Investigate Parallel Scanning

[Breakthrough]

Investigate a few different modes of parallelization of scans (in order of general difficulty):

1. scanning multiple videos that are independent
2. scanning multiple videos being concatenated with multiple readers, stitching the results together where they overlap
3. scanning the same video with multiple readers, stitching the results together where they overlap (need to ensure seek works correctly, which it does not on all videos)