UC3_expected_CV_8U_isColor_false"),
    make_tuple(CV_16UC3, CV_8U, false, false, "input_CV_16UC3_expected_CV_8U_isColor_false"),
    make_tuple(CV_8UC3, CV_16U, false, false, "input_CV_8UC3_expected_CV_16U_isColor_false"),
    make_tuple(CV_16UC3, CV_16U, false, false, "input_CV_16UC3_expected_CV_16U_isColor_false"),
    make_tuple(CV_8UC1, CV_16U, false, true, "input_CV_8UC1_expected_CV_16U_isColor_false_valid"),
    make_tuple(CV_16UC1, CV_8U, false, true, "input_CV_16UC1_expected_CV_8U_isColor_false_valid"),
};

inline static std::string videoio_ffmpeg_mismatch_name_printer(const testing::TestParamInfo<videoio_ffmpeg_channel_mismatch::ParamType>& info)
{
    std::ostringstream os;
    os << get<4>(info.param);
    return os.str();
}

INSTANTIATE_TEST_CASE_P(/**/, videoio_ffmpeg_channel_mismatch, testing::ValuesIn(mismatch_cases), videoio_ffmpeg_mismatch_name_printer);

// related issue: https://github.com/opencv/opencv/issues/23088
TEST(ffmpeg_cap_properties, set_pos_get_msec)
{
    if (!videoio_registry::hasBackend(CAP_FFMPEG))
        throw SkipTestException("FFmpeg backend was not found");

    string video_file = findDataFile("video/big_buck_bunny.mp4");
    VideoCapture cap;
    EXPECT_NO_THROW(cap.open(video_file, CAP_FFMPEG));
    ASSERT_TRUE(cap.isOpened()) << "Can't open the video";

    cap.set(CAP_PROP_POS_FRAMES, 25);
    EXPECT_EQ(cap.get(CAP_PROP_POS_MSEC), 1000.0);

    cap.set(CAP_PROP_POS_MSEC, 525);
    EXPECT_EQ(cap.get(CAP_PROP_POS_MSEC), 500.0);

    cap.set(CAP_PROP_POS_AVI_RATIO, 0);
    EXPECT_EQ(cap.get(CAP_PROP_POS_MSEC), 0.0);
}

// Test that seeking twice to the same frame in videos with negative DTS
// does not result in negative position or timestamp values
// related issue: https://github.com/opencv/opencv/issues/27819
TEST(videoio_ffmpeg, seek_with_negative_dts)
{
    if (!videoio_registry::hasBackend(CAP_FFMPEG))
        throw SkipTestException("FFmpeg backend was not found");

    const std::string filename = findDataFile("video/negdts_h264.mp4");
    VideoCapture cap(filename, CAP_FFMPEG);

    if (!cap.isOpened())
        throw SkipTestException("Video stream is not supported");

    // after open, a single grab() should not yield negative POS_MSEC.
    ASSERT_TRUE(cap.grab());
    EXPECT_GE(cap.get(CAP_PROP_POS_MSEC), 0.0) << "Negative ts immediately after open+grab()";

    ASSERT_TRUE(cap.set(CAP_PROP_POS_FRAMES, 0));
    (void)cap.get(CAP_PROP_POS_FRAMES);

    const int framesToProbe[] = {2, 3, 4, 5};

    for (int f : framesToProbe)
    {
        // Reset to frame 0
        ASSERT_TRUE(cap.set(CAP_PROP_POS_FRAMES, 0));
        cap.get(CAP_PROP_POS_FRAMES);

        // Seek to target frame
        ASSERT_TRUE(cap.set(CAP_PROP_POS_FRAMES, f));
        const double posAfterFirstSeek = cap.get(CAP_PROP_POS_FRAMES);

        // Seek to the same frame again
        ASSERT_TRUE(cap.set(CAP_PROP_POS_FRAMES, f));
        const double posAfterSecondSeek = cap.get(CAP_PROP_POS_FRAMES);
        const double tsAfterSecondSeek = cap.get(CAP_PROP_POS_MSEC);

        EXPECT_GE(posAfterSecondSeek, 0)
            << "Frame index became negative after second seek to frame " << f
            << " (first seek gave " << posAfterFirstSeek << ")";
        EXPECT_GE(tsAfterSecondSeek, 0.0)
            << "Timestamp became negative after second seek to frame " << f;

        // Per-iteration decode check: grab() + ts non-negative
        ASSERT_TRUE(cap.grab());
        EXPECT_GE(cap.get(CAP_PROP_POS_MSEC), 0.0) << "Negative timestamp after grab() at frame " << f;

        // Verify that reading a frame works and position advances
        Mat frame;
        ASSERT_TRUE(cap.read(frame));
        ASSERT_FALSE(frame.empty());
        EXPECT_GE(cap.get(CAP_PROP_POS_FRAMES), f);
    }
}

}} // namespace