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// KEY SAMPLE CODE ENDS HERE
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/// <summary>
/// This method parses the JSON ouput, and converts to a sequence of time frames with highlight region. A full video highlight is created if there is motion detected in the frame.
/// </summary>
/// <param name="json">JSON output of motion detection result.</param>
/// <returns>Sequence of time frames with highlight regions.</returns>
private static IEnumerable<FrameHighlight> GetHighlights(string json)
{
MotionDetectionResult motionDetectionResult = Helpers.FromJson<MotionDetectionResult>(json);
double timescale = motionDetectionResult.Timescale;
if (motionDetectionResult.Regions == null) yield break;
List<int> regionIds = motionDetectionResult.Regions.Select(x => x.Id).ToList();
Rect hasMotionRect = new Rect(new Point(0, 0), new Size(1, 1)); // Uses this full-frame rectangle to represent motion is detected in one frame
Rect noMotionRect = new Rect(new Point(0, 0), new Size(0, 0)); // Uses this empty rectangle to represent motion is not detected
foreach (Fragment<MotionEvent> fragment in motionDetectionResult.Fragments)
{
if (fragment.Events == null || fragment.Events.Length == 0)
{
// If 'Events' is empty, there isn't any motion detected in this fragment
Rect[] rects = new Rect[regionIds.Count];
for (int i = 0; i < rects.Length; i++) rects[i] = noMotionRect;
yield return new FrameHighlight() { Time = fragment.Start / timescale, HighlightRects = rects.ToArray() };
}
else
{
long interval = fragment.Interval.GetValueOrDefault();
for (int i = 0; i < fragment.Events.Length; i++)
{
double currentTime = (fragment.Start + interval*i)/timescale;
MotionEvent[] evts = fragment.Events[i];
Rect[] rects = regionIds.Select(id =>
{
MotionEvent evt = evts.FirstOrDefault(x => x.RegionId == id);
if (evt == null) return noMotionRect;
return hasMotionRect;
}).ToArray();
yield return new FrameHighlight() {Time = currentTime, HighlightRects = rects};
}
}
}
}
