""" JPEG picture parser. Information: - APP14 documents http://partners.adobe.com/public/developer/en/ps/sdk/5116.DCT_Filter.pdf http://java.sun.com/j2se/1.5.0/docs/api/javax/imageio/metadata/doc-files/jpeg_metadata.html#color - APP12: http://search.cpan.org/~exiftool/Image-ExifTool/lib/Image/ExifTool/TagNames.pod - JPEG Data Format http://www.w3.org/Graphics/JPEG/itu-t81.pdf Author: Victor Stinner, Robert Xiao """ from hachoir.parser import Parser from hachoir.field import (FieldSet, ParserError, FieldError, UInt8, UInt16, Enum, Field, Bit, Bits, NullBits, NullBytes, PaddingBits, String, RawBytes) from hachoir.parser.image.common import PaletteRGB from hachoir.core.endian import BIG_ENDIAN from hachoir.core.text_handler import textHandler, hexadecimal from hachoir.parser.image.exif import Exif from hachoir.parser.image.photoshop_metadata import PhotoshopMetadata from hachoir.parser.archive.zlib import build_tree from hachoir.core.tools import paddingSize, alignValue MAX_FILESIZE = 100 * 1024 * 1024 # The four tables (hash/sum for color/grayscale JPEG) comes # from ImageMagick project QUALITY_HASH_COLOR = ( 1020, 1015, 932, 848, 780, 735, 702, 679, 660, 645, 632, 623, 613, 607, 600, 594, 589, 585, 581, 571, 555, 542, 529, 514, 494, 474, 457, 439, 424, 410, 397, 386, 373, 364, 351, 341, 334, 324, 317, 309, 299, 294, 287, 279, 274, 267, 262, 257, 251, 247, 243, 237, 232, 227, 222, 217, 213, 207, 202, 198, 192, 188, 183, 177, 173, 168, 163, 157, 153, 148, 143, 139, 132, 128, 125, 119, 115, 108, 104, 99, 94, 90, 84, 79, 74, 70, 64, 59, 55, 49, 45, 40, 34, 30, 25, 20, 15, 11, 6, 4, 0) QUALITY_SUM_COLOR = ( 32640, 32635, 32266, 31495, 30665, 29804, 29146, 28599, 28104, 27670, 27225, 26725, 26210, 25716, 25240, 24789, 24373, 23946, 23572, 22846, 21801, 20842, 19949, 19121, 18386, 17651, 16998, 16349, 15800, 15247, 14783, 14321, 13859, 13535, 13081, 12702, 12423, 12056, 11779, 11513, 11135, 10955, 10676, 10392, 10208, 9928, 9747, 9564, 9369, 9193, 9017, 8822, 8639, 8458, 8270, 8084, 7896, 7710, 7527, 7347, 7156, 6977, 6788, 6607, 6422, 6236, 6054, 5867, 5684, 5495, 5305, 5128, 4945, 4751, 4638, 4442, 4248, 4065, 3888, 3698, 3509, 3326, 3139, 2957, 2775, 2586, 2405, 2216, 2037, 1846, 1666, 1483, 1297, 1109, 927, 735, 554, 375, 201, 128, 0) QUALITY_HASH_GRAY = ( 510, 505, 422, 380, 355, 338, 326, 318, 311, 305, 300, 297, 293, 291, 288, 286, 284, 283, 281, 280, 279, 278, 277, 273, 262, 251, 243, 233, 225, 218, 211, 205, 198, 193, 186, 181, 177, 172, 168, 164, 158, 156, 152, 148, 145, 142, 139, 136, 133, 131, 129, 126, 123, 120, 118, 115, 113, 110, 107, 105, 102, 100, 97, 94, 92, 89, 87, 83, 81, 79, 76, 74, 70, 68, 66, 63, 61, 57, 55, 52, 50, 48, 44, 42, 39, 37, 34, 31, 29, 26, 24, 21, 18, 16, 13, 11, 8, 6, 3, 2, 0) QUALITY_SUM_GRAY = ( 16320, 16315, 15946, 15277, 14655, 14073, 13623, 13230, 12859, 12560, 12240, 11861, 11456, 11081, 10714, 10360, 10027, 9679, 9368, 9056, 8680, 8331, 7995, 7668, 7376, 7084, 6823, 6562, 6345, 6125, 5939, 5756, 5571, 5421, 5240, 5086, 4976, 4829, 4719, 4616, 4463, 4393, 4280, 4166, 4092, 3980, 3909, 3835, 3755, 3688, 3621, 3541, 3467, 3396, 3323, 3247, 3170, 3096, 3021, 2952, 2874, 2804, 2727, 2657, 2583, 2509, 2437, 2362, 2290, 2211, 2136, 2068, 1996, 1915, 1858, 1773, 1692, 1620, 1552, 1477, 1398, 1326, 1251, 1179, 1109, 1031, 961, 884, 814, 736, 667, 592, 518, 441, 369, 292, 221, 151, 86, 64, 