Youtube Guitar Tab Parser
CLI that turns a YouTube guitar-lesson video into a PDF of the guitar tab.
It downloads the video, samples frames, uses Claude vision to locate the tab
region, crops every frame to that region, de-duplicates the crops by the bar
number printed on each line of the score, and stitches the distinct tab lines
vertically into a PDF. It works out of the box with no configuration — the PDF
is written to out/<video-title>.pdf, with the video title as a heading on the
first page and in the document metadata.
Requirements
Node.js ≥ 20
yt-dlp and ffmpeg on your PATH
(brew install yt-dlp ffmpeg)
An Anthropic API key
Setup
Usage
During development you can skip the build step:
The result is written to out/<video-title>.pdf (its path is also printed to
stdout); progress goes to stderr.
Options
Everything has a sensible default; you normally only need the URL.
How it works
Download — yt-dlp fetches the video (≤ --max-height).
Frames — ffmpeg extracts one frame every --interval seconds.
Detect — a labeled horizontal-band grid is drawn on --sample frames and
Claude vision reports which bands contain sheet music. The median first/last
music band (robust to an outlier) gives the vertical extent; width is kept full.
(Coarse labeled bands are far more reliable than asking a vision model for
precise pixel coordinates.)
Crop — sharp crops every frame to that region.
Pre-dedup — a dHash perceptual hash drops near-identical consecutive crops.
This is only a cost control to reduce the number of vision calls in the next step.
Bar-number dedup — Claude reads the measure/bar number printed at the start
of each line and whether the crop is real sheet music. The tool keeps exactly
one crop per distinct bar number (first appearance wins) and drops non-tab
crops (title cards, intros/outros). Because the bar number is constant while
the playback cursor sweeps a line and only changes when the score advances,
this collapses all the near-identical cursor frames of a line into a single page.
PDF — pdf-lib stacks the distinct tab lines vertically down A4 pages,
in the order they appear in the video. The video title (read from yt-dlp)
becomes the file name, a heading on the first page, and the document metadata
title. Output: out/<video-title>.pdf.