pyDubMod.py 文件源码

def read(self, size = -1):
            buffer = self.audio_reader.readframes(self.audio_reader.getnframes() if size == -1 else size)
            if not isinstance(buffer, bytes): buffer = b"" # workaround for https://bugs.python.org/issue24608

            sample_width = self.audio_reader.getsampwidth()
            if not self.little_endian: # big endian format, convert to little endian on the fly
                if hasattr(audioop, "byteswap"): # ``audioop.byteswap`` was only added in Python 3.4 (incidentally, that also means that we don't need to worry about 24-bit audio being unsupported, since Python 3.4+ always has that functionality)
                    buffer = audioop.byteswap(buffer, sample_width)
                else: # manually reverse the bytes of each sample, which is slower but works well enough as a fallback
                    buffer = buffer[sample_width - 1::-1] + b"".join(buffer[i + sample_width:i:-1] for i in range(sample_width - 1, len(buffer), sample_width))

            # workaround for https://bugs.python.org/issue12866
            if self.samples_24_bit_pretending_to_be_32_bit: # we need to convert samples from 24-bit to 32-bit before we can process them with ``audioop`` functions
                buffer = b"".join("\x00" + buffer[i:i + sample_width] for i in range(0, len(buffer), sample_width)) # since we're in little endian, we prepend a zero byte to each 24-bit sample to get a 32-bit sample
            if self.audio_reader.getnchannels() != 1: # stereo audio
                buffer = audioop.tomono(buffer, sample_width, 1, 1) # convert stereo audio data to mono
            return buffer