Atlas Audio: Reaper Extractor

The Reaper extractor analyzes REAPER DAW project files to discover audio sources, sample origins, plugin references, and render outputs. It’s part of the Atlas Audio extractor pack.

Extensions: .rpp, .rpp-bak

What It Finds

The Reaper extractor discovers four categories of references in project files:

Audio Sources (FILE Directives)

REAPER projects reference audio files via FILE directives. The extractor finds every audio source used in the project — recordings, samples, bounces, imported audio.

Edge type: input

Both relative and absolute paths are handled. Relative paths are resolved against the project file’s directory. Duplicate references to the same file across multiple tracks are deduplicated.

Import Origins (ORIGINAL_FILENAME)

When audio is imported or recorded in REAPER, the project may store the original filename inside <EXT> blocks. The extractor captures these to track where audio files originally came from — useful for tracing samples back to their source.

Atlas records this as a source_path on the target entity rather than as an edge, providing provenance breadcrumbs without cluttering the edge graph.

Plugin References (VST Blocks)

The extractor parses <VST> blocks to identify every plugin used in the project. For each plugin, it extracts:

Plugin name
Vendor
Format (VSTi, VST3i, VST, VST3, etc.)
Plugin file path (when available)

Edge type: input

References are formatted as: "Plugin Name (Vendor) [Format]"

Supported formats:

Format	Description
VSTi	VST2 instrument
VST	VST2 effect
VST3i	VST3 instrument
VST3	VST3 effect

Kontakt Product IDs

When a VST block contains a Kontakt instance, the extractor goes deeper. It decodes the plugin’s state data (base64-encoded) and scans the NI container blob for the loaded Kontakt library’s product ID.

If Native Instruments’ komplete.db3 is available on the system, Atlas resolves the product ID to the library’s human-readable name. Otherwise, it records the raw product ID as kontakt:product_id:<id>.

Edge type: input

Render Outputs (RENDER_FILE + RENDER_PATTERN)

REAPER projects declare where rendered audio is written via RENDER_FILE (output directory) and RENDER_PATTERN (filename pattern). The extractor combines these to produce an output edge pointing to the rendered file.

Edge type: output

Render output extraction is skipped for .rpp-bak files — backups are snapshots and are never actually rendered from, so their render paths would create misleading output edges.

The RENDER_PATTERN may contain Reaper wildcards like $project, $track, $date, and $region. The extractor expands $project using the RPP filename (e.g., MySong.RPP → MySong). If no unexpanded wildcards remain after substitution, the edge resolves to a file-level path. Otherwise, it falls back to the directory.

The output file extension is determined by RENDER_FMT, which encodes the render format:

Code	Format	Extension
0	WAV	`.wav`
3	OGG Vorbis	`.ogg`
4	FLAC	`.flac`
5	MP3	`.mp3`
6	WavPack	`.wv`
7	AIF/AIFF	`.aif`

If RENDER_FMT is absent, the extractor defaults to .wav.

When paired with the WAV Metadata extractor, Atlas can confirm render provenance: the RPP declares its output path, and the rendered WAV’s BEXT metadata confirms the origin project. This enables both forward tracing (RPP → rendered file) and backward tracing (rendered file → source RPP).

Example Usage

# Scan a Reaper project
atlas scan ~/music/sessions/my-song.rpp

# View what the project needs
atlas inputs ~/music/sessions/my-song.rpp

# View what the project produces
atlas outputs ~/music/sessions/my-song.rpp

Example output from atlas inputs:

Inputs for "my-song.rpp":

  Plugins:
    Kontakt 7 (Native Instruments) [VST3i]
    Pro-Q 3 (FabFilter) [VST3]
    Valhalla Room (Valhalla DSP) [VST]

  Audio:
    audio/drums-main.wav
    audio/bass-di.wav
    samples/foley-rain.wav

Example output from atlas outputs:

Outputs of my-song.rpp:

  ◈ /Users/me/music/sessions/Renders/my-song.wav

Use Cases

Session auditing — See every plugin and audio file a project needs before sharing or archiving
Missing file detection — Run atlas broken to find audio files referenced by the project that have been moved or deleted
Plugin inventory — Catalog which plugins are used across all your projects
Sample provenance — Track where imported audio originally came from via source_path
Render tracking — See where a project renders its output, and trace forward from project to deliverable
Project portability — Before moving a project to another machine, check that all inputs are accounted for