Mix every audio-bearing layer of a composition into one master track with fades, normalize, and master volume, then export WAV or MP3.
Where: canvas → left rail → Add → Export → Audio Render — Add an Audio Render node and wire a composer into its Composition In handle
Key ideas
- Audio-bearing layers: The mix pulls standalone audio layers (with a src) plus video layers whose volume > 0. The Tracks stat shows how many qualify; the Render button reads 'No audio in source' if none do.
- Master controls: Master Volume (0–2×), linear Fade In / Fade Out (seconds), and a Normalize-peaks toggle that scales the final mix to ~-0.1 dBFS. Each layer's own volume, trim, and playback rate are honored.
- Format & fidelity: Choose WAV (16-bit PCM) or MP3, plus sample rate (22.05k/44.1k/48k) and Mono/Stereo. MP3 adds a bitrate picker (128–320 kbps). Est. Size updates live and warns red over 50 MB.
- Pitch-preserving path: If any layer needs a non-unity playback rate with preserve-pitch, the render switches from the fast offline mix to a real-time capture path (the same native time-stretcher the live preview uses) for cleaner tonal/voice output.
- Audio Render card: AudioRenderNode uses the generic shared-card path. Mix connected audio/video layers into a downloadable WAV or MP3 result.
- Properties sidebar: genOutputNodes.tsx
- Opened surfaces: Rendered audio player; Add to canvas; Paste to Replace
Steps
- Add an Audio Render node and connect a composer to its Composition In handle.
- Pick Format (WAV / MP3); for MP3 also choose a Bitrate. Set Sample Rate and Mono/Stereo.
- Tune Master Volume, and add Fade In / Fade Out seconds if needed; toggle Normalize peaks to even out loudness.
- Confirm the Duration / Tracks / Est. Size stats, then click Render Audio and watch the progress fill.
- Use the in-card audio player to preview, then ⋯ → Download to save the WAV/MP3.
Audio Render controls and presets
- Add path: Flowgen → Add → Sound → Audio Render.
- Card: AudioRenderNode.
- Properties: genOutputNodes.tsx.
- Controls: Layers; duration; WAV/MP3; sample rate; channels; bitrate; master volume; normalize; fades.
- Opened surfaces: Rendered audio player; Add to canvas; Paste to Replace.
FAQ
What if my composition has no audio?
The button shows 'No audio in source' and stays disabled while the source is connected. The renderer can still emit deterministic silence as a fallback, but you'll normally add at least one audio or volumed video layer first.
Why does MP3 sometimes come out as WebM?
MP3 encoding goes through MediaRecorder; if the browser can't encode audio/mpeg it falls back to audio/webm (opus). WAV is always available as a lossless fallback.