V1.4.2

Fixed

• Critical: repaired a thresholdold corruption (from a botched thresh→threshold
  replace) that broke the FFmpeg threshold filter, leaving motion(), motiongrams()
  and related functions producing no frames and crashing. Motion analysis works again.
• skip with large values no longer crashes: atempo filters are chained for ratios
  above FFmpeg's per-filter limit of 100, and colons are stripped from output filenames.
• Restored consistent behaviour of the threshold/filtertype options in motiongrams().

Added

• info(type='summary') now reports video codec/profile, pixel format, color space,
  and audio codec/sample-rate/bit-rate alongside resolution, frames, fps, and duration.
• audio.mfcc(), audio.tempo() (beat tracking with tempo, beat times, inter-beat
  intervals and beat regularity), and audio.beat_statistics() (circular timing analysis).
• musicalgestures/_analysis.py: general signal/statistics utilities (smooth,
  bandpass, dominant_frequency, circular_stats, rayleigh_test, synchrony),
  exported at package level.