Rip all chapters from a DVD to separate files

rip_dvd.py

#!/usr/bin/env python3

import argparse
import datetime
import os
import os.path
import subprocess
import time

def log_message(message):
    print("{}: {}".format(datetime.datetime.now().isoformat(), message))

def get_chapter_lengths(device_file):
    result = subprocess.run(["lsdvd", "-c", "-Oy", device_file], stdout=subprocess.PIPE, encoding="utf-8")
    result.check_returncode()
    locs = {}
    # lsdvd = {...}
    exec(result.stdout, {}, locs)
    return [(title['ix'], chapter['ix'], chapter['length']) for title in
            locs['lsdvd']['track'] for chapter in title['chapter']]

def build_handbrake_args(input_device, title, chapter, output_path):
    return [
        "HandBrakeCLI",
        "-v",
        "-i", str(input_device),
        "-t", str(title),
        "-c", str(chapter),
        "-o", str(output_path),
        "-f", "av_mp4",
        "-e", "x264",
        "-E", "av_aac",
        "--no-markers",
        "--optimize",
        "--no-ipod-atom",
        "--encoder-profile", "main",
        "--encoder-preset", "slow",
        "-q", "16.0",
        "--no-two-pass",
    ]

def rip_chapter(title, chapter, output_dir, device_file, log_file):
    fname = "{:02d}_{:02d}.mp4".format(title, chapter)
    output_path = os.path.join(output_dir, fname)
    log_message("ripping {}/{} to {}".format(title, chapter, output_path))
    args = build_handbrake_args(device_file, title, chapter, output_path)
    result = subprocess.run(args, stdout=log_file, stderr=log_file)
    log_file.flush()
    result.check_returncode()
    log_message("finished {}/{}".format(title, chapter))

def main():
    parser = argparse.ArgumentParser(description="Rip all titles and chapters from a DVD.")
    parser.add_argument("--output_dir", type=str, required=True, help="Output directory")
    parser.add_argument("--log_file", type=argparse.FileType("a",
        encoding="UTF-8"), default=open(os.devnull, "w"), help="Log file")
    parser.add_argument("--device_file", type=str, default="/dev/dvd",
        help="DVD device file to read from")
    args = parser.parse_args()
    if not os.path.isdir(args.output_dir):
        raise Exception("No such directory: {}".format(args.output_dir))
    if not os.path.exists(args.device_file):
        raise Exception("No such DVD device file: {}".format(args.device_file))
    metadata = get_chapter_lengths(args.device_file)
    total_length = sum(x[2] for x in metadata)
    progress = 0.0
    start_time = time.time()
    for title, chapter, length in metadata:
        rip_chapter(title, chapter, args.output_dir, args.device_file, args.log_file)
        progress += length
        progress_fraction = progress / total_length
        remaining_fraction = (total_length - progress) / total_length
        elapsed_sec = time.time() - start_time
        remaining_sec = elapsed_sec / progress_fraction * remaining_fraction
        log_message("Progress: {:03.3f}%    Elapsed: {:02.2f} min    Remaining: {:02.2f} min".format(
            progress_fraction * 100.0,
            elapsed_sec / 60.0,
            remaining_sec / 60.0))
    args.log_file.close()

if __name__ == "__main__":
    main()