0) JPEG_NATURAL_ORDER = ( 0, 1, 8, 16, 9, 2, 3, 10, 17, 24, 32, 25, 18, 11, 4, 5, 12, 19, 26, 33, 40, 48, 41, 34, 27, 20, 13, 6, 7, 14, 21, 28, 35, 42, 49, 56, 57, 50, 43, 36, 29, 22, 15, 23, 30, 37, 44, 51, 58, 59, 52, 45, 38, 31, 39, 46, 53, 60, 61, 54, 47, 55, 62, 63) class JpegChunkApp0(FieldSet): UNIT_NAME = { 0: "pixels", 1: "dots per inch", 2: "dots per cm", } def createFields(self): yield String(self, "jfif", 5, "JFIF string", charset="ASCII") if self["jfif"].value != "JFIF\0": raise ParserError( "Stream doesn't look like JPEG chunk (wrong JFIF signature)") yield UInt8(self, "ver_maj", "Major version") yield UInt8(self, "ver_min", "Minor version") yield Enum(UInt8(self, "units", "Units"), self.UNIT_NAME) if self["units"].value == 0: yield UInt16(self, "aspect_x", "Aspect ratio (X)") yield UInt16(self, "aspect_y", "Aspect ratio (Y)") else: yield UInt16(self, "x_density", "X density") yield UInt16(self, "y_density", "Y density") yield UInt8(self, "thumb_w", "Thumbnail width") yield UInt8(self, "thumb_h", "Thumbnail height") thumb_size = self["thumb_w"].value * self["thumb_h"].value if thumb_size != 0: yield PaletteRGB(self, "thumb_palette", 256) yield RawBytes(self, "thumb_data", thumb_size, "Thumbnail data") class Ducky(FieldSet): BLOCK_TYPE = { 0: "end", 1: "Quality", 2: "Comment", 3: "Copyright", } def createFields(self): yield Enum(UInt16(self, "type"), self.BLOCK_TYPE) if self["type"].value == 0: return yield UInt16(self, "size") size = self["size"].value if size: yield RawBytes(self, "data", size) class APP12(FieldSet): """ The JPEG APP12 "Picture Info" segment was used by some older cameras, and contains ASCII-based meta information. """ def createFields(self): yield String(self, "ducky", 5, '"Ducky" string', charset="ASCII") while not self.eof: yield Ducky(self, "item[]") class SOFComponent(FieldSet): def createFields(self): yield UInt8(self, "component_id") yield Bits(self, "horiz_sample", 4, "Horizontal sampling factor") yield Bits(self, "vert_sample", 4, "Vertical sampling factor") yield UInt8(self, "quant_table", "Quantization table destination selector") class StartOfFrame(FieldSet): def createFields(self): yield UInt8(self, "precision") yield UInt16(self, "height") yield UInt16(self, "width") yield UInt8(self, "nr_components") for index in range(self["nr_components"].value): yield SOFComponent(self, "component[]") class Comment(FieldSet): def createFields(self): yield String(self, "comment", self.size // 8, strip="\0") class AdobeChunk(FieldSet): COLORSPACE_TRANSFORMATION = { 1: "YCbCr (converted from RGB)", 2: "YCCK (converted from CMYK)", } def createFields(self): if self.stream.readBytes(self.absolute_address, 5) != "Adobe": yield RawBytes(self, "raw", self.size // 8, "Raw data") return yield String(self, "adobe", 5, "\"Adobe\" string", charset="ASCII") yield UInt16(self, "version", "DCT encoder version") yield Enum(Bit(self, "flag00"), {False: "Chop down or subsampling", True: "Blend"}) yield NullBits(self, "flags0_reserved", 15) yield NullBytes(self, "flags1", 2) yield Enum(UInt8(self, "color_transform", "Colorspace transformation code"), self.COLORSPACE_TRANSFORMATION) class SOSComponent(FieldSet): def createFields(self): comp_id = UInt8(self, "component_id") yield comp_id if not (1 <= comp_id.value <= self["../nr_components"].value): raise ParserError("JPEG error: Invalid component-id") yield