/usr/lib/python2.7/dist-packages/pyavm/extract.py is in python-pyavm 0.9.4-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 | from __future__ import print_function, division
import re
import warnings
from .jpeg import is_jpeg, JPEGFile
from .png import is_png, PNGFile
from .exceptions import NoXMPPacketFound
__all__ = ['extract_xmp']
def extract_xmp(image, xmp_packet_index=None):
if is_jpeg(image):
# Read in input file
jpeg_file = JPEGFile.read(image)
xmp_segments = []
# Loop through segments and search for XMP packet
for segment in jpeg_file.segments:
if segment.type == 'APP1':
if segment.bytes[4:32] == b'http://ns.adobe.com/xap/1.0/':
xmp_segments.append(segment.bytes[32:])
if len(xmp_segments) > 0:
if xmp_packet_index is None:
if len(xmp_segments) > 1:
warnings.warn("Multiple XMP packets are present but "
"xmp_packet_index was not specified, assuming "
"xmp_packet_index=0")
xmp_packet_index = 0
elif xmp_packet_index >= len(xmp_segments):
raise IndexError("xmp_packet was set to {0} but only {1} "
"packets are present".format(xmp_packet_index,
len(xmp_segments)))
return xmp_segments[xmp_packet_index]
else: # No XMP data was found
raise NoXMPPacketFound("No XMP packet present in file")
elif is_png(image):
# Read in input file
png_file = PNGFile.read(image)
xmp_chunks = []
# Loop through chunks and search for XMP packet
for chunk in png_file.chunks:
if chunk.type == b'iTXt':
if chunk.data.startswith(b'XML:com.adobe.xmp'):
xmp_chunks.append(chunk.data[22:])
if len(xmp_chunks) > 0:
if xmp_packet_index is None:
if len(xmp_chunks) > 1:
warnings.warn("Multiple XMP packets are present but "
"xmp_packet_index was not specified, assuming "
"xmp_packet_index=0")
xmp_packet_index = 0
elif xmp_packet_index >= len(xmp_chunks):
raise IndexError("xmp_packet was set to {0} but only {1} "
"packets are present".format(xmp_packet_index,
len(xmp_chunks)))
return xmp_chunks[xmp_packet_index]
else: # No XMP data was found
raise NoXMPPacketFound("No XMP packet present in file")
else:
warnings.warn("Only PNG and JPEG files can be properly parsed "
"- scanning file contents for XMP packet")
with open(image, 'rb') as fileobj:
contents = fileobj.read()
start_positions = [m.start() for m in re.finditer(b"<?xpacket begin=", contents)]
if len(start_positions) > 0:
if xmp_packet_index is None:
if len(start_positions) > 1:
warnings.warn("Multiple XMP packets are present but "
"xmp_packet_index was not specified, assuming "
"xmp_packet_index=0")
xmp_packet_index = 0
elif xmp_packet_index >= len(start_positions):
raise IndexError("xmp_packet was set to {0} but only {1} "
"packets are present".format(xmp_packet_index,
len(start_positions)))
start = start_positions[xmp_packet_index] - 2
end = contents.index(b"</x:xmpmeta>", start) + 12
else:
raise NoXMPPacketFound("No XMP packet present in file")
return contents[start:end]
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