Video caption conversion script using the PBS pycaption library

convert-subtitles.py

#!/usr/bin/env python
# encoding: utf-8
"""Convert caption files to different formats

One or more caption files will be converted to the specified output format, saved next to the input file

Requires the pycaption library from PBS: https://pypi.python.org/pypi/pycaption/
"""

from __future__ import absolute_import, print_function, unicode_literals

import logging
import os
import sys
from argparse import ArgumentParser, FileType

try:
    import pycaption
except ImportError:
    print('Unable to import pycaption: have you installed it?', file=sys.stderr)
    raise


SUPPORTED_WRITERS = {
    'dfxp': pycaption.DFXPWriter,
    'sami': pycaption.SAMIWriter,
    'srt': pycaption.SRTWriter,
    'scc': pycaption.SCCWriter,
    'webvtt': pycaption.WebVTTWriter,
}

FILE_EXTENSIONS = {
    'dfxp': 'dfxp.xml',
    'sami': 'sami',
    'srt': 'srt',
    'scc': 'scc',
    'webvtt': 'vtt',
}


def convert_file(input_captions, output_writer):
    reader = pycaption.detect_format(input_captions)

    if not reader:
        raise RuntimeError('Unrecognized format')

    converter = pycaption.CaptionConverter()
    converter.read(input_captions, reader())
    return converter.write(output_writer)


if __name__ == "__main__":
    parser = ArgumentParser(description=__doc__.strip())
    parser.add_argument('--output-format', type=lambda i: i.lower(), metavar='FORMAT', default='WebVTT',
                        choices=SUPPORTED_WRITERS.keys(),
                        help='Output format: %(choices)s (default: %(default)s)')
    parser.add_argument('caption_file', type=FileType('r'), nargs='+',
                        help='Caption files to convert')
    args = parser.parse_args()

    if args.output_format not in SUPPORTED_WRITERS:
        parser.error('Output format must be one of %s' % ' '.join(SUPPORTED_WRITERS.keys()))
    else:
        output_writer_class = SUPPORTED_WRITERS[args.output_format]

    logging.basicConfig()

    for f in args.caption_file:
        output_file = '%s.%s' % (os.path.splitext(f.name)[0],
                                 FILE_EXTENSIONS[args.output_format])

        print(output_file)

        try:
            with open(output_file, 'wb') as output_f:
                output_f.write(convert_file(f.read(), output_writer_class()))
        except Exception as exc:
            import pdb; pdb.xpm()
            logging.error('Unable to convert %s: %s', f.name, exc)
            f.close()
            continue

hi, tried this script and got this:

D:\series>python d:\python27\scripts\convert-subtitles.py --output-format webvtt
 abc.srt
abc.vtt
Traceback (most recent call last):
  File "d:\python27\scripts\convert-subtitles.py", line 78, in <module>
    import pdb; pdb.xpm()
AttributeError: 'module' object has no attribute 'xpm'

and a vtt file with 0kb
any idea how to fix?

Hi @acdha,
First, great job!
I have done some changes to fix some problems (xpm function and unicode format) in your code. I forked your script.

@cdiazbas Where is your fork?