class Frame(object):
"""Basic frame object, all other frametypes extend from this."""
_buffer = None
length = None
@property
def view(self):
"""view() -> memoryview
Returns a memoryview of the frame's data.
"""
return self._buffer.view()
def bytes(self):
"""bytes() -> bytearray()
Returns a copy of the frame's data.
"""
return self._buffer.bytes()
def __eq__(self, other):
if isinstance(other, Frame):
return self._buffer == other._buffer
else:
return self._buffer == other
def _frame_assembled(self):
"""Implement this method if you need to do sth. as soon
as the frames buffer is available."""
pass
def append(self, buf):
"""append(buf) -> nothing
Append data from buf to this frame, up to the frame's
length. Expects a ZeroCopyBuffer as input.
"""
self._buffer = ZeroCopyBuffer(self.length)
buf.delete(self._buffer.extend(buf))
if (len(self._buffer) < self.length):
assert(len(buf) == 0)
self._buffer.fill(buf._fileobj, completely=True)
assert(len(self._buffer) == self.length)
self._frame_assembled()
def append(self, buf):
"""append(buf) -> nothing
Append data from buf to this frame, up to the frame's
length. Expects a ZeroCopyBuffer as input.
"""
self._buffer = ZeroCopyBuffer(self.length)
buf.delete(self._buffer.extend(buf))
if (len(self._buffer) < self.length):
assert(len(buf) == 0)
self._buffer.fill(buf._fileobj, completely=True)
assert(len(self._buffer) == self.length)
self._frame_assembled()
def frames(self, skip_invalid_data = True, emit_meta_frames = True, \
emit_riff_frames = True, emit_id3_frames = True, emit_ape_frames = True):
"""frames(skip_invalid_data = True, emit_meta_frames = True, \
emit_riff_frames = True, emit_id3_frames = True, emit_ape_frames = True) -> frame data
Reads frames one-by-one, according to the method's arguments.
Raises an MP3Error if invalid data is encountered and ingore_invalid_data
is False.
"""
in_sync = True
try:
buf = ZeroCopyBuffer(self._buffer_size, self._inobj)
buf.fill()
while len(buf) > 4: # We need at least 4 bytes for our shortest header
# Try to parse a frame
frame = None
for frame_class in self._FRAME_TYPES:
try:
frame = frame_class(buf, self, strict=not in_sync)
break
except _InvalidFrame:
pass
if frame and not in_sync:
# Recover from lost sync
try:
buf.fill(at_least = frame.length + 12)
# See if there is a consequent valid frame
for frame_class in self._FRAME_TYPES:
try:
frame_class(buf, self, offset=frame.length, strict=True)
in_sync = True
break
except _InvalidFrame:
pass
frame = in_sync and frame or None
except EOFError:
# Not enough data left to check the next frame, accept it anyways
pass
if frame:
# Consumed data is removed from the buffer in Frame.append()
frame.append(buf)
if (isinstance(frame, ID3Frame) and (emit_meta_frames or emit_id3_frames)) or \
(isinstance(frame, APEFrame) and (emit_meta_frames or emit_ape_frames)) or \
(isinstance(frame, RIFFFrame) and emit_riff_frames) or \
isinstance(frame, MPEGFrame):
yield frame
else:
in_sync = False
if not skip_invalid_data:
raise MP3Error('encountered invalid data')
buf.delete(1)
if len(buf) < 12:
buf.fill(self._inobj)
except EOFError:
if not skip_invalid_data:
raise MP3Error('encountered invalid data')
finally:
del buf
