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;;; tiff4cl.lisp --- TIFF parsing
;;; Copyright (C) 2009 by Walter C. Pelissero
;;; Author: Walter C. Pelissero <>
;;; Project: tiff4cl
#+cmu (ext:file-comment "$Module: tiff.lisp $")
;;; This library is free software; you can redistribute it and/or
;;; modify it under the terms of the GNU Lesser General Public License
;;; as published by the Free Software Foundation; either version 2.1
;;; of the License, or (at your option) any later version.
;;; This library is distributed in the hope that it will be useful,
;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;; Lesser General Public License for more details.
;;; You should have received a copy of the GNU Lesser General Public
;;; License along with this library; if not, write to the Free
;;; Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
;;; 02111-1307 USA
(in-package #:tiff4cl)
(defclass tiff-stream ()
((stream :initarg :stream
:reader tiff-stream)
(start :initarg :start
:initform 0
:type integer
:reader tiff-start)
(end :initarg :end
:initform nil
:type (or integer null)
:reader tiff-end)))
(defclass tiff-little-endian-stream (tiff-stream) ())
(defclass tiff-big-endian-stream (tiff-stream) ())
(defclass tiff-big-endian-stream-nef (tiff-big-endian-stream)
(defgeneric decode-integer (tiff buffer &key start end))
(defmethod decode-integer ((tiff tiff-little-endian-stream) buffer &key (start 0) end)
(decode-integer-le buffer
:start start
:end end))
(defmethod decode-integer ((tiff tiff-big-endian-stream) buffer &key (start 0) end)
(decode-integer-be buffer
:start start
:end end))
(defgeneric read-16bit (tiff))
(defmethod read-16bit ((tiff tiff-little-endian-stream))
(read-16bit-le (tiff-stream tiff)))
(defmethod read-16bit ((tiff tiff-big-endian-stream))
(read-16bit-be (tiff-stream tiff)))
(defgeneric read-32bit (tiff))
(defmethod read-32bit ((tiff tiff-little-endian-stream))
(read-32bit-le (tiff-stream tiff)))
(defmethod read-32bit ((tiff tiff-big-endian-stream))
(read-32bit-be (tiff-stream tiff)))
(defun parse-endianness (stream)
(let ((buffer (read-bytes stream 2)))
(cond ((equalp +little-endian-signature+ buffer)
;; Intel's little endian
((equalp +big-endian-signature+ buffer)
;; Motorola's big endian
(error 'not-a-tiff)))))
(defun parse-file-format-version (tiff)
(read-16bit tiff))
(defun read-ifd-pointer (tiff)
(let ((pointer (read-32bit tiff)))
(when (or (and (< pointer 8)
;; the last pointer is always zero
(not (zerop pointer)))
(not (zerop (mod pointer 2)))
(let ((end (tiff-end tiff)))
(when end
(> pointer (- end (tiff-start tiff))))))
(error 'invalid-pointer :pointer pointer))
(defun tiff-position (tiff &optional position)
(- (tiff-start tiff)
(if position
(file-position (tiff-stream tiff)
(+ position (tiff-start tiff))))
(file-position (tiff-stream tiff)))))
(defun read-ifd-tags-number (tiff)
(read-16bit tiff))
(defun tag-type-size (type)
(caddr (find type +tag-types+ :key #'cadr)))
(defun fetch-tag-data (file address length)
(tiff-position file (decode-integer file address))
(read-bytes (tiff-stream file) length))
(defclass tiff-tag ()
((id :initarg :id
:reader tag-id)
(type :initarg :type
:reader tag-type)
(value :initarg :value
:reader tag-value)))
(defclass tiff-ifd ()
((tags :initarg :tags
:type list
:reader ifd-tags)
(next :initarg :next
:reader ifd-next)))
(defmethod print-object ((object tiff-tag) stream)
(if *print-readably*
(print-unreadable-object (object stream :type t)
(format stream "~A" (tag-id object)))))
(defun get-tag-value (file type count data)
(let ((item-size (tag-type-size type)))
(if item-size
(let ((max-positive (ash 1 (1- (* 8 item-size)))))
(labels ((maybe-negative (x)
(if (< x max-positive)
(lognot x)))
(parse-byte (buffer pos)
(aref buffer pos))
(parse-int (buffer start end)
