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- ;;; -*- Mode: Lisp; show-trailing-whitespace: t; Base: 10; indent-tabs: nil; Syntax: ANSI-Common-Lisp; Package: MP4-ATOM; -*-
- ;;; Copyright (c) 2013, Mark VandenBrink. All rights reserved.
- (in-package #:mp4-atom)
- (log5:defcategory cat-log-mp4-atom)
- (defmacro log-mp4-atom (&rest log-stuff) `(log5:log-for (cat-log-mp4-atom) ,@log-stuff))
- (define-condition mp4-atom-condition ()
- ((location :initarg :location :reader location :initform nil)
- (object :initarg :object :reader object :initform nil)
- (messsage :initarg :message :reader message :initform "Undefined Condition"))
- (:report (lambda (condition stream)
- (format stream "mp4-atom condition at location: <~a> with object: <~a>: message: <~a>"
- (location condition) (object condition) (message condition)))))
- (defmethod print-object ((me mp4-atom-condition) stream)
- (format stream "location: <~a>, object: <~a>, message: <~a>" (location me) (object me) (message me)))
- (defmethod as-string ((atom-type integer))
- "Given an integer representing an atom type, return the string form"
- (with-output-to-string (s nil)
- (write-char (code-char (ldb (byte 8 24) atom-type)) s)
- (write-char (code-char (ldb (byte 8 16) atom-type)) s)
- (write-char (code-char (ldb (byte 8 8) atom-type)) s)
- (write-char (code-char (ldb (byte 8 0) atom-type)) s)))
- (eval-when (:compile-toplevel :load-toplevel :execute)
- (defun as-octet (c)
- "Used below so that we can create atom 'types' from char/ints"
- (cond ((typep c 'standard-char) (coerce (char-code c) '(unsigned-byte 8)))
- ((typep c 'integer) (coerce c '(unsigned-byte 8)))
- (t (error "can any handle characters and integers"))))
- (defmacro mk-mp4-atom-type (l1 l2 l3 l4)
- "Given 4 chars/ints, create a 32-bit word representing an atom 'type' (aka name)"
- `(let ((retval 0))
- (setf (ldb (byte 8 24) retval) ,(as-octet l1))
- (setf (ldb (byte 8 16) retval) ,(as-octet l2))
- (setf (ldb (byte 8 8) retval) ,(as-octet l3))
- (setf (ldb (byte 8 0) retval) ,(as-octet l4))
- retval))
- (defconstant +m4-ftyp+ (mk-mp4-atom-type #\f #\t #\y #\p)
- "This should be the first atom type found in file")
- (defconstant +itunes-ilst-data+ (mk-mp4-atom-type #\d #\a #\t #\a)
- "Carries the actual data under an ilst atom")
- (defconstant +itunes-lyrics+ (mk-mp4-atom-type #xa9 #\l #\y #\r)) ; text
- (defconstant +itunes-copyright+ (mk-mp4-atom-type #\c #\p #\r #\t)) ; text
- (defconstant +itunes-album+ (mk-mp4-atom-type #xa9 #\a #\l #\b)) ; text
- (defconstant +itunes-artist+ (mk-mp4-atom-type #xa9 #\A #\R #\T)) ; text
- (defconstant +itunes-comment+ (mk-mp4-atom-type #xa9 #\c #\m #\t)) ; text
