| name | youtube-fast-download |
| description | Download public YouTube videos or Shorts quickly with yt-dlp, always save an MP4 into raw_assets/videos/downloaded and a compatible MP3 audio file into raw_assets/audio/downloaded. Use when the user gives a YouTube URL and asks to download the video, get the audio, export MP3, or optimize the workflow for speed and low token usage. |
YouTube Fast Download
Core Rule
Prefer the bundled script instead of reconstructing long yt-dlp and ffmpeg commands in chat.
Always output both files for YouTube/Shorts downloads:
- MP4 video in
raw_assets/videos/downloaded/
- MP3 audio in
raw_assets/audio/downloaded/
.venv/bin/python skills/youtube-fast-download/scripts/download_youtube_fast.py \
"https://www.youtube.com/shorts/VIDEO_ID"
Workflow
- Use
yt-dlp from .venv when available; avoid installing anything unless the module is missing.
- Download best MP4-compatible output using fragment concurrency (
-N 16) and merge to MP4.
- Save video to
raw_assets/videos/downloaded/<id>_<title>.mp4.
- Always export MP3 to
raw_assets/audio/downloaded/<id>_<title>.mp3 with ffmpeg + libmp3lame.
- Verify output with
ffprobe only when the user needs confirmation or the downstream task depends on metadata.
Fast Paths
.venv/bin/python skills/youtube-fast-download/scripts/download_youtube_fast.py "<url>"
- Backward-compatible explicit MP3 flag:
.venv/bin/python skills/youtube-fast-download/scripts/download_youtube_fast.py "<url>" --mp3
- MP3 from an existing local video, without redownloading:
.venv/bin/python skills/youtube-fast-download/scripts/download_youtube_fast.py \
--from-video raw_assets/videos/downloaded/input.mp4
Defaults
- Video output dir:
raw_assets/videos/downloaded
- Audio output dir:
raw_assets/audio/downloaded
- Format:
bv*[ext=mp4]+ba[ext=m4a]/b[ext=mp4]/best
- Merge container:
mp4
- MP3 bitrate:
192k
- Fragment concurrency:
16
Do not print signed direct media URLs. Report only local file paths, duration, codec, size, and any important warning.
