[Okta Webinar] Learn how to a build a cloud-first strategyRegister Now

x
?
Solved

Get microphone state

Posted on 1997-07-04
2
Medium Priority
?
527 Views
Last Modified: 2013-11-20
I would know if there are MFC (or API) in Windows 95 that retrieve the microphone state when I switch on/off it by hand. My input is only by microphone and not by mouse or keyboard.
How can I do ? Thanks a lot
0
Comment
Question by:grimaldi
2 Comments
 

Author Comment

by:grimaldi
ID: 1302454
Adjusted points to 100
0
 
LVL 23

Accepted Solution

by:
chensu earned 200 total points
ID: 1302455
If I understand correctly, you mean the switch on the microphone. Some microphones have such switches, some don't have. There is no way to retrieve the state. What you can do is to detect the audio signal coming into the microphone. I copied the following PAQ answered by me in Microsoft Windows Programming Topic Area. You can also use Audio Mixers functions to select or deselect the microphone (switch on/off by software control, it is different from the phisical switch).

Question:
I want to capture the realtime amplitude of the microphone using the mixer functions in
                  Win32. I would like to to have this value returned in the range of 0 to 255. How do I do
                  this?

        Answer:
                   Use Audio Mixers functions. The following are some sample codes.

                   // open the first mixer
                   ::mixerOpen(&m_hMixer, 0, (DWORD)this->GetSafeHwnd(), NULL,
                   MIXER_OBJECTF_MIXER | CALLBACK_WINDOW);

                   ...

                   // get the mixer control
                   if (m_hMixer == NULL)
                   return FALSE;

                   // get dwLineID
                   MIXERLINE mxl;
                   mxl.cbStruct = sizeof(MIXERLINE);
                   mxl.dwComponentType = MIXERLINE_COMPONENTTYPE_DST_WAVEIN;
                   if (::mixerGetLineInfo((HMIXEROBJ)m_hMixer,
                   &mxl,
                   MIXER_OBJECTF_HMIXER |
                   MIXER_GETLINEINFOF_COMPONENTTYPE)
                   != MMSYSERR_NOERROR)
                   return FALSE;

                   // get dwControlID
                   MIXERCONTROL mxc;
                   MIXERLINECONTROLS mxlc;
                   mxlc.cbStruct = sizeof(MIXERLINECONTROLS);
                   mxlc.dwLineID = mxl.dwLineID;
                   mxlc.dwControlType = MIXERCONTROL_CONTROLTYPE_PEAKMETER;
                   mxlc.cControls = 1;
                   mxlc.cbmxctrl = sizeof(MIXERCONTROL);
                   mxlc.pamxctrl = &mxc;
                   if (::mixerGetLineControls((HMIXEROBJ)m_hMixer,
                   &mxlc,
                   MIXER_OBJECTF_HMIXER |
                   MIXER_GETLINECONTROLSF_ONEBYTYPE)
                   != MMSYSERR_NOERROR)
                   return FALSE;

                       m_dwMeterControlID = mxc.dwControlID;


                   // get the value, lVal is in the range of -32768 to 32767, you can convert it to 0-255.
                   BOOL GetMeterValue(LONG &lVal)
                   {
                   if (m_hMixer == NULL)
                   return FALSE;

                   MIXERCONTROLDETAILS_SIGNED mxcdMeter;
                       MIXERCONTROLDETAILS mxcd;
                   mxcd.cbStruct = sizeof(MIXERCONTROLDETAILS);
                       mxcd.dwControlID = m_dwMeterControlID;
                       mxcd.cChannels = 1;
                       mxcd.cMultipleItems = 0;
                       mxcd.cbDetails = sizeof(MIXERCONTROLDETAILS_SIGNED);
                       mxcd.paDetails = &mxcdMeter;
                   if (::mixerGetControlDetails((HMIXEROBJ)m_hMixer,
                   &mxcd,
                   MIXER_OBJECTF_HMIXER |
                   MIXER_GETCONTROLDETAILSF_VALUE)
                   != MMSYSERR_NOERROR)
                   return FALSE;

                   lVal = mxcdMeter.lValue;

                   return TRUE;
                   }


                   ::mixerClose(m_hMixer);
                   m_hMixer = NULL;


                   You can call GetMeterValue() with a timer.

                   For more information, see Win32 SDK documentations about Audio Mixers.

0

Featured Post

Free Tool: Site Down Detector

Helpful to verify reports of your own downtime, or to double check a downed website you are trying to access.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Here is how to use MFC's automatic Radio Button handling in your dialog boxes and forms.  Beginner programmers usually start with a OnClick handler for each radio button and that's just not the right way to go.  MFC has a very cool system for handli…
Introduction: Dynamic window placements and drawing on a form, simple usage of windows registry as a storage place for information. Continuing from the first article about sudoku.  There we have designed the application and put a lot of user int…
This video will show you how to get GIT to work in Eclipse.   It will walk you through how to install the EGit plugin in eclipse and how to checkout an existing repository.
This lesson discusses how to use a Mainform + Subforms in Microsoft Access to find and enter data for payments on orders. The sample data comes from a custom shop that builds and sells movable storage structures that are delivered to your property. …
Suggested Courses
Course of the Month19 days, 3 hours left to enroll

834 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question