Python wave 模块，Wave_read() 实例源码

def _open_wav(wav):
    '''Internal helper function to open an unknown parameter as a
    wave file.

    wav:
        An open `wave.Wave_read` object, a `bytes` object containing
        a wave file, or a valid argument to `wave.open`.
    '''
    if isinstance(wav, wave.Wave_read):
        yield wav
        return

    if isinstance(wav, bytes) and wav[:4] == b'RIFF':
        w = wave.open(BytesIO(wav), 'rb')
    else:
        w = wave.open(wav, 'rb')
    yield w
    w.close()

def _wave(self):
        """Return a wave.Wave_read instance from the ``wave`` module."""
        try:
            return wave.open(StringIO(self.contents))
        except wave.Error, err:
            err.message += "\nInvalid wave file: %s" % self
            err.args = (err.message,)
            raise

def play(wav, device_id=None):
    '''Plays a wave file using a playback device.
    The function will block until playback is complete.

    wav:
        An open `wave.Wave_read` object, a `bytes` object containing
        a wave file, or a valid argument to `wave.open`.
    device_id:
        The device to play over. Defaults to the first available.
    '''
    if device_id is None:
        device_id = get_playback_devices()[0][1]

    with _open_wav(wav) as w:
        return _play(device_id, w)

def build_data(wav,begin=None,end=None):
    wav_in_file = wave.Wave_read(wav)
    wav_in_num_samples = wav_in_file.getnframes()
    N = wav_in_file.getnframes()
    dstr = wav_in_file.readframes(N)
    data = np.fromstring(dstr, np.int16)
    if begin is not None and end is not None:
        return data[begin*16000:end*16000]
    X = []
    l = len(data)
    for i in range(0, l-100, 160):
        X.append(data[i:i + 480])
    return X

def is_valid_wav(filename):
    # check the sampling rate and number bits of the WAV
    try:
        wav_file = wave.Wave_read(filename)
    except:
        return False
    if wav_file.getframerate() != 16000 or wav_file.getsampwidth() != 2 or wav_file.getnchannels() != 1 \
        or wav_file.getcomptype() != 'NONE':
        return False
    return True

def is_valid_wav(filename):
    # check the sampling rate and number bits of the WAV
    try:
        wav_file = wave.Wave_read(filename)
    except:
        return False
    if wav_file.getframerate() != 16000 or wav_file.getsampwidth() != 2 or wav_file.getnchannels() != 1 \
        or wav_file.getcomptype() != 'NONE':
        return False
    return True

def __init__(self, audio_reader, little_endian, samples_24_bit_pretending_to_be_32_bit):
            self.audio_reader = audio_reader # an audio file object (e.g., a `wave.Wave_read` instance)
            self.little_endian = little_endian # whether the audio data is little-endian (when working with big-endian things, we'll have to convert it to little-endian before we process it)
            self.samples_24_bit_pretending_to_be_32_bit = samples_24_bit_pretending_to_be_32_bit # this is true if the audio is 24-bit audio, but 24-bit audio isn't supported, so we have to pretend that this is 32-bit audio and convert it on the fly