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ReaProcessor: Batch Apply Reaper FX Chains in Wwise

ReaProcessor is a unique WAAPI tool that allows you to batch apply Reaper FX chains to audio files in your Wwise project. This creates a powerful hybrid workflow combining Reaper's flexible effects processing with Wwise's game audio integration.

What Is ReaProcessor?

Reaper (Cockos Reaper) is a powerful DAW known for its scripting capabilities and extensive effects library. ReaProcessor lets you leverage Reaper's processing power on Wwise assets without manually exporting and importing files.

This tool is particularly useful when you need to:

  • Apply complex effect chains to large batches of audio
  • Use Reaper-specific plugins (JS effects, ReaPlugs, etc.)
  • Maintain consistent processing across many variations
  • Automate repetitive audio processing tasks

How to Use ReaProcessor

Prerequisites

Before using ReaProcessor, you need:

  • Cockos Reaper installed on your system
  • Your desired FX chain saved as an FX Chain file (.RfxChain)
  • WAAPI enabled in your Wwise project

Step 1: Create Your FX Chain in Reaper

In Reaper, set up your desired effects chain on a track. This could include EQ, compression, reverb, distortion, or any combination of effects. Once satisfied with the processing:

  1. Right-click on the track's FX button
  2. Select "Save track FX chain..."
  3. Save the .RfxChain file to a memorable location

Step 2: Select Audio in Wwise

In Wwise, select the audio file(s) or container(s) you want to process. You can select multiple items for batch processing.

Step 3: Launch ReaProcessor

Right-click your selection and choose "waapi-tools" → "ReaProcessor" from the context menu.

Step 4: Configure Processing

A dialog will appear with the following options:

  • FX Chain File: Browse to select your saved .RfxChain file
  • Reaper Executable: Point to your Reaper installation (auto-detected in most cases)
  • Render Settings: Choose output format, sample rate, and bit depth
  • Backup Option: Enable to create backups before processing

Step 5: Process

Click "Process" and ReaProcessor will:

  1. Export audio files from Wwise to a temporary directory
  2. Launch Reaper in batch processing mode
  3. Apply the FX chain to each file
  4. Replace the original files in Wwise with processed versions
  5. Refresh Wwise to reflect the changes

Real-World Use Cases

Weapon Impact Processing

Apply a consistent "impact" FX chain (high-pass filter, transient shaper, compression) to dozens of impact variations at once.

Voice Radio Effect

Process all dialogue files with a radio/walkie-talkie effect chain including EQ, distortion, and noise.

Ambience Sweetening

Add subtle reverb and stereo widening to multiple ambience layers consistently.

Footstep Surface Treatment

Apply surface-specific EQ and resonance to different footstep material variations.

How It Works: Technical Details

Architecture Overview

ReaProcessor acts as a bridge between Wwise and Reaper using a multi-step process:

1. WAAPI Communication

The tool connects to Wwise via WebSocket using the waapi-client library. It queries selected objects and retrieves their file paths:

  • Uses ak.wwise.ui.getSelectedObjects to get current selection
  • Queries audioSource:originalWavFilePath for each object
  • Builds a list of files to process

2. Temporary File Management

ReaProcessor creates a temporary workspace to prevent conflicts:

  • Creates temp directory with unique ID
  • Copies source files to temp location
  • Backs up originals if backup option is enabled

3. Reaper Batch Processing

This is where the magic happens. ReaProcessor generates a Reaper script that runs in batch mode:

  • Creates a .lua script dynamically
  • Script loads each audio file into a Reaper project
  • Applies the specified FX chain
  • Renders the output with specified settings
  • Cleans up and moves to the next file

4. Subprocess Execution

ReaProcessor launches Reaper as a subprocess with the generated script:

  • Uses Python's subprocess module
  • Passes command-line arguments to Reaper
  • Monitors process completion
  • Captures any error output for debugging

5. File Replacement

After Reaper finishes processing:

  • Verifies all output files were created successfully
  • Replaces original Wwise files with processed versions
  • Preserves file metadata and timestamps
  • Cleans up temporary files

6. Wwise Refresh

Finally, ReaProcessor tells Wwise to reload the modified files:

  • Calls ak.wwise.core.project.save to ensure changes persist
  • Triggers a refresh of affected audio source objects
  • Updates the Audio File Editor display

Key Code Components

The tool uses several critical Python libraries:

  • waapi-client: Wwise API communication
  • subprocess: Launch Reaper as external process
  • shutil: File operations (copy, move, delete)
  • json: Parse Reaper FX chain files
  • tkinter: User interface dialogs

Error Handling and Safety

ReaProcessor includes comprehensive error handling:

  • Pre-flight Checks: Validates Reaper installation and FX chain file before processing
  • File Locks: Detects if files are in use and waits for availability
  • Process Monitoring: Tracks Reaper process and handles crashes gracefully
  • Rollback Capability: Can restore from backups if processing fails
  • Detailed Logging: Records all operations for troubleshooting

Advanced Tips

Creating Specialized FX Chains

Save multiple FX chains for different purposes:

  • "Impact_Punch" - transient enhancement for impacts
  • "Dialogue_Radio" - radio communication effect
  • "Ambience_Wide" - stereo enhancement for ambiences
  • "Footsteps_Wood" - specific resonance for wood surfaces

Automation Workflows

Combine ReaProcessor with Wwise's import workflow:

  1. Import raw audio into Wwise
  2. Apply ReaProcessor with appropriate FX chain
  3. Use Wwise's built-in effects for interactive parameters

Performance Optimization

  • Process files in batches during downtime (lunch, end of day)
  • Use lightweight FX chains for large batches
  • Consider processing only changed files in iterative workflows

Conclusion

ReaProcessor exemplifies the power of cross-application integration. By combining Reaper's processing capabilities with Wwise's game audio workflow, sound designers gain unprecedented efficiency in their asset pipeline.

The tool is completely open source, allowing you to customize it for your specific needs or use it as inspiration for other DAW integrations.

View ReaProcessor on GitHub →