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summarize slides

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summarize slides

summarize slides <url> [flags]

Extracts slide-shaped keyframes from a YouTube or direct video URL using ffmpeg scene detection. Output is a directory of PNGs (and optional OCR text). This is the standalone form of the --slides flag on the main command — useful when you only want the slides without a summary.

#Synopsis

summarize slides "https://youtu.be/..."
summarize slides "https://youtu.be/..." --render auto
summarize slides "https://youtu.be/..." --slides-ocr -o ./out
summarize slides "https://example.com/lecture.mp4" --slides-max 12

#Requirements

  • ffmpeg on PATH (scene detection + frame extraction).
  • yt-dlp on PATH for YouTube URLs.
  • tesseract on PATH for --slides-ocr.

If a tool is missing, summarize prints a clear warning and exits non-zero.

#Flags

--slides-ocr : Run OCR on every extracted slide. Saves a .txt next to each PNG.

--slides-dir <dir> : Output base directory. Default: ./slides. A per-video subfolder is created inside.

-o, --output <dir> : Alias for --slides-dir.

--slides-scene-threshold <value> : Scene detection threshold, 0.1–1.0. Default 0.3. Lower values detect more scenes (more slides); higher values are stricter.

--slides-max <count> : Cap on extracted slides. Default 6.

--slides-min-duration <seconds> : Minimum gap between slides. Default 2.

--render <mode> : Inline render of thumbnails: auto, kitty, iterm, none. Default none — paths are printed instead.

--theme <name> : Pick a CLI theme.

--timeout <duration> : Cap the download + extraction. Default 2m.

--no-cache : Force re-download and re-extraction (bypasses both caches).

--json : JSON envelope on stdout. Disables inline rendering.

--verbose / --debug : Detailed progress on stderr.

-V, --version : Print version and exit.

#Output

Each run writes a directory like:

slides/<video-id>/
  001.png
  002.png
  ...
  001.txt    # only with --slides-ocr

In --json mode, stdout is:

{
  "url": "...",
  "outDir": "slides/<id>",
  "slides": [{ "index": 1, "path": "...001.png", "timeSeconds": 18.6, "ocr": "..." }]
}

#Inline rendering

--render auto detects Kitty (KITTY_WINDOW_ID) and iTerm (TERM_PROGRAM=iTerm.app) and uses the matching image protocol. On unsupported terminals, slides are listed by path instead.

#Examples

# Quick preview in iTerm/Kitty.
summarize slides "https://youtu.be/..." --render auto

# Big lecture, more granular cuts.
summarize slides "https://youtu.be/..." \
  --slides-max 24 --slides-scene-threshold 0.2

# Pipe-friendly JSON for an automation.
summarize slides "https://youtu.be/..." --json | jq '.slides[].path'

# Force re-extraction after editing the source video.
summarize slides "./talk.mp4" --no-cache -o ./out

#See also