First commit for mp3splitter

README.md

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+# MP3 Chapter Splitter
+
+This utility reads the headers of MP3 audiobook files and splits them according to the information found in the tags. For each original file, it will create a new directory and then create a numbered sequence of files each with a section of the original file. **It requires the `ffmpeg` command line utility to split the files**
+
+It is currently written to split files that are downloaded from the Overdrive service from our library.  These files store the chapter markers in the `UserTextFrames` MP3 header.  The markers are stored in an xml format:
+
+```xml
+<Markers>
+   <Marker>
+      <Name>Episode 5</Name>
+      <Time>00:00.000</Time>
+   </Marker>
+   <Marker>
+      <Name>      Episode 5 (03:42)</Name>
+      <Time>03:42.227</Time>
+   </Marker>
+   <Marker>
+      <Name>      Episode 5 (04:32)</Name>
+      <Time>04:32.093</Time>
+   </Marker>
+   <Marker>
+      <Name>      Episode 5 (05:10)</Name>
+      <Time>05:10.067</Time>
+   </Marker>
+   <Marker>
+      <Name>Episode 6</Name>
+      <Time>28:04.493</Time>
+   </Marker>
+   <Marker>
+      <Name>      Episode 6 (30:57)</Name>
+      <Time>30:57.360</Time>
+   </Marker>
+   <Marker>
+      <Name>      Episode 6 (35:41)</Name>
+      <Time>35:41.547</Time>
+   </Marker>
+</Markers>
+```
+
+
+
+The project is currently in the "userful tool for me" stage and has not been tested beyond seeing that it works on the files I needed splitting.  
+
+If you're interested in more features or have a file it doesn't work with, send me a note or create an issue and I'll see what I can do! 

splitter.py

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+#!/usr/bin/env python3
+import eyed3
+import pathlib
+import subprocess
+import sys
+import xml.etree.ElementTree as ET
+
+def convert_time(time_secs):
+    fraction = int((time_secs % 1) * 1000)
+    seconds = int(time_secs)
+    min, sec = divmod(seconds, 60)
+    hour, min = divmod(min, 60)
+    return f"{hour:02}:{min:02}:{sec:02}.{fraction:03}"
+
+def build_segments(filename):
+    audio = eyed3.load(filename)
+    end_time = convert_time(audio.info.time_secs)
+    x = audio.tag.user_text_frames
+    xmltext = x.get("OverDrive MediaMarkers").text
+    markers = ET.fromstring(xmltext)
+    base_chapter = "invalid I hope I never have chapters like this"
+    chapter_section = 0
+    segments = []
+    for marker in markers:
+        # chapters can be split into several shorter sections and end up being
+        # shown like this:
+        #    Chapter 1         00:00.000
+        #    Chapter 1 (03:21) 03:21.507
+        #    Chapter 1 (06:27) 06:27.227
+        #  Use the chapter name with a counter to create:
+        #    Chapter 1-00      00:00.000
+        #    Chapter 1-01      03:21.507
+        #    Chapter 1-02      06:27.227
+        name = marker[0].text.strip()
+        if not name.startswith(base_chapter):
+            base_chapter = name
+            chapter_section = 0
+        name = f"{base_chapter}_{chapter_section:02}"
+        chapter_section += 1
+        start_time =  marker[1].text
+        name = name.replace(" ", "_")
+        segments.append((name, start_time))
+    return end_time, segments
+
+
+def complete_segments(segments, final_time):
+    new_segments = []
+    for index, segment in enumerate(segments):
+        if index < len(segments) - 1:
+            end_time = segments[index+1][1]
+        else:
+            end_time = final_time
+        new_segments.append((segment[0], segment[1], end_time))
+        print((segment[0], segment[1], end_time))
+    return new_segments
+
+def split_file(filename, segments):
+    fn = pathlib.Path(filename)
+    subdir = pathlib.Path(fn.stem)
+    subdir.mkdir()
+    for segment in segments:
+        segname = f"{subdir}/{fn.stem}_{segment[0]}{fn.suffix}"
+        cmd = f"ffmpeg -i {filename} -acodec copy -ss {segment[1]} -to {segment[2]} {segname}"
+        command = cmd.split()
+        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 = subprocess.check_output(command, stderr=subprocess.STDOUT, universal_newlines=True)
+        except Exception as e:
+            print("exception", e)
+        else:
+            for line in output.splitlines():
+                print(f"Got line: {line}")
+
+
+
+for filename in sys.argv[1:]:
+    print(filename)
+    end_time, segments = build_segments(filename)
+    segments = complete_segments(segments, end_time)
+    split_file(filename, segments)
+
+