- (defconstant +itunes-compilation+ (mk-mp4-atom-type #\c #\p #\i #\l)) ; byte/boolean
- (defconstant +itunes-composer+ (mk-mp4-atom-type #xa9 #\c #\o #\m)) ; text
- (defconstant +itunes-cover-art+ (mk-mp4-atom-type #\c #\o #\v #\r)) ; octets
- (defconstant +itunes-year+ (mk-mp4-atom-type #xa9 #\d #\a #\y)) ; text
- (defconstant +itunes-disk+ (mk-mp4-atom-type #\d #\i #\s #\k)) ; octets
- (defconstant +itunes-tool+ (mk-mp4-atom-type #xa9 #\t #\o #\o)) ; text
- (defconstant +itunes-genre+ (mk-mp4-atom-type #\g #\n #\r #\e)) ; octet
- (defconstant +itunes-genre-x+ (mk-mp4-atom-type #xa9 #\n #\r #\e)) ; text
- (defconstant +itunes-groups+ (mk-mp4-atom-type #xa9 #\g #\r #\p)) ; text
- (defconstant +itunes-title+ (mk-mp4-atom-type #xa9 #\n #\a #\m)) ; text
- (defconstant +itunes-tempo+ (mk-mp4-atom-type #\t #\m #\p #\o)) ; octet
- (defconstant +itunes-track+ (mk-mp4-atom-type #xa9 #\t #\r #\k)) ; octet
- (defconstant +itunes-track-n+ (mk-mp4-atom-type #\t #\r #\k #\n)) ; octet
- (defconstant +itunes-writer+ (mk-mp4-atom-type #xa9 #\w #\r #\t)) ; text
- (defconstant +itunes-encoder+ (mk-mp4-atom-type #xa9 #\e #\n #\c)) ; text
- (defconstant +itunes-album-artist+ (mk-mp4-atom-type #\a #\A #\R #\T)) ; text
- (defconstant +itunes-purchased-date+ (mk-mp4-atom-type #\p #\u #\r #\d)) ; text
- (defparameter *itunes-text-atom-types*
- (list
- +itunes-album+
- +itunes-album-artist+
- +itunes-artist+
- +itunes-comment+
- +itunes-composer+
- +itunes-copyright+
- +itunes-year+
- +itunes-encoder+
- +itunes-groups+
- +itunes-genre-x+
- +itunes-lyrics+
- +itunes-purchased-date+
- +itunes-title+
- +itunes-tool+
- +itunes-writer+)
- "These are all the itunes atoms that are stored as text")
- (defparameter *itunes-atom-types*
- (append *itunes-text-atom-types*
- (list
- +itunes-compilation+
- +itunes-cover-art+
- +itunes-disk+
- +itunes-genre+
- +itunes-tempo+
- +itunes-track+
- +itunes-track-n+))
- "The iTunes atom types we can decode")
- (defconstant +mp4-atom-moov+ (mk-mp4-atom-type #\m #\o #\o #\v))
- (defconstant +mp4-atom-udta+ (mk-mp4-atom-type #\u #\d #\t #\a))
- (defconstant +mp4-atom-mdia+ (mk-mp4-atom-type #\m #\d #\i #\a))
- (defconstant +mp4-atom-meta+ (mk-mp4-atom-type #\m #\e #\t #\a))
- (defconstant +mp4-atom-ilst+ (mk-mp4-atom-type #\i #\l #\s #\t))
- (defparameter *atoms-of-interest*
- (list +mp4-atom-moov+
- +mp4-atom-udta+
- +mp4-atom-mdia+
- +mp4-atom-meta+
- +mp4-atom-ilst+)
- "For these container atoms, we look inside these atoms to read nested atoms")
- (defparameter *tag-path* (list +mp4-atom-moov+ +mp4-atom-udta+ +mp4-atom-meta+ +mp4-atom-ilst+)
- "The 'path' of nested atoms at which tag data can be found.")
