WIN 95 MMSYSTEM.dll function calls

Posted on 1997-09-07
Last Modified: 2013-12-03
Which Functions from mmsystem.dll are (in which sequence) necessarry to get the samples from a soundcard?
Do I have to use waveinstart, waveinopen, wavein....
The purpose is to 1. Reduce the access to the soundcard to
a mmsystem.dll function call(s).
2. I want to process the data afterwards and I don't need
continuous sampling but single samples from both channels
(left and right). I'm using a graphical development environment which allows dll function calls.
And where to find information about these things are done?

Question by:pertex
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
  • 2
  • 2

Expert Comment

ID: 1406045
Do you want to sample data from the sound card? If so, what do you want to do with the samples, save to disk or process?

Author Comment

ID: 1406046
Edited text of question

Accepted Solution

y96andha earned 200 total points
ID: 1406047
This is source in Visual Basic to record 1 second of 8kHz mono. This should show both the sequence of the calls, and the parameters needed in the structures. Please comment if you have any questions.

Dim hWaveIn As Long
Dim error As Long
wf.wFormatTag = WAVE_FORMAT_PCM
wf.nChannels = 1
wf.nSamplesPerSec = 8000
wf.wBitsPerSample = 8
wf.nBlockAlign = wf.nChannels * wf.wBitsPerSample / 8
wf.nAvgBytesPerSec = wf.nSamplesPerSec * wf.nBlockAlign
wf.cbSize = 0
error = waveInOpen(hWaveIn, WAVE_MAPPER, wf, 0, 0, 0)
If error <> 0 Then
    Print "Error "; error; " in waveInOpen"
    Exit Sub
End If

Dim data(8000) As Byte
wh.lpData = VarPtr(data(1))
wh.dwBufferLength = 8000
wh.dwUser = 0
wh.dwFlags = 0
wh.dwLoops = 0
wh.lpNext = 0
wh.Reserved = 0
error = waveInPrepareHeader(hWaveIn, wh, Len(wh))
If error <> 0 Then
    waveInClose hWaveIn
    Print "Error "; error; " in waveInPrepareHeader"
    Exit Sub
End If

error = waveInAddBuffer(hWaveIn, wh, Len(wh))
If error <> 0 Then
    waveInUnprepareHeader hWaveIn, wh, Len(wh)
    waveInClose hWaveIn
    Print "Error "; error; " in waveInAddBuffer"
    Exit Sub
End If

error = waveInStart(hWaveIn)
If error <> 0 Then
    waveInReset hWaveIn
    waveInUnprepareHeader hWaveIn, wh, Len(wh)
    waveInClose hWaveIn
    Print "Error "; error; " in waveInStart"
    Exit Sub
End If

Print "Recording"
While (wh.dwFlags And WHDR_DONE) <> WHDR_DONE
Print "Finished"

error = waveInUnprepareHeader(hWaveIn, wh, Len(wh))
If error <> 0 Then
    waveInClose hWaveIn
    Print "Error "; error; "in waveInUnprepareHeader"
    Exit Sub
End If

waveInClose hWaveIn
Print "Recorded data successfully"


Author Comment

ID: 1406048
Thanks a lot! I will check it out

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

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

This article surveys and compares options for encoding and decoding base64 data.  It includes source code in C++ as well as examples of how to use standard Windows API functions for these tasks. We'll look at the algorithms — how encoding and decodi…
As more and more people are shifting to the latest .Net frameworks, the windows presentation framework is gaining importance by the day. Many people are now turning to WPF controls to provide a rich user experience. I have been using WPF controls fo…
This is Part 3 in a 3-part series on Experts Exchange to discuss error handling in VBA code written for Excel. Part 1 of this series discussed basic error handling code using VBA.…
Michael from AdRem Software outlines event notifications and Automatic Corrective Actions in network monitoring. Automatic Corrective Actions are scripts, which can automatically run upon discovery of a certain undesirable condition in your network.…

729 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