DJI drone post-flight analysis toolkit written in Go.

downwash processes DJI MP4 video files and produces a complete post-flight package — GPX tracks, altitude charts, flight-path maps, Markdown reports, and aviation-themed PDF briefings — from the embedded telemetry captured by your drone.

Downwash is the aviation term for the air pushed downward by a rotor — your drone's data, pushed straight to you.

Tested with: DJI Mini 4 Pro

• Telemetry extraction — reads the DJI djmd protobuf stream via exiftool, parsing GPS, altitude, attitude, and camera settings at ~30 Hz
• GPX 1.1 track file — compatible with Google Earth, Garmin Basecamp, and any GPX-capable mapping tool
• Altitude & speed chart — three-panel PNG: altitude ASL, AGL, and ground speed over time, dark aviation theme
• Flight track map — top-down GPS path over dark OSM map tiles (CartoDB dark_matter), with automatic fallback to plain dark chart if tiles are unavailable
• Markdown report — structured summary of flight statistics, GPS, camera settings
• PDF post-flight briefing — four-page A4 landscape PDF with cover stats, altitude/speed profiles, flight dynamics, and detailed telemetry tables
• Metadata JSON export — machine-readable JSON file with all flight statistics and per-frame telemetry for integration with other tools
• ZIP packaging — optionally bundle all output artefacts into a single ZIP file (--zip flag or TUI toggle)
• Video transcode — optional re-encode to H.264 (AVC) or H.265 (HEVC) at a target bitrate via ffmpeg
• Interactive TUI — terminal interface with file picker, options menu (toggle outputs, configure transcoding), real-time pipeline progress, and styled output (powered by Bubble Tea)
• Configurable outputs — choose which artefacts to produce: GPX, charts, markdown, metadata JSON, PDF — all toggleable from the TUI options menu or via skip flags
• Batch processing — process an entire SD-card directory in one command; select a folder directly in the TUI file picker with s
• Scriptable — --no-tui flag disables the interactive interface for CI/CD pipelines and shell scripting
• Cross-platform — static binaries for macOS (arm64/amd64), Linux (amd64), Windows (amd64/arm64)

Both tools must be available on $PATH. If they are missing, downwash will log a warning and skip the affected step rather than aborting.

Grab the latest release for your platform from the Releases page:

# macOS (Apple Silicon)
curl -L https://github.com/askrejans/downwash/releases/latest/download/downwash_darwin_arm64.tar.gz | tar xz
sudo mv downwash /usr/local/bin/

# Linux (amd64)
curl -L https://github.com/askrejans/downwash/releases/latest/download/downwash_linux_amd64.tar.gz | tar xz
sudo mv downwash /usr/local/bin/

# Windows (PowerShell, amd64)
Invoke-WebRequest https://github.com/askrejans/downwash/releases/latest/download/downwash_windows_amd64.zip -OutFile downwash.zip
Expand-Archive downwash.zip

# Debian / Ubuntu (.deb)
wget https://github.com/askrejans/downwash/releases/latest/download/downwash_amd64.deb
sudo dpkg -i downwash_amd64.deb

# Fedora / RHEL / CentOS (.rpm)
wget https://github.com/askrejans/downwash/releases/latest/download/downwash_amd64.rpm
sudo rpm -i downwash_amd64.rpm

git clone https://github.com/askrejans/downwash.git
cd downwash
go build -o downwash ./cmd/downwash
# or
make build

Requires Go 1.21+.

downwash auto-detects what you give it — a file, a directory, or nothing — and picks the right mode:

# Interactive TUI — opens a file picker starting from your home directory
downwash

# Process a single video (plain CLI, no TUI)
downwash DJI_0001.MP4

# Process all MP4s in a directory → outputs to <dir>/processed/
downwash /Volumes/DJI/DCIM/100MEDIA

# Process with transcoding
downwash --transcode --codec h265 --bitrate 20M DJI_0001.MP4

# Custom output directory
downwash --output ~/flights/2025-06 DJI_0001.MP4

# Explicit subcommands still work too
downwash process DJI_0001.MP4
downwash batch --recursive /Volumes/DJI

Output files (names derived from input basename):

Print version information.

# Current platform only
make build

# All supported platforms (output in dist/)
make cross-build

This produces static binaries (CGO_ENABLED=0):

Requires nfpm:

go install github.com/goreleaser/nfpm/v2/cmd/nfpm@latest

make package-deb   # produces dist/*.deb
make package-rpm   # produces dist/*.rpm

Requires goreleaser:

go install github.com/goreleaser/goreleaser@latest

make release-snapshot   # dry run, no git tag required
make release            # publish (requires GITHUB_TOKEN + git tag)

# Run tests
make test

# Run tests with verbose output
make test-verbose

# Run integration tests (requires exiftool + ffmpeg)
# Set DJI_TEST_VIDEO to a real MP4 to exercise the full pipeline
DJI_TEST_VIDEO=path/to/flight.MP4 make test-integration

# Lint
make lint

# Regenerate sample artefacts in samples/
make sample

Pre-generated samples using synthetic figure-8 flight data are in samples/.

downwash/
├── cmd/downwash/        # CLI entry point (cobra)
├── internal/
│   ├── telemetry/       # exiftool extraction, frame parsing, FlightStats
│   ├── ffmpeg/          # ffmpeg/ffprobe wrappers
│   ├── geo/             # shared geodesy helpers (haversine, rounding)
│   ├── gpx/             # GPX 1.1 writer
│   ├── chart/           # gonum/plot chart renderers
│   ├── report/          # Markdown and PDF report generators
│   ├── pipeline/        # Orchestrates the full processing workflow
│   └── tui/             # Bubble Tea interactive terminal interface
├── samples/             # Pre-generated sample artefacts + generator
├── .goreleaser.yml      # Cross-platform release configuration
├── Makefile
└── go.mod

GPL-3.0 — see LICENSE.

This repository and its contents are not licensed for use in AI/ML training datasets. See robots.txt and .ai-labeling for machine-readable opt-out metadata.