ARMBIAN 5.65 stable Debian GNU/Linux 9 (stretch) 4.14.84-sunxi

Linux orangepizero 4.14.84-sunxi #3 SMP Sat Dec 1 07:18:41 CET 2018 armv7l GNU/Linux

vailla@orangepizero:~$ ffmpeg -f alsa -ac 1 -ar 8000 -i plughw:0,0 -map 0:0 -codec:a libmp3lame -qscale:a 2 -f segment -strftime 1 -segment_time 600 -segment_atclocktime 1 Ch33_%Y-%m-%d_%H-%M-%S.mp3 -nostdin -nostats </dev/null >output33.log 2>&1 &
[1] 4472
vailla@orangepizero:~$ ffmpeg -re -f alsa -i plughw:0,0 -acodec libmp3lame -ab 32k -ac 1 -f rtp rtp://234.4.10.5:50003
[alsa @ 0xca65d0] cannot open audio device plughw:0,0 (Device or resource busy)
plughw:0,0: Input/output error

My goal:
I want ALSA to stably capture audio to a file and, at the same time, to stream audio on demand.
Note:
- If the ALSA is not kept busy by the audio capture to a file the rtp audio stream works flawlessly.
- The error "resource busy" is clear to me and I understand that.

My question:
Is there a solution to address my goal? In that case how to?

Thank you a lot for the help!

not with alsa.
(well, i did manage once by plugging a cable into audio OUT, and then back into line IN)

you need pulseaudio or jackaudio.

some magicians apparently managed this with alsa too, but the knowledge is lost in the mist of the ages...

1 members found this post helpful.

thank you.
So you mirrored the MIC into LINE OUT in order to make it seem LINE IN is an new source and stream it separately.
Am I correctly understanding??

Question (which is barely related, but I want to take the chance of your experience):
my ALSA produces some loud noises periodically. Let's say every minute and for about a second.
I hear those noises connecting a loudspeaker to LINE OUT, even if the system is idle and not performing any user related task.
I hear those noises even in the recorded files.
Did you experience a similar issue? In that case, how did you manage it? (I have tested different power supplies with no effects)


PS: based on my previous test on same system (orange pi zero), where I have installed pulseaudio, I prefer to use just ALSA. Am I just a newbie or pulseaudio could really limit the system stability? If so I think I'll solve with a quick and dirty workaround: two separate orange pi (or similar SBC) systems. BTW my d-link camera performs simultaneous recording and streaming on demand.

never.
sounds like a serious problem.
I wouldn't even know how to troubleshoot that - maybe have a look at these results.
could it be orangepi specific?

i think you're really just a newbie.
pulseaudio is generally stable, and shouldn't take too many resources either (i don't know how powerful orangepi is).

In the attached screen shot the noise waveform as shown by the audio editor.
I think the orange pi produces that noise since:
1) I can hear the noise even if alsa line out is muted
2) no noise if the loudspeaker jack is unplugged

Unfortunately *.wav file can't be attached. You can image the noise as a metallic item (like a screwdriver or a fork) scraping a rough concrete surface.
It must be a HW problem. Therefore could be either orange pi specific or just a defective sample.
As I said I have already tested two different power supplies w/o changes.

To perform audio streaming, have you tested clvc instead of ffmpeg? I do not think it'll solve the "Device or resource busy" issue, but it could be worth a try.

Attached Thumbnails

 

the noise seems to come in very regular intervals.
that might give you a hint as to what's going on.