split-near

#!/usr/bin/env python
#
# Copyright 2016 by Chris Osborn <fozztexx@fozztexx.com>
#
# This file is part of viddin.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License at <http://www.gnu.org/licenses/> for
# more details.

import argparse
import os
import datetime
from viddin import viddin

def build_argparser():
  parser = argparse.ArgumentParser()
  parser.add_argument("filename", help="Video to split")
  parser.add_argument("offset", help="Split at black scene closest to offset. Use negative number for offset from end.")
  return parser

def bestMatch(offset, filename):
  video, ext = os.path.splitext(filename)
  print("Finding offset")
  if offset < 0:
    cmd = "vidinf %s | grep ID_LENGTH | sed -e 's/ID_LENGTH=//'" % filename
    process = os.popen(cmd)
    len = float(process.read())
    process.close()
    offset = len + offset
    
  best = None
  with open(video + ".split") as f:
    for line in f:
      info = line.split()
      begin = float(info[1])
      end = float(info[2])
      seconds = begin + (end - begin) / 2
      diff = abs(seconds - offset)
      if not best or diff < best[0]:
        best = [diff, seconds, begin, end]
        
  bestsil = None
  with open(video + ".sil") as f:
    for line in f:
      info = line.split()
      begin = float(info[1])
      end = float(info[2])
      seconds = begin + (end - begin) / 2
      diff = abs(seconds - best[1])
      if ((begin >= best[2] and begin <= best[3]) or (end >= best[2] and end <= best[3])) \
            and (not bestsil or diff < bestsil[0]):
        bestsil = [diff, seconds, begin, end]

  if bestsil:
    print("Silence: ", bestsil, best)
    begin = bestsil[2]
    if begin < best[2]:
      begin = best[2]
    end = bestsil[3]
    if end > best[3]:
      end = best[3]
    split = begin + (end - begin) / 2
    print("Splitting at ", split)
    return split

  print("Black: ", best)
  return best[1]

def splitVideo(pos, filename, before):
  print("Splitting")
  video, ext = os.path.splitext(filename)
  if before:
    start = "0:00.00"
    end = str(datetime.timedelta(seconds = pos))
    len = pos
  else:
    start = str(datetime.timedelta(seconds = pos))
    cmd = "vidinf %s | grep ID_LENGTH | sed -e 's/ID_LENGTH=//'" % filename
    process = os.popen(cmd)
    len = float(process.read())
    process.close()
    end = str(datetime.timedelta(seconds = len))
    len -= pos

  cmd = "mkvmerge --split parts:%s-%s -o %sb%s %s > /dev/null" % (start, end, video, ext, filename)
  print(cmd)
  os.system(cmd)

  if before:
    splitname = "%s-pre%s" % (video, ext)
  else:
    splitname = "%s-post%s" % (video, ext)
    
  if os.path.exists(splitname):
    os.remove(splitname)
  cmd = "ffmpeg -i %sb%s -t %f -codec copy %s > /dev/null 2>&1" % (video, ext, len, splitname)
  os.system(cmd)
  os.remove("%sb%s" % (video, ext))
  print(splitname)

def main():
  args = build_argparser().parse_args()
  offset = float(args.offset)
  viddin.findBlack(args.filename)
  viddin.findSilence(args.filename)
  split = bestMatch(offset, args.filename)

  if args.offset[0] != '+':
     splitVideo(split, args.filename, True)
  if offset >= 0:
     splitVideo(split, args.filename, False)
  return

if __name__ == '__main__':
  exit(main() or 0)