# -*- coding: utf-8 -*- ####################################################################################### # Photo is a part of Plinn - http://plinn.org # # Copyright (C) 2008 Benoît PIN # # # # This program is free software; you can redistribute it and/or # # modify it under the terms of the GNU General Public License # # as published by the Free Software Foundation; either version 2 # # of the License, or (at your option) any later version. # # # # This program 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 General Public License for more details. # # # # You should have received a copy of the GNU General Public License # # along with this program; if not, write to the Free Software # # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. # ####################################################################################### """ Jpeg plugin for xmp read/write support. """ from xmp import XMP from types import StringType class JpegXmpIO(object): JPEG_XMP_LEADIN = 'http://ns.adobe.com/xap/1.0/\x00' JPEG_XMP_LEADIN_LENGTH = len(JPEG_XMP_LEADIN) MARKERS = { 0xFFC0: ("SOF0", "Baseline DCT", True), 0xFFC1: ("SOF1", "Extended Sequential DCT", True), 0xFFC2: ("SOF2", "Progressive DCT", True), 0xFFC3: ("SOF3", "Spatial lossless", True), 0xFFC4: ("DHT", "Define Huffman table", True), 0xFFC5: ("SOF5", "Differential sequential DCT", True), 0xFFC6: ("SOF6", "Differential progressive DCT", True), 0xFFC7: ("SOF7", "Differential spatial", True), 0xFFC8: ("JPG", "Extension", False), 0xFFC9: ("SOF9", "Extended sequential DCT (AC)", True), 0xFFCA: ("SOF10", "Progressive DCT (AC)", True), 0xFFCB: ("SOF11", "Spatial lossless DCT (AC)", True), 0xFFCC: ("DAC", "Define arithmetic coding conditioning", True), 0xFFCD: ("SOF13", "Differential sequential DCT (AC)", True), 0xFFCE: ("SOF14", "Differential progressive DCT (AC)", True), 0xFFCF: ("SOF15", "Differential spatial (AC)", True), 0xFFD0: ("RST0", "Restart 0", False), 0xFFD1: ("RST1", "Restart 1", False), 0xFFD2: ("RST2", "Restart 2", False), 0xFFD3: ("RST3", "Restart 3", False), 0xFFD4: ("RST4", "Restart 4", False), 0xFFD5: ("RST5", "Restart 5", False), 0xFFD6: ("RST6", "Restart 6", False), 0xFFD7: ("RST7", "Restart 7", False), 0xFFD8: ("SOI", "Start of image", False), 0xFFD9: ("EOI", "End of image", False), 0xFFDA: ("SOS", "Start of scan", True), 0xFFDB: ("DQT", "Define quantization table", True), 0xFFDC: ("DNL", "Define number of lines", True), 0xFFDD: ("DRI", "Define restart interval", True), 0xFFDE: ("DHP", "Define hierarchical progression", True), 0xFFDF: ("EXP", "Expand reference component", True), 0xFFE0: ("APP0", "Application segment 0", True), 0xFFE1: ("APP1", "Application segment 1", True), 0xFFE2: ("APP2", "Application segment 2", True), 0xFFE3: ("APP3", "Application segment 3", True), 0xFFE4: ("APP4", "Application segment 4", True), 0xFFE5: ("APP5", "Application segment 5", True), 0xFFE6: ("APP6", "Application segment 6", True), 0xFFE7: ("APP7", "Application segment 7", True), 0xFFE8: ("APP8", "Application segment 8", True), 0xFFE9: ("APP9", "Application segment 9", True), 0xFFEA: ("APP10", "Application segment 10", True), 0xFFEB: ("APP11", "Application segment 11", True), 0xFFEC: ("APP12", "Application segment 12", True), 0xFFED: ("APP13", "Application segment 13", True), 0xFFEE: ("APP14", "Application segment 14", True), 0xFFEF: ("APP15", "Application segment 15", True), 0xFFF0: ("JPG0", "Extension 0", False), 0xFFF1: ("JPG1", "Extension 1", False), 0xFFF2: ("JPG2", "Extension 2", False), 0xFFF3: ("JPG3", "Extension 3", False), 0xFFF4: ("JPG4", "Extension 4", False), 0xFFF5: ("JPG5", "Extension 5", False), 