class BitStream: def __init__(self, data: array = []): self.bits_used = 0 self.read_offset = 0 self.data = data def write(self, c_bytes): # ?bytes_to_write bytes_to_write = len(c_bytes) if not len(c_bytes): return self.write_bits(c_bytes, bytes_to_write << 3, True) def read(self, bytes_to_read: int): bits_to_read = bytes_to_read << 3 if self.read_offset & 7 == 0: if self.read_offset + bits_to_read > self.bits_used: return False read_offset_bytes = self.read_offset >> 3 data = self.data[read_offset_bytes:read_offset_bytes + bytes_to_read] self.read_offset += bits_to_read return data return self.read_bits(bits_to_read) def read_bits(self, bits_to_read: int, align_right: bool = False): if bits_to_read <= 0: return False if self.read_offset + bits_to_read > self.bits_used: return False offset = 0 bits_read_offset_mod8 = self.read_offset & 7 def write_bits(self, c_bytes, bits_to_write: int, align_right: bool = False): if not bits_to_write: return offset = 0 bits_used_mod8 = self.bits_used & 7 while bits_to_write: byte = c_bytes[offset] if bits_to_write < 8 and align_right: byte <<= 8 - bits_to_write if bits_used_mod8 == 0: self.data[self.bits_used >> 3] = byte else: self.data[self.bits_used >> 3] |= byte >> bits_used_mod8 if 8 - bits_used_mod8 < 8 and 8 - bits_used_mod8 < bits_to_write: self.data[(self.bits_used >> 3) + 1] = byte << (8 - bits_used_mod8) if bits_to_write >= 8: self.bits_used += 8 else: self.bits_used += bits_to_write bits_to_write -= 8 offset += 1