120 lines
3.5 KiB
Python
120 lines
3.5 KiB
Python
"""Decoder for RIFF Wave files, using the standard library wave module.
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"""
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import wave
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from pyglet.util import DecodeException
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from .base import StreamingSource, AudioData, AudioFormat, StaticSource
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from . import MediaEncoder, MediaDecoder
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class WAVEDecodeException(DecodeException):
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pass
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class WaveSource(StreamingSource):
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def __init__(self, filename, file=None):
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if file is None:
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file = open(filename, 'rb')
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self._file = file
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try:
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self._wave = wave.open(file)
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except wave.Error as e:
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raise WAVEDecodeException(e)
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nchannels, sampwidth, framerate, nframes, comptype, compname = self._wave.getparams()
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self.audio_format = AudioFormat(channels=nchannels, sample_size=sampwidth * 8, sample_rate=framerate)
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self._bytes_per_frame = nchannels * sampwidth
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self._duration = nframes / framerate
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self._duration_per_frame = self._duration / nframes
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self._num_frames = nframes
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self._wave.rewind()
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def __del__(self):
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if hasattr(self, '_file'):
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self._file.close()
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def get_audio_data(self, num_bytes, compensation_time=0.0):
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num_frames = max(1, num_bytes // self._bytes_per_frame)
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data = self._wave.readframes(num_frames)
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if not data:
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return None
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timestamp = self._wave.tell() / self.audio_format.sample_rate
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duration = num_frames / self.audio_format.sample_rate
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return AudioData(data, len(data), timestamp, duration, [])
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def seek(self, timestamp):
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timestamp = max(0.0, min(timestamp, self._duration))
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position = int(timestamp / self._duration_per_frame)
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self._wave.setpos(position)
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#########################################
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# Decoder class:
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#########################################
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class WaveDecoder(MediaDecoder):
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def get_file_extensions(self):
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return '.wav', '.wave', '.riff'
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def decode(self, filename, file, streaming=True):
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if streaming:
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return WaveSource(filename, file)
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else:
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return StaticSource(WaveSource(filename, file))
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class WaveEncoder(MediaEncoder):
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def get_file_extensions(self):
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return '.wav', '.wave', '.riff'
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def encode(self, source, filename, file):
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"""Save the Source to disk as a standard RIFF Wave.
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A standard RIFF wave header will be added to the raw PCM
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audio data when it is saved to disk.
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:Parameters:
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`filename` : str
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The file name to save as.
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`file` : file-like object
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A file-like object, opened with mode 'wb'.
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"""
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opened_file = None
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if file is None:
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file = open(filename, 'wb')
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opened_file = True
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source.seek(0)
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wave_writer = wave.open(file, mode='wb')
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wave_writer.setnchannels(source.audio_format.channels)
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wave_writer.setsampwidth(source.audio_format.bytes_per_sample)
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wave_writer.setframerate(source.audio_format.sample_rate)
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# Save the data in 1-second chunks:
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chunksize = source.audio_format.bytes_per_second
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audiodata = source.get_audio_data(chunksize)
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while audiodata:
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wave_writer.writeframes(audiodata.data)
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audiodata = source.get_audio_data(chunksize)
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else:
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wave_writer.close()
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if opened_file:
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file.close()
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def get_decoders():
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return [WaveDecoder()]
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def get_encoders():
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return [WaveEncoder()]
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