def test_callback_stream(self):
with PortAudio():
SAMPLE_RATE = 44100
CHANNELS = 2
out_stream = Stream(sample_rate=SAMPLE_RATE, channel_count=CHANNELS)
def callback(input, output, frame_count, time_info, status_flags, user_data):
BufferArray = (ctypes.c_float * (frame_count*CHANNELS))
buffer = BufferArray(*(ctypes.c_float(random.random()) for i in range(frame_count)))
ctypes.memmove(output, buffer, frame_count*CHANNELS)
return _portaudio.paContinue
out_stream.open(mode='w', callback=callback, user_data=[])
out_stream.start()
for i in range(4):
time.sleep(1)
out_stream.stop()
out_stream.close()
def test_blocking(self):
with PortAudio():
NUM_SECONDS = 0.25
SAMPLE_RATE = 44100
FRAMES_PER_BUFFER = 10240
TABLE_SIZE = 200
CHANNELS = 2
out_stream = Stream(sample_rate=SAMPLE_RATE, frames_per_buffer=FRAMES_PER_BUFFER,
channel_count=CHANNELS)
out_stream.open(mode='w')
buff = ((ctypes.c_float * CHANNELS) * FRAMES_PER_BUFFER)()
# initialise sinusoidal wavetable
sine_constructor = (ctypes.c_float * TABLE_SIZE)
values = [ctypes.c_float(sin(( float(i)/TABLE_SIZE ) * pi * 2. )) for i in range(TABLE_SIZE) ]
sine = sine_constructor(*values)
left_phase = 0
right_phase = 0
left_inc = 1
right_inc = 4
buffer_count = int(((NUM_SECONDS * SAMPLE_RATE) / FRAMES_PER_BUFFER))
for k in range(10):
out_stream.start()
for i in range(buffer_count):
for j in range(FRAMES_PER_BUFFER):
buff[j][0] = sine[left_phase]
buff[j][1] = sine[right_phase]
left_phase += left_inc
if left_phase >= TABLE_SIZE:
left_phase -= TABLE_SIZE
right_phase += right_inc
if right_phase >= TABLE_SIZE:
right_phase -= TABLE_SIZE
out_stream.write(buff, FRAMES_PER_BUFFER)
out_stream.stop()
left_inc += 1
right_inc += 1
out_stream.close()
