Is there an elegant way to split a file by chapter using ffmpeg?

Question

In this page, Albert Armea share a code to split videos by chapter using ffmpeg. The code is straight forward, but not quite good-looking.

ffmpeg -i "$SOURCE.$EXT" 2>&1 | grep Chapter | sed -E "s/ *Chapter #([0-9]+\.[0-9]+): start ([0-9]+\.[0-9]+), end ([0-9]+\.[0-9]+)/-i \"$SOURCE.$EXT\" -vcodec copy -acodec copy -ss \2 -to \3 \"$SOURCE-\1.$EXT\"/" | xargs -n 11 ffmpeg 

Is there an elegant way to do this job?

Answer 1

(Edit: This tip came from https://github.com/phiresky via this issue: https://github.com/harryjackson/ffmpeg_split/issues/2)

You can get chapters using:

ffprobe -i fname -print_format json -show_chapters -loglevel error 

If I was writing this again I'd use ffprobe's json options

(Original answer follows)

This is a working python script. I tested it on several videos and it worked well. Python isn't my first language but I noticed you use it so I figure writing it in Python might make more sense. I've added it to Github. If you want to improve please submit pull requests.

#!/usr/bin/env python import os import re import subprocess as sp from subprocess import * from optparse import OptionParser  def parseChapters(filename):   chapters = []   command = [ "ffmpeg", '-i', filename]   output = ""   try:     # ffmpeg requires an output file and so it errors      # when it does not get one so we need to capture stderr,      # not stdout.     output = sp.check_output(command, stderr=sp.STDOUT, universal_newlines=True)   except CalledProcessError, e:     output = e.output     for line in iter(output.splitlines()):     m = re.match(r".*Chapter #(\d+:\d+): start (\d+\.\d+), end (\d+\.\d+).*", line)     num = 0      if m != None:       chapters.append({ "name": m.group(1), "start": m.group(2), "end": m.group(3)})       num += 1   return chapters  def getChapters():   parser = OptionParser(usage="usage: %prog [options] filename", version="%prog 1.0")   parser.add_option("-f", "--file",dest="infile", help="Input File", metavar="FILE")   (options, args) = parser.parse_args()   if not options.infile:     parser.error('Filename required')   chapters = parseChapters(options.infile)   fbase, fext = os.path.splitext(options.infile)   for chap in chapters:     print "start:" +  chap['start']     chap['outfile'] = fbase + "-ch-"+ chap['name'] + fext     chap['origfile'] = options.infile     print chap['outfile']   return chapters  def convertChapters(chapters):   for chap in chapters:     print "start:" +  chap['start']     print chap     command = [         "ffmpeg", '-i', chap['origfile'],         '-vcodec', 'copy',         '-acodec', 'copy',         '-ss', chap['start'],         '-to', chap['end'],         chap['outfile']]     output = ""     try:       # ffmpeg requires an output file and so it errors        # when it does not get one       output = sp.check_output(command, stderr=sp.STDOUT, universal_newlines=True)     except CalledProcessError, e:       output = e.output       raise RuntimeError("command '{}' return with error (code {}): {}".format(e.cmd, e.returncode, e.output))  if __name__ == '__main__':   chapters = getChapters()   convertChapters(chapters)