Voxbound / Help / Formats, chapters and tags

Formats, chapters and tags in Voxbound

The audio files Voxbound opens, the files it writes, how it makes chapters, and which tags and cover end up in the finished book. This describes Voxbound 4.1.13.

Files you can add

MP3, M4A, M4B, AAC, FLAC, WAV and MP4. From an MP4, only the audio is used. Voxbound doesn't open DRM-protected downloads such as Audible's .aax files.

Files don't have to match. If their formats, sample rates or channel counts differ, Voxbound shows a Source file warnings dialog before merging, and converts them all to one format so the book plays at the right speed.

File order

When you drop a folder, its files are sorted by the numbers in their names, so 2 comes before 10. Files you drop or pick one at a time are added in the order Windows passes them. To change the order, drag files in the list, or use Sort: A → Z sorts by name, and Track # by the first number in each file name.

A folder with disc subfolders, such as CD1 and CD2, is sorted as one list by the numbers in the file names, so CD1\01 and CD2\01 end up next to each other. Add the disc folders one at a time, in order, with Choose folder…, and check the list before you merge. The first folder's name fills in an empty Title, so check the title too. Chapter titles are kept by file name, so if two discs both have a 01.mp3, the two share one title; rename the files first, or import a chapter list.

Get the order right before you edit or import chapters. Adding, removing, dragging or sorting files clears an edited or imported chapter list, and the book goes back to one chapter per file.

What Voxbound writes

• M4B: one audiobook file with AAC audio, chapters, tags and cover. This is the format audiobook players expect.
• MP3: one MP3 file with tags and cover, but no chapters.

The format, Quality and profile are in the Output card: click Change to open it. Quality is 64k, 128k, 192k or 256k. Choosing a profile sets Quality back to 128k, so pick the profile first, then the quality. A player profile also lowers the quality to its own limit; see player profiles and the file check.

Chapters

An M4B gets one chapter per source file, named from the file name with a leading track number removed, so 01 - The Start.mp3 becomes The Start. Rename chapters in the file list, or on the Chapters tab after clicking Auto-generate from files. Auto-number puts Chapter 01 —, Chapter 02 — and so on in front of each title.

You can also import a chapter list with Import .txt or Import .cue. A text list has one chapter per line, a start time and then the title:

00:00 Opening Credits
02:15 Chapter 1
1:04:30.500 Chapter 2

A CUE sheet needs to describe the whole book as one file, with an INDEX 01 time for each track. Export .txt and Export .cue save the current list.

The Chapters tab flags chapters that are empty, out of order or overlapping, and Auto-fix repairs the list. If a list you've edited or imported still has problems when you click Merge files, Voxbound offers to fix it first.

Chapters are written in both formats players read, the QuickTime chapter track and the Nero chapter list. When you merge M4B files, the chapters inside them aren't kept: you get one chapter per file, or the list you import.

Tags and cover

The Book card's fields are written into the file. Look up can fill in the description, publisher, year and cover online, and Import tags fills them from the first file's own tags.

These are the names ffprobe shows. Audiobookshelf reads the series from them; see the Audiobookshelf settings.

For the cover, choose a JPG, PNG or BMP image. Without one, Voxbound uses the artwork from the first file, if it has any.

Merging without re-encoding

Voxbound can copy the audio of matching AAC files straight into an M4B without re-encoding it, which is faster and loses no quality. That happens when all of these are true:

• every file is AAC, with the same sample rate and number of channels, and none has a video track;
• the profile is Generic M4B;
• Smart mode is on;
• loudness normalisation, trimming and EQ are off, and Gaps is set to Preserve.

Matching MP3 files merged into an MP3 with Smart mode on are copied the same way. When the audio is copied, Quality doesn't apply: to change the bitrate, turn Smart mode off. Otherwise the audio is re-encoded at the Quality you chose.

The Lossless copy possible note under the file list only looks at the files, not the profile or options, so it can say a copy is possible when the merge will still re-encode, and for matching MP3 files it says Re-encoding required even though they'll be copied.