auto tracking, some comments and thoughts

[quantenschaum]

First, motion is great piece of software. Thank you!

setup

• motion 4.2.2
• on Ubuntu 18.04 x64 on an i5 based machine
• using 2 D-Link WiFi Cams (mjpeg streams)
• one cam is PTZ capable, controlled via http requests using a custom script and curl (track_type 4)

problem/idea

1. The default value for track_move_wait seems to be 10, not 0 as stated in the docs.

2. When track_move_wait > 0 it does not just disable tracking, but disables motion detection by setting the value of changed pixel to 0 to keep it below threshold. The doc says

Delay during which tracking is disabled after auto tracking has moved the camera.

So I would expect, that further tracking (calls of track_generic_move script) is suppressed for the given number of frames, but not the motion detection.

text_changes on should always show the number of changed pixels, even if tracking or motion detection is disabled. These pixel have actually changed. You cannot suppress the pixels from changing, but you can suppress the action to be taken.

There should be 2 settings, one to disable tracking for a certain time (not frames or allow both via appending a unit like s or f) and one to disable motion detection (2 different things).

Moving the camera causes motion, so a tracking delay is necessary to prevent an infinit loop. The motion during tracking should be recorded, because it usually follows the object, that triggered the event initially. With track_move_wait > 0 only the initial frame is recorded and the post_capture frames. Pausing tracking for a certain time is usually sufficient to settle.

Only when moving back to center position on event end, motion detection should be suppressed.

If tracking is suppressed by the script, it should report this back to motion via the return code, so that motion knows, that the camera did not actually move (0=moved, 0!= not moved).

workaround

Setting track_move_wait 0 and block tracking in the script for a certain time. Only block TRACK_ACTION=move, but not TRACK_ACTION=center.