sox-users Mailing List for SoX - Sound eXchange

On Mar 06 10:08:33, rod...@gm... wrote:
> I have a multichannel audio file: suppose three channels.  What I want is to
> listen to that file by listening to each of those channels through a different
> loud speaker.

Do you have three loudspeakers?

> In order to do so, I imagine each channel being sent
> to a different sound card.

Not necessarily. A typical soundcard will have a stereo output,
a fancy soundcard might have more (rear speakers, subwoofer, etc).
https://en.wikipedia.org/wiki/5.1_surround_sound

Also, playing to more than one audio device might not be synchronized,
depending on your OS's audio subsystem.

> Can sox perform that, and how?

I don't think this has anythng to do with SoX.
SoX will read the three channels and will send them to your
audio hardware (or whatever audio subsystem you have between
SoX and the hardware, such as ALSA). It's their problem then.

If your actual audio HW can only play two channels simultaneously
(as is usual), a cheap version would be to stereo-mix your 3 channels
to one in the middle, one left, one right (in the stereo panorama).
That can be one with SoX.

> Two different soundcards, and three devices, seem to be detected:
> 
> $ arecord -l

Recording (capturing) devices are irrelevant to this, obviously ...

> **** List of CAPTURE Hardware Devices ****
> card 1: Generic [HD-Audio Generic], device 0: ALC662 rev3 Analog [ALC662 rev3 Analog]
>   Subdevices: 1/1
>   Subdevice #0: subdevice #0
> card 1: Generic [HD-Audio Generic], device 2: ALC662 rev3 Alt Analog [ALC662 rev3 Alt Analog]
>   Subdevices: 1/1
>   Subdevice #0: subdevice #0
> card 2: Device [USB Audio Device], device 0: USB Audio [USB Audio]
>   Subdevices: 0/1
>   Subdevice #0: subdevice #0

... but you probably have two soundcards (sorry, I don't do ALSA).

> Since sox can split a three-channel file into three one-channel files, the
> problem is virtually solved once we manage to send two audio outputs into two
> different audio cards.  This seems to be done simply with `&&', e.g:
>  $ mplayer -ao alsa:device=hw=2.0 file1.wav && mplayer file2.wav
> , but unfortunately only one output is heard at a time...

The way you wrote it, the second mplayer process
is waiting for the forst one to finish.

On Mar 06 14:26:27, ma...@ma... wrote:
> Sox can't do that.  However, you can configure ALSA to present a virtual
> 3-channel card with each channel routed to a different slave device.

Yes; it's not a SoX problem, it's an audio system problem:
what to do with the three channels that SoX (or any other
audio application for that matter) is sending.

(You might want to try installing OpenBSD on a spare machine
and try its 'sndio' audio system, which is both fly and dope.)

	Jan

Rodolfo Medina <rod...@gm...> writes:

> If I could have sox (or any other software) send different channel outputs to
> different soundcards, I could think of plugging a loud speaker into each
> soundcard and so getting sound out to three separate places...

Sox can't do that.  However, you can configure ALSA to present a virtual
3-channel card with each channel routed to a different slave device.
See the "multi" plugin documentation here:
https://www.alsa-project.org/alsa-doc/alsa-lib/pcm_plugins.html

-- 
Måns Rullgård

Rodolfo Medina <rod...@gm...> writes:

