MovementAnalyzer is a Guru Analyzer that provides helper analysis methods related to human movement. It is useful for building fitness or sport-focused apps.

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Functions

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repsByKeypointDistance

This function, given the frames of a person, find repetitions of a movement defined by the movement between two keypoints. For example, you could use Keypoint.rightHip and Keypoint.rightAnkle to count the number of squat reps in a video.

  /**
   * Find the repetitions of a movement a person is performing, by measuring
   * the distance over time between two keypoints. For example, if a person
   * is performing a squat, then measuring the distance between hips and ankles
   * will give a good signal for identifying squat reps.
   *
   * By default this function will identify when the two keypoints get closer together
   * and count that as a rep. If reps should instead be counted by the keypoints getting
   * further apart, set
   *
   * @param {[FrameObject]} personFrames - The location of the person in each frame of the video.
   * @param {Keypoint} keypoint1 - The first keypoint to measure between.
   * @param {Keypoint} keypoint2 - The second keypoint to measure between.
   * @param {boolean} keypointsContract - True if a rep is identified as the distance between the keypoints contracting.
   *    Set to false if the keypoint distance expands during a rep. Defaults true.
   * @param {number} threshold - The distance required between the keypoints before a rep is counted.
   *    This number is abstract, it does not translate directly to pixel distance.
   * @param {number} smoothing - How much smoothing should be applied to keypoints before reps are counted.
   *    Higher values will apply more smoothing, which can help with lower quality or obscured videos.
   * @param {number} ignoreStartMs - The number of milliseconds to ignore at the start of the video when counting reps.
   *    If null, attempts to estimate the start time. Default null.
   * @param {number} ignoreEndMs - The number of milliseconds to ignore at the end of the video when counting reps.
   *    If null, attempts to estimate the end time. Default null.
   * @returns {[]} - An array of objects, each one having a start, middle, and end property that is
   *    the millisecond timestamp of the boundaries for that rep.
   */
  static repsByKeypointDistance(
    personFrames,
    keypoint1,
    keypoint2, {
      keypointsContract = true,
      threshold = 0.2,
      smoothing = 2.0,
      ignoreStartMs = null,
      ignoreEndMs = null,
    } = {}) {

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Example

async function analyzeVideo(frameResults) {
  const personId = frameResults.objectIds("person")[0];
  const personFrames = frameResults.objectFrames(personId);
  const reps = MovementAnalyzer.repsByKeypointDistance(
    personFrames,
    Keypoint.rightHip,
    Keypoint.rightAnkle
  );
  return {
    reps: reps,
  };
}

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personMostlyFacing

Given the frames of a person, determine which direction they were mostly facing during the course of the video. Returns a value from the ObjectFacing enum.

  /**
   * Determines which direction the person is mostly facing throughout the video.
   *
   * @param {[FrameObject]} personFrames - The frames of the person.
   * @return {ObjectFacing} The direction that the person is mostly facing throughout the video.
   */
  static personMostlyFacing(personFrames) {

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personMostlyStanding

Given the frames of a person, determine whether they were standing for the majority of the video. Returns a boolean.

  /**
   * Determines if the person is mostly standing upright throughout the video or not.
   * If false, then they are likely lying down.
   *
   * @param {[FrameObject]} personFrames - The frames of the person.
   * @return {boolean} True if the person is mostly standing up in the video.
   */
  static personMostlyStanding(personFrames) {