Grabación de sonido usando python

Estoy tratando de grabar algo de sonido con RPI usando la biblioteca python y pyaudio y me enfrento a algunos problemas interesantes: la salida de la consola junky cuando intento usar pyaudio y mucho ruido mezclado en la grabación.

Esto es lo que estoy haciendo en mi script de Python:

import pyaudio, wave, utils

BUFFER_SIZE = 1024
REC_SECONDS = 5
RATE = 44100
WAV_FILENAME = utils.generate_random_token()
FORMAT = pyaudio.paInt16

#init sound stream
pa = pyaudio.PyAudio()
stream = pa.open(
    format = FORMAT,
    input = True,
    channels = 1,
    rate = RATE,
    input_device_index = 7,
    frames_per_buffer = BUFFER_SIZE
)

#run recording
print('Recording...')
data_frames = []
for f in range(0, RATE/BUFFER_SIZE * REC_SECONDS):
    data = stream.read(BUFFER_SIZE)
    data_frames.append(data)
print('Finished recording...')
stream.stop_stream()
stream.close()
pa.terminate()

La siguiente salida de la consola sale cuando ejecuto PyAudio (). ¿Me falta algún tipo de configuración que necesito hacer para solucionar el problema?

pi@raspberrypi ~/speach $ python recordandrecognize.py
ALSA lib confmisc.c:1286:(snd_func_refer) Unable to find definition 'cards.BRCM bcm2835 AL.pcm.front.0:CARD=0'
ALSA lib conf.c:4241:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4720:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM front
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.rear
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.center_lfe
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.side
ALSA lib confmisc.c:1286:(snd_func_refer) Unable to find definition 'cards.BRCM bcm2835 AL.pcm.surround40.0:CARD=0'
ALSA lib conf.c:4241:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4720:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM surround40
ALSA lib confmisc.c:1286:(snd_func_refer) Unable to find definition 'cards.BRCM bcm2835 AL.pcm.surround51.0:CARD=0'
ALSA lib conf.c:4241:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4720:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM surround41
ALSA lib confmisc.c:1286:(snd_func_refer) Unable to find definition 'cards.BRCM bcm2835 AL.pcm.surround51.0:CARD=0'
ALSA lib conf.c:4241:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4720:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM surround50
ALSA lib confmisc.c:1286:(snd_func_refer) Unable to find definition 'cards.BRCM bcm2835 AL.pcm.surround51.0:CARD=0'
ALSA lib conf.c:4241:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4720:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM surround51
ALSA lib confmisc.c:1286:(snd_func_refer) Unable to find definition 'cards.BRCM bcm2835 AL.pcm.surround71.0:CARD=0'
ALSA lib conf.c:4241:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4720:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM surround71
ALSA lib confmisc.c:1286:(snd_func_refer) Unable to find definition 'cards.BRCM bcm2835 AL.pcm.iec958.0:CARD=0,AES0=4,AES1=130,AES2=0,AES3=2'
ALSA lib conf.c:4241:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4720:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM iec958
ALSA lib confmisc.c:1286:(snd_func_refer) Unable to find definition 'cards.BRCM bcm2835 AL.pcm.iec958.0:CARD=0,AES0=4,AES1=130,AES2=0,AES3=2'
ALSA lib conf.c:4241:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4720:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM spdif
ALSA lib confmisc.c:1286:(snd_func_refer) Unable to find definition 'cards.BRCM bcm2835 AL.pcm.iec958.0:CARD=0,AES0=4,AES1=130,AES2=0,AES3=2'
ALSA lib conf.c:4241:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4720:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM spdif
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.hdmi
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.hdmi
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.modem
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.modem
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.phoneline
ALSA lib pcm.c:2217:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.phoneline
ALSA lib pcm_dmix.c:957:(snd_pcm_dmix_open) The dmix plugin supports only playback stream
ALSA lib pcm_direct.c:877:(snd1_pcm_direct_initialize_slave) slave plugin does not support mmap interleaved or mmap noninterleaved access
ALSA lib pcm_dmix.c:1030:(snd_pcm_dmix_open) unable to initialize slave
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jack server is not running or cannot be started
Recording...

Ejecutando esta versión de Linux:

pi@raspberrypi ~/speach $ uname -a
Linux raspberrypi 3.2.27+ #250 PREEMPT Thu Oct 18 19:03:02 BST 2012 armv6l GNU/Linux

Hay / hubo un problema con el puerto USB de Pi que significa que puede / podría verse abrumado1 con datos que provocan que se incluyan ruidos emergentes y burbujeantes en sus grabaciones, esto se puede solucionar con una actualización del firmware de Pi:

$ sudo apt-get update
$ sudo apt-get upgrade
$ sudo apt-get install rpi-update
$ sudo rpi-update

más detalles sobre cómo grabar sonido en tu Pi,

http://www.g7smy.co.uk/?p=283

Grabación y reproducción de audio PyAudio Esto debería solucionar el problema.