Bits(self, "dc_coding_table", 4, "DC entropy coding table destination selector") yield Bits(self, "ac_coding_table", 4, "AC entropy coding table destination selector") class StartOfScan(FieldSet): def createFields(self): yield UInt8(self, "nr_components") for index in range(self["nr_components"].value): yield SOSComponent(self, "component[]") yield UInt8(self, "spectral_start", "Start of spectral or predictor selection") yield UInt8(self, "spectral_end", "End of spectral selection") yield Bits(self, "bit_pos_high", 4, "Successive approximation bit position high") yield Bits(self, "bit_pos_low", 4, "Successive approximation bit position low or point transform") class RestartInterval(FieldSet): def createFields(self): yield UInt16(self, "interval", "Restart interval") class QuantizationTable(FieldSet): def createFields(self): # Code based on function get_dqt() (jdmarker.c from libjpeg62) yield Bits(self, "is_16bit", 4) yield Bits(self, "index", 4) if self["index"].value >= 4: raise ParserError("Invalid quantification index (%s)" % self["index"].value) if self["is_16bit"].value: coeff_type = UInt16 else: coeff_type = UInt8 for index in xrange(64): natural = JPEG_NATURAL_ORDER[index] yield coeff_type(self, "coeff[%u]" % natural) def createDescription(self): return "Quantification table #%u" % self["index"].value class DefineQuantizationTable(FieldSet): def createFields(self): while self.current_size < self.size: yield QuantizationTable(self, "qt[]") class HuffmanTable(FieldSet): def createFields(self): # http://www.w3.org/Graphics/JPEG/itu-t81.pdf, page 40-41 yield Enum(Bits(self, "table_class", 4, "Table class"), { 0: "DC or Lossless Table", 1: "AC Table"}) yield Bits(self, "index", 4, "Huffman table destination identifier") for i in xrange(1, 17): yield UInt8(self, "count[%i]" % i, "Number of codes of length %i" % i) lengths = [] remap = {} for i in xrange(1, 17): for j in xrange(self["count[%i]" % i].value): field = UInt8(self, "value[%i][%i]" % ( i, j), "Value of code #%i of length %i" % (j, i)) yield field remap[len(lengths)] = field.value lengths.append(i) self.tree = {} for i, j in build_tree(lengths).iteritems(): self.tree[i] = remap[j] class DefineHuffmanTable(FieldSet): def createFields(self): while self.current_size < self.size: yield HuffmanTable(self, "huffman_table[]") class HuffmanCode(Field): """Huffman code. Uses tree parameter as the Huffman tree.""" def __init__(self, parent, name, tree, description=""): Field.__init__(self, parent, name, 0, description) endian = self.parent.endian stream = self.parent.stream addr = self.absolute_address value = 0 met_ff = False while (self.size, value) not in tree: if addr % 8 == 0: last_byte = stream.readBytes(addr - 8, 1) if last_byte == '\xFF': next_byte = stream.readBytes(addr, 1) if next_byte != '\x00': raise FieldError( "Unexpected byte sequence %r!" % (last_byte + next_byte)) addr += 8 # hack hack hack met_ff = True self._description = "[skipped 8 bits after 0xFF] " bit = stream.readBits(addr, 1, endian) value <<= 1 value += bit self._size += 1 addr += 1 self.createValue = lambda: value self.realvalue = tree[(self.size, value)] if met_ff: self._size += 8 class JpegHuffmanImageUnit(FieldSet): """8x8 block of sample/coefficient values""" def __init__(self, parent, name, dc_tree, ac_tree, *args, **kwargs): FieldSet.