record audio stream with mplayer

[bill-lancaster]

Is it possible to record the output from my sound card using mplayer?

[tgalati4]

There are several ways to do it.

You could install streamripper if the sound source is a streaming file.

You could install sox and use rec (record) to capture the sound. It requires several parameters to get exactly what you want.

You could use audacity if you need to manually monitor the recording--input levels, EQ, noise, etc.

You can use mplayer to rip a WAV file. See Tip #3: https://help.ubuntu.com/community/MPlayerTips

You can use mencoder to encode a DVD into a digital stream.

[bill-lancaster]

Thanks, I'd like to use mplayer.
Example #3 recommends:-

mplayer input.wma -vc null -vo null -ao pcm:fast:waveheader:file=output.wav
So, I guess input.wma is the source. How would I replace that to record anything audio from the sound card?

[tgalati4]

Since all devices are files in linux you can usually just substitute the sound card designation (say /dev/snd/pmcC0D0c) for the input file. Similarly you can specify an output device instead of a file to get the device to "play" the file. Experiment and let us know what works.

[bill-lancaster]

Here's an interim report!

~$aplay -l produces :-
**** List of PLAYBACK Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: ALC662 rev1 Analog [ALC662 rev1 Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0

So, running
mplayer plughw:0,0 -vc null -vo null -ao pcm:fast:waveheader:file=output.wav

or
mplayermplayer /dev/snd/pmcC0D0c -vc null -vo null -ao pcm:fast:waveheader:file=output.wav
or
mplayer hw:0.0 -vc null -vo null -ao pcm:fast:waveheader:file=output.wav
Produces reports like:-
MPlayer svn r34540 (Ubuntu), built with gcc-4.7 (C) 2000-2012 MPlayer Team
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.

Playing hw:0.0.
File not found: 'hw:0.0'
Failed to open hw:0.0.

I'll continue fiddling for a bit more!

[tgalati4]

ls -la /dev/snd

tgalati4@Mint14-Extensa ~ $ ls -la /dev/snd
total 0
drwxr-xr-x 3 root root 220 Sep 9 11:02 .
drwxr-xr-x 16 root root 4320 Oct 22 07:57 ..
drwxr-xr-x 2 root root 60 Sep 9 11:02 by-path
crw-rw---T+ 1 root audio 116, 7 Sep 9 11:02 controlC0
crw-rw---T+ 1 root audio 116, 6 Sep 9 11:02 hwC0D0
crw-rw---T+ 1 root audio 116, 5 Sep 9 11:02 hwC0D1
crw-rw---T+ 1 root audio 116, 4 Sep 9 11:02 pcmC0D0c
crw-rw---T+ 1 root audio 116, 3 Oct 18 15:17 pcmC0D0p
crw-rw---T+ 1 root audio 116, 2 Sep 9 11:02 pcmC0D2c
crw-rw---T+ 1 root audio 116, 1 Sep 9 11:02 seq
crw-rw---T+ 1 root audio 116, 33 Sep 9 11:02 timer


I'm going to guess that seq (sequencer) and timer (master audio clock) are not helpful in this case. The other devices are either your capture (c) or playback (p) devices.

You also need to add yourself to group audio:

tgalati4@Mint14-Extensa ~ $ groups
tgalati4 adm cdrom sudo dip plugdev lpadmin


man addgroup
sudo addgroup bill-lancaster audio
groups bill-lancaster


Here are some other tips: http://superuser.com/questions/597227/linux-arecord-capture-sound-card-output-rather-than-microphone-input


man arecord
arecord -L

Use the -D switch to specify the device that was listed above.

[bill-lancaster]

I tried them all! (except the clock & sequence)

mplayer //dev/snd/pmcC0D0p -vc null -vo null -ao file=output.wav
gives:-
MPlayer svn r34540 (Ubuntu), built with gcc-4.7 (C) 2000-2012 MPlayer Team
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.

Playing //dev/snd/pmcC0D0p.
File not found: '//dev/snd/pmcC0D0p'
Failed to open //dev/snd/pmcC0D0p.

[SeijiSensei]

There should be only one slash before /dev. I don't know if that will fix the problem, though.

I used OutRec (http://sourceforge.net/projects/outrec/files/) for this purpose, but it's no longer maintained. It worked in 10.04, but it's written in something called "Gambas" and the packaged version has dependency problems. I suppose I could try compiling from source, but I'd have to install Gambas support first.

[tgalati4]

Try:


arecord -D front -f cd front_speaker_audio_output.wav

Control-C to stop.

Then play it back:


aplay front_speaker_audio_output.wav

There is no pmc device, it is pcm.

This appears to do something, but it is not putting out the wave file: (so it requires further tweaking)

(You must start playing something first to fill the device file.)

mplayer /dev/snd/pcmC0D0p -vc null -vo null -ao pcm:fast:waveheader:file=output.wav