"""
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
Author: Victor Stinner
"""
from hachoir_core.error import HachoirError
from hachoir_parser import Parser
from hachoir_core.field import (FieldSet, ParserError,
UInt8, UInt16, Enum,
Bit, Bits, NullBits, NullBytes,
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
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 StartOfFrame(FieldSet):
def createFields(self):
yield UInt8(self, "precision")
if self["precision"].value != 8:
raise ParserError("JPEG error: Only 8-bit precision is supported")
yield UInt16(self, "height")
yield UInt16(self, "width")
yield UInt8(self, "nr_components")
if self["nr_components"].value not in (1, 3):
raise ParserError("JPEG error: Only gray or true-color JPEGS supported")
for index in range(self["nr_components"].value):
yield UInt8(self, "component_id[]")
yield UInt8(self, "high[]")
yield UInt8(self, "low[]")
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")
if self["nr_components"].value not in (1, 3):
raise ParserError("JPEG error: Invalid SOS marker")
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),
0xED: ("photoshop", "Photoshop", PhotoshopMetadata),
0xEE: ("adobe", "Image encoding information for DCT filters (Adobe)", AdobeChunk),
0xFE: ("comment[]", "Comment", None),
}
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 in self.TAG_INFO:
self._name, self._description, self._parser = self.TAG_INFO[tag]
elif tag == 0xE1:
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
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"
}
def validate(self):
if self.stream.readBytes(0, 2) != "\xFF\xD8":
return "Invalid file signature"
try:
self.readFirstFields(3)
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
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