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More testing for jpx wrapping. Needs some refactoring, though. #206

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jevans 2014-03-25 21:17:29 -04:00
commit 9b4e0a10fb
3 changed files with 97 additions and 18 deletions
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39
glymur/jp2k.py
View file

@ -607,7 +607,12 @@ class Jp2k(Jp2kBox):
self.parse()
def wrap(self, filename, boxes=None):
"""Create a new JP2/JPX file wrapped in a new jacket.
"""Create a new JP2/JPX file wrapped in a new set of JP2 boxes.
This method is primarily aimed at wrapping a raw codestream in a set of
of JP2 boxes (turning it into a JP2 file instead of just a raw
codestream), or rewrapping a codestream in a JP2 file in a new "jacket"
of JP2 boxes.
Parameters
----------
@ -617,6 +622,8 @@ class Jp2k(Jp2kBox):
JP2 box definitions to define the JP2 file format. If not
provided, a default ""jacket" is assumed, consisting of JP2
signature, file type, JP2 header, and contiguous codestream boxes.
A JPX file rewrapped without the boxes argument results in a JP2
file encompassing the first codestream.
Returns
-------
@ -675,20 +682,46 @@ class Jp2k(Jp2kBox):
with open(self.filename, 'rb') as ifile:
ofile.write(ifile.read())
else:
# OK, I'm a jp2 file. Need to find out where the
# OK, I'm a jp2/jpx file. Need to find out where the
# raw codestream actually starts.
offset = box.offset
length = box.length
if offset == -1:
if self.box[1].brand == 'jpx ':
msg = "The codestream box must have its offset "
msg += "and length attributes fully specified "
msg += "if the file type brand is JPX."
raise IOError(msg)
# Find the first codestream in the file.
jp2c = [box for box in self.box
if box.box_id == 'jp2c']
offset = jp2c[0].offset
length = jp2c[0].length
# Verify that the specified codestream is right.
with open(self.filename, 'rb') as ifile:
ifile.seek(offset)
ofile.write(ifile.read(length))
read_buffer = ifile.read(8)
L, T = struct.unpack_from('>I4s', read_buffer, 0)
if T != b'jp2c':
msg = "Unable to locate the specified codestream."
raise IOError(msg)
if L == 0:
# The length of the box is presumed to last
# until the end of the file. Compute the
# effective length of the box.
L = os.path.getsize(ifile.name) - fptr.tell() + 8
elif L == 1:
# The length of the box is in the XL field, a
# 64-bit value.
read_buffer = ifile.read(8)
L, = struct.unpack('>Q', read_buffer)
ifile.seek(offset)
read_buffer = ifile.read(L)
ofile.write(read_buffer)
ofile.flush()

61
glymur/test/test_jp2box.py
View file

@ -858,6 +858,67 @@ class TestWrap(unittest.TestCase):
with self.assertRaises(IOError):
j2k.wrap(tfile.name, boxes=boxes)
def test_wrap_jpx_to_jp2_with_unadorned_jpch(self):
"""A JPX file rewrapped with plain jpch is not allowed."""
with tempfile.NamedTemporaryFile(suffix='.jp2') as tfile1:
jpx = Jp2k(self.jpxfile)
boxes = [jpx.box[0], jpx.box[1], jpx.box[2],
glymur.jp2box.ContiguousCodestreamBox()]
with self.assertRaises(IOError):
jpx.wrap(tfile1.name, boxes=boxes)
def test_wrap_jpx_to_jp2_with_incorrect_jp2c_offset(self):
"""Reject A JPX file rewrapped with bad jp2c offset."""
with tempfile.NamedTemporaryFile(suffix='.jp2') as tfile1:
jpx = Jp2k(self.jpxfile)
jpch = jpx.box[5]
# The offset should be 902.
jpch.offset = 901
jpch.length = 313274
boxes = [jpx.box[0], jpx.box[1], jpx.box[2], jpch]
with self.assertRaises(IOError):
jpx.wrap(tfile1.name, boxes=boxes)
def test_wrap_jpx_to_jp2_with_correctly_specified_jp2c(self):
"""Accept A JPX file rewrapped with good jp2c."""
with tempfile.NamedTemporaryFile(suffix='.jp2') as tfile1:
jpx = Jp2k(self.jpxfile)
jpch = jpx.box[5]
# This time get it right.
jpch.offset = 903
jpch.length = 313274
boxes = [jpx.box[0], jpx.box[1], jpx.box[2], jpch]
jp2 = jpx.wrap(tfile1.name, boxes=boxes)
act_ids = [box.box_id for box in jp2.box]
exp_ids = ['jP ', 'ftyp', 'jp2h', 'jp2c']
self.assertEqual(act_ids, exp_ids)
act_offsets = [box.offset for box in jp2.box]
exp_offsets = [0, 12, 40, 887]
self.assertEqual(act_offsets, exp_offsets)
act_lengths = [box.length for box in jp2.box]
exp_lengths = [12, 28, 847, 313274]
self.assertEqual(act_lengths, exp_lengths)
def test_full_blown_jpx(self):
"""Rewrap a jpx file."""
with tempfile.NamedTemporaryFile(suffix='.jp2') as tfile1:
jpx = Jp2k(self.jpxfile)
idx = list(range(5)) + list(range(9, 12)) + list(range(6, 9)) + [12]
boxes = [jpx.box[j] for j in idx]
jpx2 = jpx.wrap(tfile1.name, boxes=boxes)
exp_ids = [box.box_id for box in boxes]
lengths = [box.length for box in jpx.box]
exp_lengths = [lengths[j] for j in idx]
act_ids = [box.box_id for box in jpx2.box]
act_lengths = [box.length for box in jpx2.box]
self.assertEqual(exp_ids, act_ids)
self.assertEqual(exp_lengths, act_lengths)
class TestJp2Boxes(unittest.TestCase):
"""Tests for canonical JP2 boxes."""

15
glymur/test/test_jp2box_jpx.py
View file

@ -45,21 +45,6 @@ class TestJPXWrap(unittest.TestCase):
def tearDown(self):
os.unlink(self.xmlfile)
def test_full_blown_jpx(self):
"""Rewrap a jpx file."""
with tempfile.NamedTemporaryFile(suffix='.jp2') as tfile1:
jpx = Jp2k(self.jpxfile)
idx = list(range(5)) + list(range(9, 12)) + list(range(6, 9)) + [12]
boxes = [jpx.box[j] for j in idx]
jpx2 = jpx.wrap(tfile1.name, boxes=boxes)
exp_ids = [box.box_id for box in boxes]
lengths = [box.length for box in jpx.box]
exp_lengths = [lengths[j] for j in idx]
act_ids = [box.box_id for box in jpx2.box]
act_lengths = [box.length for box in jpx2.box]
self.assertEqual(exp_ids, act_ids)
self.assertEqual(exp_lengths, act_lengths)
def test_jpx_ftbl_no_codestream(self):
"""Can have a jpx with no codestream."""
with tempfile.NamedTemporaryFile(suffix='.jp2') as tfile1: