Solved

Detecting sound...

Posted on 1999-01-04
6
219 Views
Last Modified: 2010-04-04
Hi, I have to write an application simmilar to internet phone or netscape's live conference.  One speaks through the microphone, and the voice is heard in another computer some place.

I haven't found the way to detect if the microphone is receiving noice, can anyone tell me how to detect this?

I will raise the points if some one tells me or gives me the source of an app that does the task i'm trying to develope.

Thank

Paul

0
Comment
Question by:pbk
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
6 Comments
 
LVL 7

Expert Comment

by:jconde
ID: 1354574
I once saw an application that did that....let me see if I can find it again...
0
 
LVL 20

Expert Comment

by:Madshi
ID: 1354575
You'll probably need to use the mixer* functions. Unfortunately they're quite complicated. Perhaps this will help you to start digging:

http://www.wilsonc.demon.co.uk/delphi.htm

Regards, Madshi.
0
 
LVL 8

Expert Comment

by:ZifNab
ID: 1354576
Maybe this one can help? http://www2.sienanet.it/users/guido/TMsgVoc.htm#TMsgVoc Version 1.1
0
Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 

Author Comment

by:pbk
ID: 1354577
Hi!

ZifNab, that component doesn't work for me....it's for use with a modem, and it's quite complicated ;(

Madashi, The url you sent me has something that might be usefull to me, but I have a problem:  The component called Multimedia Level Data and Meter has everything I need, but the devices vary accroding to each sound/multimedia card.  Is there any way I can specify what devices to use for each computer?

Thank you,

Paul
0
 
LVL 20

Expert Comment

by:Madshi
ID: 1354578
You're right. The devices really vary accross each sound card. You'll have to enumerate the devices to find the right one for you. That's quite difficult, I know.
Perhaps this helps you:

var booleanToChar : array [boolean] of string = ('-','+');
procedure ShowMixerControls;
var mix     : integer;
    mixCaps : TMixerCaps;
    ml      : TMixerLine;
    c1      : cardinal;
    str     : string;
 function ContainsControl(ml: TMixerLine; ct: cardinal) : boolean;
 var mlc : TMixerLineControls;
     mc  : TMixerControl;
 begin
   with mlc do begin
     cbStruct:=SizeOf(mlc);
     dwLineID:=ml.dwLineID; cControls:=ml.cControls;
     dwControlType:=ct;
     cbmxctrl:=SizeOf(mc); pamxctrl:=@mc;
   end;
   result:=mixerGetLineControls(mix,@mlc,MIXER_GETLINECONTROLSF_ONEBYTYPE)=MMSYSERR_NOERROR;
 end;
 procedure EnumMixerSources(dstComponentType: cardinal);
 var i1      : cardinal;
     s1      : string;
     ml1,ml2 : TMixerLine;
 begin
   with ml1 do begin
     cbStruct:=SizeOf(ml1); dwComponentType:=dstComponentType;
   end;
   if mixerGetLineInfo(mix,@ml1,MIXER_GETLINEINFOF_COMPONENTTYPE)<>MMSYSERR_NOERROR then exit;
   s1:=ml1.szName; while length(s1)<25 do s1:=s1+' ';
   str:=str+Copy(s1,1,25)+'  ';
   str:=str+booleanToChar[ContainsControl(ml1,MIXERCONTROL_CONTROLTYPE_VOLUME   )]+'    ';
   str:=str+booleanToChar[ContainsControl(ml1,MIXERCONTROL_CONTROLTYPE_MUTE     )]+'    ';
   str:=str+booleanToChar[ContainsControl(ml1,MIXERCONTROL_CONTROLTYPE_PEAKMETER)]+'    ';
   str:=str+booleanToChar[ContainsControl(ml1,MIXERCONTROL_CONTROLTYPE_MUX      )]+'    ';
   str:=str+booleanToChar[ContainsControl(ml1,MIXERCONTROL_CONTROLTYPE_MIXER    )]+'    '#$D#$A;
   for i1:=0 to ml1.cConnections-1 do begin
     with ml2 do begin
       cbStruct:=SizeOf(ml2); dwDestination:=ml1.dwDestination; dwSource:=i1;
     end;
     if mixerGetLineInfo(mix,@ml2,MIXER_GETLINEINFOF_SOURCE)<>MMSYSERR_NOERROR then exit;
     s1:='  '+ml2.szName; while length(s1)<25 do s1:=s1+' ';
     str:=str+Copy(s1,1,25)+'  ';
     str:=str+booleanToChar[ContainsControl(ml2,MIXERCONTROL_CONTROLTYPE_VOLUME   )]+'    ';
     str:=str+booleanToChar[ContainsControl(ml2,MIXERCONTROL_CONTROLTYPE_MUTE     )]+'    ';
     str:=str+booleanToChar[ContainsControl(ml2,MIXERCONTROL_CONTROLTYPE_PEAKMETER)]+#$D#$A;
   end;
 end;
begin
  if (mixerGetNumDevs>0) and (mixerOpen(@mix,0,0,0,MIXER_OBJECTF_MIXER)=MMSYSERR_NOERROR) and
     (mixerGetDevCaps(0,@mixCaps,sizeOf(mixCaps))=MMSYSERR_NOERROR) then
    try
      str:='Name                       Vol. Mute Peak Mux Mixer'#$D#$A;
      ml.cbStruct:=sizeOf(ml);
      for c1:=0 to mixCaps.cDestinations-1 do begin
        ml.dwDestination:=c1;
        mixerGetLineInfo(mix,@ml,MIXER_GETLINEINFOF_DESTINATION);
        EnumMixerSources(ml.dwComponentType);
        //MIXERLINE_COMPONENTTYPE_DST_SPEAKERS);
        //EnumMixerSources(MIXERLINE_COMPONENTTYPE_DST_WAVEIN);
      end;
      MessageBox(0,PChar(str),'Mixer',0);
    finally mixerClose(mix) end;
end;

Regards, Madshi.
0
 

Accepted Solution

by:
_art_ earned 50 total points
ID: 1354579
http://www.cog.brown.edu/~mertus/

get there TAudioIO freeware component. Demos are there...
0

Featured Post

[Webinar] Learn How Hackers Steal Your Credentials

Do You Know How Hackers Steal Your Credentials? Join us and Skyport Systems to learn how hackers steal your credentials and why Active Directory must be secure to stop them. Thursday, July 13, 2017 10:00 A.M. PDT

Question has a verified solution.

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

A lot of questions regard threads in Delphi.   One of the more specific questions is how to show progress of the thread.   Updating a progressbar from inside a thread is a mistake. A solution to this would be to send a synchronized message to the…
Introduction The parallel port is a very commonly known port, it was widely used to connect a printer to the PC, if you look at the back of your computer, for those who don't have newer computers, there will be a port with 25 pins and a small print…
Come and listen to Percona CEO Peter Zaitsev discuss what’s new in Percona open source software, including Percona Server for MySQL (https://www.percona.com/software/mysql-database/percona-server) and MongoDB (https://www.percona.com/software/mongo-…
In this video, viewers are given an introduction to using the Windows 10 Snipping Tool, how to quickly locate it when it's needed and also how make it always available with a single click of a mouse button, by pinning it to the Desktop Task Bar. Int…

717 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