Solved

wavein-problems

Posted on 1997-04-24
6
278 Views
Last Modified: 2013-12-04
I wrote the following Callback-Function in order to
add the filled buffer, which is returned by the driver, again to drivers queue. I don't know why it doesn't work.
The driver stopps recording when the buffer is filled.
I would be verry glad if you could help me.

stephan




void CALLBACK  __export  WaveProc(

       HWAVE  hWave,      // handle of waveform device
       UINT  uMsg,      // sent message
       DWORD  dwInstance,      // instance data
       DWORD  dwParam1,      // application-defined parameter
       DWORD  dwParam2      // application-defined parameter
       )
{

 LPWAVEHDR lpWaveHdrTemp = (LPWAVEHDR) dwParam1;

  if( uMsg == WIM_DATA)
       {

             waveInUnprepareHeader((HWAVEIN) hWave, lpWaveHdrTemp ,sizeof(WAVEHDR) ) ;
              waveInPrepareHeader((HWAVEIN)hWave, lpWaveHdrTemp, sizeof(WAVEHDR));
              waveInAddBuffer((HWAVEIN)hWave, lpWaveHdrTemp, sizeof(WAVEHDR));
             
       }
}


0
Comment
Question by:stephan papadakis
  • 3
  • 3
6 Comments
 
LVL 15

Accepted Solution

by:
NickRepin earned 30 total points
ID: 1396904
API Reference for WaveProc says:Applications should not call any system-defined functions from inside a callback function, except for EnterCriticalSection, LeaveCriticalSection, midiOutLongMsg, midiOutShortMsg, OutputDebugString, PostMessage, PostThreadMessage, SetEvent, timeGetSystemTime, timeGetTime, timeKillEvent, and timeSetEvent. Calling other wave functions will cause deadlock.

0
 
LVL 15

Expert Comment

by:NickRepin
ID: 1396905
By the way, I said it before in answer to your question Q861187135 (4/16/97). But 'this question is locked until stephan papadakis evaluates the answer'  :(.
0
 

Author Comment

by:stephan papadakis
ID: 1396906
Thank's a lot for your answere.

The only problem is, how can i solve my problem?

What should i do know. Should i create a dummy Callback -Window?

If i do so the waveinopen-function returns errorcode 11h

wich means "function is called with wrong parameters".

0
Announcing the Most Valuable Experts of 2016

MVEs are more concerned with the satisfaction of those they help than with the considerable points they can earn. They are the types of people you feel privileged to call colleagues. Join us in honoring this amazing group of Experts.

 

Author Comment

by:stephan papadakis
ID: 1396907
Thank's a lot for your answere.

The only problem is, how can i solve my problem?

What should i do know. Should i create a dummy Callback -Window?

If i do so the waveinopen-function returns errorcode 11h

wich means "function is called with wrong parameters".

0
 
LVL 15

Expert Comment

by:NickRepin
ID: 1396908
To avoid crash, you can try to process buffers in your window procedure, not in the callback function. For example:// Define our notify message#define WMU_FINISHED   (WM_USER+1)// Fill it with handle of our windowHWND wnd;// Callback functionvoid CALLBACK WaveProc(HWAVE hWave, UINT uMsg, DWORD dwInstance, DWORD dwParam1, DWORD dwParam2)
{
  if( uMsg == WIM_DATA) {
      // Device driver is finished!      // Notify our window.      PostMessage(wnd,WMU_FINISHED,0,(LPARAM) dwParam1);   }}// Here is our window procedure... wndProc(HWND hWnd,UINT uMsg,WPARAM wParam,LPARAM lParam){   LPWAVEHDR lpWaveHdrTemp = (LPWAVEHDR) lParam;
  switch(uMsg) {      // ...      case WMU_FINISHED:
          waveInUnprepareHeader((HWAVEIN) hWave, lpWaveHdrTemp, sizeof(WAVEHDR));
          waveInPrepareHeader((HWAVEIN)hWave, lpWaveHdrTemp, sizeof(WAVEHDR));
          waveInAddBuffer((HWAVEIN)hWave, lpWaveHdrTemp, sizeof(WAVEHDR));
      // .....
}Also you can try to use callback window instead of callback function. May be there are no restrictions on calling wave* functions from inside of callback window.P.S. It will be nice if you can post me your source code to nick@rtzi.ru

0
 

Author Comment

by:stephan papadakis
ID: 1396909
Thank's a lot.

I got it.
The problem is solved.


stephan
0

Featured Post

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

Question has a verified solution.

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

Suggested Solutions

With most software applications trying to cater to multiple user needs nowadays, the focus is to make them as configurable as possible. For e.g., when creating Silverlight applications which will connect to WCF services, the service end point usuall…
After several hours of googling I could not gather any information on this topic. There are several ways of controlling the USB port connected to any storage device. The best example of that is by changing the registry value of "HKEY_LOCAL_MACHINE\S…
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. http://www.experts-exchange.com/videos/1478/Excel-Error-Handlin…
Two types of users will appreciate AOMEI Backupper Pro: 1 - Those with PCIe drives (and haven't found cloning software that works on them). 2 - Those who want a fast clone of their boot drive (no re-boots needed) and it can clone your drive wh…

828 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