- (defgeneric decode-ilst-data-atom (type atom atom-parent-type mp4-file))
- (defmacro generate-generic-text-methods ()
- "generate the decode methods for text atoms"
- (let ((methods))
- (dolist (type *itunes-text-atom-types*)
- (push `(defmethod decode-ilst-data-atom ((type (eql +itunes-ilst-data+)) atom (atom-parent-type (eql ,type)) mp4-file)
- (stream-read-string-with-len mp4-file (- (atom-size atom) 16))) methods))
- `(progn ,@methods)))
- )
- (generate-generic-text-methods)
- (defmethod decode-ilst-data-atom ((type (eql +itunes-ilst-data+)) atom (atom-parent-type (eql +itunes-disk+)) mp4-file)
- "decode itunes DISK atom"
- (declare (ignore atom))
- (stream-read-u16 mp4-file) ; throw away
- (let ((a) (b))
- (setf a (stream-read-u16 mp4-file))
- (setf b (stream-read-u16 mp4-file))
- (list a b)))
- (defmethod decode-ilst-data-atom ((type (eql +itunes-ilst-data+)) atom (atom-parent-type (eql +itunes-track+)) mp4-file)
- "decode itunes TRK atom"
- (declare (ignore atom))
- (stream-read-u16 mp4-file) ; throw away
- (let ((a) (b))
- (setf a (stream-read-u16 mp4-file))
- (setf b (stream-read-u16 mp4-file))
- (stream-read-u16 mp4-file) ; throw away
- (list a b)))
- (defmethod decode-ilst-data-atom ((type (eql +itunes-ilst-data+)) atom (atom-parent-type (eql +itunes-track-n+)) mp4-file)
- "decode itunes TRKN atom"
- (declare (ignore atom))
- (stream-read-u16 mp4-file) ; throw away
- (let ((a) (b))
- (setf a (stream-read-u16 mp4-file))
- (setf b (stream-read-u16 mp4-file))
- (stream-read-u16 mp4-file) ; throw away
- (list a b)))
- (defmethod decode-ilst-data-atom ((type (eql +itunes-ilst-data+)) atom (atom-parent-type (eql +itunes-tempo+)) mp4-file)
- "decode itunes TMPO atom"
- (declare (ignore atom))
- (stream-read-u16 mp4-file))
- (defmethod decode-ilst-data-atom ((type (eql +itunes-ilst-data+)) atom (atom-parent-type (eql +itunes-genre+)) mp4-file)
- "decode itunes GNRE atom"
- (declare (ignore atom))
- (stream-read-u16 mp4-file))
- (defmethod decode-ilst-data-atom ((type (eql +itunes-ilst-data+)) atom (atom-parent-type (eql +itunes-compilation+)) mp4-file)
- "decode itunes CPIL atom"
- (declare (ignore atom))
- (stream-read-u8 mp4-file))
- (defmethod decode-ilst-data-atom ((type (eql +itunes-ilst-data+)) atom (atom-parent-type (eql +itunes-cover-art+)) mp4-file)
- (let ((blob (make-instance 'mp4-unhandled-data)))
- (setf (slot-value blob 'blob) (stream-read-sequence mp4-file (- (atom-size atom) 16)))
- blob))
- (defclass mp4-atom ()
- ((atom-file-position :accessor atom-file-position :initarg :atom-file-position)
- (atom-size :accessor atom-size :initarg :atom-size)
- (atom-type :accessor atom-type :initarg :atom-type)
- (atom-children :accessor atom-children :initform (make-mp4-atom-collection)))
- (:documentation "The minimal mp4-atom. Note: not all atoms have children, but we put them here anyway to make things 'simple'"))
- (defclass mp4-ilst-atom (mp4-atom)
- ())
- (defmethod initialize-instance :after ((me mp4-ilst-atom) &key (mp4-file nil) &allow-other-keys)
- "Construct an ilst atom"
- (log5:with-context "mp4-ilst-atom-initializer"
- (assert (not (null mp4-file)) () "Must pass a stream into this method")
- (with-slots (atom-size atom-type atom-children) me
- (let* ((start (stream-seek mp4-file 0 :current))
- (end (+ start (- atom-size 8))))
- (log-mp4-atom "mp4-ilst-atom-initializer:entry, start = ~:d, end = ~:d" start end)
- (do* ()
- ((>= (stream-seek mp4-file 0 :current) end))
- (log-mp4-atom "ilst atom top of loop: start = ~:d, current = ~:d, end = ~:d"
- start (stream-seek mp4-file 0 :current) end)
- (let ((child (make-mp4-atom mp4-file atom-type)))
- (log-mp4-atom "adding new child ~a" (vpprint child nil))
- (add atom-children child)))))
- (log-mp4-atom "Returning ilst atom: ~a" (vpprint me nil))))
- (defclass mp4-ilst-generic-data-atom (mp4-atom)
- ((atom-version :accessor atom-version :initarg :atom-version)
- (atom-flags :accessor atom-flags :initarg :atom-flags)
- (atom-value :accessor atom-value :initarg :atom-value)
- (atom-parent-type :accessor atom-parent-type :initarg :atom-parent-type :initform nil))
- (:documentation "Represents the 'data' portion of ilst data atom"))
- (defmethod initialize-instance :after ((me mp4-ilst-generic-data-atom) &key mp4-file &allow-other-keys)
- (log5:with-context "mp4-ilst-generic-data-atom-initializer"
- (assert (not (null mp4-file)) () "Must pass a stream into this method")
- (log-mp4-atom "mp4-ilst-generic-data-atom-initializer:entry")
- (with-slots (atom-size atom-type atom-version atom-flags atom-value atom-parent-type) me
- (setf atom-version (stream-read-u8 mp4-file))
- (setf atom-flags (stream-read-u24 mp4-file))
- (if (= atom-type +itunes-ilst-data+)
- (assert (= 0 (stream-read-u32 mp4-file)) () "a data atom lacks the required null field"))
- (log-mp4-atom "size = ~:d, name = ~a, version = ~d, flags = ~x"
- atom-size (as-string atom-type) atom-version atom-flags)
- (setf atom-value (decode-ilst-data-atom atom-type me atom-parent-type mp4-file))
- (log-mp4-atom "generic atom: ~a" (vpprint me nil)))))
- (defclass mp4-container-atom (mp4-atom)
- ()
- (:documentation "The class representing an mp4 container atom"))
- (defmethod initialize-instance :after ((me mp4-container-atom) &key (mp4-file nil) &allow-other-keys)
- "Upon initializing a container mp4 atom, read the nested atoms within it.'"
