Fixed incorrect default initialisation of punch in/out value.

Fixed logging of SegmentError (renamed to follow conventions) — ref #32.

Fixed use of itertools.count() to generate segment numbers (ref #32).

Converted os.path to pathlib and all #! lines to python3 (ref #32).

• Deleted leftover development debugging output. ...

• Added code to resize frame inputs to the size of the smallest video segment where applicable (closes #23). Still need to add resizing for differently sized video inputs.

• Redesigned FFprobeCommand to retrieve media file entries in JSON format for easier extraction and processing. ...

• Changed default of --input-prefix to “.”.
• Added check that the input prefix actually exists.
• Ensured that the segments list variable actually exists when cleanup happens.

• Ensured that prefix isn’t added if input filename is “^”. ...

• Rearranged display of frame processing progress bar.
• Better handling of frame segment processing errors:
    – Added SegmentException.
    – Checked all subprocess exit status values.
• Moved cleanup() call into finally clause.
• Added Segment._temp_files_list to make deletion of temporary files more predictable, and eliminate inadvertent deletion of original source files for PDF frame inputs.
• Refactored segment temporary file generation (closes #22).

• Moved frame segment post-processing into a function. ...

• Ensured warnings about unequal stream durations are only output if there is both an audio and a video stream (closes #20).
• Fixed obsolete leftover occurrence of “options” in VideoSegment.get_last_frame_number().

• Refactored input/output options variables and methods from FFmpegCommand into ShellCommand, so that all subclasses can use them. ...

• Enhanced ConvertCommand to do more intelligent processing of PDF frames of varying sizes and aspect ratios.

• Finished support for generating frames directly from PDF slides (closes #8). ...

• Specified defaults for audio and video stream numbers.
• Fixed some typos on comments and debug output.
• Added "/" as a valid filename character for config files.
• Added some comments explaining the more obscure class variables in the Segment class.
• Generalised Segment.generate_last_frame() into generate_frame().
• Ensured that generate_temp_file() returns the generated filename.

• Moved segment classes into separate module (closes #7). ...

• Moved global configuration into separate module.
• Made format of debug logging more consistent.
• Added a few more info logging messages.
• Renamed configuration parser module.