# Chapter Editor

MPEG-4 files can contain chapters which are essentially bookmarks into the audio stream. Typically these are used with (but not restricted to) audiobooks with an m4b filename extension.

The Chapter Editor can be used to modify existing chapter names in these files. Edit>Chapter Editor... will be enabled when at least one selected file contains chapters. When a file is saved, modifications to chapter names will be committed.

When saving changes to chapter names the entire file must be read into memory. For video files this can be a lengthy process.

The following columns are displayed:

Identifier
  Many audiobooks are divided into separate files each containing a single chapter. This can make editing each file separately tedious. If you select multiple files this column shows an identifier describing which file was the source of the chapter. You can opt to display the album name, the filename without an extension, the filename, the full path or the title. This column is only displayed if multiple files are being processed.
#
  The chapter index.
Initial
  The initial name associated with the chapter.
New
  An editable field where you assign new chapter names. This column will only display a name if one is entered which is different than the original name.

You can elect to display spaces in the Initial and New columns as centered dots via the Display spaces as centered dots checkbox. Note that this setting only affects the display of the columns, not the retained values.

You can revert to one of three possible sets of values by means of the Revert to disclosure button. The choices are:

Values when Opened
  Reset all the chapter names to the values they had when the Chapter Editor was opened.
Initial Values
  Reset all the chapter names to the values currently stored in the files.
Editing Values
  Reset all the chapter names to the values in place when the Editing State was last set.

The Font menu and associated keyboard shortcuts can be used to change the size of the display font.

When a row is selected if you do an Edit>Copy, the initial value of the column will be copied.

You can tab and backtab between rows.

You can use the main window's Has Chapters filter to locate files containing chapters (via File>Filter).

If you are updating existing Audiobooks in iTunes, the files need not be linked. iTunes will update the chapter names the next time the book is played.

If the Edit>Chapter Editor... menu item is disabled and you feel that a file should have chapters, you can do a View>Raw Data. If a fault was found which caused the reading of the chapter names to be disabled, it will be displayed.

The Chapters statement can be used to automate the renaming of chapter names.