From: info <info@dressmaker.ca>
To: alsa-devel@alsa-project.org
Subject: Re: Discover a microphone device, to later discover if it is receiving input
Date: Fri, 9 Oct 2020 08:39:05 -0400 [thread overview]
Message-ID: <5378606a-5b71-5d1b-f7f4-a6f33dce60b3@dressmaker.ca> (raw)
In-Reply-To: <de6ebf17-8f71-c497-28bc-7819338baddb@dressmaker.ca>
Can maintainers of this list please give a straight answer: is asking
questions and leaving comments here a waste of time?
On 2020-10-04 12:22 PM, info wrote:
> Hi all,
>
>
> I am writing a program that aims to auto-discover the microphone
> device that the user is speaking into. I started off by querying
> device hints and collected all devices with the IO types of null,
> since I have not found any devices with the type of Input. I am
> puzzled how it is possible that there is no Input, where a microphone
> device should not be able to emit sound. This is the list on my
> particular machine:
>
> Name of device: sysdefault:CARD=SB
> Description of device: HDA ATI SB, ALC892 Analog
> Default Audio Device
> I/O type of device: (null)
>
> Name of device: front:CARD=SB,DEV=0
> Description of device: HDA ATI SB, ALC892 Analog
> Front speakers
> I/O type of device: (null)
>
> Name of device: surround21:CARD=SB,DEV=0
> Description of device: HDA ATI SB, ALC892 Analog
> 2.1 Surround output to Front and Subwoofer speakers
> I/O type of device: Output
>
> Name of device: surround41:CARD=SB,DEV=0
> Description of device: HDA ATI SB, ALC892 Analog
> 4.1 Surround output to Front, Rear and Subwoofer speakers
> I/O type of device: Output
>
> Name of device: surround50:CARD=SB,DEV=0
> Description of device: HDA ATI SB, ALC892 Analog
> 5.0 Surround output to Front, Center and Rear speakers
> I/O type of device: Output
>
> Name of device: surround71:CARD=SB,DEV=0
> Description of device: HDA ATI SB, ALC892 Analog
> 7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
> I/O type of device: Output
>
> Name of device: sysdefault:CARD=SB
> Description of device: HDA ATI SB, ALC892 Analog
> Default Audio Device
> I/O type of device: (null)
>
> Name of device: front:CARD=SB,DEV=0
> Description of device: HDA ATI SB, ALC892 Analog
> Front speakers
> I/O type of device: (null)
>
> Now, I am more puzzled, because none of them is a microphone device
> explicitly. How can my program determine which of them is actually a
> microphone?
>
> Also, why are devices are duplicated in the output from
> snd_device_name_hint()? The very first device is also repeated as the
> 2nd last one...
>
>
> Regards,
> Alex
>
>
next prev parent reply other threads:[~2020-10-09 12:40 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-04 16:22 Discover a microphone device, to later discover if it is receiving input info
2020-10-04 21:17 ` Dead link in wiki under Tutorials info
2020-10-16 17:33 ` info
2020-10-09 12:39 ` info [this message]
2020-10-09 14:07 ` Discover a microphone device, to later discover if it is receiving input Jaroslav Kysela
2020-10-09 15:35 ` Takashi Iwai
2020-10-09 16:11 ` info
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