Realign Chapters¶

The realignment workflow keeps the titles of an existing Chapter Reference and attempts to automatically fix misaligned timestamps by detecting cues in the audio.

When to use it¶

Realignment is for situations where you have a Chapter Reference whose titles are correct, but whose timestamps are slightly off. For example, when using the chapter (Audnexus) lookup feature in Audiobookshelf, you'll often see this familiar message when the durations differ:

A duration mismatch between your audiobook and the Audnexus data almost always means that the Audnexus chapters will not correctly align with your book's audio. The realignment workflow fixes this by performing targeted smart detection around the areas where it thinks the chapters should go, and then shifts the timestamps to the best-fitting locations.

Steps¶

1. Select a book from Achew's main screen.
2. Choose Realign Chapters on the Select a Workflow screen.
3. Pick a Reference, e.g. Audnexus. If there are no References, or you wish use another Reference, click the Add Chapter Reference button near the bottom.
4. Choose a Detection mode. Auto (the default) samples a small portion of the audio to decide for you. Pick Standard for plain narration, or Dramatized for books that contain music or sound effects. Dramatized detection takes much longer, so Auto only switches to it if necessary.
5. (Rarely needed) Toggle the Find large shifts checkbox if you believe one or more chapters have shifted unusually far from the Reference timestamps. This scans more of the audio to help find cues beyond the expected range, but takes significantly longer. Achew automatically widens its search when it detects that a chapter may have shifted out of scope, so it is recommended to leave this option unchecked most of the time.
6. Click the Realign button to start the realignment process.
7. After realignment has finished, use the Chapter Editor to review and polish the chapters.

The Offset column¶

In the editor, the Offset column shows how far each chapter moved during realignment. If the chapter's offset is a guess or is low-confidence, it will have a warning icon and a different color:

You will want to manually review the accuracy of the chapter timestamps, especially for those marked as guesses. Use the play button () on each chapter to hear the first few seconds and confirm the timestamp is correct. You can click on timestamps to edit them directly, using the space bar to start/stop playback and the ↑/↓ keys to shift the timestamp by ±1 second.