video-download

name	video-download
description	Download online videos with yt-dlp for CLI-WeChat-Bridge and send them back to WeChat as local video attachments. Use when the user asks to download, save, fetch, or send a video from Bilibili, YouTube, X/Twitter, or another yt-dlp supported URL.

Video Download

Use this skill when the user wants a remote video downloaded and sent back through CLI-WeChat-Bridge.

Bridge-Specific Rule

For CLI-WeChat-Bridge, the final reply must end with a wechat-attachments block:

video /root/meidia/example.mp4

Do not put the video path in a plain sentence. Do not use a URL in the attachment block. The path must be an absolute local path to a real file.

Workflow

1. Create the output directory:

mkdir -p "$HOME/meidia"

2. Download the URL with yt-dlp into ~/meidia.

Prefer the bundled helper if available:

helper="$(find "$HOME" -path '*/skills/video-download/scripts/download-video.sh' -print -quit)"
"$helper" "https://example.com/video"

The helper runs yt-dlp directly. If yt-dlp, ffmpeg, or ffprobe is missing, it calls the bundled install-video-tools.sh script. That installer detects the container CPU architecture and libc, then downloads upstream release binaries from:

• yt-dlp/yt-dlp latest release
• BtbN/FFmpeg-Builds latest release

On ARM64 Linux Docker, it uses yt-dlp_linux_aarch64 or yt-dlp_musllinux_aarch64, and ffmpeg-master-latest-linuxarm64-gpl.tar.xz.

If running manually, use this pattern:

yt-dlp --merge-output-format mp4 -o "$HOME/meidia/%(extractor)s_%(id)s.%(ext)s" "VIDEO_URL"

For Bilibili 1080p, login cookies may be required. If the user sends cookies, save them to:

mkdir -p "$HOME/.config/cli-wechat-bridge/cookies"
chmod 700 "$HOME/.config/cli-wechat-bridge/cookies"
cat > "$HOME/.config/cli-wechat-bridge/cookies/bilibili.txt"
chmod 600 "$HOME/.config/cli-wechat-bridge/cookies/bilibili.txt"

The helper automatically uses that cookie file. It requests up to 1080p, prefers H.264 when available, and transcodes the final file to H.264/AAC MP4 if the downloaded video is not H.264/H.265 or the audio is not AAC.

3. Verify the resulting file exists and is non-empty:

ls -lh "$HOME/meidia"

4. Reply with a short note and exactly one trailing attachment block:

video /absolute/path/to/downloaded.mp4

Do not run rm on the attachment file before returning the final reply. CLI-WeChat-Bridge needs the file to still exist while it uploads the attachment.

Notes

• In Docker, $HOME is normally /root, so ~/meidia becomes /root/meidia.
• Use .mp4 when possible because WeChat video upload is most reliable with MP4.
• If yt-dlp is not installed, run the bundled installer first; do not fall back to sending a remote video URL unless the user explicitly allows a link.
• Files up to 300MB are within the bridge's default video limit. Do not tell the AI to shrink or transcode just to reduce size unless the final file exceeds 300MB or the codec/container is not WeChat-friendly.
• Files sent from ~/meidia are cleaned up by the bridge after a successful WeChat upload. The helper also deletes the original pre-transcode file when it creates a .wechat.mp4 replacement.