- (log5:with-context "mp4-container-atom-initializer"
- (assert (not (null mp4-file)) () "Must pass a stream into this method")
- (log-mp4-atom "mp4-container-atom-initializer")
- (with-slots (atom-children atom-file-position atom-of-interest atom-size atom-type atom-decoded) me
- (log-mp4-atom "entry: starting file position = ~:d, atom ~a" atom-file-position (vpprint me nil))
- (log-mp4-atom "type ~a is container atom of interest; read the nested atoms" (as-string atom-type))
- (cond ((= atom-type +mp4-atom-meta+)
- (log-mp4-atom "got META, moving file position forward 4 bytes") ;null field
- (stream-seek mp4-file 4 :current)))
- ;; we are now at the file-position we are need to be at, so start reading those atoms!
- (block stream-read-file
- (log-mp4-atom "starting stream-read-file block with file-position = ~:d and end = ~:d" atom-file-position (+ atom-file-position atom-size))
- (do ()
- ((>= (stream-seek mp4-file 0 :current) (+ atom-file-position atom-size)))
- (log-mp4-atom "Top of loop: currently at file-position ~:d (reading up to ~:d)" (stream-seek mp4-file 0 :current) (+ atom-file-position atom-size))
- (let ((child (make-mp4-atom mp4-file)))
- (log-mp4-atom "adding new child ~a" (vpprint child nil))
- (add atom-children child))))
- (log-mp4-atom "ended stream-read-file block, file position now ~:d" (stream-seek mp4-file 0 :current)))))
- (defun make-mp4-atom (mp4-file &optional atom-parent-type)
- "Get current file position, read in size/type, then construct the correct atom.
- If type is an ilst type, read it all it. If it is a container atom of interest,
- leave file position as is, since caller will want to read in nested atoms. Otherwise,
- seek forward past end of this atom."
- (log5:with-context "make-mp4-atom"
- (let* ((pos (stream-seek mp4-file 0 :current))
- (siz (stream-read-u32 mp4-file))
- (typ (stream-read-u32 mp4-file))
- (atom))
- (declare (type integer pos siz typ))
- (when (= 0 siz)
- (warn "trying to make an atom ~a with size of 0 at offset ~:d in ~a, ammending size to be 8" (as-string typ) pos (stream-filename mp4-file))
- (setf siz 8))
- (log-mp4-atom "pos = ~:d, size = ~:d, type = ~a" pos siz (as-string typ))
- (cond ((member typ *atoms-of-interest*)
- (log-mp4-atom "~a is a container atom we are interested in" (as-string typ))
- (setf atom (make-instance 'mp4-container-atom :atom-size siz :atom-type typ :atom-file-position pos :mp4-file mp4-file)))
- ((member typ *itunes-atom-types*)
- (log-mp4-atom "~a is an ilst atom, read it all in" (as-string typ))
- (setf atom (make-instance 'mp4-ilst-atom :atom-size siz :atom-type typ :atom-file-position pos :mp4-file mp4-file)))
- ((= typ +itunes-ilst-data+)
- (log-mp4-atom "~a is an ilst data atom, read it all in" (as-string typ))
- (setf atom (make-instance 'mp4-ilst-generic-data-atom :atom-parent-type atom-parent-type :atom-size siz :atom-type typ :atom-file-position pos :mp4-file mp4-file)))
- (t
- (log-mp4-atom "~a is an atom we are NOT interested in; seek past it" (as-string typ))
- (setf atom (make-instance 'mp4-atom :atom-size siz :atom-type typ :atom-file-position pos))
- (stream-seek mp4-file (- siz 8) :current)))
- (log-mp4-atom "returning ~a" (vpprint atom nil))
- atom)))
