Python audioop.byteswap方法代码示例

# 需要导入模块: import audioop [as 别名]
# 或者: from audioop import byteswap [as 别名]
def readframes(self, nframes):
        if self._data_seek_needed:
            self._data_chunk.seek(0, 0)
            pos = self._soundpos * self._framesize
            if pos:
                self._data_chunk.seek(pos, 0)
            self._data_seek_needed = 0
        if nframes == 0:
            return b''
        data = self._data_chunk.read(nframes * self._framesize)
        if self._sampwidth != 1 and sys.byteorder == 'big':
            data = audioop.byteswap(data, self._sampwidth)
        if self._convert and data:
            data = self._convert(data)
        self._soundpos = self._soundpos + len(data) // (self._nchannels * self._sampwidth)
        return data

    #
    # Internal methods.
    # 

# 需要导入模块: import audioop [as 别名]
# 或者: from audioop import byteswap [as 别名]
def test_byteswap(self):
        swapped_datas = {
            1: datas[1],
            2: packs[2](0, 0x3412, 0x6745, -0x6646, -0x81, 0x80, -1),
            3: packs[3](0, 0x563412, -0x7698bb, 0x7798ba, -0x81, 0x80, -1),
            4: packs[4](0, 0x78563412, -0x547698bb, 0x557698ba,
                        -0x81, 0x80, -1),
        }
        for w in 1, 2, 3, 4:
            self.assertEqual(audioop.byteswap(b'', w), b'')
            self.assertEqual(audioop.byteswap(datas[w], w), swapped_datas[w])
            self.assertEqual(audioop.byteswap(swapped_datas[w], w), datas[w])
            self.assertEqual(audioop.byteswap(bytearray(datas[w]), w),
                             swapped_datas[w])
            self.assertEqual(audioop.byteswap(memoryview(datas[w]), w),
                             swapped_datas[w]) 

# 需要导入模块: import audioop [as 别名]
# 或者: from audioop import byteswap [as 别名]
def from_array(cls, array_or_list: Sequence[Union[int, float]], samplerate: int, numchannels: int, name: str = "") -> 'Sample':
        assert 1 <= numchannels <= 2
        assert samplerate > 1
        if isinstance(array_or_list, list):
            try:
                array_or_list = cls.get_array(2, array_or_list)
            except OverflowError:
                array_or_list = cls.get_array(4, array_or_list)
        elif numpy:
            if isinstance(array_or_list, numpy.ndarray) and any(array_or_list):
                if not isinstance(array_or_list[0], (int, numpy.integer)):
                    raise TypeError("the sample values must be integer")
        else:
            if any(array_or_list):
                if type(array_or_list[0]) is not int:
                    raise TypeError("the sample values must be integer")
        samplewidth = array_or_list.itemsize
        frames = array_or_list.tobytes()
        if sys.byteorder == "big":
            frames = audioop.byteswap(frames, samplewidth)
        return Sample.from_raw_frames(frames, samplewidth, samplerate, numchannels, name=name) 

# 需要导入模块: import audioop [as 别名]
# 或者: from audioop import byteswap [as 别名]
def fadeout(self, seconds: float, target_volume: float = 0.0) -> 'Sample':
        """Fade the end of the sample out to the target volume (usually zero) in the given time."""
        if self.__locked:
            raise RuntimeError("cannot modify a locked sample")
        if not self.__frames:
            return self
        seconds = min(seconds, self.duration)
        i = self.frame_idx(self.duration-seconds)
        begin = self.__frames[:i]
        end = self.__frames[i:]  # we fade this chunk
        numsamples = len(end)/self.__samplewidth
        decrease = 1.0-target_volume
        _sw = self.__samplewidth     # optimization
        _getsample = audioop.getsample   # optimization
        faded = Sample.get_array(_sw, [int(_getsample(end, _sw, i)*(1.0-i*decrease/numsamples)) for i in range(int(numsamples))])
        end = faded.tobytes()
        if sys.byteorder == "big":
            end = audioop.byteswap(end, self.__samplewidth)
        self.__frames = begin + end
        return self 

# 需要导入模块: import audioop [as 别名]
# 或者: from audioop import byteswap [as 别名]
def fadein(self, seconds: float, start_volume: float = 0.0) -> 'Sample':
        """Fade the start of the sample in from the starting volume (usually zero) in the given time."""
        if self.__locked:
            raise RuntimeError("cannot modify a locked sample")
        if not self.__frames:
            return self
        seconds = min(seconds, self.duration)
        i = self.frame_idx(seconds)
        begin = self.__frames[:i]  # we fade this chunk
        end = self.__frames[i:]
        numsamples = len(begin)/self.__samplewidth
        increase = 1.0-start_volume
        _sw = self.__samplewidth     # optimization
        _getsample = audioop.getsample   # optimization
        _incr = increase/numsamples    # optimization
        faded = Sample.get_array(_sw, [int(_getsample(begin, _sw, i)*(i*_incr+start_volume)) for i in range(int(numsamples))])
        begin = faded.tobytes()
        if sys.byteorder == "big":
            begin = audioop.byteswap(begin, self.__samplewidth)
        self.__frames = begin + end
        return self 

# 需要导入模块: import audioop [as 别名]
# 或者: from audioop import byteswap [as 别名]
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 

# 需要导入模块: import audioop [as 别名]
# 或者: from audioop import byteswap [as 别名]
def writeframesraw(self, data):
        if not isinstance(data, (bytes, bytearray)):
            data = memoryview(data).cast('B')
        self._ensure_header_written(len(data))
        nframes = len(data) // (self._sampwidth * self._nchannels)
        if self._convert:
            data = self._convert(data)
        if self._sampwidth != 1 and sys.byteorder == 'big':
            data = audioop.byteswap(data, self._sampwidth)
        self._file.write(data)
        self._datawritten += len(data)
        self._nframeswritten = self._nframeswritten + nframes 

# 需要导入模块: import audioop [as 别名]
# 或者: from audioop import byteswap [as 别名]
def modulate_amp(self, modulation_source: Union[Oscillator, Sequence[float], 'Sample', Iterator[float]]) -> 'Sample':
        """
        Perform amplitude modulation by another waveform or oscillator.
        You can use a Sample (or array of sample values) or an oscillator as modulator.
        If you use a Sample (or array), it will be cycled if needed and its maximum amplitude
        is scaled to be 1.0, effectively using it as if it was an oscillator.
        """
        if self.__locked:
            raise RuntimeError("cannot modify a locked sample")
        frames = self.get_frame_array()
        if isinstance(modulation_source, (Sample, list, array.array)):
            # modulator is a waveform, turn that into an 'oscillator' ran
            if isinstance(modulation_source, Sample):
                modulation_source = modulation_source.get_frame_array()
            biggest = max(max(modulation_source), abs(min(modulation_source)))
            actual_modulator = (v/biggest for v in itertools.cycle(modulation_source))   # type: ignore
        elif isinstance(modulation_source, Oscillator):
            actual_modulator = itertools.chain.from_iterable(modulation_source.blocks())    # type: ignore
        else:
            actual_modulator = iter(modulation_source)  # type: ignore
        for i in range(len(frames)):
            frames[i] = int(frames[i] * next(actual_modulator))
        self.__frames = frames.tobytes()
        if sys.byteorder == "big":
            self.__frames = audioop.byteswap(self.__frames, self.__samplewidth)
        return self