Get a sequence of tags.

def _process_tags(self):
        """Get a sequence of tags."""
        tags = []

        while True:
            tag_bf = unpack_ui16(self._src)
            tag_type = tag_bf >> 6   # upper 10 bits
            if tag_type == 0:
                # the end
                break
            tag_len = tag_bf & 0x3f  # last 6 bits
            if tag_len == 0x3f:
                # the length is the next four bytes!
                tag_len = unpack_ui32(self._src)

            try:
                tag_name = TAG_NAMES[tag_type]
            except KeyError:
                # malformed SWF, create and unknown object with malformed tag
                tag_payload = self._src.read(tag_len)
                _dict = {
                    '__str__': _repr,
                    '__repr__': _repr,
                    'name': 'UnspecifiedObject(tag={!r})'.format(tag_type),
                }
                tag = type("UnknownObject", (SWFObject,), _dict)()
                tag.raw_payload = tag_payload
                tags.append(tag)
                continue

            try:
                tag_meth = getattr(self, "_handle_tag_" + tag_name.lower())
            except AttributeError:
                if self.unknown_alert:
                    raise ValueError("Unknown tag: " + repr(tag_name))

                tag_payload = self._src.read(tag_len)
                _dict = {'__str__': _repr, '__repr__': _repr, 'name': tag_name}
                tag = type("UnknownObject", (SWFObject,), _dict)()
                tag.raw_payload = tag_payload
                tags.append(tag)
                continue

            # we know the tag type, and have the handler, let's process it
            prev_pos = self._src.tell()
            self._src.guard = tag_len
            try:
                with ReadQuantityController(self._src, tag_len):
                    tag = tag_meth()
                assert tag is not None, tag_name
            except ValueError:
                # an attempt to read too much happened; create a failing
                # object with the raw payload
                self._src.guard = None
                self._src.seek(prev_pos)
                tag_payload = self._src.read(tag_len)
                _dict = {'__str__': _repr, '__repr__': _repr, 'name': tag_name}
                tag = type("FailingObject", (SWFObject,), _dict)()
                tag.raw_payload = tag_payload
            tags.append(tag)
        return tags