Sound recording using python

Question

I'm trying to record some sound with RPI using python and pyaudio library and facing a few interesting issues - junky console output when attempting to use pyaudio and lots of noise mixing into the recording.

Here is what I'm doing in my python script:

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()

The following console output comes right out when I instantiate PyAudio() - am I missing some sort of alsa setup that I need to do in order to fix the issue?

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...

Running this version of linux:

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

Please write what external sound card are you using. From your post I can see that you are trying to record from a playback-only device. — dicoder, Mar 01 '13 at 00:33

Sufiyan Ghori · Answer 1 · 2014-02-14T14:38:48.227

5

There is/was an issue with the Pi’s USB port that meant it can/could become overwhelmed1 with data which causes popping and bubbling noises to be included in your recordings, this can be fixed with an update of the Pi’s firmware:

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

more details on how to Record sound on your Pi,

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

PyAudio Audio Recording and Playback This should Fix the issue.

edited Feb 14 '14 at 14:38

answered Sep 28 '13 at 19:53

Sufiyan Ghori

433
9
18

This answer is now obsolete. Most users should never need to run rpi-update now. – scruss Mar 29 '17 at 14:49

Sound recording using python

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