Compression for Continuous Recording
  • It seems that SecuritySpy is ignoring compression settings for continuous video capture. If I set it up to be at full frame rate, 10 minute clip of HD capture takes up more than 5 GB of space.
  • If you open the Browser in SecuritySpy (via the Browser menu) and select the file in question, you will see in the information displayed under the movie what the format is - this should match what setting you have selected in the Compression Settings window in SecuritySpy.

    Or, if this is a network device and you have enabled the setting "No recompression of video data" in the Video Device Settings window, in this case the video sent by the device will be recorded directly to the movie files, with no further compression performed by SecuritySpy. So the format of the movie files will match what the camera is actually sending to SecuritySpy.

    Aside from the compression codec and quality used for the recorded, the reason why you are getting such large files is simply that 30fps HD video has a high data rate! This is a much higher frame rate than typically used for video surveillance systems: 5-10 fps is normally sufficient.

    If you are getting SecuritySpy to compress the video footage, I would suggest using the MPEG-4 code with a quality setting of 50-60 and a key frame rate of 20. If your camera is capable of sending H.264 video then I suggest you use this instead, and tell SecuritySpy to record this video directly with no recompression, as described above.

    Hope this helps!
  • Ben, you mentioned the feature that I was just about to post about. I want to enable "No recompression of video data" and the audio option as well but there is a note in SecuritySpy that I'm hoping to have clarified. I currently use the timestamps added by SecuritySpy rather than direct from the camera. I believe the note states that even with "No recompression of video data" checked, if you're using the SecuritySpy timestamps then it will recompress the video data regardless. If I disable SS timestamps on my camera streams will I then see a performance increase? If not a performance increase, will I notice a quality improvement?

    Lastly, regarding the "No recompression of video data" function; is this only for h.264 streams? I would imagine so since MJPEG streams are not video files, right? MJPEG has to be compressed into a video file since it doesn't originate as one.

    Thank you!
  • If you have enabled the text overlay (time stamp) in SecuritySpy, then the video has to be decompressed, the time stamp added, and then the video is recompressed again for capture to the movie files. So in this case the "No recompression" option will be ignored. Unfortunately there is no way around this; it is impossible to add the text overlay to an already-compressed stream.

    Virtually all cameras have this feature built in, so I'd therefore recommend that you disable the text overlay in SecuritySpy and instead enable it in the camera. Then, with the "no recompression" option, you will get the best performance and quality, as the video from the camera will be saved directly to disk with no further processing. Just make sure that you have set a network time server (NTP server) in the camera's settings so that it automatically maintains the correct time (for example time.apple.com).

    SecuritySpy saves captures as standard QuickTime Movie files, which can contain video of any format (codec). Such formats include JPEG, MPEG-4 and H.264. So whatever format the camera is sending, it can be captured directly to the movie files without recompression. This is most useful for MPEG-4 and H.264 though: with JPEG you do get the same advantages in terms of performance and quality but the file sizes of the captured movies will be very large, as it is the least efficient format for encoding video streams.

    Hope this helps!
  • That's exactly the information I was looking for. Thank you for writing that up. Very clear and easy to understand.

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