PyAudio

"""PyAudio Example: Play a wave file."""

import wave
import sys

import pyaudio

CHUNK = 1024

if len(sys.argv) < 2:
    print(f'Plays a wave file. Usage: {sys.argv[0]} filename.wav')
    sys.exit(-1)

with wave.open(sys.argv[1], 'rb') as wf:
    # Instantiate PyAudio and initialize PortAudio system resources (1)
    p = pyaudio.PyAudio()

    # Open stream (2)
    stream = p.open(format=p.get_format_from_width(wf.getsampwidth()),
                    channels=wf.getnchannels(),
                    rate=wf.getframerate(),
                    output=True)

    # Play samples from the wave file (3)
    while len(data := wf.readframes(CHUNK)):  # Requires Python 3.8+ for :=
        stream.write(data)

    # Close stream (4)
    stream.close()

    # Release PortAudio system resources (5)
    p.terminate()

"""PyAudio Example: Record a few seconds of audio and save to a wave file."""

import wave
import sys

import pyaudio

CHUNK = 1024
FORMAT = pyaudio.paInt16
CHANNELS = 1 if sys.platform == 'darwin' else 2
RATE = 44100
RECORD_SECONDS = 5

with wave.open('output.wav', 'wb') as wf:
    p = pyaudio.PyAudio()
    wf.setnchannels(CHANNELS)
    wf.setsampwidth(p.get_sample_size(FORMAT))
    wf.setframerate(RATE)

    stream = p.open(format=FORMAT, channels=CHANNELS, rate=RATE, input=True)

    print('Recording...')
    for _ in range(0, RATE // CHUNK * RECORD_SECONDS):
        wf.writeframes(stream.read(CHUNK))
    print('Done')

    stream.close()
    p.terminate()

"""PyAudio Example: full-duplex wire between input and output."""

import sys

import pyaudio

RECORD_SECONDS = 5
CHUNK = 1024
RATE = 44100

p = pyaudio.PyAudio()
stream = p.open(format=p.get_format_from_width(2),
                channels=1 if sys.platform == 'darwin' else 2,
                rate=RATE,
                input=True,
                output=True,
                frames_per_buffer=CHUNK)

print('* recording')
for i in range(0, int(RATE / CHUNK * RECORD_SECONDS)):
    stream.write(stream.read(CHUNK))
print('* done')

stream.close()
p.terminate()

"""PyAudio Example: Play a wave file (callback version)."""

import wave
import time
import sys

import pyaudio

if len(sys.argv) < 2:
    print(f'Plays a wave file. Usage: {sys.argv[0]} filename.wav')
    sys.exit(-1)

with wave.open(sys.argv[1], 'rb') as wf:
    # Define callback for playback (1)
    def callback(in_data, frame_count, time_info, status):
        data = wf.readframes(frame_count)
        # If len(data) is less than requested frame_count, PyAudio automatically
        # assumes the stream is finished, and the stream stops.
        return (data, pyaudio.paContinue)

    # Instantiate PyAudio and initialize PortAudio system resources (2)
    p = pyaudio.PyAudio()

    # Open stream using callback (3)
    stream = p.open(format=p.get_format_from_width(wf.getsampwidth()),
                    channels=wf.getnchannels(),
                    rate=wf.getframerate(),
                    output=True,
                    stream_callback=callback)

    # Wait for stream to finish (4)
    while stream.is_active():
        time.sleep(0.1)

    # Close the stream (5)
    stream.close()

    # Release PortAudio system resources (6)
    p.terminate()

"""PyAudio Example: Audio wire between input and output. Callback version."""

import time
import sys

import pyaudio

DURATION = 5  # seconds

def callback(in_data, frame_count, time_info, status):
    return (in_data, pyaudio.paContinue)

p = pyaudio.PyAudio()
stream = p.open(format=p.get_format_from_width(2),
                channels=1 if sys.platform == 'darwin' else 2,
                rate=44100,
                input=True,
                output=True,
                stream_callback=callback)

start = time.time()
while stream.is_active() and (time.time() - start) < DURATION:
    time.sleep(0.1)

stream.close()
p.terminate()

"""PyAudio Example: macOS-only: Play a wave file with channel maps."""

import wave
import sys

import pyaudio


CHUNK = 1024

if len(sys.argv) < 2:
    print(f'Plays a wave file. Usage: {sys.argv[0]} filename.wav')
    sys.exit(-1)

# standard L-R stereo
# channel_map = (0, 1)

# reverse: R-L stereo
# channel_map = (1, 0)

# no audio
# channel_map = (-1, -1)

# left channel audio --> left speaker; no right channel
# channel_map = (0, -1)

# right channel audio --> right speaker; no left channel
# channel_map = (-1, 1)

# left channel audio --> right speaker
# channel_map = (-1, 0)

# right channel audio --> left speaker
channel_map = (1, -1)
# etc...
try:
    stream_info = pyaudio.PaMacCoreStreamInfo(
        flags=pyaudio.PaMacCoreStreamInfo.paMacCorePlayNice,
        channel_map=channel_map)
except AttributeError:
    print(
        'Could not find PaMacCoreStreamInfo. Ensure you are running on macOS.')
    sys.exit(-1)

print('Stream Info Flags:', stream_info.flags)
print('Stream Info Channel Map:', stream_info.channel_map)

with wave.open(sys.argv[1], 'rb') as wf:
    p = pyaudio.PyAudio()
    stream = p.open(
        format=p.get_format_from_width(wf.getsampwidth()),
        channels=wf.getnchannels(),
        rate=wf.getframerate(),
        output=True,
        output_host_api_specific_stream_info=stream_info)

    # Play stream
    while len(data := wf.readframes(CHUNK)):  # Requires Python 3.8+ for :=
        stream.write(data)

    stream.close()
    p.terminate()