# Holistic Replay

This example demonstrates how to replay previously recorded holistic data, feeding multiple synchronized streams such as video and
IMU back into a DepthAI pipeline for testing and development.

This example requires the DepthAI v3 API, see [installation instructions](https://docs.luxonis.com/software-v3/depthai.md).

## Pipeline

## Source code

#### Python

```python
#!/usr/bin/env python3

import cv2
import depthai as dai
import argparse

parser = argparse.ArgumentParser()
parser.add_argument("-s", "--source", default="recordings/recording.tar", help="Recording path")
args = parser.parse_args()

# Create pipeline
with dai.Pipeline(True) as pipeline:
    pipeline.enableHolisticReplay(args.source)

    # Define source and output
    camRgb = pipeline.create(dai.node.Camera).build(dai.CameraBoardSocket.CAM_A)
    camRgbOut = camRgb.requestOutput((600, 400), fps = 30)

    imu = pipeline.create(dai.node.IMU)
    imu.enableIMUSensor(dai.IMUSensor.ACCELEROMETER_RAW, 500);
    imu.enableIMUSensor(dai.IMUSensor.GYROSCOPE_RAW, 400);
    imu.setBatchReportThreshold(100)

    videoQueue = camRgbOut.createOutputQueue()
    imuQueue = imu.out.createOutputQueue()

    # Connect to device and start pipeline
    pipeline.start()
    while pipeline.isRunning():
        videoIn : dai.ImgFrame = videoQueue.get()
        imuData : dai.IMUData = imuQueue.get()

        # Get BGR frame from NV12 encoded video frame to show with opencv
        # Visualizing the frame on slower hosts might have overhead
        cv2.imshow("video", videoIn.getCvFrame())

        for packet in imuData.packets:
            print(f"IMU Accelerometer: {packet.acceleroMeter}")
            print(f"IMU Gyroscope: {packet.gyroscope}")

        if cv2.waitKey(1) == ord('q'):
            break
```

#### C++

```cpp
#include <opencv2/highgui.hpp>

#include "depthai/depthai.hpp"

#ifndef DEPTHAI_MERGED_TARGET
    #error This example needs OpenCV support, which is not available on your system
#endif

int main(int argc, char** argv) {
    dai::Pipeline pipeline;

    pipeline.enableHolisticReplay(argc > 1 ? std::string(argv[1]) : "recording.tar");

    auto camRgb = pipeline.create<dai::node::Camera>()->build(dai::CameraBoardSocket::CAM_A);
    auto* camOut = camRgb->requestOutput({600, 400});

    auto imu = pipeline.create<dai::node::IMU>();

    // enable ACCELEROMETER_RAW at 500 hz rate
    imu->enableIMUSensor(dai::IMUSensor::ACCELEROMETER_RAW, 500);
    // enable GYROSCOPE_RAW at 400 hz rate
    imu->enableIMUSensor(dai::IMUSensor::GYROSCOPE_RAW, 400);
    imu->setBatchReportThreshold(100);

    auto videoQueue = camOut->createOutputQueue();
    auto q = imu->out.createOutputQueue();

    pipeline.start();

    auto start = std::chrono::steady_clock::now();

    while(pipeline.isRunning()) {
        auto videoIn = videoQueue->get<dai::ImgFrame>();
        auto imuData = q->get<dai::IMUData>();

        cv::imshow("video", videoIn->getCvFrame());

        for(auto& imuPacket : imuData->packets) {
            auto& acceleroValues = imuPacket.acceleroMeter;
            auto& gyroValues = imuPacket.gyroscope;

            printf("Accelerometer [m/s^2]: x: %.3f y: %.3f z: %.3f \n", acceleroValues.x, acceleroValues.y, acceleroValues.z);
            printf("Gyroscope [rad/s]: x: %.3f y: %.3f z: %.3f \n", gyroValues.x, gyroValues.y, gyroValues.z);
        }

        if(cv::waitKey(1) == 'q') {
            break;
        }
    }

    pipeline.stop();
}
```

### Need assistance?

Head over to [Discussion Forum](https://discuss.luxonis.com/) for technical support or any other questions you might have.