Simply hand keyframe it. These types of shots are pretty much un-trackable in any software. At best you may be able to pick some fixed points e.g. in a background scaffolding and track them to at least derive a bit of basic rotation and position information, which might be useful to remove some shaking, but the actual scaling/ zooming will almost definitely require to be done by hand.
Not all shots will work with camera tracking but if your shot has enough fixed geometry to get a good camera track it is probably your only automated solution. You may have to roto remove the belt so it doesn't foul up the track. We can't give any better advice without seeing the shot.
Here's a section of the footage.
you could use planar tracking for this.
Just track one of the rods that hold the roof part of the conveyor belt, for example.
This will be quicker and more robust than a camera track.
For details of such a workflow see
Personally, I agree with Mylenium. The speed of the conveyor is fairly constant, so I'd just manually keyframe it. There's plenty of reference points in the bracket-things. You only have to get the speed right on one layer, then cut and paste to new layers and reposition in time.
That shot would camera track just fine if you corrected the shot for the lens distortion. This can be done with the GoPro app. Once the lens distortion is removed Camera tracking will work on the shot just fine. I tried it and everything matched up.
If you don't what to do that then I'd suggest that you just manually keyframe scale on a 2D layer. It should be just fine. You could even use AE's original tracker to track scale rotation and position and apply that track to a null. I also tried that and it worked just fine.
Thanks for everyone's input, all your assistance is much appreciated.