double speedUpFactor = 100.0;

S text = [[
  Coding 9:25-12:50
  Coding 13:08-13:20
  Coding 13:50-17:00
  Coding 23:29-24:21 
  Coding 25:00-26:22
  Coding 28:06-44:15
  Coding 44:38-45:20
]];

new L<DoubleRange> speedUpRanges;
for (S line : lines(text)) {
  LS l = regexpFirstGroups("(\\d+):(\\d+)-(\\d+):(\\d+)", line);
  if (l == null) continue;
  speedUpRanges.add(doubleRange(minSecToSec(parseInt(l.get(0)), parseInt(l.get(1))),
    minSecToSec(parseInt(l.get(2)), parseInt(l.get(3)));
}

pnl(speedUpRanges);

File inFile = videosDir("scribble.mkv");

// make q files (parts to be sped up)

/*int i = 0;
for (DoubleRange r : speedUpRanges)
  ffmpeg_cutVideo(inFile, videosDir("scribble/scribble-q" + ++i + ".mkv"),
    r.start, r.end);*/

// make n files (parts to stay normal speed)
  
/*ffmpeg_cutVideo(inFile, videosDir("scribble/scribble-n0.mkv"),
  0, first(speedUpRanges).start);

ffmpeg_cutVideoRest(inFile, videosDir("scribble/scribble-n" + l(speedUpRanges) + ".mkv"),
  last(speedUpRanges).end);

for (int i = 1; i < l(speedUpRanges); i++)
  ffmpeg_cutVideo(inFile, videosDir("scribble/scribble-n" + i + ".mkv"),
    speedUpRanges.get(i-1).end, speedUpRanges.get(i).start);*/

// speed up q files
/*for i over speedUpRanges: {
  File in = videosDir("scribble/scribble-q" + (i+1) + ".mkv");
  continue unless fileExists(in);
  ffmpeg_speedUpVideo(in,
    videosDir("scribble/scribble-qq" + (i+1) + ".mkv"),
    speedUpFactor);
}*/

// merge
new L<File> inFiles;
for (int i = 0; i <= l(speedUpRanges)+1; i++) {
  addFileIfExists(inFiles, videosDir("scribble/scribble-n" + i + ".mkv"));
  addFileIfExists(inFiles, videosDir("scribble/scribble-qq" + (i+1) + ".mkv"));
}

ffmpeg_concatVideos(
  inFiles,
  videosDir("scribble/scribble-merged-" + speedUpFactor + ".mkv"));