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111 lines
3.2 KiB
Python
111 lines
3.2 KiB
Python
import ctypes
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from . import vorbis
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from .pyogg_error import PyOggError
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class VorbisFileStream:
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def __init__(self, path, buffer_size=8192):
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self.exists = False
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self._buffer_size = buffer_size
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self.vf = vorbis.OggVorbis_File()
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error = vorbis.ov_fopen(path, ctypes.byref(self.vf))
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if error != 0:
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raise PyOggError("file couldn't be opened or doesn't exist. Error code : {}".format(error))
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info = vorbis.ov_info(ctypes.byref(self.vf), -1)
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#: Number of channels in audio file.
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self.channels = info.contents.channels
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#: Number of samples per second (per channel). Always
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# 48,000.
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self.frequency = info.contents.rate
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array = (ctypes.c_char*(self._buffer_size*self.channels))()
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self.buffer_ = ctypes.cast(ctypes.pointer(array), ctypes.c_char_p)
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self.bitstream = ctypes.c_int()
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self.bitstream_pointer = ctypes.pointer(self.bitstream)
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self.exists = True # TODO: is this the best place for this statement?
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#: Bytes per sample
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self.bytes_per_sample = 2 # TODO: Where is this defined?
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def __del__(self):
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if self.exists:
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vorbis.ov_clear(ctypes.byref(self.vf))
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self.exists = False
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def clean_up(self):
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vorbis.ov_clear(ctypes.byref(self.vf))
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self.exists = False
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def get_buffer(self):
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"""get_buffer() -> bytesBuffer, bufferLength
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Returns None when all data has been read from the file.
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"""
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if not self.exists:
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return None
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buffer = []
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total_bytes_written = 0
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while True:
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new_bytes = vorbis.ov_read(ctypes.byref(self.vf), self.buffer_, self._buffer_size*self.channels - total_bytes_written, 0, 2, 1, self.bitstream_pointer)
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array_ = ctypes.cast(self.buffer_, ctypes.POINTER(ctypes.c_char*(self._buffer_size*self.channels))).contents
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buffer.append(array_.raw[:new_bytes])
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total_bytes_written += new_bytes
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if new_bytes == 0 or total_bytes_written >= self._buffer_size*self.channels:
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break
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out_buffer = b"".join(buffer)
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if total_bytes_written == 0:
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self.clean_up()
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return(None)
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return out_buffer
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def get_buffer_as_array(self):
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"""Provides the buffer as a NumPy array.
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Note that the underlying data type is 16-bit signed
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integers.
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Does not copy the underlying data, so the returned array
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should either be processed or copied before the next call
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to get_buffer() or get_buffer_as_array().
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"""
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import numpy # type: ignore
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# Read the next samples from the stream
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buf = self.get_buffer()
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# Check if we've come to the end of the stream
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if buf is None:
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return None
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# Convert the bytes buffer to a NumPy array
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array = numpy.frombuffer(
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buf,
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dtype=numpy.int16
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)
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# Reshape the array
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return array.reshape(
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(len(buf)
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// self.bytes_per_sample
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// self.channels,
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self.channels)
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)
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