examples/tutorial_api_cpp/10_asynchronous_custom_input.cpp

// ------------------------- OpenPose C++ API Tutorial - Example 10 - Custom Input -------------------------
// Asynchronous mode: ideal for fast prototyping when performance is not an issue.
// In this function, the user can implement its own way to create frames (e.g., reading his own folder of images)
// and emplaces/pushes the frames to OpenPose.

// Third-party dependencies
#include <opencv2/opencv.hpp>
// Command-line user interface
#define OPENPOSE_FLAGS_DISABLE_PRODUCER
#include <openpose/flags.hpp>
// OpenPose dependencies
#include <openpose/headers.hpp>

// Custom OpenPose flags
// Producer
DEFINE_string(image_dir,                "examples/media/",
    "Process a directory of images. Read all standard formats (jpg, png, bmp, etc.).");

// This worker will just read and return all the basic image file formats in a directory
class UserInputClass
{
public:
    UserInputClass(const std::string& directoryPath) :
        mImageFiles{op::getFilesOnDirectory(directoryPath, op::Extensions::Images)}, // For all basic image formats
        // If we want only e.g., "jpg" + "png" images
        // mImageFiles{op::getFilesOnDirectory(directoryPath, std::vector<std::string>{"jpg", "png"})},
        mCounter{0},
        mClosed{false}
    {
        if (mImageFiles.empty())
            op::error("No images found on: " + directoryPath, __LINE__, __FUNCTION__, __FILE__);
    }

    std::shared_ptr<std::vector<std::shared_ptr<op::Datum>>> createDatum()
    {
        // Close program when empty frame
        if (mClosed || mImageFiles.size() <= mCounter)
        {
            op::opLog("Last frame read and added to queue. Closing program after it is processed.", op::Priority::High);
            // This function stops this worker, which will eventually stop the whole thread system once all the frames
            // have been processed
            mClosed = true;
            return nullptr;
        }
        else // if (!mClosed)
        {
            // Create new datum
            auto datumsPtr = std::make_shared<std::vector<std::shared_ptr<op::Datum>>>();
            datumsPtr->emplace_back();
            auto& datumPtr = datumsPtr->at(0);
            datumPtr = std::make_shared<op::Datum>();

            // Fill datum
            const cv::Mat cvInputData = cv::imread(mImageFiles.at(mCounter++));
            datumPtr->cvInputData = OP_CV2OPCONSTMAT(cvInputData);

            // If empty frame -> return nullptr
            if (datumPtr->cvInputData.empty())
            {
                op::opLog("Empty frame detected on path: " + mImageFiles.at(mCounter-1) + ". Closing program.",
                        op::Priority::High);
                mClosed = true;
                datumsPtr = nullptr;
            }

            return datumsPtr;
        }
    }

    bool isFinished() const
    {
        return mClosed;
    }

private:
    const std::vector<std::string> mImageFiles;
    unsigned long long mCounter;
    bool mClosed;
};

void configureWrapper(op::Wrapper& opWrapper)
{
    try
    {
        // Configuring OpenPose

        // logging_level
        op::checkBool(
            0 <= FLAGS_logging_level && FLAGS_logging_level <= 255, "Wrong logging_level value.",
            __LINE__, __FUNCTION__, __FILE__);
        op::ConfigureLog::setPriorityThreshold((op::Priority)FLAGS_logging_level);
        op::Profiler::setDefaultX(FLAGS_profile_speed);

        // Applying user defined configuration - GFlags to program variables
        // outputSize
        const auto outputSize = op::flagsToPoint(op::String(FLAGS_output_resolution), "-1x-1");
        // netInputSize
        const auto netInputSize = op::flagsToPoint(op::String(FLAGS_net_resolution), "-1x368");
        // faceNetInputSize
        const auto faceNetInputSize = op::flagsToPoint(op::String(FLAGS_face_net_resolution), "368x368 (multiples of 16)");
        // handNetInputSize
        const auto handNetInputSize = op::flagsToPoint(op::String(FLAGS_hand_net_resolution), "368x368 (multiples of 16)");
        // poseMode
        const auto poseMode = op::flagsToPoseMode(FLAGS_body);
        // poseModel
        const auto poseModel = op::flagsToPoseModel(op::String(FLAGS_model_pose));
        // JSON saving
        if (!FLAGS_write_keypoint.empty())
            op::opLog(
                "Flag `write_keypoint` is deprecated and will eventually be removed. Please, use `write_json`"
                " instead.", op::Priority::Max);
        // keypointScaleMode
        const auto keypointScaleMode = op::flagsToScaleMode(FLAGS_keypoint_scale);
        // heatmaps to add
        const auto heatMapTypes = op::flagsToHeatMaps(FLAGS_heatmaps_add_parts, FLAGS_heatmaps_add_bkg,
                                                      FLAGS_heatmaps_add_PAFs);
        const auto heatMapScaleMode = op::flagsToHeatMapScaleMode(FLAGS_heatmaps_scale);
        // >1 camera view?
        const auto multipleView = (FLAGS_3d || FLAGS_3d_views > 1);
        // Face and hand detectors
        const auto faceDetector = op::flagsToDetector(FLAGS_face_detector);
        const auto handDetector = op::flagsToDetector(FLAGS_hand_detector);
        // Enabling Google Logging
        const bool enableGoogleLogging = true;

