def test_non_match(self, regex, sequence):
m = Matcher(regex)
for i, symbol in enumerate(sequence):
if i == len(sequence) - 1:
assert m.match_symbol(symbol) is False
else:
assert m.match_symbol(symbol) is True
def test_incomplete_match(self):
m = Matcher("foo bar+")
assert not m.is_complete()
assert m.match_symbol("foo")
assert not m.is_complete()
assert m.match_symbol("bar")
assert m.is_complete()
assert m.match_symbol("bar")
assert m.is_complete()
def test_bad_parse_code(self):
state = bytes_to_state(
serialise_to_bytes(bitstream.ParseInfo(parse_code=0x11)))
state["_generic_sequence_matcher"] = Matcher(".*")
with pytest.raises(decoder.BadParseCode) as exc_info:
decoder.parse_info(state)
assert exc_info.value.parse_code == 0x11
def parse_parameters(state):
"""(11.2.1)"""
state["major_version"] = read_uint(state)
# (11.2.2) Check the major_version is at least 1. (It may need to be
# higher depending on the features used on the sequence, but this will be
# checked as the stream is processed. Later, at the end of the stream we'll
# also check the major_version was not too high for the set of features
# actually used.)
## Begin not in spec
if state["major_version"] < MINIMUM_MAJOR_VERSION:
raise MajorVersionTooLow(state["major_version"])
## End not in spec
state["minor_version"] = read_uint(state)
# (11.2.2) Check the minor_version is 0.
## Begin not in spec
if state["minor_version"] != 0:
raise MinorVersionNotZero(state["minor_version"])
## End not in spec
state["profile"] = read_uint(state)
# (C.2) Profile must be a supported value
assert_in_enum(state["profile"], Profiles, BadProfile) ## Not in spec
# (11.2.2) Profile must be supported by current version
## Begin not in spec
minimum_required_version = profile_version_implication(state["profile"])
if state["major_version"] < minimum_required_version:
raise ProfileNotSupportedByVersion(state["profile"], state["major_version"])
log_version_lower_bound(state, minimum_required_version)
## End not in spec
state["level"] = read_uint(state)
# (C.3) Level must be a supported value
assert_in_enum(state["level"], Levels, BadLevel) ## Not in spec
# (C.3) Levels may constrain the order and choice of data units in a
# sequence. See the various level standards documents (e.g. ST 2042-2) for
# details.
## Begin not in spec
if "_level_sequence_matcher" not in state:
state["_level_sequence_matcher"] = Matcher(
LEVEL_SEQUENCE_RESTRICTIONS[state["level"]].sequence_restriction_regex
)
# If we're at this point we're currently reading the first sequence
# header (in the first data unit) of a sequence. Advance the state
# machine accordingly.
assert state["_level_sequence_matcher"].match_symbol("sequence_header")
## End not in spec
# (C.3) Levels may constrain the allowed profiles and versions
## Begin not in spec
assert_level_constraint(state, "level", state["level"])
assert_level_constraint(state, "profile", state["profile"])
assert_level_constraint(state, "major_version", state["major_version"])
assert_level_constraint(state, "minor_version", state["minor_version"])
def test_level_restricts_sequence(self):
state = bytes_to_state(
serialise_to_bytes(
bitstream.ParseInfo(
parse_code=tables.ParseCodes.end_of_sequence, )))
state["_generic_sequence_matcher"] = Matcher(".*")
state["_level_sequence_matcher"] = Matcher("sequence_header")
state["level"] = tables.Levels.unconstrained
with pytest.raises(decoder.LevelInvalidSequence) as exc_info:
decoder.parse_info(state)
assert exc_info.value.parse_code is tables.ParseCodes.end_of_sequence
assert exc_info.value.expected_parse_codes == [
tables.ParseCodes.sequence_header
]
assert exc_info.value.expected_end is False
assert exc_info.value.level == tables.Levels.unconstrained
def test_allowed_zero_next_parse_offset_for_pictures(self, parse_code):
state = bytes_to_state(
serialise_to_bytes(
bitstream.ParseInfo(
parse_code=parse_code,
next_parse_offset=0,
)))
state["major_version"] = 3
state["_generic_sequence_matcher"] = Matcher(".*")
decoder.parse_info(state)
def test_never_allowed_invalid_offset(self, parse_code, next_parse_offset):
state = bytes_to_state(