__init__(self, parent, name, *args, **kwargs) self.dc_tree = dc_tree self.ac_tree = ac_tree def createFields(self): field = HuffmanCode(self, "dc_data", self.dc_tree) field._description = "DC Code %i (Huffman Code %i)" % ( field.realvalue, field.value) + field._description yield field if field.realvalue != 0: extra = Bits(self, "dc_data_extra", field.realvalue) if extra.value < 2 ** (field.realvalue - 1): corrected_value = extra.value + (-1 << field.realvalue) + 1 else: corrected_value = extra.value extra._description = "Extra Bits: Corrected DC Value %i" % corrected_value yield extra data = [] while len(data) < 63: field = HuffmanCode(self, "ac_data[]", self.ac_tree) value_r = field.realvalue >> 4 if value_r: data += [0] * value_r value_s = field.realvalue & 0x0F if value_r == value_s == 0: field._description = "AC Code Block Terminator (0, 0) (Huffman Code %i)" % \ field.value + field._description yield field return field._description = "AC Code %i, %i (Huffman Code %i)" % ( value_r, value_s, field.value) + field._description yield field if value_s != 0: extra = Bits(self, "ac_data_extra[%s" % field.name.split('[')[1], value_s) if extra.value < 2 ** (value_s - 1): corrected_value = extra.value + (-1 << value_s) + 1 else: corrected_value = extra.value extra._description = "Extra Bits: Corrected AC Value %i" % corrected_value data.append(corrected_value) yield extra else: data.append(0) class JpegImageData(FieldSet): def __init__(self, parent, name, frame, scan, restart_interval, restart_offset=0, *args, **kwargs): FieldSet.__init__(self, parent, name, *args, **kwargs) self.frame = frame self.scan = scan self.restart_interval = restart_interval self.restart_offset = restart_offset # try to figure out where this field ends start = self.absolute_address while True: end = self.stream.searchBytes("\xff", start, MAX_FILESIZE * 8) if end is None: # this is a bad sign, since it means there is no terminator # we ignore this; it likely means a truncated image break if self.stream.readBytes(end, 2) == '\xff\x00': # padding: false alarm start = end + 16 continue else: self._size = end - self.absolute_address break def createFields(self): if self.frame["../type"].value in [0xC0, 0xC1]: # yay, huffman coding! if not hasattr(self, "huffman_tables"): self.huffman_tables = {} for huffman in self.parent.array("huffman"): for table in huffman["content"].array("huffman_table"): for _dummy_ in table: # exhaust table, so the huffman tree is built pass self.huffman_tables[table["table_class"].value, table[ "index"].value] = table.tree components = [] # sos_comp, samples max_vert = 0 max_horiz = 0 for component in self.scan.array("component"): for sof_comp in self.frame.array("component"): if sof_comp["component_id"].value == component["component_id"].value: vert = sof_comp["vert_sample"].value horiz = sof_comp["horiz_sample"].value components.append((component, vert * horiz)) max_vert = max(max_vert, vert) max_horiz = max(max_horiz, horiz) mcu_height = alignValue( self.frame["height"].value, 8 * max_vert) // (8 * max_vert) mcu_width = alignValue( self.frame["width"].value, 8 * max_horiz) // (8 * max_horiz) if self.restart_interval and self.restart_offset > 0: mcu_number = self.restart_interval * self.restart_offset else: mcu_number = 0 initial_mcu = mcu_number while True: if (self.restart_interval and mcu_number != initial_mcu and mcu_number % self.restart_interval == 0) or \ mcu_number == mcu_height * mcu_width: padding = paddingSize(self.current_size, 8) if padding: yield PaddingBits(self, "padding[]", padding) # all 1s last_byte = self.stream.readBytes( self.absolute_address + self.current_size - 8, 1) if last_byte == '\xFF': next_byte = self.stream.readBytes( self.absolute_address + self.current_size, 1) if next_byte != '\x00': raise FieldError( "Unexpected byte sequence %r!" % (last_byte + next_byte)) yield NullBytes(self, "stuffed_byte[]", 1) break for sos_comp, num_units in components: for interleave_count in range(num_units): yield JpegHuffmanImageUnit(self, "block[%i]component[%i][]" % ( mcu_number, sos_comp["component_id"].value), self.huffman_tables[ 0, sos_comp["dc_coding_table"].value], self.huffman_tables[1, sos_comp["ac_coding_table"].value]) mcu_number += 1 else: self.warning( "Sorry, only supporting Baseline & Extended Sequential JPEG images so far!") return class JpegChunk(FieldSet): TAG_SOI = 0xD8 TAG_EOI = 0xD9 TAG_SOS = 0xDA TAG_DQT = 0xDB TAG_DRI = 0xDD TAG_INFO = { 0xC4: ("huffman[]", "Define Huffman Table (DHT)", DefineHuffmanTable), 0xD8: ("start_image", "Start of image (SOI)", None), 0xD9: ("end_image", "End of image (EOI)", None), 0xD0: ("restart_marker_0[]", "Restart Marker (RST0)", None), 0xD1: ("restart_marker_1[]", "Restart Marker (RST1)", None), 0xD2: ("restart_marker_2[]", "Restart Marker (RST2)", None), 0xD3: ("restart_marker_3[]", "Restart Marker (RST3)", None), 0xD4: ("restart_marker_4[]", "Restart Marker (RST4)", None), 0xD5: ("restart_marker_5[]", "Restart Marker (RST5)", None), 0xD6: ("restart_marker_6[]", "Restart Marker (RST6)", None), 0xD7: ("restart_marker_7[]", "Restart Marker (RST7)", None), 0xDA: ("start_scan[]", "Start Of Scan (SOS)", StartOfScan), 0xDB: ("quantization[]", "Define Quantization Table (DQT)", DefineQuantizationTable), 0xDC: ("nb_line", "Define number of Lines (DNL)", None), 0xDD: ("restart_interval", "Define Restart Interval (DRI)", RestartInterval), 0xE0: ("app0", "APP0", JpegChunkApp0), 0xE1: ("exif", "Exif metadata", Exif), 0xE2: ("icc", "ICC profile", None), 0xEC: ("app12", "APP12", APP12), 0xED: ("photoshop", "Photoshop", PhotoshopMetadata), 0xEE: ("adobe", "Image encoding information for DCT filters (Adobe)", AdobeChunk), 0xFE: ("comment[]", "Comment", Comment), } START_OF_FRAME = { 0xC0: u"Baseline", 0xC1: u"Extended sequential", 0xC2: u"Progressive", 0xC3: u"Lossless", 0xC5: u"Differential sequential", 0xC6: u"Differential progressive", 0xC7: u"Differential lossless", 0xC9: u"Extended sequential, arithmetic coding", 0xCA: u"Progressive, arithmetic coding", 0xCB: u"Lossless, arithmetic coding", 0xCD: u"Differential sequential, arithmetic coding", 0xCE: u"Differential progressive, arithmetic coding", 0xCF: u"Differential lossless, arithmetic coding", } for key, text in START_OF_FRAME.iteritems(): TAG_INFO[key] = ("start_frame", "Start of frame (%s)" % text.lower(), StartOfFrame) def __init__(self, parent, name, description=None): FieldSet.