Implementation of interpolate_tracks and how to speed them up.

[pvmilk]

Discussed in #907

^{Originally posted by pvmilk September 6, 2023}
Does anyone have brief explanation of how this is implemented?

https://github.com/open-mmlab/mmtracking/blob/e79491ec8f0b8c86fda947fbaaa824c66ab2a991/mmtrack/core/track/interpolation.py#L5C16-L5C16

I would like to find out whether it is possible to speed up the calculation using parallelism.
I am currently using it and found out that the calculation time seems to be exponential to the number of frames, e.g.

• 25k frames would use ~70s
• 75k frames would use ~700s

I am not sure whether this is proportionate to the number of frames OR the number of track_id.