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
Solved

How to capture voice input?

Posted on 2000-03-03
6
426 Views
Last Modified: 2010-04-10
I am writing a Visual C++ program that have to capture the time whenever there is a voice input towards the microphone. I have no idea how to work it out as I am a novice towards multimedia programming. Please help, it is very urgent.
0
Comment
Question by:LiWangOn
  • 3
  • 2
6 Comments
 
LVL 5

Expert Comment

by:Wyn
ID: 2582552
Qed...
1. MCIWnd Window Class

Recording with MCIWnd Controls
http://msdn.microsoft.com/library/psdk/multimed/mciwnd_0e43.htm 

2. MCI

Recording with a Waveform-Audio Device
http://msdn.microsoft.com/library/psdk/multimed/mci_4wpx.htm 

3. Waveform Audio

Example of Writing Waveform Data
http://msdn.microsoft.com/library/psdk/multimed/wave_8rj5.htm 

Recording and Playing Waveform Audio
http://msdn.microsoft.com/library/techart/msdn_spellit.htm 

4. DirectSound

Tutorial 2: Capturing a Sound
http://msdn.microsoft.com/library/psdk/directx/dstut_9ox0.htm
0
 

Author Comment

by:LiWangOn
ID: 2582631
Thx for the reply, but that's not what exactly I want to do. What I want to do is to know when there is a voice input towards the microphone so that I could ask the program to progress on other activity.
0
 
LVL 5

Expert Comment

by:Wyn
ID: 2583271
->What I want to do is to know when there is a voice input towards the microphone so that I could ask the program to progress on other activity.
===================
hmm...I think the answer is what you want.plz check it and You will find the answer there.
Anyway,good luck.
0
Networking for the Cloud Era

Join Microsoft and Riverbed for a discussion and demonstration of enhancements to SteelConnect:
-One-click orchestration and cloud connectivity in Azure environments
-Tight integration of SD-WAN and WAN optimization capabilities
-Scalability and resiliency equal to a data center

 

Author Comment

by:LiWangOn
ID: 2584241
I think I get your point. You mean I should analyze the data in the buffer while capturing the sound?

But I still confuse that how could I know which sample is having the "voice", and how to know the corresponding time of that sample?

(Actually I am writing a program to get respond time)
0
 

Author Comment

by:LiWangOn
ID: 2584978
I want to get the time difference (in ms) between a word presented on the computer screen and the user's respond towards the microphone.
0
 
LVL 2

Accepted Solution

by:
bkdc earned 50 total points
ID: 2682153
1. open the wave device with waveInOpen
with let's say callback function
2. create some buffers (one might be enough) of 1/2 (or other period) seconds.
3. get and store the system time - GetSysteTime (or use a timer) and then call waveInStart
4. when a buffer is recorded your callback function will be called (obvious that 1/2 sec elapsed)
5. any buffer will have some values in it differing from 0 (background noise).
If it's noise then it's usually in a narrow range (for example my sb./mic. generates noise between  -800 till -580
If the samples are not in this range then it's voice.
6. calculate the exact time when voice starts (using the sample index in the buffer and the sampling frequency)

7. of course you must have the time when the word was shown on the monitor

8. a simple substraction should give you the answer


0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering 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

Suggested Solutions

Templates For Beginners Or How To Encourage The Compiler To Work For You Introduction This tutorial is targeted at the reader who is, perhaps, familiar with the basics of C++ but would prefer a little slower introduction to the more ad…
Written by John Humphreys C++ Threading and the POSIX Library This article will cover the basic information that you need to know in order to make use of the POSIX threading library available for C and C++ on UNIX and most Linux systems.   [s…
The goal of the video will be to teach the user the difference and consequence of passing data by value vs passing data by reference in C++. An example of passing data by value as well as an example of passing data by reference will be be given. Bot…
The viewer will be introduced to the member functions push_back and pop_back of the vector class. The video will teach the difference between the two as well as how to use each one along with its functionality.

840 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