__init__(self, parent, name, description) tag = self["type"].value if tag == 0xE1: # Hack for Adobe extension: XAP metadata (as XML) bytes = self.stream.readBytes(self.absolute_address + 32, 6) if bytes == "Exif\0\0": self._name = "exif" self._description = "EXIF" self._parser = Exif else: self._parser = None elif tag in self.TAG_INFO: self._name, self._description, self._parser = self.TAG_INFO[tag] else: self._parser = None def createFields(self): yield textHandler(UInt8(self, "header", "Header"), hexadecimal) if self["header"].value != 0xFF: raise ParserError("JPEG: Invalid chunk header!") yield textHandler(UInt8(self, "type", "Type"), hexadecimal) tag = self["type"].value # D0 - D7 inclusive are the restart markers if tag in [self.TAG_SOI, self.TAG_EOI] + range(0xD0, 0xD8): return yield UInt16(self, "size", "Size") size = (self["size"].value - 2) if 0 < size: if self._parser: yield self._parser(self, "content", "Chunk content", size=size * 8) else: yield RawBytes(self, "data", size, "Data") def createDescription(self): return "Chunk: %s" % self["type"].display class JpegFile(Parser): endian = BIG_ENDIAN PARSER_TAGS = { "id": "jpeg", "category": "image", "file_ext": ("jpg", "jpeg"), "mime": (u"image/jpeg",), "magic": ( ("\xFF\xD8\xFF\xE0", 0), # (Start Of Image, APP0) ("\xFF\xD8\xFF\xE1", 0), # (Start Of Image, EXIF) ("\xFF\xD8\xFF\xEE", 0), # (Start Of Image, Adobe) ), "min_size": 22 * 8, "description": "JPEG picture", "subfile": "skip", } def validate(self): if self.stream.readBytes(0, 2) != "\xFF\xD8": return "Invalid file signature" try: for index, field in enumerate(self): chunk_type = field["type"].value if chunk_type not in JpegChunk.TAG_INFO: return "Unknown chunk type: 0x%02X (chunk #%s)" % (chunk_type, index) if index == 2: # Only check 3 fields break except Exception: return "Unable to parse at least three chunks" return True def createFields(self): frame = None scan = None restart_interval = None restart_offset = 0 while not self.eof: chunk = JpegChunk(self, "chunk[]") yield chunk if chunk["type"].value in JpegChunk.START_OF_FRAME: # SOF0 [Baseline], SOF1 [Extended Sequential] if chunk["type"].value not in [0xC0, 0xC1]: self.warning( "Only supporting Baseline & Extended Sequential JPEG images so far!") frame = chunk["content"] if chunk["type"].value == JpegChunk.TAG_SOS: if not frame: self.warning("Missing or invalid SOF marker before SOS!") continue scan = chunk["content"] # hack: scan only the fields seen so far (in _fields): don't # use the generator if "restart_interval" in self._fields: restart_interval = self[ "restart_interval/content/interval"].value else: restart_interval = None yield JpegImageData(self, "image_data[]", frame, scan, restart_interval) elif chunk["type"].value in range(0xD0, 0xD8): restart_offset += 1 yield JpegImageData(self, "image_data[]", frame, scan, restart_interval, restart_offset) # TODO: is it possible to handle piped input? if self._size is None: raise NotImplementedError has_end = False size = (self._size - self.current_size) // 8 if size: if 2 < size \ and self.stream.readBytes(self._size - 16, 2) == "\xff\xd9": has_end = True size -= 2 yield RawBytes(self, "data", size, "JPEG data") if has_end: yield JpegChunk(self, "chunk[]") def createDescription(self): desc = "JPEG picture" if "start_frame/content" in self: header = self["start_frame/content"] desc += ": %ux%u pixels" % (header["width"].value, header["height"].value) return desc def createContentSize(self): if "end" in self: return self["end"].absolute_address + self["end"].size if "data" in self: start = self["data"].absolute_address elif "image_data[0]" in self: start = self["image_data[0]"].absolute_address else: return None end = self.stream.searchBytes(b"\xff\xd9", start, MAX_FILESIZE * 8) if end is not None: return end + 16 return None