Gyroflow Player

Overview

The Gyroflow Player module is designed to control a motion simulator by synchronizing video playback from an action camera with IMU data exported in a JSON file using Gyroflow. The module seamlessly loads and synchronizes the video and telemetry data, allowing the motion simulator to move in sync with the video playback. The telemetry data is used to control the simulator based on the recorded motion.

Features

• Automatic File Matching: The module automatically loads the corresponding MP4 video file that shares the same base filename as the loaded JSON file.

• Motion Synchronization: When the video is played, the motion simulator moves in sync with the IMU data from the JSON file.

• Adjustable Time Offset: Synchronization between video and telemetry data can be fine-tuned using the time offset control.

• Telemetry Data Smoothing: Use the Average Samples setting to smooth noisy IMU telemetry data for a more accurate motion experience.

Export IMU Data Using Gyroflow CLI

Follow these steps to export the IMU data from a video file using the Gyroflow CLI:

1. Download Gyroflow

• First, download and install Gyroflow from the official website: Gyroflow Download.

2. Open Command Prompt

• Press Windows + R, type cmd, and press Enter to open the Command Prompt.

3. Run the Gyroflow CLI Command

• Replace the file paths with your specific input and output locations, then run the following command:

Gyroflow.exe "C:\path\to\your\video_name.mp4" --export-metadata 2:"C:\path\to\output\video_name.json"

• Replace "C:\path\to\your\video_name.mp4" with the path to your video file.

• Replace "C:\path\to\output\video_name.json" with the path where you want the metadata JSON file to be saved.

• Use the same base filename as the video file as the JSON file.

Playing a Video

1. Load JSON File:

   • Click the Load JSON button to select a JSON file containing IMU data.

   • The module will automatically search for and load the corresponding MP4 video file with the same base filename.

2. Play Video and Motion:

   • Press the Play button to start video playback and the synchronized motion control.

   • The motion simulator will move based on the telemetry data while the video plays.

3. Adjust Time Offset:

   • The Time Offset spinner allows you to synchronize the telemetry data with the video by shifting the data forward or backward in time.

   • Adjust the offset to ensure the video and motion are perfectly synchronized.

4. Average Samples:

   • The Average Samples setting helps smooth out noisy IMU data.

   • Increasing the sample average will reduce noise in the motion simulator, making movements smoother.

5. IMU Orientation:

   • Use the IMU Orientation text field to override the default orientation.

   • Adjust the orientation string as needed based on your setup (see IMU Orientation section).

6. Fullscreen Mode:

   • Click Fullscreen or double-click on the video to toggle fullscreen mode.

   • Press Esc or double-click again to exit fullscreen.

IMU Orientation

Understanding IMU orientation is crucial for correctly mapping the recorded motion data to the simulator's axes. The IMU orientation is represented by a three-letter string (e.g., 'XYZ') indicating the order and direction of the axes. Press the Enter key after making any changes to the IMU string.

1. Axes Definitions:

   • X (Sway and Pitch): Represents lateral movement (side to side) and pitch rotation.

   • Y (Surge and Roll): Represents longitudinal movement (forward and backward) and roll rotation.

   • Z (Heave and Yaw): Represents vertical movement (up and down) and yaw rotation.

2. Swapping Axes:

   • If pitch and roll are swapped in your setup, you need to swap the letters X and Y in the orientation string. For example, change 'XYZ' to 'YXZ'.

3. Inverting Axes:

   • To invert an axis, change the corresponding letter to lowercase. For example:

     • Invert X-axis: 'xYZ'

     • Invert Y-axis: 'XyZ'

     • Invert Z-axis: 'XYz'

Note: The orientation string adjusts how the IMU data maps to your simulator's coordinate system. Correctly setting this ensures the motion matches the video accurately.

Controls

• Play/Pause: Start or pause the video and motion.

• Load JSON: Select and load the JSON file with IMU data.

• Fullscreen: Toggle fullscreen video playback.

• Volume: Adjust the playback volume.

• Time Offset (s): Adjust the synchronization offset between video and motion data (in seconds).

• Average Samples: Set the number of samples for IMU data smoothing.

• IMU Orientation: Override the orientation of the IMU data to match your simulator's coordinate system.

Tips

• Synchronizing Motion and Video: Start with a small time offset adjustment if you notice any lag or delay between the motion and video. Fine-tune the setting until the motion feels synchronized with the action on-screen.

• Smoothing Telemetry Data: If the motion simulator feels too jerky or noisy, try increasing the number of Average Samples. However, setting it too high may introduce a delay or overly smooth the motion.

• If a video doesn't play, your system may be missing a codec. Try downloading HEVC Video Extensions from Microsoft Corporation in the Microsoft Store.

Keyboard Shortcuts

• Esc: Exit fullscreen mode.

• Double-click Video: Enter or exit fullscreen mode.