diff options
| -rw-r--r-- | emms-info-native.el | 150 |
1 files changed, 73 insertions, 77 deletions
diff --git a/emms-info-native.el b/emms-info-native.el index 91b3ff5..e0b3906 100644 --- a/emms-info-native.el +++ b/emms-info-native.el @@ -223,10 +223,39 @@ exhaustion in case of garbled or malicious inputs. This limit is used with Opus and FLAC streams as well, since their comments have almost the same format as Vorbis.") +(defconst emms-info-native--accepted-vorbis-fields + '("album" + "albumartist" + "albumartistsort" + "albumsort" + "artist" + "artistsort" + "composer" + "composersort" + "date" + "discnumber" + "genre" + "label" + "originaldate" + "originalyear" + "performer" + "title" + "titlesort" + "tracknumber" + "year") + "Emms info fields that are extracted from Vorbis comments.") + (defconst emms-info-native--vorbis-magic-array [118 111 114 98 105 115] "Header packet magic pattern ‘vorbis’.") +(defconst emms-info-native--vorbis-headers-bindat-spec + '((identification-header struct emms-info-native--vorbis-identification-header-bindat-spec) + (comment-header struct emms-info-native--vorbis-comment-header-bindat-spec)) + "Specification for first two Vorbis header packets. +They are always an identification header followed by a comment +header.") + (defconst emms-info-native--vorbis-identification-header-bindat-spec '((packet-type u8) (eval (unless (= last 1) @@ -287,35 +316,6 @@ their comments have almost the same format as Vorbis.") (user-comment vec (length))) "Vorbis comment field specification.") -(defconst emms-info-native--vorbis-headers-bindat-spec - '((identification-header struct emms-info-native--vorbis-identification-header-bindat-spec) - (comment-header struct emms-info-native--vorbis-comment-header-bindat-spec)) - "Specification for first two Vorbis header packets. -They are always an identification header followed by a comment -header.") - -(defconst emms-info-native--accepted-vorbis-fields - '("album" - "albumartist" - "albumartistsort" - "albumsort" - "artist" - "artistsort" - "composer" - "composersort" - "date" - "discnumber" - "genre" - "label" - "originaldate" - "originalyear" - "performer" - "title" - "titlesort" - "tracknumber" - "year") - "Emms info fields that are extracted from Vorbis comments.") - (defun emms-info-native--extract-vorbis-comments (user-comments) "Return a decoded list of comments from USER-COMMENTS. USER-COMMENTS should be a list of Vorbis comments according to @@ -369,11 +369,12 @@ outside itself.") [79 112 117 115 84 97 103 115] "Opus comment header magic pattern ‘OpusTags’.") -(defconst emms-info-native--opus-channel-mapping-table - '((stream-count u8) - (coupled-count u8) - (channel-mapping vec (eval emms-info-native--opus-channel-count))) - "Opus channel mapping table specification.") +(defconst emms-info-native--opus-headers-bindat-spec + '((identification-header struct emms-info-native--opus-identification-header-bindat-spec) + (comment-header struct emms-info-native--opus-comment-header-bindat-spec)) + "Specification for two first Opus header packets. +They are always an identification header followed by a comment +header.") (defconst emms-info-native--opus-identification-header-bindat-spec '((opus-head vec 8) @@ -396,6 +397,12 @@ outside itself.") (t (struct emms-info-native--opus-channel-mapping-table)))) "Opus identification header specification.") +(defconst emms-info-native--opus-channel-mapping-table + '((stream-count u8) + (coupled-count u8) + (channel-mapping vec (eval emms-info-native--opus-channel-count))) + "Opus channel mapping table specification.") + (defconst emms-info-native--opus-comment-header-bindat-spec '((opus-tags vec 8) (eval (unless (equal last emms-info-native--opus-tags-magic-array) @@ -415,13 +422,6 @@ outside itself.") (struct emms-info-native--vorbis-comment-field-bindat-spec))) "Opus comment header specification.") -(defconst emms-info-native--opus-headers-bindat-spec - '((identification-header struct emms-info-native--opus-identification-header-bindat-spec) - (comment-header struct emms-info-native--opus-comment-header-bindat-spec)) - "Specification for two first Opus header packets. -They are always an identification header followed by a comment -header.") - ;;;; FLAC code (defconst emms-info-native--flac-metadata-block-header-bindat-spec @@ -446,6 +446,20 @@ header.") (struct