| 1 | ;;; emms-info-native.el --- Native Emacs Lisp info method for EMMS -*- lexical-binding: t; -*- |
| 2 | |
| 3 | ;; Copyright (C) 2020-2023 Free Software Foundation, Inc. |
| 4 | |
| 5 | ;; Author: Petteri Hintsanen <petterih@iki.fi> |
| 6 | |
| 7 | ;; This file is part of EMMS. |
| 8 | |
| 9 | ;; EMMS is free software; you can redistribute it and/or modify it |
| 10 | ;; under the terms of the GNU General Public License as published by |
| 11 | ;; the Free Software Foundation; either version 3, or (at your option) |
| 12 | ;; any later version. |
| 13 | |
| 14 | ;; EMMS is distributed in the hope that it will be useful, but WITHOUT |
| 15 | ;; ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
| 16 | ;; or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public |
| 17 | ;; License for more details. |
| 18 | |
| 19 | ;; You should have received a copy of the GNU General Public License |
| 20 | ;; along with EMMS; see the file COPYING. If not, write to the Free |
| 21 | ;; Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, |
| 22 | ;; MA 02110-1301, USA. |
| 23 | |
| 24 | ;;; Commentary: |
| 25 | |
| 26 | ;; This file provides a native emms-info-method for EMMS. Here |
| 27 | ;; "native" means a pure Emacs Lisp implementation instead of one |
| 28 | ;; relying on external tools or libraries like |
| 29 | ;; `emms-info-native-ogginfo' or `emms-info-libtag'. |
| 30 | ;; |
| 31 | ;; To use this method, add `emms-info-native' to |
| 32 | ;; `emms-info-functions'. |
| 33 | ;; |
| 34 | ;; The following file formats are supported: |
| 35 | ;; |
| 36 | ;; - Vorbis: Ogg Vorbis I Profile, filename extension `.ogg', |
| 37 | ;; elementary streams only. |
| 38 | ;; |
| 39 | ;; - Opus: Ogg Opus profile, filename extension `.opus', elementary |
| 40 | ;; streams only. |
| 41 | ;; |
| 42 | ;; - FLAC streams in native encapsulation format, filename extension |
| 43 | ;; `.flac'. |
| 44 | ;; |
| 45 | ;; - MP3 files with extension `.mp3' and ID3v2 tags. All ID3v2 |
| 46 | ;; versions should work, but many features like compression and |
| 47 | ;; encryption are not supported. |
| 48 | ;; |
| 49 | ;; - SPC files with extension `.spc' and ID666 tags. This is an audio |
| 50 | ;; file based on a memory dump from an SPC700, a special audio chip |
| 51 | ;; found within Super Nintendos. |
| 52 | ;; |
| 53 | ;; Format detection is based solely on filename extension, which is |
| 54 | ;; matched case-insensitively. |
| 55 | |
| 56 | ;;; Code: |
| 57 | |
| 58 | (require 'emms-info) |
| 59 | (require 'emms-info-native-flac) |
| 60 | (require 'emms-info-native-ogg) |
| 61 | (require 'emms-info-native-mp3) |
| 62 | (require 'emms-info-native-spc) |
| 63 | |
| 64 | (defun emms-info-native (track) |
| 65 | "Set info fields for TRACK. |
| 66 | Supports Ogg Vorbis/Opus, FLAC, MP3 and SPC files." |
| 67 | (condition-case env |
| 68 | (let* ((filename |
| 69 | (emms-track-name track)) |
| 70 | (info-fields |
| 71 | (emms-info-native--decode-info-fields filename))) |
| 72 | (dolist (field info-fields) |
| 73 | (let ((name (intern (concat "info-" (car field)))) |
| 74 | (value (cdr field))) |
| 75 | (when (stringp value) |
| 76 | (setq value (string-trim-right value))) |
| 77 | (emms-track-set track name value)))) |
| 78 | (error (message "emms-info-native error processing %s: %s" |
| 79 | (emms-track-name track) env)))) |
| 80 | |
| 81 | (defun emms-info-native--decode-info-fields (filename) |
| 82 | "Decode info fields from FILENAME. |
| 83 | Return a list of (FIELD . VALUE) cons cells, where FIELD is an |
| 84 | info field and VALUE is the corresponding info value. Both are |
| 85 | strings." |
| 86 | (let ((stream-type (emms-info-native--find-stream-type filename))) |
| 87 | (cond ((or (eq stream-type 'vorbis) (eq stream-type 'opus)) |
| 88 | (emms-info-native-ogg-decode-metadata filename stream-type)) |
| 89 | ((eq stream-type 'flac) |
| 90 | (emms-info-native-flac-decode-metadata filename)) |
| 91 | ((eq stream-type 'mp3) |
| 92 | (emms-info-native-mp3-decode-metadata filename)) |
| 93 | ((eq stream-type 'spc) |
| 94 | (emms-info-native-spc-decode-id666 filename)) |
| 95 | (t nil)))) |
| 96 | |
| 97 | (defun emms-info-native--find-stream-type (filename) |
| 98 | "Deduce the stream type from FILENAME. |
| 99 | This is a naive implementation that relies solely on filename |
| 100 | extension. |
| 101 | |
| 102 | Return one of `vorbis', `opus', `flac', `mp3' or `spc', or nil if |
| 103 | the stream type cannot be deduced." |
| 104 | (let ((case-fold-search t)) |
| 105 | (cond ((string-match ".ogg$" filename) 'vorbis) |
| 106 | ((string-match ".opus$" filename) 'opus) |
| 107 | ((string-match ".flac$" filename) 'flac) |
| 108 | ((string-match ".mp3$" filename) 'mp3) |
| 109 | ((string-match ".spc$" filename) 'spc) |
| 110 | (t nil)))) |
| 111 | |
| 112 | (provide 'emms-info-native) |
| 113 | |
| 114 | ;;; emms-info-native.el ends here |