Information regarding the audio input jacks

markcarter02

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Mar 9, 2010
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Hi Folks,

I have an ASUS motherboard with details-

Manufacturer- ASUSTeK Computer INC.
Model- P5KPL-AM IN
Version- System Version
Chipset vendor- Intel
Chipset model- P35/G33/G31
Chipset revision- 10
Southbridge vendor- Intel
Southbridge model- 82801GB (ICH7/R)
Southbridge revision- A1


I found that I CANNOT use two different audio input devices simultaneously -

Let me explain, but before that for a moment, please forget which is the default audio input device,
please consider the following -

1. I plug Mic into the rear CPU jack (red one) meant for audio input.
2. I plug Line-In into the other rear CPU jack (blue one) meant for audio input.

Now I find that if I use Mic, the Line-In becomes unavailable
And if I am using Line-In, the Mic becomes unavailable.


This means that Line-In and the Mic both are using the "same system bus". Is it so ?

Is there no way I can use Line-In and Mic simultaneously ?


Now, I mentioned about this "same system bus" because my intention of using two different devices simultaneously is possible with an INTEL motherboard with details-

Manufacturer- Intel Corporation
Model- D945GCNL
Chipset vendor- Intel
Chipset model- i945G
Chipset revision- A2
Southbridge vendor- Intel
Southbridge model- 82801GB (ICH7/R)
Southbridge revision- A1

My experiment of using Mic and Line-In and Mic has been successful with INTEL motherboard.
Now, this makes me infer that INTEL is using two separate system buses for Mic and Line-In from the rear CPU jacks.

Anyone please help...

Is there no way I can use Line-In and Mic simultaneously ?


Thanks in advance,
Mark.
 

markcarter02

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Mar 9, 2010
10
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18,510



Hi outlw6669,


<<I would recommend you start by ensuring the latest drivers are installed (either from ASUS or VIA)>>
I have ensured the presence of latest drivers.

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<<Could you go a little more in depth with how you are trying to use these dual inputs? >>

I am using the Microsoft API for speech-to-text transcrption.

Now, in Microsoft windows API, there is something called as "Token" for every object.
Likewise, Every audio capture device is an object and hence assigned a "Token" by the OS.


What I am doing is -

I search for the "Token" of the desired device.
Then assign the token for this device as an input to the speech API.

Now consider the following example-

-->I assign the "Token" for Mic as an input to ONE instance of Voice Recognizer.
-->I am getting the speech-to-text transcription smoothly.
-->Now I assign the "Token" for Line-In as an input to ANOTHER instance of the Voice Recognizer.
-->I find that assigning the "Token" for Line-In as an input to the Voice Recognizer itself gives an error.

I tried the same above three (first three) steps on a system with INTEL (details mentioned in previous post) motherboard and I could very well get the speech-to-text transcription smoothly for both the devices simultaneously.

Now, when I discussed the above issue with Microsoft people, they said that
"If the two devices have the same MUX, then both cannot be used simultaneously."


It were the aforesaid developments that led me to conclude that:-

"In ASUS P5KPL-AM IN motherboard, the Mic and Line-In at the rear CPU jacks share the same MUX"
whereas
"In INTELD945GCNL motherboard, the Mic and Line-In at the rear CPU jacks DO NOT share the same MUX"



Sorry if I made a mistake in understanding the Device Topology during all above developments.
If so, please clarify...

Please help.


Thanks in advance,
Mark

Therefore, there is a token for every device