0xFFF6: ("JPG6", "Extension 6", False), 0xFFF7: ("JPG7", "Extension 7", False), 0xFFF8: ("JPG8", "Extension 8", False), 0xFFF9: ("JPG9", "Extension 9", False), 0xFFFA: ("JPG10", "Extension 10", False), 0xFFFB: ("JPG11", "Extension 11", False), 0xFFFC: ("JPG12", "Extension 12", False), 0xFFFD: ("JPG13", "Extension 13", False), 0xFFFE: ("COM", "Comment", True) } @staticmethod def i16(c,o=0): return ord(c[o+1]) + (ord(c[o])<<8) @staticmethod def getBlockInfo(marker, f): start = f.tell() length = JpegXmpIO.i16(f.read(2)) markerInfo = JpegXmpIO.MARKERS[marker] blockInfo = { 'name' : markerInfo[0] , 'description' : markerInfo[1] , 'start' : start , 'length' : length} jump = start + length f.seek(jump) return blockInfo @staticmethod def getBlockInfos(f) : f.seek(0) s = f.read(1) blockInfos = [] while 1: s = s + f.read(1) i = JpegXmpIO.i16(s) if JpegXmpIO.MARKERS.has_key(i): name, desciption, handle = JpegXmpIO.MARKERS[i] if handle: blockInfo = JpegXmpIO.getBlockInfo(i, f) blockInfos.append(blockInfo) if i == 0xFFDA: # start of scan break s = f.read(1) elif i == 0 or i == 65535: # padded marker or junk; move on s = "\xff" return blockInfos @staticmethod def genJpegXmpBlock(uXmpData, paddingSize=2) : block = u'' block += JpegXmpIO.JPEG_XMP_LEADIN block += XMP.genXMPPacket(uXmpData, paddingSize) # utf-8 mandatory in jpeg files (xmp specification) block = block.encode('utf-8') length = len(block) + 2 # TODO : reduce padding size if this assertion occurs assert length <= 0xfffd, "Jpeg block too long: %d (max: 0xfffd)" % hex(length) chrlength = chr(length >> 8 & 0xff) + chr(length & 0xff) block = chrlength + block return block @staticmethod def read(f) : blockInfos = JpegXmpIO.getBlockInfos(f) app1BlockInfos = [b for b in blockInfos if b['name'] == 'APP1'] xmpBlocks = [] for info in app1BlockInfos : f.seek(info['start']) data = f.read(info['length'])[2:] if data.startswith(JpegXmpIO.JPEG_XMP_LEADIN) : xmpBlocks.append(data) assert len(xmpBlocks) <= 1, "Multiple xmp block data is not yet supported." if len(xmpBlocks) == 1 : data = xmpBlocks[0] packet = data[len(JpegXmpIO.JPEG_XMP_LEADIN):] return packet else : return None @staticmethod def write(original, new, uxmp) : blockInfos = JpegXmpIO.getBlockInfos(original) app1BlockInfos = [b for b in blockInfos if b['name'] == 'APP1'] xmpBlockInfos = [] for info in app1BlockInfos : original.seek(info['start']) lead = original.read(JpegXmpIO.JPEG_XMP_LEADIN_LENGTH+2)[2:] if lead == JpegXmpIO.JPEG_XMP_LEADIN : xmpBlockInfos.append(info) assert len(xmpBlockInfos) <= 1, "Multiple xmp block data is not yet supported." if isinstance(uxmp, StringType) : uxmp = unicode(uxmp, 'utf-8') if len(xmpBlockInfos) == 0 : blockInfo = [b for b in blockInfos if b['name'] == 'APP13'] if not blockInfo : blockInfo = [b for b in blockInfos if b['name'] == 'APP1'] if not blockInfo : blockInfo = [b for b in blockInfos if b['name'] == 'APP0'] if not blockInfo : raise ValueError, "No suitable place to write xmp segment" info = blockInfo[0] print 'create xmp after: %s' % info['name'] original.seek(0) before = original.read(info['start'] + info['length']) after = original.read() jpegBlock = '\xFF\xE1' + JpegXmpIO.genJpegXmpBlock(uxmp) else : info = xmpBlockInfos[0] original.seek(0) before = original.read(info['start']) original.seek(info['start'] + info['length']) after = original.read() jpegBlock = JpegXmpIO.genJpegXmpBlock(uxmp) new.seek(0) new.write(before) new.write(jpegBlock) new.write(after) # if original == new : # new.seek(0) # else : # new.close() # original.close() XMP.registerReader('image/jpeg', JpegXmpIO.read) XMP.registerWriter('image/jpeg', JpegXmpIO.write)