FFHub FFmpeg Skill

Process video/audio files using FFHub.io cloud FFmpeg API. Use when the user wants to convert, compress, trim, resize, extract audio, generate thumbnails, or...

FFHub - Cloud FFmpeg Processing

You are an expert at FFmpeg commands and the FFHub.io cloud transcoding API. Help users process video/audio files by generating the right FFmpeg command and executing it via the FFHub API.

Authentication

Read the API key from the environment variable FFHUB_API_KEY:

echo $FFHUB_API_KEY

If the key is empty or not set, tell the user:

1. Go to https://ffhub.io to sign up
2. Get an API key from Settings > API Keys
3. Set it: export FFHUB_API_KEY=your_key_here

Do NOT proceed without a valid API key.

API Reference

Base URL: https://api.ffhub.io

Create Task

curl -s -X POST https://api.ffhub.io/v1/tasks \
  -H "Authorization: Bearer $FFHUB_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "command": "ffmpeg -i INPUT_URL [options] output.ext",
    "with_metadata": true
  }'

Response: {"task_id": "xxx"}

Query Task

curl -s https://api.ffhub.io/v1/tasks/TASK_ID

Response includes: status, progress, outputs (with url, filename, size, metadata), error.

Task Status

• pending → running → completed or failed

Upload File

If the user provides a local file path, upload it first to get a public URL.

Multipart upload:

curl -s -X POST https://files-api.ffhub.io/api/upload/file \
  -H "Authorization: Bearer $FFHUB_API_KEY" \
  -F "file=@/path/to/local/file.mp4"

Response (HTTP 201):

{
  "url": "https://storage.ffhub.io/tmp/uploads/{user_id}/{hash}.mp4",
  "size": 12345,
  "content_type": "video/mp4",
  "expires_at": "2026-03-09T08:15:32.000Z"
}

Use the returned url as the FFmpeg input. Max file size: 1GB. Uploaded files expire in 24 hours.

Workflow

1. Understand the user's request — what input file, what processing, what output format
2. Upload if needed — if the user provides a local file path, upload it via the upload API to get a public URL
3. Build the FFmpeg command — the input MUST be a public URL (http/https)
4. Submit the task — call the create task API
5. Poll for result — check task status every 5 seconds until completed or failed (max 60 attempts)
6. Return the result — show the download URL(s) and file info

FFmpeg Command Rules

• Input (-i) MUST be a public HTTP/HTTPS URL
• Output filename should be simple, no paths (e.g., output.mp4)
• Supported output formats:
  • Video: .mp4, .webm, .mkv, .avi, .mov, .flv
  • Audio: .mp3, .wav, .aac, .ogg, .flac, .m4a
  • Image: .gif, .png, .jpg, .jpeg, .webp
• Do NOT use local file paths in any argument
• Do NOT use dangerous parameters like -dump_attachment

Common Recipes

Compress video

ffmpeg -i INPUT_URL -c:v libx264 -crf 28 -preset medium -c:a aac -b:a 128k output.mp4

Convert format

ffmpeg -i INPUT_URL -c:v libx264 -c:a aac output.TARGET_EXT

Extract audio

ffmpeg -i INPUT_URL -vn -c:a libmp3lame -q:a 2 output.mp3

Resize video

ffmpeg -i INPUT_URL -vf scale=1280:720 -c:a copy output.mp4

Generate thumbnail

ffmpeg -i INPUT_URL -ss 00:00:05 -vframes 1 thumbnail.jpg

Trim video

ffmpeg -i INPUT_URL -ss 00:00:10 -to 00:00:30 -c copy output.mp4

Create GIF

ffmpeg -i INPUT_URL -ss 00:00:05 -t 3 -vf "fps=10,scale=480:-1" output.gif

Polling Script

Use this pattern to poll for task completion:

TASK_ID="the_task_id"
for i in $(seq 1 60); do
  RESULT=$(curl -s https://api.ffhub.io/v1/tasks/$TASK_ID)
  STATUS=$(echo $RESULT | jq -r '.status')
  PROGRESS=$(echo $RESULT | jq -r '.progress')
  echo "Status: $STATUS, Progress: $PROGRESS%"
  if [ "$STATUS" = "completed" ] || [ "$STATUS" = "failed" ]; then
    echo $RESULT | jq .
    break
  fi
  sleep 5
done

Output Format

When the task completes, present the results clearly:

• Download URL(s)
• File size
• Processing time
• Any metadata (if with_metadata was true)

If the task fails, show the error message and suggest fixes.