From 615079070a5521c26b5864b4f5560f02c7cd63a3 Mon Sep 17 00:00:00 2001
From: Elias Schriefer <elischriefer@gmail.com>
Date: Fri, 12 Apr 2024 18:04:43 +0200
Subject: [PATCH] Add script and config

---
 ffmpeg-mka-thumbnailer | 102 +++++++++++++++++++++++++++++++++++++++++
 ffmpeg-mka.thumbnailer |   4 ++
 2 files changed, 106 insertions(+)
 create mode 100755 ffmpeg-mka-thumbnailer
 create mode 100644 ffmpeg-mka.thumbnailer

diff --git a/ffmpeg-mka-thumbnailer b/ffmpeg-mka-thumbnailer
new file mode 100755
index 0000000..2bec0bb
--- /dev/null
+++ b/ffmpeg-mka-thumbnailer
@@ -0,0 +1,102 @@
+#!/usr/bin/zsh
+
+help_args=(-h --help)
+if [[ "${@:*help_args}" != "" ]] {
+    cat <<-END
+		ffmpeg-mka-thumbnailer
+		Extract album cover art from Matroska audio files (.mka)
+
+		Usage:
+		  ffmpeg-mka-thumbnailer [OPTIONS] -i <INPUT FILE> -o <OUTPUT FILE>
+
+		Options:
+		  -h, --help		Show this help text
+		  -i <INPUT FILE>	Matroska audio file to read
+		  -o <OUTPUT FILE>	Where to write the output
+		  -s <SIZE>			Not implemented yet
+	END
+    exit 1
+}
+
+required_args=(-i -o)
+if [[ "${==${(o)@:*required_args}}" != "-i -o" ]] {
+    supplied_args=("${@:*required_args}")
+    for p ("${(@)required_args:|supplied_args}") {
+        echo "Missing argument $p" >&2
+    }
+    exit 1
+}
+
+input=
+output=
+
+while [[ $# -gt 0 ]] {
+    case "$1" {
+        -i)
+            input="$2"
+            shift
+            ;;
+        -o)
+            output="$2"
+            shift
+            ;;
+        -s)
+            echo "-s is not implemented yet" >&2
+            exit 1
+            ;;
+        *)
+            echo "Unrecognized option $1" >&2
+            exit 1
+            ;;
+    }
+
+    shift
+}
+
+if [[ ! (-r "$input" && -f "$input") ]] {
+    echo "Input $input is not a readable file" >&2
+    exit 1
+}
+
+dir="$(dirname "$output")"
+if [[ ! (-d "$dir" && -w "$dir") ]] {
+    echo "Output $output is not under a writable directory" >&2
+    exit 1
+}
+
+attachment_streams="$(ffprobe -of json -v error -select_streams t -show_streams "$input" | jq -c)"
+
+if [[ "$(echo -n "$attachment_streams" | jq ".streams | length")" -lt 1 ]] {
+    echo "Input does not have any attachment streams" >&2
+    exit 1
+}
+
+attachment_filename="$(echo -n "$attachment_streams" | jq -r '[.streams[] | select((.tags.filename | (startswith("cover") or startswith("small_cover"))) and (.tags.mimetype | startswith("image/")))] | sort_by(.index) | first | .tags.filename | strings')"
+
+if [[ "$attachment_filename" = "" ]] {
+    echo "No suitable attachment found" >&2
+    exit 1
+}
+
+prev_pwd="$(pwd)"
+tmpdir="$(mktemp -d)"
+tmpdir_success=$?
+if [[ $tmpdir_success -ne 0 ]] {
+    echo "Could not create temporary directory" >&2
+    exit 1
+} else {
+    cd "$tmpdir"
+}
+
+return_code=0
+repeat 1 {
+    ffmpeg -v error -dump_attachment:t "$attachment_filename" -f matroska -i "$input" -t 0 -f null null || { return_code=$?; break }
+    if [[ "${attachment_filename##*.}" = "${output##*.}" || ("${attachment_filename##*.}" =~ ^jpe?g$ && "${output##*.}" =~ ^jpe?g$) ]] {
+        mv "$attachment_filename" "$output"
+    } else {
+        convert "$attachment_filename" "$output" || { return_code=$?; break }
+    }
+}
+cd "$prev_pwd"
+rm -rf "$tmpdir"
+exit $return_code
diff --git a/ffmpeg-mka.thumbnailer b/ffmpeg-mka.thumbnailer
new file mode 100644
index 0000000..82924f8
--- /dev/null
+++ b/ffmpeg-mka.thumbnailer
@@ -0,0 +1,4 @@
+[Thumbnailer Entry]
+TryExec=ffmpeg-mka-thumbnailer
+Exec=ffmpeg-mka-thumbnailer -i %i -o %o
+MimeType=audio/x-matroska;