(decode-integer file buffer :start start :end end))
(parse-data-item (buffer pos)
(case type
(parse-byte buffer pos))
(code-char (aref buffer pos)))
((:short :long)
(parse-int buffer (* pos item-size) (* (1+ pos) item-size)))
(/ (parse-int buffer
(* pos item-size)
(+ (* pos item-size) (/ item-size 2)))
(parse-int buffer
(+ (* pos item-size) (/ item-size 2))
(* (1+ pos) item-size))))
(maybe-negative (parse-byte buffer pos)))
(aref buffer pos))
((:signed-short :signed-long)
(parse-int buffer
(* pos item-size)
(* (1+ pos) item-size))))
(/ (maybe-negative
(parse-int buffer
(* pos item-size)
(+ (* pos item-size) (/ item-size 2))))
(parse-int buffer
(+ (* pos item-size) (/ item-size 2))
(* (1+ pos) item-size)))))
(decode-ieee-float ;; ieee-754:decode-ieee-float
(parse-int buffer
(* pos item-size)
(* (1+ pos) item-size))))
(decode-ieee-double ;; ieee-754:decode-ieee-double
(parse-int buffer
(* pos item-size)
(* (1+ pos) item-size))))))
(parse-tag-data (buffer)
(if (= 1 count)
(parse-data-item buffer 0)
with result = (make-array count)
for i from 0 below count
do (setf (aref result i) (parse-data-item buffer i))
finally (return (if (eq type :ascii)
(coerce (subseq result 0
;; get rid of the trailing null
(1- (length result)))
(cond ((> (* item-size count) 4)
(fetch-tag-data file data (* item-size count))))
(parse-tag-data data)))))
;; the value is in the data field itself
(defun parse-flash-value (value)
(let ((features '()))
(macrolet ((bf (feature bit)
`(when (logbitp ,bit value)
(push ,feature features))))
(bf :fired 0)
(when (logbitp 2 value)
(push (if (logbitp 1 value)
(case (ldb (byte 2 3) value)
(1 (push :flash-forced-on features))
(2 (push :flash-disabled features))
(3 (push :auto-mode features)))
(bf :flash-present 5)
(bf :red-eye-suppression 6))
(declaim (inline %parse-starts-with))
(defun %parse-starts-with (prefix value)
for i across prefix
for j across value
always (= i j)))
;; Following adapted from zpb-exif's exif-type parser for user-comment
(defun parse-user-comment-value (value)
;; If VALUE is empty returns the empty string.
(declare (inline %parse-starts-with))
(labels ( ;; (starts-with (prefix)
;; (loop
;; for i across prefix
;; for j across value
;; always (= i j)))
(string-all-empty-check (mapped-comment)
;; For reading the value of an empty user-comment this should be fine.
;; However, if we start writing it back out it may not be...
(if (every #'(lambda (x) (char= #\SPACE x)) mapped-comment)
(make-string 0 :element-type 'character :initial-element #\nul)
(map-comment ()
(let ((first-null (or (position 0 value :start 8)
(length value))))
(setf first-null
(map 'string #'code-char (subseq value 8 first-null)))
(string-all-empty-check first-null))))
;; (if (or (starts-with #(0 0 0 0 0 0 0 0))
;; (starts-with #(#x41 #x53 #x43 #x49 #x49)))
(if (or (%parse-starts-with #(0 0 0 0 0 0 0 0) value)
(%parse-starts-with #(65 83 67 73 73) value))
;; ASCII encoding
(defun parse-maker-note-value (file value)
(declare (inline %parse-starts-with))
(unless (typep file 'tiff-big-endian-stream-nef)
(return-from parse-maker-note-value value))
(if (%parse-starts-with #(78 105 107 111 110) value)
(defun interpret-tag-value (file id value)
(case id
((:exif-ifd :gps-ifd :interoperability-ifd)
(parse-ifd file value))
((:flashpix-version :exif-version)
(let ((str (map 'string #'code-char value)))
(cons (parse-integer str :start 0 :end 2)
(parse-integer str :start 2))))
;; (let ((features '()))
;; (macrolet ((bf (feature bit)
;; `(when (logbitp ,bit value)
;; (push ,feature features))))
;; (bf :fired 0)
;; (when (logbitp 2 value)
;; (push (if (logbitp 1 value)
;; :strobe-detected
;; :strobe-undetected)
;; features))
;; (case (ldb (byte 2 3) value)
;; (1 (push :flash-forced-on features))
;; (2 (push :flash-disabled features))
;; (3 (push :auto-mode features)))