- (defparameter *pprint-mp4-atom* nil
- "Controls whether we pretty print an atom")
- (defmethod print-object ((me mp4-atom) stream)
- (if (null *pprint-mp4-atom*)
- (call-next-method)
- ;; else
- (format stream "~a" (with-output-to-string (s)
- (with-slots (atom-children atom-file-position atom-size atom-type) me
- (format s "Atom <~a> @ ~:d of size ~:d and child count of ~d"
- (as-string atom-type) atom-file-position atom-size (size atom-children)))
- (if (typep me 'mp4-ilst-generic-data-atom)
- (with-slots (atom-version atom-flags atom-value atom-type atom-parent-type) me
- (format s " having ilst fields: atom-parent-type = ~a, verison = ~d, flags = ~x, data = ~x"
- (as-string atom-parent-type) atom-version atom-flags atom-value)))))))
- (defmethod vpprint ((me mp4-atom) stream &key (indent 0))
- "set *pprint-mp4-atom* to get pretty printing and call print-object via format"
- (let ((*pprint-mp4-atom* t))
- (format stream "~vt~a" (* indent 1) me)))
- (defclass mp4-unhandled-data ()
- ((blob :accessor blob :initarg :blob :initform nil))
- (:documentation "abstraction for a 'blob' of data we don't want to or can't parse"))
- (defparameter *pprint-max-array-len* 10
- "Controls how long an array (atom-value, typically) we will print in pprint-atom")
- (defmethod print-object ((me mp4-unhandled-data) stream)
- "Print a 'blob' (unstructered data), limiting it to no more than *PPRINT-MAX-ARRAY-LEN* octets"
- (let* ((len (length (slot-value me 'blob)))
- (print-len (min len *pprint-max-array-len*))
- (printable-array (make-array print-len :displaced-to (slot-value me 'blob))))
- (format stream "[~:d of ~:d bytes] <~x>" print-len len printable-array)))
- ;;;;;;;;;;;;;;;;;;;; A collection of atoms (siblings) ;;;;;;;;;;;;;;;;;;;;
- (defclass atom-collection ()
- ((atoms :accessor atoms :initform nil))
- (:documentation "A collection of sibling atoms"))
- (defun make-mp4-atom-collection () (make-instance 'atom-collection))
- (defmethod add ((me atom-collection) new-atom)
- "Adds new atom to the *end* (need to keep them in order we found them in the file) of this collection"
- (log5:with-context "add-atom-collection"
- (with-slots (atoms) me
- (log-mp4-atom "adding ~a to atom collection: ~a" new-atom atoms)
- (setf atoms (append atoms (list new-atom)))
- (log-mp4-atom "collection now: ~a" atoms))))
- (defmethod size ((me atom-collection))
- "Returns the number of atoms in this collection"
- (length (slot-value me 'atoms)))
- (defmethod map-mp4-atom ((me atom-collection) &key (func nil) (depth nil))
- "Given a collection of atoms, call map-mp4-atom for each one"
- (log5:with-context "map-mp4-atom(collection)"
- (log-mp4-atom "mapping collection: ~a" (slot-value me 'atoms))
- (dolist (a (slot-value me 'atoms))
- (map-mp4-atom a :func func :depth depth))))
- (defun is-valid-m4-file (mp4-file)
- "Make sure this is an MP4 file. Quick check: is first atom (at file-offset 4) == FSTYP?"
- (stream-seek mp4-file 0 :start)
- (let* ((size (stream-read-u32 mp4-file))
- (header (stream-read-u32 mp4-file)))
- (declare (ignore size))
- (stream-seek mp4-file 0 :start)
- (= header +m4-ftyp+)))
- (defun find-mp4-atoms (mp4-file)
- "Given a valid MP4 file mp4-file, look for the 'right' atoms and return them.