        // Pose configuration (use WrapperStructPose{} for default and recommended configuration)
        const op::WrapperStructPose wrapperStructPose{
            poseMode, netInputSize, FLAGS_net_resolution_dynamic, outputSize, keypointScaleMode, FLAGS_num_gpu,
            FLAGS_num_gpu_start, FLAGS_scale_number, (float)FLAGS_scale_gap,
            op::flagsToRenderMode(FLAGS_render_pose, multipleView), poseModel, !FLAGS_disable_blending,
            (float)FLAGS_alpha_pose, (float)FLAGS_alpha_heatmap, FLAGS_part_to_show, op::String(FLAGS_model_folder),
            heatMapTypes, heatMapScaleMode, FLAGS_part_candidates, (float)FLAGS_render_threshold,
            FLAGS_number_people_max, FLAGS_maximize_positives, FLAGS_fps_max, op::String(FLAGS_prototxt_path),
            op::String(FLAGS_caffemodel_path), (float)FLAGS_upsampling_ratio, enableGoogleLogging};
        opWrapper.configure(wrapperStructPose);
        // Face configuration (use op::WrapperStructFace{} to disable it)
        const op::WrapperStructFace wrapperStructFace{
            FLAGS_face, faceDetector, faceNetInputSize,
            op::flagsToRenderMode(FLAGS_face_render, multipleView, FLAGS_render_pose),
            (float)FLAGS_face_alpha_pose, (float)FLAGS_face_alpha_heatmap, (float)FLAGS_face_render_threshold};
        opWrapper.configure(wrapperStructFace);
        // Hand configuration (use op::WrapperStructHand{} to disable it)
        const op::WrapperStructHand wrapperStructHand{
            FLAGS_hand, handDetector, handNetInputSize, FLAGS_hand_scale_number, (float)FLAGS_hand_scale_range,
            op::flagsToRenderMode(FLAGS_hand_render, multipleView, FLAGS_render_pose), (float)FLAGS_hand_alpha_pose,
            (float)FLAGS_hand_alpha_heatmap, (float)FLAGS_hand_render_threshold};
        opWrapper.configure(wrapperStructHand);
        // Extra functionality configuration (use op::WrapperStructExtra{} to disable it)
        const op::WrapperStructExtra wrapperStructExtra{
            FLAGS_3d, FLAGS_3d_min_views, FLAGS_identification, FLAGS_tracking, FLAGS_ik_threads};
        opWrapper.configure(wrapperStructExtra);
        // Output (comment or use default argument to disable any output)
        const op::WrapperStructOutput wrapperStructOutput{
            FLAGS_cli_verbose, op::String(FLAGS_write_keypoint), op::stringToDataFormat(FLAGS_write_keypoint_format),
            op::String(FLAGS_write_json), op::String(FLAGS_write_coco_json), FLAGS_write_coco_json_variants,
            FLAGS_write_coco_json_variant, op::String(FLAGS_write_images), op::String(FLAGS_write_images_format),
            op::String(FLAGS_write_video), FLAGS_write_video_fps, FLAGS_write_video_with_audio,
            op::String(FLAGS_write_heatmaps), op::String(FLAGS_write_heatmaps_format), op::String(FLAGS_write_video_3d),
            op::String(FLAGS_write_video_adam), op::String(FLAGS_write_bvh), op::String(FLAGS_udp_host),
            op::String(FLAGS_udp_port)};
        opWrapper.configure(wrapperStructOutput);
        // GUI (comment or use default argument to disable any visual output)
        const op::WrapperStructGui wrapperStructGui{
            op::flagsToDisplayMode(FLAGS_display, FLAGS_3d), !FLAGS_no_gui_verbose, FLAGS_fullscreen};
        opWrapper.configure(wrapperStructGui);
        // Set to single-thread (for sequential processing and/or debugging and/or reducing latency)
        if (FLAGS_disable_multi_thread)
            opWrapper.disableMultiThreading();
    }
    catch (const std::exception& e)
    {
        op::error(e.what(), __LINE__, __FUNCTION__, __FILE__);
    }
}

int tutorialApiCpp()
{
    try
    {
        op::opLog("Starting OpenPose demo...", op::Priority::High);
        const auto opTimer = op::getTimerInit();

        // Configuring OpenPose
        op::opLog("Configuring OpenPose...", op::Priority::High);
        op::Wrapper opWrapper{op::ThreadManagerMode::AsynchronousIn};
        configureWrapper(opWrapper);

        // Start, run, and stop processing - exec() blocks this thread until OpenPose wrapper has finished
        op::opLog("Starting thread(s)...", op::Priority::High);
        opWrapper.start();

        // User processing
        UserInputClass userInputClass(FLAGS_image_dir);
        bool userWantsToExit = false;
        while (!userWantsToExit && !userInputClass.isFinished())
        {
            // Push frame
            auto datumToProcess = userInputClass.createDatum();
            if (datumToProcess != nullptr)
            {
                auto successfullyEmplaced = opWrapper.waitAndEmplace(datumToProcess);
                if (!successfullyEmplaced)
                    op::opLog("Processed datum could not be emplaced.", op::Priority::High);
            }
        }

        op::opLog("Stopping thread(s)", op::Priority::High);
        opWrapper.stop();

        // Measuring total time
        op::printTime(opTimer, "OpenPose demo successfully finished. Total time: ", " seconds.", op::Priority::High);

        // Return
        return 0;
    }
    catch (const std::exception&)
    {
        return -1;
    }
}

int main(int argc, char *argv[])
{
    // Parsing command line flags
    gflags::ParseCommandLineFlags(&argc, &argv, true);

    // Running tutorialApiCpp
    return tutorialApiCpp();
}