serialise_to_bytes(
bitstream.ParseInfo(
parse_code=parse_code,
next_parse_offset=next_parse_offset,
)))
state["_generic_sequence_matcher"] = Matcher(".*")
with pytest.raises(decoder.InvalidNextParseOffset) as exc_info:
decoder.parse_info(state)
assert exc_info.value.next_parse_offset == next_parse_offset
def test_not_allowed_zero_next_parse_offset_for_non_pictures(
self, parse_code):
state = bytes_to_state(
serialise_to_bytes(
bitstream.ParseInfo(
parse_code=parse_code,
next_parse_offset=0,
)))
state["_generic_sequence_matcher"] = Matcher(".*")
with pytest.raises(decoder.MissingNextParseOffset) as exc_info:
decoder.parse_info(state)
assert exc_info.value.parse_code == parse_code
def test_non_zero_previous_parse_offset_for_start_of_sequence(self):
state = bytes_to_state(
serialise_to_bytes(
bitstream.ParseInfo(
parse_code=tables.ParseCodes.end_of_sequence,
previous_parse_offset=1,
)))
state["_generic_sequence_matcher"] = Matcher(".*")
with pytest.raises(decoder.NonZeroPreviousParseOffsetAtStartOfSequence
) as exc_info:
decoder.parse_info(state)
assert exc_info.value.previous_parse_offset == 1
def test_invalid_generic_sequence(self):
state = bytes_to_state(
serialise_to_bytes(
bitstream.ParseInfo(
parse_code=tables.ParseCodes.end_of_sequence, )))
state["_generic_sequence_matcher"] = Matcher("sequence_header")
with pytest.raises(decoder.GenericInvalidSequence) as exc_info:
decoder.parse_info(state)
assert exc_info.value.parse_code is tables.ParseCodes.end_of_sequence
assert exc_info.value.expected_parse_codes == [
tables.ParseCodes.sequence_header
]
assert exc_info.value.expected_end is False
def test_parse_code_in_sequence(regex, expected_parse_codes, expected_end):
m = Matcher(regex)
class CustomException(Exception):
def __init__(
self, parse_code, actual_expected_parse_codes, actual_expected_end, foo
):
assert parse_code is ParseCodes.auxiliary_data
assert set(actual_expected_parse_codes) == expected_parse_codes
assert actual_expected_end == expected_end
assert foo == "bar"
with pytest.raises(CustomException):
assert_parse_code_in_sequence(
ParseCodes.auxiliary_data, m, CustomException, "bar"
)
def test_parse_code_sequence_ended(regex, expected_parse_codes):
m = Matcher(regex)
class CustomException(Exception):
def __init__(
self, parse_code, actual_expected_parse_codes, actual_expected_end, foo
):
assert parse_code is None
if expected_parse_codes is None:
assert actual_expected_parse_codes is None
else:
assert set(actual_expected_parse_codes) == expected_parse_codes
assert actual_expected_end is False
assert foo == "bar"
with pytest.raises(CustomException):
assert_parse_code_sequence_ended(m, CustomException, "bar")
def test_profile_restricts_allowed_parse_codes(self, parse_code, allowed):
state = bytes_to_state(
serialise_to_bytes(
bitstream.ParseInfo(
parse_code=parse_code,
next_parse_offset=tables.PARSE_INFO_HEADER_BYTES,
)))
state["_generic_sequence_matcher"] = Matcher(".*")
state["profile"] = tables.Profiles.high_quality
if allowed:
decoder.parse_info(state)
else:
with pytest.raises(
decoder.ParseCodeNotAllowedInProfile) as exc_info:
decoder.parse_info(state)
assert exc_info.value.parse_code == tables.ParseCodes.low_delay_picture
assert exc_info.value.profile == tables.Profiles.high_quality
def test_inconsistent_next_parse_offset(self):
state = bytes_to_state(
serialise_to_bytes(
bitstream.ParseInfo(
parse_code=tables.ParseCodes.padding_data,
next_parse_offset=tables.PARSE_INFO_HEADER_BYTES + 10,
)) + b"\x00" * 9 +
serialise_to_bytes(
bitstream.ParseInfo(
parse_code=tables.ParseCodes.end_of_sequence,
previous_parse_offset=tables.PARSE_INFO_HEADER_BYTES + 9,
)))
state["_generic_sequence_matcher"] = Matcher(".*")
decoder.parse_info(state)
decoder.read_uint_lit(state, 9)
with pytest.raises(decoder.InconsistentNextParseOffset) as exc_info:
decoder.parse_info(state)
assert exc_info.value.parse_info_offset == 0
assert exc_info.value.next_parse_offset == tables.PARSE_INFO_HEADER_BYTES + 10
assert exc_info.value.true_parse_offset == tables.PARSE_INFO_HEADER_BYTES + 9
def parse_sequence(state):
"""
(10.4.1) Parse a complete VC-2 sequence.
