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I'm attempting to track a slightly longish shot, and I don't want to fill up all my ram.

I can play the animation with ⎇ AltA and blender caches and displays uncached frames in near real-time (~35 fps with 60fps footage). Blender will track cached frames faster than real-time.

Yet when trying track uncached frames, blender takes longer than 10 seconds per frame! Often as long as 15 seconds.

What is going on here? Why does tracking uncached frames take far longer than the time needed to both cache and track separately?

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  • $\begingroup$ A lot of it depends on the video codec you are using and how fast the CPU interprets them. If you create proxies as a JPEG sequence (very low CPU overhead) you'll see better performance... $\endgroup$ – cegaton Mar 28 '15 at 1:45
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    $\begingroup$ Speed might also be impacted by the size of the frame and the speed of your drives...Also, using a smaller search area for the tracker helps tremendously. $\endgroup$ – cegaton Mar 28 '15 at 1:48
  • $\begingroup$ What codec is the video encoded in? $\endgroup$ – cegaton Mar 28 '15 at 1:56
  • $\begingroup$ @cegaton h264 I believe. I can understand it going a little slower when caching as it's tracking (cache time + track time + a little overhead would be perfectly acceptable). But it's going far slower.. $\endgroup$ – gandalf3 Mar 28 '15 at 2:56
  • $\begingroup$ In other words: It's tracking very fast (the trackers are quite small). It's caching very fast (30 fps). However when doing both at once it goes many many times slower (>10spf). $\endgroup$ – gandalf3 Mar 28 '15 at 3:00

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