> Jeremy Nicoll - ml sox users <jn....@wi...> writes:
>
>> On 2018-03-06 09:08, Rodolfo Medina wrote:
>>> Hi all sox users.
>>>
>>> I have a multichannel audio file: suppose three channels.  What I want is
>>> to listen to that file by listening to each of those channels through a
>>> different loud speaker.  In order to do so, I imagine
>
> ...though I may be wrong...
>
>
>>> each channel being sent to a different sound card.  Can sox perform that,
>>> and how?  In sox manual I couldn't find an answer.
>>
>> What sound hardware does your computer have?  Do you actually have more than
>> one soundcard?
>>
>> Since you posted on Debian-Users, is there a way in Debian to list what these
>> separate sound devices' names are?
>
> Two different soundcards, and three devices, seem to be detected:
>
> $ arecord -l
> **** List of CAPTURE Hardware Devices ****
> card 1: Generic [HD-Audio Generic], device 0: ALC662 rev3 Analog [ALC662 rev3
> Analog]
>   Subdevices: 1/1
>   Subdevice #0: subdevice #0
> card 1: Generic [HD-Audio Generic], device 2: ALC662 rev3 Alt Analog [ALC662
> rev3 Alt Analog]
>   Subdevices: 1/1
>   Subdevice #0: subdevice #0
> card 2: Device [USB Audio Device], device 0: USB Audio [USB Audio]
>   Subdevices: 0/1
>   Subdevice #0: subdevice #0
>
>
>> Do you have a way (forgetting your audio file for a moment) of getting sound
>> out to three separate places?
>
> If I could have sox (or any other software) send different channel outputs to
> different soundcards, I could think of plugging a loud speaker into each
> soundcard and so getting sound out to three separate places...
>
>
>> Do you have any other sound-playing software?
>
> I normally use mplayer to play sound.


Since sox can split a three-channel file into three one-channel files, the
problem is virtually solved once we manage to send two audio outputs into two
different audio cards.  This seems to be done simply with `&&', e.g:

 $ mplayer -ao alsa:device=hw=2.0 file1.wav && mplayer file2.wav

, but unfortunately only one output is heard at a time...

Rodolfo

Jeremy Nicoll - ml sox users <jn....@wi...> writes:

> On 2018-03-06 09:08, Rodolfo Medina wrote:
>> Hi all sox users.
>>
>> I have a multichannel audio file: suppose three channels.  What I want is to
>> listen to that file by listening to each of those channels through a
>> different loud speaker.  In order to do so, I imagine

...though I may be wrong...


>> each channel being sent to a different sound card.  Can sox perform that,
>> and how?  In sox manual I couldn't find an answer.
>
> What sound hardware does your computer have?  Do you actually have more than
> one soundcard?
>
> Since you posted on Debian-Users, is there a way in Debian to list what these
> separate sound devices' names are?

Two different soundcards, and three devices, seem to be detected:

$ arecord -l
**** List of CAPTURE Hardware Devices ****
card 1: Generic [HD-Audio Generic], device 0: ALC662 rev3 Analog [ALC662 rev3 Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: Generic [HD-Audio Generic], device 2: ALC662 rev3 Alt Analog [ALC662 rev3 Alt Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 2: Device [USB Audio Device], device 0: USB Audio [USB Audio]
  Subdevices: 0/1
  Subdevice #0: subdevice #0


> Do you have a way (forgetting your audio file for a moment) of getting sound
> out to three separate places?

If I could have sox (or any other software) send different channel outputs to
different soundcards, I could think of plugging a loud speaker into each
soundcard and so getting sound out to three separate places...


> Do you have any other sound-playing software?

I normally use mplayer to play sound.

Thanks,

Rodolfo

On 2018-03-06 09:08, Rodolfo Medina wrote:
> Hi all sox users.
> 
> I have a multichannel audio file: suppose three channels.  What I want 
> is to
> listen to that file by listening to each of those channels through a 
> different
> loud speaker.  In order to do so, I imagine each channel being sent to 
> a
> different sound card.  Can sox perform that, and how?  In sox manual I 
> couldn't
> find an answer.

What sound hardware does your computer have?  Do you actually have more 
than one
soundcard?

Since you posted on Debian-Users, is there a way in Debian to list what 
these
separate sound devices' names are?

Do you have a way (forgetting your audio file for a moment) of getting 
sound out
to three separate places?

Do you have any other sound-playing software?

-- 
Jeremy Nicoll - my opinions are my own

Hi all sox users.

I have a multichannel audio file: suppose three channels.  What I want is to
listen to that file by listening to each of those channels through a different
loud speaker.  In order to do so, I imagine each channel being sent to a
different sound card.  Can sox perform that, and how?  In sox manual I couldn't
find an answer.

Thanks for any help.

Rodolfo