"""
reset_state(state)
# (10.4.1) Check that the sequence starts with a sequence_header and ends
# with and end_of_sequence.
## Begin not in spec
state["_generic_sequence_matcher"] = Matcher("sequence_header .* end_of_sequence")
## End not in spec
state["_num_pictures_in_sequence"] = 0 ## Not in spec
state["_fragment_slices_remaining"] = 0 ## Not in spec
parse_info(state)
while not is_end_of_sequence(state):
if is_seq_header(state):
state["video_parameters"] = sequence_header(state)
elif is_picture(state):
# Errata: fragments under-specified in spec
#
# (14.2) Picture data units may not be interleaved with in-progress
# fragmented pictures.
## Begin not in spec
if state["_fragment_slices_remaining"] != 0:
raise PictureInterleavedWithFragmentedPicture(
state["_picture_initial_fragment_offset"],
tell(state),
state["fragment_slices_received"],
state["_fragment_slices_remaining"],
)
## End not in spec
picture_parse(state)
picture_decode(state)
elif is_fragment(state):
fragment_parse(state)
if state["fragmented_picture_done"]:
picture_decode(state)
elif is_auxiliary_data(state):
auxiliary_data(state)
elif is_padding_data(state):
padding(state)
parse_info(state)
# (10.4.1) and (C.3) Check sequence structure allowed to end at this point
## Begin not in spec
assert_parse_code_sequence_ended(
state["_generic_sequence_matcher"], GenericInvalidSequence
)
if "_level_sequence_matcher" in state:
assert_parse_code_sequence_ended(
state["_level_sequence_matcher"],
LevelInvalidSequence,
state["level"],
)
## End not in spec
# Errata: fragments under-specified in spec
#
# (14.2) Ensure that any fragmented picture has been received completely by
# the end of the stream.
## Begin not in spec
if state["_fragment_slices_remaining"] != 0:
raise SequenceContainsIncompleteFragmentedPicture(
state["_picture_initial_fragment_offset"],
state["fragment_slices_received"],
state["_fragment_slices_remaining"],
)
## End not in spec
# (10.4.3) When pictures are fields, a sequence should contain a whole
# number of frames
## Begin not in spec
if state["picture_coding_mode"] == PictureCodingModes.pictures_are_fields:
if state["_num_pictures_in_sequence"] % 2 != 0:
raise OddNumberOfFieldsInSequence(state["_num_pictures_in_sequence"])
## End not in spec
# (11.2.2) Check that the major_version number used was the lowest which
# would be permissible for the features actually used
assert_major_version_is_minimal(state) ## Not in spec
def test_valid_next_symbols(self, regex, next_symbols):
m = Matcher(regex)
assert m.valid_next_symbols() == next_symbols
def test_complete_matches(self, regex, sequence):
m = Matcher(regex)
for symbol in sequence:
assert m.match_symbol(symbol) is True
assert m.is_complete() is True
