m1-transcoder

Frontend Mach1 Transcode application that utilizes m1-transcode and other dependencies to prepare multichannel audio/video deliverables

Installation

First prepare your electron development environment:

To clone and run this repository you'll need Git and Node.js (which comes with npm) installed on your computer. From your command line:

• [macOS] Create a .env file in this directory and add the following with the vars filled in properly:

APPLEID=
APPLEIDPASS=
APPLE_TEAM_ID=

• [unix] Setup

./scripts/setup.sh # setup the dependencies

• [win] Setup

./scripts/setup.bat # setup the dependencies

• Install and build

cd to_m1transcoder_path
# Install dependencies
npm install

# package macOS app
npm run package-mac
# package windows app
npm run package-win

Batch conversion

Open File → Batch Convert… to add one row per dropped input, set per-row formats and destinations, attach optional stereo/JSON/video assets, and save or load versioned JSON manifests. Outputs default to the input folder with the selected format appended to the source name. The batch runner processes rows sequentially, continues after a row failure, and refuses collisions unless overwrite is explicitly selected. The Output Layout column selects a single interleaved multichannel file or one numbered mono file per channel. Multi-mono output requires uncompressed WAV or AIF and publishes files with _01, _02, and subsequent channel suffixes. JSON manifests use output.layout: "multichannel" or "multi-mono".

The same manifest can run without the UI:

npm run batch -- --batch examples/batch-m1spatial-8-to-4.json \
  --report /tmp/transcoder-report.json

# Validate and print resolved recipes without rendering
npm run batch -- --batch batch.json --dry-run

# Packaged application
"/Applications/M1-Transcoder.app/Contents/MacOS/M1-Transcoder" \
  --batch batch.json --report report.csv --overwrite

Options:

• --batch <manifest> selects the versioned manifest.
• --report <json-or-csv> saves the aggregate gain/loudness report.
• --dry-run validates inputs, probes media, and prints resolved plans.
• --overwrite permits replacing existing outputs.
• --no-analysis skips before/after measurements.

Exit codes are deterministic: 0 success, 1 usage/manifest error, 2 missing dependency, 3 one or more failed jobs, and 4 cancellation. See schemas/batch-manifest-v1.schema.json and examples/batch-m1spatial-8-to-4.json.

For gain-preserving Mach1Spatial-8 to Mach1Spatial-4 renders, use explicit "proToolsOrder": "pro-tools-8" when applicable. The shared path runs the Mach1Spatial-8 to Mach1Spatial-4 matrix through Mach1 Transcode, applies a fixed -3.0103 dB API master-gain compensation, and does not normalize. The compensation turns the API's constant-power 0.7071 coefficients into gain-matched 0.5 vertical-pair coefficients so the four-channel result retains headroom. It preserves source sample rate and PCM depth and reports native per-channel peak/RMS plus a versioned M1Horizon-to-stereo LUFS/LRA/dBTP comparison.