def __save_new(self, fileobj, atoms, ilst_data, padding_func):
hdlr = Atom.render(b"hdlr", b"\x00" * 8 + b"mdirappl" + b"\x00" * 9)
meta_data = b"\x00\x00\x00\x00" + hdlr + ilst_data
try:
path = atoms.path(b"moov", b"udta")
except KeyError:
path = atoms.path(b"moov")
offset = path[-1]._dataoffset
# ignoring some atom overhead... but we don't have padding left anyway
# and padding_size is guaranteed to be less than zero
content_size = get_size(fileobj) - offset
padding_size = -len(meta_data)
assert padding_size < 0
info = PaddingInfo(padding_size, content_size)
new_padding = info._get_padding(padding_func)
new_padding = min(0xFFFFFFFF, new_padding)
free = Atom.render(b"free", b"\x00" * new_padding)
meta = Atom.render(b"meta", meta_data + free)
if path[-1].name != b"udta":
# moov.udta not found -- create one
data = Atom.render(b"udta", meta)
else:
data = meta
insert_bytes(fileobj, len(data), offset)
fileobj.seek(offset)
fileobj.write(data)
self.__update_parents(fileobj, path, len(data))
self.__update_offsets(fileobj, atoms, len(data), offset)
def __save_existing(self, fileobj, atoms, path, ilst_data, padding_func):
# Replace the old ilst atom.
ilst = path[-1]
offset = ilst.offset
length = ilst.length
# Use adjacent free atom if there is one
free = _find_padding(path)
if free is not None:
offset = min(offset, free.offset)
length += free.length
# Always add a padding atom to make things easier
padding_overhead = len(Atom.render(b"free", b""))
content_size = get_size(fileobj) - (offset + length)
padding_size = length - (len(ilst_data) + padding_overhead)
info = PaddingInfo(padding_size, content_size)
new_padding = info._get_padding(padding_func)
# Limit padding size so we can be sure the free atom overhead is as we
# calculated above (see Atom.render)
new_padding = min(0xFFFFFFFF, new_padding)
ilst_data += Atom.render(b"free", b"\x00" * new_padding)
resize_bytes(fileobj, length, len(ilst_data), offset)
delta = len(ilst_data) - length
fileobj.seek(offset)
fileobj.write(ilst_data)
self.__update_parents(fileobj, path[:-1], delta)
self.__update_offsets(fileobj, atoms, delta, offset)
def __save_existing(self, fileobj, atoms, path, ilst_data, padding_func):
# Replace the old ilst atom.
ilst = path[-1]
offset = ilst.offset
length = ilst.length
# Use adjacent free atom if there is one
free = _find_padding(path)
if free is not None:
offset = min(offset, free.offset)
length += free.length
# Always add a padding atom to make things easier
padding_overhead = len(Atom.render(b"free", b""))
content_size = get_size(fileobj) - (offset + length)
padding_size = length - (len(ilst_data) + padding_overhead)
info = PaddingInfo(padding_size, content_size)
new_padding = info._get_padding(padding_func)
# Limit padding size so we can be sure the free atom overhead is as we
# calculated above (see Atom.render)
new_padding = min(0xFFFFFFFF, new_padding)
ilst_data += Atom.render(b"free", b"\x00" * new_padding)
resize_bytes(fileobj, length, len(ilst_data), offset)
delta = len(ilst_data) - length
fileobj.seek(offset)
fileobj.write(ilst_data)
self.__update_parents(fileobj, path[:-1], delta)
self.__update_offsets(fileobj, atoms, delta, offset)
def __save_new(self, fileobj, atoms, ilst_data, padding_func):
hdlr = Atom.render(b"hdlr", b"\x00" * 8 + b"mdirappl" + b"\x00" * 9)
meta_data = b"\x00\x00\x00\x00" + hdlr + ilst_data
try:
path = atoms.path(b"moov", b"udta")
except KeyError:
path = atoms.path(b"moov")
offset = path[-1]._dataoffset
# ignoring some atom overhead... but we don't have padding left anyway
# and padding_size is guaranteed to be less than zero
content_size = get_size(fileobj) - offset
padding_size = -len(meta_data)
assert padding_size < 0
info = PaddingInfo(padding_size, content_size)
new_padding = info._get_padding(padding_func)
new_padding = min(0xFFFFFFFF, new_padding)
free = Atom.render(b"free", b"\x00" * new_padding)
meta = Atom.render(b"meta", meta_data + free)
if path[-1].name != b"udta":
# moov.udta not found -- create one
data = Atom.render(b"udta", meta)
else:
data = meta
insert_bytes(fileobj, len(data), offset)
fileobj.seek(offset)
fileobj.write(data)
self.__update_parents(fileobj, path, len(data))
self.__update_offsets(fileobj, atoms, len(data), offset)
def test_props(self):
info = PaddingInfo(10, 100)
self.assertEqual(info.size, 100)
self.assertEqual(info.padding, 10)
info = PaddingInfo(-10, 100)
self.assertEqual(info.size, 100)
self.assertEqual(info.padding, -10)
def test_default_strategy(self):
s = 100000
self.assertEqual(PaddingInfo(10, s).get_default_padding(), 10)
self.assertEqual(PaddingInfo(-10, s).get_default_padding(), 1124)
self.assertEqual(PaddingInfo(0, s).get_default_padding(), 0)
self.assertEqual(PaddingInfo(20000, s).get_default_padding(), 1124)
self.assertEqual(PaddingInfo(10, 0).get_default_padding(), 10)
self.assertEqual(PaddingInfo(-10, 0).get_default_padding(), 1024)
self.assertEqual(PaddingInfo(1050, 0).get_default_padding(), 1050)
self.assertEqual(PaddingInfo(20000, 0).get_default_padding(), 1024)
def test_repr(self):
info = PaddingInfo(10, 100)
self.assertEqual(repr(info), "<PaddingInfo size=100 padding=10>")
