Reads a C3D file and returns the data as an aniframe with associated metadata including source software, units, and sampling rate.
Value
An aniframe with columns time, keypoint, x, y, and z.
Metadata includes source software, filename, time/space units, and
sampling rate. Time is 0-indexed (in frames).
See also
c3dr::c3d_read() for lower-level C3D access.