degal: comparison degal/exif.py

equal deleted inserted replaced

-:effae6f38749
+:a4f605bd122c
 return self.tag_data.name
 else :
 return None
+def is_subifd (self) :
+"""
+Tests if this Tag is of a IFDTag type
+"""
+return self.tag_data and isinstance(self.tag_data, exif_data.IFDTag)
+@lazy_load
+def subifd (self) :
+"""
+Load the sub-IFD for this tag
+"""
+# the tag_dict to use
+tag_dict = self.tag_data.ifd_tags or self.ifd.tag_dict
+# construct, return
+return self.ifd.exif._load_subifd(self, tag_dict)
 def process_values (self, raw_values) :
 """
 Process the given raw values unpacked from the file.
 """
 class IFD (Buffer) :
 """
 Represents an IFD (Image file directory) region in EXIF data.
 """
-def __init__ (self, buffer, tag_dict, **buffer_opts) :
+def __init__ (self, exif, buffer, tag_dict, **buffer_opts) :
 """
 Access the IFD data from the given bufferable object with given buffer opts.
 This will read the `count` and `next_offset` values.
 """
 # init
 super(IFD, self).__init__(buffer, **buffer_opts)
 # store
+self.exif = exif
 self.tag_dict = tag_dict
 # read header
 self.count = self.pread_item(0, 'H')
 for offset in self.iter_offsets(self.count, IFD_ENTRY_SIZE, 0x02) :
 # read the tag data
 tag, type, count, data_raw = self.pread_struct(offset, 'HHI4s')
 # yield the new Tag
-yield Tag(self, offset, tag, type, count, data_raw)
+yield Tag(self, self.offset + offset, tag, type, count, data_raw)
+def get_tags (self, filter=None) :
+"""
+Yield a series of tag objects for this IFD and all sub-IFDs.
+"""
+for tag in self.tags :
+if tag.is_subifd() :
+# recurse
+for subtag in tag.subifd.get_tags(filter=filter) :
+yield subtag
+else :
+# normal tag
+yield tag
 class EXIF (Buffer) :
 """
 Represents the EXIF data embedded in some image file in the form of a Region.
 """
-def __init__ (self, buffer, tags=None, **buffer_opts) :
+def __init__ (self, buffer, **buffer_opts) :
 """
 Access the EXIF data from the given bufferable object with the given buffer options.
-`tags`, if given, specifies that only the given named tags should be loaded.
 """
 # init Buffer
 super(EXIF, self).__init__(buffer, **buffer_opts)
 # starting offset
 offset = self.pread_item(0x04, 'I')
 while offset :
 # create and read the IFD, operating on the right sub-buffer
-ifd = IFD(self.buf, exif_data.EXIF_TAGS, offset=offset)
+ifd = IFD(self, self.buf, exif_data.EXIF_TAGS, offset=offset)
 # yield it
 yield ifd
 # skip to next offset
 offset = ifd.next_offset
-def iter_all_ifds (self) :
+def _load_subifd (self, tag, tag_dict) :
 """
-Iterate over all of the IFDs contained within this EXIF, or within other IFDs.
+Creates and returns a sub-IFD for the given tag.
 """
+# locate it
+offset, = self.tag_values_raw(tag)
+# construct the new IFD
+return IFD(self, self.buf, tag_dict, offset=offset)
 def tag_data_info (self, tag) :
 """
 Calculate the location, format and size of the given tag's data.
 Returns a (fmt, offset, size) tuple.
 if not values :
 return ""
 # return as comma-separated formatted string, yes
 return tag.readable_value(values)
+def get_main_tags (self, **opts) :
+"""
+Get the tags for the main image's IFD as a dict.
+"""
+if not self.ifds :
+# weird case
+raise Exception("No IFD for main image found")
