mediaproc

Process media files (video, audio, images) via a locked-down SSH container with ffmpeg, sox, and imagemagick. Use when the user wants to transcode video, pro...

Security Scan

The skill's described purpose (remote media processing over SSH) matches the included commands, but there are inconsistencies and some risky installation/usage recommendations you should understand before installing.

Purpose & Capability

The SKILL.md requires MEDIAPROC_HOST and MEDIAPROC_PORT and SSH access to a mediaproc instance, but the registry metadata lists no required env vars or credentials — that mismatch is incoherent. Otherwise the commands and wrapper script align with the stated media-processing purpose.

Instruction Scope

Runtime instructions allow uploading files and running arbitrary media commands on a remote container via SSH, which is consistent with the purpose. However the wrapper uses ssh with StrictHostKeyChecking=accept-new (automatic acceptance of new host keys), which raises MITM risk. The instructions also point users to running an install script that provisions SSH keys and a local mediaproc host; those setup directions increase the attack surface if the remote image or install script is untrusted.

Install Mechanism

There is no formal install spec in the registry, but references/setup.md tells users to run curl -fsSL https://raw.githubusercontent.com/psyb0t/docker-mediaproc/main/install.sh | sudo bash. Piping a remote script to sudo bash is a high-risk recommendation even when hosted on GitHub raw; it can run arbitrary code as root. The skill itself doesn’t install code, but the provided setup guidance is risky.

Credentials

The skill does not declare required env vars in the registry metadata, yet both SKILL.md and scripts/mediaproc.sh require MEDIAPROC_HOST and MEDIAPROC_PORT. That inconsistency hides the fact that the agent/user must supply network endpoints and SSH access (and will expose file transfer through that channel). No API keys are requested, which is appropriate, but the missing declared env vars is misleading.

Persistence & Privilege

The skill is not always-enabled and does not request system-level privileges in the registry. The wrapper is a simple SSH proxy and does not modify other skills or agent config. Autonomous invocation is allowed (default) but that is normal behavior and not by itself a concern.

What to consider before installing

This skill appears to do what it says (run media tools inside a remote container over SSH), but there are some practical and security issues to consider before using it: - Environment mismatch: The registry metadata does not declare MEDIAPROC_HOST and MEDIAPROC_PORT, yet the script and SKILL.md require them. Expect to set these to point at a trusted mediaproc server you control. - SSH risks: The provided wrapper will automatically accept new host keys (StrictHostKeyChecking=accept-new). That simplifies first-time use but increases the risk of a man-in-the-middle attack. Prefer to verify host keys manually or use known_hosts management. - Install recommendation is risky: references/setup.md suggests piping a GitHub raw install.sh into sudo bash. Do NOT run that blind. Inspect the install.sh contents locally (git clone or curl to a file and review) before running, or build/run the container yourself. - Trust the remote host: Media and file uploads are sent to the mediaproc server; a compromised or malicious server can read/exfiltrate uploaded files or execute arbitrary commands. Only point MEDIAPROC_HOST at a host you control or fully trust. - Mitigations: review the install script, run the mediaproc container locally if possible, use an ephemeral SSH key restricted to the mediaproc instance, verify host keys, and avoid using sudo piping from the web. If you need stronger assurance, ask the publisher for signed releases or source code you can audit. If the publisher updates the registry metadata to declare the required env vars and removes or documents safer install steps (no sudo curl|bash), the incoherence and install risk would be resolved and my confidence would increase.

Locked-down media processing over SSH. Built on lockbox — no shell access, no injection, no bullshit.

For installation and deployment, see references/setup.md.

SSH Wrapper

Use scripts/mediaproc.sh for all commands. It handles host, port, and host key acceptance via MEDIAPROC_HOST and MEDIAPROC_PORT env vars.

scripts/mediaproc.sh <command> [args]
scripts/mediaproc.sh <command> < input_file
scripts/mediaproc.sh <command> > output_file

Media Tools

Command	Description
ffmpeg	Video/audio encoding, transcoding, filtering
ffprobe	Media file analysis
sox	Audio processing
soxi	Audio file info
convert	Image conversion/manipulation (ImageMagick)
identify	Image file info (ImageMagick)
magick	ImageMagick CLI

Upload, Process, Download

# Upload
scripts/mediaproc.sh "put input.mp4" < input.mp4

# Transcode
scripts/mediaproc.sh "ffmpeg -i /work/input.mp4 -c:v libx264 /work/output.mp4"

# Download result
scripts/mediaproc.sh "get output.mp4" > output.mp4

# Clean up
scripts/mediaproc.sh "remove-file input.mp4"
scripts/mediaproc.sh "remove-file output.mp4"

Video Operations

# Get video info as JSON
scripts/mediaproc.sh "ffprobe -v quiet -print_format json -show_format -show_streams /work/video.mp4"

# Apply frei0r glow effect
scripts/mediaproc.sh "ffmpeg -i /work/in.mp4 -vf frei0r=glow:0.5 /work/out.mp4"

# Extract audio from video
scripts/mediaproc.sh "ffmpeg -i /work/video.mp4 -vn -acodec libmp3lame /work/audio.mp3"

# Create thumbnail from video
scripts/mediaproc.sh "ffmpeg -i /work/video.mp4 -ss 00:00:05 -vframes 1 /work/thumb.jpg"

Audio Operations

# Convert audio format
scripts/mediaproc.sh "sox /work/input.wav /work/output.mp3"

# Get audio info
scripts/mediaproc.sh "soxi /work/audio.wav"

# Normalize audio
scripts/mediaproc.sh "sox /work/input.wav /work/output.wav norm"

Image Operations

# Resize image
scripts/mediaproc.sh "convert /work/input.png -resize 50% /work/output.png"

# Create thumbnail
scripts/mediaproc.sh "convert /work/input.jpg -thumbnail 200x200 /work/thumb.jpg"

# Get image info
scripts/mediaproc.sh "identify /work/image.png"

File Operations

All paths relative to the work directory. Traversal blocked.

Command	Description
put <path>	Upload file from stdin
get <path>	Download file to stdout
list-files [--json]	List directory
remove-file <path>	Delete a file
create-dir <path>	Create directory
remove-dir <path>	Remove empty directory
remove-dir-recursive <path>	Remove directory recursively
move-file <src> <dst>	Move or rename
copy-file <src> <dst>	Copy a file
file-info <path>	Get file metadata as JSON
file-exists <path>	Check if file exists (true/false)
file-hash <path>	Get SHA256 hash
disk-usage [path]	Get bytes used
search-files <glob>	Glob search
append-file <path>	Append stdin to a file

# List files
scripts/mediaproc.sh "list-files"

# List as JSON (size, modified, isDir, permissions)
scripts/mediaproc.sh "list-files --json"

# List subdirectory
scripts/mediaproc.sh "list-files project1"

# File operations
scripts/mediaproc.sh "create-dir project1"
scripts/mediaproc.sh "move-file old.mp4 new.mp4"
scripts/mediaproc.sh "copy-file input.mp4 backup.mp4"
scripts/mediaproc.sh "file-info video.mp4"
scripts/mediaproc.sh "file-exists video.mp4"
scripts/mediaproc.sh "file-hash video.mp4"
scripts/mediaproc.sh "search-files '*.mp4'"
scripts/mediaproc.sh "disk-usage"
scripts/mediaproc.sh "remove-dir-recursive project1"

Plugins

• frei0r — Video effect plugins (used via -vf frei0r=...)
• LADSPA — Audio effect plugins: SWH, TAP, CMT (used via -af ladspa=...)
• LV2 — Audio plugins (used via -af lv2=...)

Fonts

2200+ fonts included covering emoji, CJK, Arabic, Thai, Indic, monospace, and more. Custom fonts can be mounted to /usr/share/fonts/custom.