Motion Tracking Tutorial

I have a need to blur objects (mainly faces) in videos that are shot with body cameras. Because the objects AND the cameras are normally both moving at the same time, it makes using the auto tracking feature almost impossible - especially when the scene is dark, and because the object frequently goes out of frame.

Is there an in-depth tutorial that shows how to do manual keyframe tracking. My efforts have not been that successful.

Thank you for your help!
David

a simple way is to use the tracking tab for keyframing.

create a window

go to the tracker tab, switch the clip/frame to frame

then move the window where you want it, and Resolve will automatically create a keyframe.

when you've added the keyframes you need, remember to switch the clip/frame back to clip.

Is there an in-depth tutorial that shows how to do manual keyframe tracking. My efforts have not been that successful.

Yes, there have been some good Insights on manual tracking on MixingLight.com, and they also cover it very well in the Advanced Resolve training they offer. Note these are not free, but I think the cost is modest given how much information they're covering.

The real trick in tracking comes when dealing with Occlusion, where another object or person gets inbetween the subject being tracked and the camera. That can get tricky and involved. It's all doable -- it just takes time and patience.

BCC's "witness protection" uses mocha for tracking....

it's slow, but it's faster than muck'n about with the less than stellar native trackers to get anywhere near the ballpark as Mocha

Good point, and it's not so slow any more with GPU support now.

Since posting YT links still doesn't work for me,

go to YT and search: "Goats eye view tracking"

they have two excellent tutorials, one with tracking windows through obstructions

Wow, thanks for all the help and suggestions! I have been keyframing within Resolve 12.5 and adding additional nodes when more than one object required tracking within the same frames.

My problem today is that Resolve has crashed three times within the last few minutes. This gets most frustrating. Adobe Premiere Elements also decides to crash on occasion but I am finding Resolve to me a much easier application to use for my purposes because of the nodes. It does bring my computer to its knees when adding additional nodes with blurs. If I add additional nodes I turn off the other nodes until I have finished tracking and that helps.

Because I am working with police body-cameras that are moving and with subjects that are also moving, I have to add a whole lot of keyframes in order to blur each frame of the subject(s) I am tracking. Tedious to say the least. The auto tracker works pretty well for daytime footage but there is not enough contrast at night so manual tracking is what I have to do. Plus, I haven't learned yet how to mix the auto clip tracking with frame tracking.

I will look at other apps to see how they compare.

Because I am working with police body-cameras that are moving and with subjects that are also moving, I have to add a whole lot of keyframes in order to blur each frame of the subject(s) I am tracking. Tedious to say the least.

Boris FX has a plug-in specifically for face-blurring called (amusingly) "Witness Protection." This might give you the same functionality with better results... but it's not free. What's in Resolve can work pretty well.

One thing I have done in some cases is just to go to manual mode, set the first frame, go to the last frame, set the last frame, then stop down every second or so and manually move the window where necessary. You can also move the playhead to the first frame that movement occurs and then move the window when necessary. It helps to have a control surface so you can have one hand on the mouse and one hand on the PTZR controls.

Thanks Marc. I have been using the method you suggested where I start by creating a window, begin at the first frame where I need to blur (redact) a face or other object, change to Frame mode, add a box blur effect and track the object from beginning to end. If the object leaves the screen I turn off the blur until it returns and then continue to track until finished.

If an additional object that requires redaction appears within the some of the same frames as the first object, I add another node, disable the first node and repeat the above process. I disable the first node to save resources or else I will bring my Windows 10 PC to its knees after a while.

I had one clip where I had four objects to redact within the first few minutes. Thankfully the video was shot with an in-car camera so only the objects were moving while the camera was stationary. They are much easier to track than when the camera is a body-worn one.

I set my Playback/Proxy Mode to Half-resolution and have set my Pre-allocated System Memory to 6100 MB (out of 16). Unfortunately our GPUs are AMD Radeon R5 340X whose drivers I updated yesterday.

I began experiencing two different problems yesterday: Resolve 12.5.5.026 crashing while working on one project with only one node, and randomly not being able to save another project, again only with one node. When the project does save it will go to 66% and stay there for a while and then jump to 88%. If it gets to 88% then it will probably finish saving but if it stays at 66% for an extremely long time I have to force shut down my PC when Ctrl-Alt-Delete doesn't work.

After each of the two events occurred I created a capture log and saved them to my desktop. I don't know how to upload them to see if Davinci can help resolve the two issues. I tried to use the Upload attachment tab located below my reply window but that gave me an error message and somehow deleted all of the typing I had already done making me start this replay all over again.

If these two issues can be resolved, I don't believe we would need to purchase Boris FX to get the Witness Protection plug-in, plus we would have to purchase the Pro version of Premiere which the government agency I work for is not going to do. That would be purchasing five copies of everything. I'm surprised they sprang for Premiere Elements!

Resolve is, from what I have been able to see, much better for our redaction purposes than Premiere Elements. Audio redaction is also a lot easier to do in Resolve than in Elements, so I am hoping I can resolve the crashing and saving problems.

Thank you again for your help.