- The 'right' atoms are those in *atoms-of-interest*"
- (log5:with-context "find-mp4-atoms"
- (when (not (is-valid-m4-file mp4-file))
- (error 'mp4-atom-condition :location "find-mp4-atoms" :object mp4-file :message "is not an mp4-file" ))
- (log-mp4-atom "before read-file loop, file-position = ~:d, end = ~:d" (stream-seek mp4-file 0 :current) (stream-size mp4-file))
- (setf (mp4-atoms mp4-file) (make-mp4-atom-collection))
- (do ((new-atom))
- ((> (+ 8 (stream-seek mp4-file 0 :current)) (stream-size mp4-file)))
- (log-mp4-atom "top of read-file loop, current file-position = ~:d, end = ~:d" (stream-seek mp4-file 0 :current) (stream-size mp4-file))
- (setf new-atom (make-mp4-atom mp4-file))
- (when new-atom (add (mp4-atoms mp4-file) new-atom)))
- (log-mp4-atom "returning atom-collection of size ~d" (size (mp4-atoms mp4-file)))))
- (defmethod map-mp4-atom ((me mp4-atom) &key (func nil) (depth nil))
- "traverse all atoms under a given atom"
- (log5:with-context "map-mp4-atom(single)"
- (labels ((_indented-atom (atom depth)
- (format t "~a~%" (vpprint atom nil :indent (if (null depth) 0 depth)))))
- (with-slots (atom-type atom-children) me
- (log-mp4-atom "Begining traversal with ~a, I have ~d children" (as-string atom-type) (size atom-children))
- (when (null func)
- (setf func #'_indented-atom))
- (funcall func me depth)
- (map-mp4-atom atom-children :func func :depth (if (null depth) nil (+ 1 depth)))))))
- (defmethod traverse ((me mp4-atom) path)
- "Used in finding nested atoms.
- Given an atom and a path, if atom-type matches first element of path, then we've found our match."
- (log5:with-context "traverse-atom"
- (log-mp4-atom "traverse-atom entered with ~a ~a" (atom-type me) path)
- (cond ((null path)
- (error "Path exhausted in travese atom") ; don't think this can happen?
- nil)
- ((= (atom-type me) (first path))
- (log-mp4-atom "current path matches thus far ~a ~a" (atom-type me) path)
- (cond
- ((= 1 (length path))
- (log-mp4-atom "length of path is 1, so found!")
- (return-from traverse me)))))
- (log-mp4-atom "Current path doesn't match ~a ~a" (atom-type me) path)
- nil))
- (defmethod traverse ((me atom-collection) path)
- "Used in finding nested atoms. Seach the collection and if we find a match with first of path,
- call traverse atom (unless length of path == 1, in which case, we've found out match)"
- (log5:with-context "traverse-atom-collection"
- (log-mp4-atom "entering with ~a ~a" me path)
- (dolist (sibling (atoms me)) ; cleaner than using map-mp4-atom, but still a kludge
- (with-slots (atom-type atom-children) sibling
- (log-mp4-atom "looking at ~x::~x" atom-type (first path))
- (when (= atom-type (first path))
- (cond
- ((= 1 (length path))
- (log-mp4-atom "Found ~a" sibling)
- (return-from traverse sibling))
- (t
- (log-mp4-atom "path matches, calling traverse atom with ~a, ~a" atom-children (rest path))
- (let ((found (traverse atom-children (rest path))))
- (if found (return-from traverse found))))))))
- (log-mp4-atom "Looked at all, found nothing")
- nil))
- (defmethod tag-get-value (atoms node)
- "Helper function to extract text from atom's data atom"
- (let ((atom (traverse atoms
- (list +mp4-atom-moov+ +mp4-atom-udta+ +mp4-atom-meta+ +mp4-atom-ilst+ node +itunes-ilst-data+))))
- (if atom
- (atom-value atom)
- nil)))
- (defun mp4-show-raw-tag-atoms (mp4-file-stream)
- (map-mp4-atom (mp4-atom::traverse (mp4-atoms mp4-file-stream) (list +mp4-atom-moov+ +mp4-atom-udta+ +mp4-atom-meta+ +mp4-atom-ilst+)))))
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