+# the main IFD is always the first one
+main_ifd = self.ifds[0]
+# do it
+return dict((tag.name, self.tag_value(tag)) for tag in main_ifd.get_tags(**opts))
 # mapping from two-byte TIFF byte order marker to struct prefix
 TIFF_BYTE_ORDER = {
 'II': '<',
 'MM': '>',
 file = open(path, 'rb')
 # try and load it
 return func(file, **opts)
+def dump_tag (exif, i, tag, indent=2) :
+"""
+Dump the given tag
+"""
+data_info = exif.tag_data_info(tag)
+if data_info :
+data_fmt, data_offset, data_size = data_info
+else :
+data_fmt = data_offset = data_size = None
+print "%sTag:%d offset=%#04x(%#08x), tag=%d/%s, type=%d/%s, count=%d, fmt=%s, offset=%#04x, size=%s, is_subifd=%s:" % (
+'\t'*indent,
+i,
+tag.offset, tag.offset + exif.offset,
+tag.tag, tag.name or '???',
+tag.type, tag.type_name if tag.type_data else '???',
+tag.count,
+data_fmt, data_offset, data_size,
+tag.is_subifd(),
+)
+if tag.is_subifd() :
+# recurse
+dump_ifd(exif, 0, tag.subifd, indent + 1)
+else :
+# dump each value
+values = exif.tag_values(tag)
+for i, value in enumerate(values) :
+print "%s\t%02d: %.120r" % ('\t'*indent, i, value)
+# and then the readable one
+print "%s\t->  %.120s" % ('\t'*indent, tag.readable_value(values), )
+def dump_ifd (exif, i, ifd, indent=1) :
+"""
+Dump the given IFD, recursively
+"""
+print "%sIFD:%d offset=%#04x(%#08x), count=%d, next=%d:" % (
+'\t'*indent,
+i,
+ifd.offset, ifd.offset + exif.offset,
+ifd.count,
+ifd.next_offset
+)
+for i, tag in enumerate(ifd.tags) :
+# dump
+dump_tag(exif, i, tag, indent + 1)
 def dump_exif (exif) :
 """
 Dump all tags from the given EXIF object to stdout
 """
 print "EXIF offset=%#08x, size=%d:" % (exif.offset, exif.size)
 for i, ifd in enumerate(exif.ifds) :
-print "\tIFD:%d offset=%#04x(%#08x), count=%d, next=%d:" % (
+# dump
-i,
+dump_ifd(exif, i, ifd)
-ifd.offset, ifd.offset + exif.offset,
-ifd.count,
-ifd.next_offset
+def list_tags (exif) :
-)
+"""
+Print a neat listing of tags to stdout
-for i, tag in enumerate(ifd.tags) :
+"""
-data_info = exif.tag_data_info(tag)
+for k, v in exif.get_main_tags().iteritems() :
-if data_info :
+print "%30s: %s" % (k, v)
-data_fmt, data_offset, data_size = data_info
+def main (path, debug=False) :
-else :
-data_fmt = data_offset = data_size = None
-print "\t\tTag:%d offset=%#04x(%#08x), tag=%d/%s, type=%d/%s, count=%d, fmt=%s, offset=%#04x, size=%s:" % (
-i,
-tag.offset, tag.offset + exif.offset,
-tag.tag, tag.name or '???',
-tag.type, tag.type_name if tag.type_data else '???',
-tag.count,
-data_fmt, data_offset, data_size,
-)
-values = exif.tag_values(tag)
-for i, value in enumerate(values) :
-print "\t\t\t%02d: %r" % (i, value)
-print "\t\t\t->  %s" % (tag.readable_value(values), )
-def main (path, quiet=False) :
 """
 Load and dump EXIF data from the given path
 """
 # try and load it
 exif = load_path(path)
 if not exif :
 raise Exception("No EXIF data found")
-if not quiet :
+if debug :
 # dump it
 print "%s: " % path
 print
 dump_exif(exif)
+else :
+# list them
+list_tags(exif)
 if __name__ == '__main__' :
 from sys import argv
-main(argv[1], '-q' in argv)
+main(argv[1], '-d' in argv)

branch	new-exif
changeset 106	a4f605bd122c
parent 105	effae6f38749
child 107	2e2ef5c99985