Adding a file handling snes spc music files.

Also update emms random album mechanism to assign low weight to the
discovery directory

1 files changed, 144 insertions, 0 deletions

diff --git a/emacs/.emacs.d/lisp/my/my-spc.el b/emacs/.emacs.d/lisp/my/my-spc.el
new file mode 100644
index 0000000..a6ecab3
--- /dev/null
+++ b/emacs/.emacs.d/lisp/my/my-spc.el
@@ -0,0 +1,144 @@
+;;; my-spc.el -- handling spc files -*- lexical-binding: t -*-
+
+;; Copyright (C) 2023 Free Software Foundation.
+
+;; Author: Yuchen Pei <id@ypei.org>
+;;         Warren Wilkinson <warrenwilkinson@gmail.com>
+;; Maintainer: Yuchen Pei <id@ypei.org>
+;; Package-Requires: ((emacs "28"))
+
+;; This file is part of dotted.
+
+;; dotted is free software: you can redistribute it and/or modify it under
+;; the terms of the GNU Affero General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; dotted is distributed in the hope that it will be useful, but WITHOUT
+;; ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+;; or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General
+;; Public License for more details.
+
+;; You should have received a copy of the GNU Affero General Public
+;; License along with dotted.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; handling spc files.
+
+;;; Code:
+
+(require 'bindat)
+
+(defconst my-spc--id666-magic-array
+  [#x53 #x4e #x45 #x53 #x2d #x53 #x50#x43 #x37 #x30 #x30 #x20 #x53 #x6f #x75 #x6e #x64 #x20 #x46 #x69 #x6c #x65 #x20 #x44 #x61 #x74 #x61 #x20 #x76 #x30 #x2e #x33 #x30]
+  "id666 header magic pattern `SNES-SPC700 Sound File Data v0.30'")
+
+(defconst my-spc--id666-header-bindat-spec
+  '((file-identifier vec 33)
+    (eval (unless (equal last my-spc--id666-magic-array)
+            (error "id666 framing mismatch: expected `%s', got `%s'"
+                   my-spc--id666-magic-array
+                   last)))
+    (unused u16)
+    (has-id666 u8)
+    (revision u8)
+    (pc-reg u16)
+    (a-reg u8)
+    (x-reg u8)
+    (y-reg u8)
+    (psw-reg u8)
+    (sp-reg u8)
+    (res-reg u16)
+    (song-title strz 32)
+    (game-title strz 32)
+    (dumper strz 16)
+    (comment strz 32)
+    (date strz 11)
+    (fadeout vec 3)
+    (fadeout-length vec 5)
+    (artist strz 32))
+  "id666 header specification.
+
+Sources:
+
+- URL `https://ocremix.org/info/SPC_Format_Specification'
+- URL `https://picard-docs.musicbrainz.org/en/appendices/tag_mapping.html'")
+
+(defun my-spc--decode-id666-header (filename)
+  "Read and decode id666 header from FILENAME."
+  (with-temp-buffer
+    (set-buffer-multibyte nil)
+    (insert-file-contents-literally filename nil 0 210)
+    (bindat-unpack my-spc--id666-header-bindat-spec
+                   (buffer-string))))
+
+(defun my-spc-decode-id666 (filename)
+  "Read and decode id666 metadata from FILENAME.
+Return metadata in a list of (FIELD . VALUE) cons cells, or nil
+in case of errors or if there were no known fields in FILENAME."
+  (condition-case nil
+      (let ((header (my-spc--decode-id666-header filename)))
+        (when (= 26 (bindat-get-field header 'has-id666))
+          `(
+            (title . ,(bindat-get-field header 'song-title))
+            (album . ,(bindat-get-field header 'game-title))
+            (artist . ,(bindat-get-field header 'artist))
+            (comment . ,(bindat-get-field header 'comment))
+            (dumper . ,(bindat-get-field header 'dumper))
+            (date . ,(bindat-get-field header 'date))
+            (fadeout . ,(bindat-get-field header 'fadeout))
+            (fadeout-length . ,(bindat-get-field header 'fadeout))
+            (extension . ,(file-name-extension filename))
+            (number . ,(replace-regexp-in-string
+                        "[^-]+-" ""
+                        (file-name-base filename)))
+            )))
+    (error nil)))
+
+(defun my-spc-format-file-name (file)
+  "Format a filename from an spc FILE.
+
+artist/album/title (note).extension"
+  (when-let* ((metadata (my-spc-decode-id666 file))
+              (artist (alist-get 'artist metadata))
+              (album (alist-get 'album metadata))
+              (title (alist-get 'title metadata))
+              (extension (alist-get 'extension metadata))
+              (number (alist-get 'number metadata)))
+    (if (or (string-empty-p artist)
+            (string-empty-p album)
+            (string-empty-p title)
+            (string-empty-p extension)
+            (string-empty-p number))
+        nil
+      (format "%s/%s/%s %s.%s" artist album number title extension))))
+
+(defun my-spc-file-rename (dir)
+  "Rename all spc files under DIR using dired."
+  (let ((pairs
+         (seq-filter
+          'cdr
+          (mapcar
+           (lambda (file)
+             (cons (expand-file-name file)
+                   (format "%s/%s"
+                           (expand-file-name my-audio-incoming-dir)
+                           (my-spc-format-file-name file))))
+           (directory-files-recursively dir "\\`.*\\.spc\\'")))))
+    (when (y-or-n-p
+           (print
+            (format
+             "Will do the following renaming: %s\nContinue?"
+             (string-join
+              (mapcar (lambda (pair)
+                        (format "%s -> %s" (car pair) (cdr pair)))
+                      pairs)
+              "\n"))))
+      (mapc
+       (lambda (pair)
+         (dired-rename-file (car pair) (cdr pair) t))
+       pairs))))
+
+(provide 'my-spc)
+;;; my-spc.el ends here