""" 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 Author: Victor Stinner """ from lib.hachoir_core.error import HachoirError from lib.hachoir_parser import Parser from lib.hachoir_core.field import (FieldSet, ParserError, UInt8, UInt16, Enum, Bit, Bits, NullBits, NullBytes, String, RawBytes) from lib.hachoir_parser.image.common import PaletteRGB from lib.hachoir_core.endian import BIG_ENDIAN from lib.hachoir_core.text_handler import textHandler, hexadecimal from lib.hachoir_parser.image.exif import Exif from lib.hachoir_parser.image.photoshop_metadata import PhotoshopMetadata 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 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 UInt8(self, "component_id[]") yield UInt8(self, "high[]") yield UInt8(self, "low[]") 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 StartOfScan(FieldSet): def createFields(self): yield UInt8(self, "nr_components") for index in range(self["nr_components"].value): 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 UInt8(self, "value[]") yield RawBytes(self, "raw", 3) # TODO: What's this??? 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 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)", None), 0xD8: ("start_image", "Start of image (SOI)", None), 0xD9: ("end_image", "End of image (EOI)", 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 if tag in (self.TAG_SOI, self.TAG_EOI): 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 HachoirError: return "Unable to parse at least three chunks" return True def createFields(self): while not self.eof: chunk = JpegChunk(self, "chunk[]") yield chunk if chunk["type"].value == JpegChunk.TAG_SOS: # TODO: Read JPEG image data... break # 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 "sof/content" in self: header = self["sof/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" not in self: return None start = self["data"].absolute_address end = self.stream.searchBytes("\xff\xd9", start, MAX_FILESIZE*8) if end is not None: return end + 16 return None