restore-ntsc

#!/usr/bin/env python3
# -*- python -*-
#
# Copyright 2019 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 re
import datetime
import sys
import tempfile
import shutil
from viddin import viddin

MULTIPLIER = 25 / (24000.0 / 1001)

def build_argparser():
  parser = argparse.ArgumentParser()
  parser.add_argument("file", help="input file")
  parser.add_argument("--normalize", action="store_true", help="normalize audio")
  parser.add_argument("--volume", help="adjust audio to specified level")
  return parser

def subTimecode(tc):
  ft = viddin.formatChapter(tc)
  ft = ft[:-4] + ":" + ft[-3:] + ","
  return ft

def slowVideo(path, tempdir):
  cmd = "mediainfo '--Inform=Video;%%FrameRate%%' \"%s\"" % (path)
  process = os.popen(cmd)
  inrate = process.read().strip()
  process.close()
  if not len(inrate):
    print("Not a constant frame rate")
    return None
  inrate = float(inrate)
  outrate = 24000.0 / 25025 * inrate

  vtemp = os.path.join(tempdir, os.path.basename(path))
  cmd = "mkvmerge -o \"%s\" --default-duration 0:%0.3ffps -d 0 \"%s\"" % (vtemp, outrate, path)
  viddin.runCommand(cmd)
  return vtemp

def slowAudio(path, tempdir):
  atemp, ext = os.path.splitext(os.path.basename(path))
  atemp += ".ac3"
  atemp = os.path.join(tempdir, atemp)
  cmd = "ffmpeg -y -i \"%s\" -vn -acodec ac3 -ab 448k -filter:a" \
      " asetpts='25025/24000*(PTS-STARTPTS)',aresample=48000:min_comp=0.01" \
      ":comp_duration=1:max_soft_comp=100000000:min_hard_comp=0.3 \"%s\"" % (path, atemp)
  viddin.runCommand(cmd)
  return atemp

def normalizeAudio(path, volume):
  atemp, ext = os.path.splitext(path)
  atemp += "-adj" + ext
  cmd = "adjust-volume"
  if not volume is None:
    cmd += " --volume %s" % (volume)
  cmd += " \"%s\"" % (path)
  viddin.runCommand(cmd)
  return atemp

def expandChapters(path):
  cmd = "edit-chapters --fix --multiplier %0.3f \"%s\"" % (MULTIPLIER, path)
  viddin.runCommand(cmd)
  return

def expandSubtitles(path, tempdir, tinfo):
  outpath, ext = os.path.splitext(os.path.basename(path))
  subs = []
  for track in tinfo.subtitles:
    subpath = outpath + "_%i" % (track['rv_track_id'])
    subpath = os.path.join(tempdir, subpath)
    cmd = "mkvextract tracks \"%s\" %i:\"%s\"" % (path, track['rv_track_id'], subpath + ".sub")
    viddin.runCommand(cmd)
    out_idx = open(subpath + "-exp.idx", "w")
    for line in open(subpath + ".idx", "r"):
      if line.startswith("timestamp:"):
        fields = line.split()
        tcstr = fields[1]
        tcstr = tcstr[:-5] + "." + tcstr[-4:-1]
        tc = viddin.decodeTimecode(tcstr)
        tc *= MULTIPLIER
        tcstr = subTimecode(tc)
        fields[1] = tcstr
        line = " ".join(fields) + "\n"
      out_idx.write(line)
    subs.append(subpath + ".idx")
    os.rename(subpath + "-exp.idx", subpath + ".idx")
  return subs
  
def main():
  args = build_argparser().parse_args()
  path = args.file
  tempdir = os.path.dirname(path)
  tempdir = tempfile.mkdtemp(dir=tempdir)

  vfile = viddin.VideoSpec(path)
  tinfo = vfile.getTitleInfo()
  vtemp = slowVideo(path, tempdir)
  atemp = slowAudio(path, tempdir)
  if args.normalize:
    atemp = normalizeAudio(atemp, args.volume)
  expandChapters(vtemp)
  subs = expandSubtitles(vtemp, tempdir, tinfo)

  outpath, ext = os.path.splitext(path)
  subpath, _ = os.path.splitext(os.path.basename(path))
  subpath = os.path.join(tempdir, subpath)
  outpath += "-NTSC" + ext
  cmd = "mkvmerge -o \"%s\" --no-audio --no-subtitles \"%s\" \"%s\"" % (outpath, vtemp, atemp)
  if len(tinfo.subtitles):
    for track in tinfo.subtitles:
      cmd += " --default-track 0:%i --forced-track 0:%i --language 0:%s \"%s\"" \
          % (int(track['default_track']), int(track['forced_track']), track['language'],
             subpath + "_%i.idx" % (track['rv_track_id']))
  viddin.runCommand(cmd)
  shutil.rmtree(tempdir)
  return

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