Exporting

What a bounce is

A bounce writes your edited results out to files. Because all editing in a9a is non-destructive, the original files stay untouched until you bounce.

In the GUI, open Bounce > Selected... (the selected files) or Bounce > All... (every file in the list) from the Files menu.

Destination and file name

Set the destination folder with Output Directory. When exporting a single file, you can also set the output file name with Output Filename.

Choosing a format

Pick one in Output Format. Same as Source writes each file back in the format it came from.

If you are unsure, choose by what matters most:

MP3 can only be selected when the LAME (libmp3lame) shared library is installed. When it is not installed the option is disabled and a message says so. See Getting Started for installation instructions.

Per-format settings

The available settings depend on the selected output format.

Carrying loops into the output

Loop ranges can be written by WAV / AIFF (as loop metadata) and FLAC / OGG (as loop comments). For FLAC and OGG, Start Key / End Key / Length Key set the comment key names — match them to what your importing tool expects.

Because MP3 and AAC are lossy formats, loop metadata and comments are not written. Looping material exported to those formats needs its loop information carried some other way.

AAC container and profile

Container offers M4A (MP4) (.m4a) and ADTS (.aac). Only M4A can carry accurate duration information (gapless metadata). ADTS has no way to express it, so some players show the file as longer by the encoder delay. Choose M4A unless something specific requires ADTS.

Profile offers AAC-LC, HE-AAC v1, and HE-AAC v2. HE-AAC targets low bitrates, and HE-AAC v2 is stereo-only.

Encoder offers Auto (prefers the OS-native encoder), OS Native, and fdk-aac. The Windows OS-native encoder only supports AAC-LC CBR at 96/128/160/192 kbps and 44.1/48 kHz, so libfdk-aac is required for HE-AAC or VBR on Windows.

AIFF container

Container offers the following:

Selecting AIFF-C (32-bit float) fixes Bit Depth to 32-bit.

Overwrite behavior

When Overwrite existing files is enabled, files with the same name are overwritten without confirmation.

When it is disabled and a file with the same name exists, a confirmation appears with these choices:

• Yes: overwrite this file
• Yes All: overwrite all subsequent files with the same name
• No: skip this file
• No All: skip all subsequent files with the same name
• Cancel: abort the bounce itself

The default is set by Overwrite existing files by default in Bounce under Preferences.

During the bounce

A progress dialog is shown while bouncing, with per-file status. No other operations are possible until it completes.

Files overwritten at their original path are reloaded into the list automatically when the bounce completes. When Load bounced files into the file list (off by default) is enabled in Bounce under Preferences, files written to paths not yet in the list are also added as new rows once the results dialog is closed. Failed and cancelled files are not added.

Exporting a job file

The contents of the bounce dialog — the target files, destination, output format, and every edit applied to each file — can be exported as a job file (TOML) that the command-line a9a runs as-is with a9a_cli render --job. It lets you carry a process you confirmed in the GUI straight into CLI or CI batch runs.

• Export Job File...: pick a destination and write the job file. The dialog stays open, so you can continue with the bounce. Enable Export job file as a preset (no input / output paths) to write only the processing steps and output format, without the target files or destination. Such a job file can be reused across different sets of files, with the inputs and destination passed on the command line (for example a9a_cli render --job preset.toml --out-dir out/ *.wav)
• Write job file alongside outputs (off by default): also writes a job file into the output directory when the bounce runs. A multi-file bounce writes a9a-job.toml; a single-file bounce writes <output file name without extension>.a9a-job.toml. The default is set by Write a CLI job file alongside outputs by default in Bounce under Preferences

The job file records the gain, loudness normalization, fades, trim, silence trim, reverse, and loop range in the order they were applied, and running it in the CLI produces the same result as the GUI bounce. Files with identical edits are collected into one job file; files with different edits, or whose output name differs from the CLI’s default (<input file name without extension>.<output extension>), are split into numbered or individual job files.

A file whose extension does not match its actual content (for example take.flac holding WAV data) cannot be exported with Same as Source, because the GUI (extension-based) and the CLI (content-based) would disagree on the output format. Likewise, when a fade or trim that was in effect during a loudness normalization or a silence trim is cleared afterwards, that history cannot be reproduced in the CLI, so the export fails with an error.

For what goes into a job file and how to use it from the CLI, see Batch Processing and Automation and the CLI Reference.

Setting defaults

Bounce under Preferences holds the defaults for WAV, FLAC, AIFF, Ogg Vorbis, MP3, and AAC. If you always export to the same spec, filling these in first saves configuring each bounce. The overwrite default, loading bounced output into the list, and writing a job file alongside outputs are also set here.

Exporting from the CLI

Use --out for a single output file and --out-dir for multiple files. The two cannot be used together.

a9a_cli render input.wav \
  --out output.flac \
  --format flac \
  --sample-rate 48000 \
  --bits-per-sample 24

Writing multiple files back in their original formats:

a9a_cli render a.wav b.wav --out-dir out --same-format

The output format comes from --format, from --same-format, or from the extension of --out. --format and --same-format cannot be used together. Add --force to overwrite existing output.

The main format options are:

--sample-rate accepts only the following standard values:

8000, 11025, 16000, 22050, 32000, 44100, 48000, 88200, 96000, 176400, 192000

Loop ranges and comments behave as they do in the GUI: tags added with --comment KEY=VALUE are preserved for FLAC / Ogg Vorbis and discarded when writing WAV / AIFF / MP3 / AAC.

The full option list and all constraints are in the CLI Reference.

This page was written with generative AI.