;; (bf :flash-present 5)
;; (bf :red-eye-suppression 6))
;; features)
(parse-flash-value value))
(if (and value (arrayp value))
(parse-user-comment-value value)
(if (and value (arrayp value))
(parse-maker-note-value file value)
(let ((symbolic-mapping (assoc value (caddr (find id *tag-ids* :key #'cadr)))))
(if symbolic-mapping
(cadr symbolic-mapping)
(defun tag-id->symbol (n)
(cadr (assoc n *tag-ids*)))
(defun read-tag-id (tiff)
(let ((x (read-16bit tiff)))
(or (tag-id->symbol x) x)))
(defun tag-type->symbol (n)
(cadr (assoc n +tag-types+)))
(defun read-tag-type (tiff)
(let ((x (read-16bit tiff)))
(or (tag-type->symbol x)
(defun read-tag-values-count (tiff)
(read-32bit tiff))
(defun read-tag-data (tiff)
(read-bytes (tiff-stream tiff) 4))
(defun parse-tag (tiff)
(let* ((id (read-tag-id tiff))
(type (read-tag-type tiff))
(n (read-tag-values-count tiff))
(data (read-tag-data tiff)))
(list id type n data)))
(defun parse-ifd (tiff &optional position)
(when position
(tiff-position tiff position))
;; First read the tags data and then create the objects, because
;; get-tag-value can seek through the file to fetch the data values,
;; thus disrupting the sequential read we do here.
(let* ((tags (loop
for i from 0 below (read-ifd-tags-number tiff)
collect (parse-tag tiff)))
(next-ifd (read-ifd-pointer tiff))
;; :NOTE Why shouldn't we use an flet'd function for the lambda form
;; below? Likewise, why not separate the entire body of the
;; tag-objects binding to a dedicated function?
(tag-objects (mapcar #'(lambda (tag)
(destructuring-bind (id type count data) tag
(let ((value (get-tag-value tiff type count data)))
(make-instance 'tiff-tag
:id id
:type type
:value (interpret-tag-value tiff id value)))))
(make-instance 'tiff-ifd :tags tag-objects :next next-ifd)))
;; :TODO It would be better to this check with magicffi instead.
(defun parse-tiff-stream-check-nef (stream)
(string-equal (pathname-type stream) "nef"))
(defun parse-tiff-stream (stream &optional end)
(let* ((start (file-position stream))
(endianness (parse-endianness stream))
;; :NOTE This is a preliminary accomodation of .nef files. Currently
;; we aren't properly descending into the subIFDs or parsing maker-note
;; correctly!
(tiff (make-instance (if (eq endianness :little-endian)
(if (parse-tiff-stream-check-nef stream)
:start start
:end end
:stream stream))
(version (parse-file-format-version tiff)))
(unless (= version +tiff-version+)
(error 'wrong-version :version version))
(let ((ifds '())
(address (read-ifd-pointer tiff)))
(when (zerop address)
(let ((ifd (parse-ifd tiff address)))
(push ifd ifds)
(setf address (ifd-next ifd))))
(defun parse-tiff (file &key start end)
(if (streamp file)
(when start
(file-position file start))
(parse-tiff-stream file end))
(with-open-file (stream file)
(when start
(file-position stream start))
(parse-tiff-stream stream end))))
(defun map-ifd-tags (function ifd)
(dolist (tag (ifd-tags ifd))
(let ((value (tag-value tag)))
(if (typep value 'tiff-ifd)
(map-ifd-tags function value)
(funcall function tag)))))
(defun map-tiff-tags (function ifds)
(dolist (ifd ifds)
(map-ifd-tags function ifd)))
(defun tiff-extract-tags (ifds tag-ids)
(let ((result '()))
(map-tiff-tags #'(lambda (tag)
(when (or (eq tag-ids t)
(find (tag-id tag) tag-ids))
(push (cons (tag-id tag) (tag-value tag))
(defun print-tiff-tags (ifds &optional stream)
(unless stream
(setf stream *standard-output*))
(labels ((print-ifd (ifd indent)
for tag in (ifd-tags ifd)
for value = (tag-value tag)
if (typep value 'tiff-ifd)
(format stream "~vT~A:~%" indent (tag-id tag))
(print-ifd value (+ 2 indent))
else do
(format stream "~vT~A = ~S~%" indent (tag-id tag) value))))
for ifd in ifds
for i from 0
(format stream "~&IFD ~A:~%" i)
(print-ifd ifd 2))))
;;; ==============================
;;; EOF