Audio Mixing - Content Management
Audio Mixing
Audio from overlay and background replacement sources mixes with the main video using a complementary volume model.
Volume Model
| Setting | Main Audio | Overlay/BG Audio |
|---|---|---|
volume=0.0 | 100% | 0% (muted) |
volume=0.3 | 70% | 30% |
volume=0.5 | 50% | 50% |
volume=0.7 | 30% | 70% |
volume=1.0 | 0% (muted) | 100% |
The formula: main volume = 1 - overlay volume. Mixed with FFmpeg amix filter (normalize=0).
Audio Attributes
Add audioAttributes to any overlay or background replacement:
-d "resource[operationAttributes][0][mediaCompositionAttributesArray][0][audioAttributes][volume]=0.3"
This plays the overlay audio at 30% and the main video audio at 70%.
Muting Overlay Audio
To keep only the main video's audio:
-d "resource[operationAttributes][0][mediaCompositionAttributesArray][0][audioAttributes][volume]=0.0"