1 files changed, 91 insertions, 0 deletions
diff --git a/contrib/scripts/chapters-to-tracks.sh b/contrib/scripts/chapters-to-tracks.sh
new file mode 100755
index 000000000..f1b84d0f2
--- /dev/null
+++ b/contrib/scripts/chapters-to-tracks.sh
@@ -0,0 +1,91 @@
+#!/usr/bin/env bash
+
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Copyright (C) 2022-2022  kcgen <kcgen@users.noreply.github.com>
+
+# Bash strict-mode
+set -euo pipefail
+IFS=$'\n\t'
+
+print_usage() {
+    local script="${0##*/}"
+    echo ""
+    echo "usage: $script URI [URI [...]]"
+    echo
+    echo "Convert a YouTube video with chapters into CD-DA tracks."
+    echo " - Multiple videos can be provided; each will be converted."
+    echo " - URIs can be the full https:// URL or just the identifier."
+    echo ""
+    echo "Depends on:"
+    echo " - yt-dlp (install with pip3 install yt-dlp)"
+    echo " - ffmpeg, and GNU find and sort: install with package manager"
+    echo ""
+}
+
+main() {
+    case ${1:--help} in
+    -h | -help | --help) print_usage ;;
+    *)
+        check-dependencies
+        convert-chapters-to-tracks "$@"
+        ;;
+    esac
+}
+
+check-dependencies() {
+    local missing_deps=0
+    for dep in yt-dlp ffmpeg find sort rm; do
+        if ! command -v "$dep" &>/dev/null; then
+            echo "Missing dependency: $dep could not be found in the PATH"
+            ((missing_deps++))
+        fi
+    done
+    # Were any missing?
+    if [[ $missing_deps -gt 0 ]]; then
+        echo "Install the above programs and try again"
+        exit 1
+    fi
+}
+
+download-chapters-from-uri() {
+    # YouTube Opus format identifiers in order of quality
+    local webm_formats="338/251/250/249"
+
+    # Directory/##-Track output layout
+    local cdda_ouput="chapter:%(title)s/%(section_number)02d-%(section_title)s.%(ext)s"
+
+    # Fetch the track and split it on chapters
+    yt-dlp \
+        --split-chapters \
+        --restrict-filenames \
+        --format "$webm_formats" \
+        --output "$cdda_ouput" \
+        "$uri" || true
+}
+
+extract-opus-from-webm() {
+    local opus="${webm%.webm}.opus"
+
+    ffmpeg \
+        -hide_banner \
+        -loglevel error \
+        -i "$webm" \
+        -vn -acodec copy "$opus"
+
+    # Delete the WebM source if we've got the Opus
+    if [[ -f $opus ]]; then
+        rm "$webm"
+    fi
+}
+
+convert-chapters-to-tracks() {
+    for uri in "$@"; do
+        download-chapters-from-uri
+    done
+    for webm in $(find . -maxdepth 2 -mindepth 2 -name '*.webm' | sort || true); do
+        extract-opus-from-webm
+    done
+}
+
+main "$@"