record output sound in python

i want to programatically record 开发者_运维知识库sound coming out of my laptop in python. i found PyAudio and came up with the following program that accomplishes the task:

import pyaudio, wave, sys

chunk = 1024
FORMAT = pyaudio.paInt16
CHANNELS = 1
RATE = 44100
RECORD_SECONDS = 5
WAVE_OUTPUT_FILENAME = sys.argv[1]

p = pyaudio.PyAudio()
channel_map = (0, 1)

stream_info = pyaudio.PaMacCoreStreamInfo(
    flags = pyaudio.PaMacCoreStreamInfo.paMacCorePlayNice,
    channel_map = channel_map)

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

all = []
for i in range(0, RATE / chunk * RECORD_SECONDS):
        data = stream.read(chunk)
        all.append(data)
stream.close()
p.terminate()

data = ''.join(all)
wf = wave.open(WAVE_OUTPUT_FILENAME, 'wb')
wf.setnchannels(CHANNELS)
wf.setsampwidth(p.get_sample_size(FORMAT))
wf.setframerate(RATE)
wf.writeframes(data)
wf.close()

the problem is i have to connect the headphone jack to the microphone jack. i tried replacing these lines:

input = True,
input_host_api_specific_stream_info = stream_info,

with these:

output = True,
output_host_api_specific_stream_info = stream_info,

but then i get this error:

Traceback (most recent call last):

File "./test.py", line 25, in

data = stream.read(chunk)

File "/Library/Python/2.5/site-packages/pyaudio.py", line 562, in read

paCanNotReadFromAnOutputOnlyStream)

IOError: [Errno Not input stream] -9975

is there a way to instantiate the PyAudio stream so that it inputs from the computer's output and i don't have to connect the headphone jack to the microphone? is there a better way to go about this? i'd prefer to stick w/ a python app and avoid cocoa.

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You can install Soundflower, which allows you to create extra audio devices and route audio between them. This way you can define your system's output to the Soundflower device and read the audio from it using PyAudio.

You can also take a look at PyJack, an audio client for Jack.

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unfortunately, theres no foolproof way to do it, but Audio Hijack and Wiretap are the best tools available for that.

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I can give an answer by not using a programmatic way. Panel > Sound > Recording >> enabling stereo mix. This needs a driver support. I also found that this makes my real sound echo. At least this solves my problem.

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Doing this programmatically will be tricky. Basically, it is not possible to intercept the audio traffic in front of your "output". Therefore, what you would have to do is create your own virtual audio device and make whatever application you want to capture play to that device.

Different third-party applications also mentioned by other people seem to provide such capabilities on MacOS. I can add Loopback but I have no experience with either of the tools.

Programmatically, you would have to mimic something exactly like that.

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Check out this script at pycorder. It records output sound in python. I would consider modifying one of the functions to record output using an output stream with the sounddevice module. You can see documentation of sounddevice here. The script works and you can implement it to your needs, but replacing the recording system with an output stream would probably make the code less messy and more efficient.