emms-info-native--vorbis-comment-field-bindat-spec))) "FLAC Vorbis comment block specification.") +(defun emms-info-native--decode-flac-comments (filename) + "Read and decode comments from FLAC file FILENAME. +Return comments in a list of (FIELD . VALUE) cons cells. Only +FIELDs that are listed in +‘emms-info-native--accepted-vorbis-fields’ are returned." + (unless (emms-info-native--has-flac-signature filename) + (error "Invalid FLAC stream")) + (let* ((block (emms-info-native--decode-flac-comment-block + filename)) + (unpacked (bindat-unpack emms-info-native--flac-comment-block-bindat-spec + block)) + (user-comments (bindat-get-field unpacked 'user-comments))) + (emms-info-native--extract-vorbis-comments user-comments))) + (defun emms-info-native--has-flac-signature (filename) "Check for FLAC stream marker at the beginning of FILENAME. Return t if there is a valid stream marker, nil otherwise." @@ -483,20 +497,6 @@ Return the comment block data in a vector." (setq offset end))) comment-block))) -(defun emms-info-native--decode-flac-comments (filename) - "Read and decode comments from FLAC file FILENAME. -Return comments in a list of (FIELD . VALUE) cons cells. Only -FIELDs that are listed in -‘emms-info-native--accepted-vorbis-fields’ are returned." - (unless (emms-info-native--has-flac-signature filename) - (error "Invalid FLAC stream")) - (let* ((block (emms-info-native--decode-flac-comment-block - filename)) - (unpacked (bindat-unpack emms-info-native--flac-comment-block-bindat-spec - block)) - (user-comments (bindat-get-field unpacked 'user-comments))) - (emms-info-native--extract-vorbis-comments user-comments))) - ;;;; id3v2 (MP3) code (defconst emms-info-native--id3v2-magic-array @@ -550,24 +550,6 @@ FIELDs that are listed in (3 . utf-8)) "id3v2 text encodings.") -(defun emms-info-native--checked-id3v2-size (bytes) - "Calculate id3v2 element size from BYTES and check its validity. -Return the size. Signal an error if the size exceeds -‘emms-info-native--max-peek-size’." - (let ((size (emms-info-native--decode-id3v2-size bytes))) - (when (or (= size 0) - (> size emms-info-native--max-peek-size)) - (error "id3v2 tag/header/frame size %s is invalid" bytes)) - size)) - -(defun emms-info-native--decode-id3v2-size (bytes) - "Decode id3v2 element size from BYTES. -BYTES are interpreted as 7-bit bytes, MSB first. Return the -size." - (apply '+ (seq-map-indexed (lambda (elt idx) - (* (expt 2 (* 7 idx)) elt)) - (reverse bytes)))) - (defun emms-info-native--decode-id3v2 (filename) "Read and decode id3v2 metadata from FILENAME. Return metadata in a list of (FIELD . VALUE) cons cells. See @@ -604,6 +586,22 @@ Return the size. Signal an error if the size exceeds (insert-file-contents-literally filename nil 10 14) (emms-info-native--checked-id3v2-size (buffer-string)))) +(defun emms-info-native--checked-id3v2-size (bytes) + "Calculate id3v2 element size from BYTES and check its validity. +Return the size." + (let ((size (emms-info-native--decode-id3v2-size bytes))) + (when (or (= size 0) (> size emms-info-native--max-peek-size)) + (error "id3v2 tag/header/frame size %s is invalid" bytes)) + size)) + +(defun emms-info-native--decode-id3v2-size (bytes) + "Decode id3v2 element size from BYTES. +BYTES are interpreted as 7-bit bytes, MSB first. Return the +size." + (apply '+ (seq-map-indexed (lambda (elt idx) + (* (expt 2 (* 7 idx)) elt)) + (reverse bytes)))) + (defun emms-info-native--decode-id3v2-frames (filename begin end) "Read and decode id3v2 text frames from FILENAME. BEGIN should be the offset of first byte after id3v2 header and @@ -625,8 +623,7 @@ Return metadata in a list of (FIELD . VALUE) cons cells. See (comment (emms-info-native--decode-id3v2-text-frame frame))) (when comment (push comment comments)) - (cl-incf offset (+ (bindat-get-field frame 'size) - 10)))) + (cl-incf offset (+ (bindat-get-field frame 'size) 10)))) (error nil)) comments))) @@ -639,8 +636,7 @@ identifier and VALUE is the decoded text. Otherwise return nil." (let ((info-id (emms-info-native--id3v2-frame-info-id frame)) (payload (bindat-get-field frame 'payload))) (when info-id - (cons info-id - (emms-info-native--decode-id3v2-string payload))))) + (cons info-id (emms-info-native--decode-id3v2-string payload))))) (defun emms-info-native--id3v2-frame-info-id (frame) "Return the emms-info identifier for FRAME. |