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Freelancer HELP needed

Posted: Thu Jul 06, 2017 12:59 am
by Rspiaudio2017
Hello,

I have an urgent project for Audio injector raspberry pi Octo sound card

I really tried following up this forum and here: http://forum.audioinjector.net/viewtopic.php?f=9&t=1222

I totally spent many hours trying with no luck due to my lack of understanding

My project is six Mics recording at the same time saving in an external SSD hard drive with directories Mic1, Mic2, Mic3 ...etc

The recording should start when you plug the Raspberry pi 3

Anyone can help please tell me

Thank you

Re: Freelancer HELP needed

Posted: Thu Jul 06, 2017 11:16 pm
by flatmax
Hi there,

I see this as breaking into two requirements :
  • Autostart a process
  • Record to filesin directories.
To solve the Autostart requirement, you will need to edit the file ~/.config/lxsession/LXDE-pi/autostart and put your command in there, for example :

Code: Select all

@lxterminal -e 'myScript.sh'
will start a terminal and run a script. You could do something similar with just a command like "arecord args &".

To solve the second record and symlink concept, you can do the following :

Code: Select all

arecord -I -c 8 -f S32_LE -r 48000 ch0/name0.wav ch1/name1.wav ... etc 8 times ...
here the captial i "-I" tells arecord to split the files.
You will end up with 8 files and you only want 6 of them. You will have to experiment to see how they are output and which file has which channel, but it should all make sense once you test it out. That command will record 8 channels, 32 bits at a 48 kHz sample rate to the files.

First however, you have to create each of your directories, for example :
mkdir ~/ch0
mkdir ~/ch1
... etc ...
You can use a bash for loop to do this as well :)
Then your command will look more like :

Code: Select all

arecord -I -c 8 -f S32_LE -r 48000 ~/ch0/name0.wav ~/ch1/name1.wav ... etc 8 times ...
If you get complaints from arecord "access type not available" then use the plughw device.

Let us know how you go !
Matt

Re: Freelancer HELP needed

Posted: Fri Jul 07, 2017 3:09 am
by Rspiaudio2017
I really appreciate the time you took to answer my questions

Is seems I am missing something here, or I did it wrong all the way

This is what I did:

pi@raspberrypi:~ $ @lxterminal -e 'myScript.sh'
bash: @lxterminal: command not found

pi@raspberrypi:~ $ arecord -I -c 8 -f S32_LE -r 48000 ch0/name0.wav ch1/name1.wav
arecord: capturev:3198: You need to specify 8 files

Although I have now five mics in Octo Sound card, but it seems the raspberry can't see them

Then I disconnected all mics except one and copied:

pi@raspberrypi:~ $ arecord -I -c 1 -f S32_LE -r 48000 ch0/name0.wav ch1/name1.wav
arecord: capturev:3198: You need to specify 1 files

Same problem

I deleted the directories ch0 and ch1, so my command was:

pi@raspberrypi:~ $ arecord -I -c 1 -f S32_LE -r 48000 /name0.wav /name1.wav
arecord: capturev:3198: You need to specify 1 files

Also the same

My question, why arecord now seeing the mics?

Thank you

Re: Freelancer HELP needed

Posted: Sat Jul 08, 2017 1:06 am
by toshazed
Assalam Khalid

Your commands to record the audio should be like this as to record from 1 mic connected to channel 1

Code: Select all

arecord -I -c 1 -f S32_LE -r 48000 ~/ch0/name0.wav
Your command should be this as to record from 5 mics using on channel 1 - 5

Code: Select all

arecord -I -c 5 -f S32_LE -r 48000 ~/ch0/name0.wav ~/ch1/name1.wav ~/ch2/name2.wav ~/ch3/name3.wav ~/ch4/name4.wav
Please remember the count and the file names plz.

Re: Freelancer HELP needed

Posted: Sat Jul 08, 2017 4:24 am
by Rspiaudio2017
I was able to record, as you said, only when I used plughw it worked

Strangely the audio file is silent, no audio, but the files were generated

My question, I am using condenser mics, what is the power spec for the inputs, maybe thats why I didn't record anything

Thaks

Re: Freelancer HELP needed

Posted: Sun Jul 09, 2017 2:58 pm
by flatmax
For less then 8 channels to work, you need to have your .asoundrc setup correctly to use anyChannelCount by default. See the how to setup post.

Normally condenser microphones require preamps and also phantom power, it is likely that your signal isn't big enough to record ... which is why you need those preamps.

Matt

Re: Freelancer HELP needed

Posted: Tue Jul 11, 2017 3:24 am
by Rspiaudio2017
Thank you, and yes it worked for line in, very clear audio

Condenser microphones, I need an external power and preamp box to test

I used audio technica Condenser Shotgun Microphone with preamp and audio is very weak, I seems to need the write specs for the external preamp

Thank you

Re: Freelancer HELP needed

Posted: Wed Mar 27, 2019 8:28 pm
by wira
Rspiaudio2017 wrote:
Tue Jul 11, 2017 3:24 am
Thank you, and yes it worked for line in, very clear audio

Condenser microphones, I need an external power and preamp box to test

I used audio technica Condenser Shotgun Microphone with preamp and audio is very weak, I seems to need the write specs for the external preamp

Thank you

Dear all,

Hope anyone could share step by step guidelines on how to make it work for the mic recording and share the .asoundrc file as well?
Thanks you very much!

Wira

Re: Freelancer HELP needed

Posted: Thu Mar 28, 2019 4:51 pm
by wira
Dear all,

Need your kind advice on how to get my 6 channel RCA inputs working for mic recording.
Hope to get step by step guidelines for it.
So far I did manage to get my 8 channel RCA outputs working for mono and stereo.
Below is the photo of my hardware setup. The asound.conf and asoundrc files are shown below as well.
Appreciate very much for your kind help.

1. Hardware setup
Image

2.asound.conf
Image

3..asoundrc
Image


Best Regards
Wira