Learn English by Douyin

URL patterns that indicate Chinese short videos:

• v.douyin.com/*, douyin.com/*
• tiktok.com/*
• bilibili.com/*, b23.tv/*

Key rule: If the user shares a link from any of the above platforms and mentions translation in ANY form, use this skill — not video-summarizer.

Output Structure

All output is saved to output/<video-title>/ in the workspace:

output/<video-title>/
├── original.mp4           # Original video (copied/downloaded)
└── translated.mp4         # English subtitles + English voiceover

Intermediate files (audio, SRT files, TTS clips) are created in a system temp directory (mktemp -d). Do NOT manually delete them — macOS automatically cleans /tmp periodically (~3 days). Keeping temp files allows quick iteration (re-translate, adjust TTS, etc.) without re-running expensive steps like transcription.

Execution Workflow

Step 1: Install Dependencies

bash "$SKILL_DIR/scripts/install_deps.sh"

This checks and installs: yt-dlp, ffmpeg, uv (Python package manager).

Step 2: Download or Locate Video

If the user provides a URL:

# Create output directory
mkdir -p "output/<video-title>"

# Download with yt-dlp
yt-dlp -f "bestvideo[ext=mp4]+bestaudio[ext=m4a]/best[ext=mp4]/best" \
  --merge-output-format mp4 \
  -o "output/<video-title>/original.mp4" \
  "<video-url>"

If the user provides a local file:

cp "<local-video-path>" "output/<video-title>/original.mp4"

Step 3: Transcribe Chinese Audio

First, extract audio from the video:

TMPDIR=$(mktemp -d)
ffmpeg -y -i "output/<video-title>/original.mp4" -vn -acodec pcm_s16le -ar 16000 -ac 1 "$TMPDIR/audio.wav"

Then run the transcription script:

uv run "$SKILL_DIR/scripts/parallel_transcribe.py" \
  --input "$TMPDIR/audio.wav" \
  --output "$TMPDIR/chinese.srt" \
  --model small \
  --language zh

This outputs a Chinese SRT file with timestamps.

Step 4: Translate to English (Agent Task)

This step is performed by the Agent (you), NOT by a script.

Read the Chinese SRT file and translate each subtitle entry to English. Follow the guidelines in $SKILL_DIR/references/translation-guidelines.md.

Key rules:

• Keep the SRT index numbers and timestamps exactly the same
• Translate each Chinese text line to natural, spoken English
• Keep translations concise to fit the time window
• Use colloquial English suitable for language learners
• Preserve the speaker's tone and intent
• For internet slang/memes, find equivalent English expressions or explain briefly
• Keep Chinese names in pinyin (e.g., 哪吒 → Nezha)

Example transformation:

Input (chinese.srt):
1