Method IK bones
Create an armature and create a bone for each object in the rig and put it in the right location. One bone for the Cylinder, one for the Piston, one for the Cylinder Arm (arm connected to the Cylinder), and one for the Piston Arm (arm connected to the Piston).
Select the armature and go into Edit mode, and go to Properties > Bone ...
Turn off sequencer:
Once you have a movie clip in your VSE it will override rendering. If you want to composit your render on top of the footage, you need to use the compositor. Don't ask me why it's not off by default.
Blender can track backwards and forward accurately with no problem. I've done it many times.
So there is your answer.
Most likely the issue is with the compression used on the video. Intraframe compression or image sequences works great. Video with long GOP does not and might lead to errors retrieving frames going backwards.
Enable the keyframe box, and then set the range of keyframes you want to use for solving in the boxes below (keyframe A and Keyframe B).
Blender will solve the frames it can solve, meaning the frames for which there is a reasonable amount of information to estimate placement in the 3d world (or a low error). The slected range is used to determine the ...
The shortcut Ctrl+P will only show the Follow Path option if the camera and the curve object are both selected and the curve object is the active(last selected) one, like shown below:
This way goes around constraints and is only based on the curve and it's parameters, thus changing the way the camera follows and it's behavior can be adjusted using the Path ...
To make a camera follow a path:
Add in a path
Select the camera
Go to object constraint properties and select follow path
Check fixed position , Follow curve and curve radius
Blender 2.79 had a hotkey Shift +Ctrl+C to add constraints