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Directshow does not repaint while a movie clip is paused.

Posted on 2003-11-20
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Last Modified: 2012-06-27
I have made a little movie player box in a dialog I have, outputing the video to a static control.  Everything works great except for when I pause the player and open a window over the application, when I make the app visible again, the video is gone and directshow does not repaint the paused frame.  During playback everything works great. Here is the code that responds to events:

void cTrailerList::HandleGraphEvent(void)
{
      // Function to take care of graph notication codes

      long lCode, lParam1, lParam2;

      LONGLONG pos = 0;

      // If the IMediaEventEx pointer is NULL return
      // to avoid an error
      if ( cTrailer.pEvent == NULL )
            return;

      while ( SUCCEEDED(cTrailer.pEvent->GetEvent(&lCode, &lParam1, &lParam2, 0)) )
      {
            cTrailer.pEvent->FreeEventParams(lCode, lParam1, lParam2);

            switch(lCode)
            {
                  case EC_COMPLETE:
                        // Reset to first frame of movie
                        cTrailer.pSeek->SetPositions(&pos, AM_SEEKING_AbsolutePositioning ,
                                                                   NULL, AM_SEEKING_NoPositioning);

                        return;

                  case EC_USERABORT:
                  case EC_ERRORABORT:
                        cTrailer.CleanUp();

                        return;
            }
      }
}

I have tried handling EC_REPAINT but with no success. I am somehow conviced it has to do with the static control but I can't find a workaround.
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Question by:georgiek50
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Expert Comment

by:_corey_
ID: 9801444
You will probably need to subclass CStatic and implement the OnDraw method so that it updates the CStatic window with the current buffer when WM_PAINT is called.
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Expert Comment

by:_corey_
ID: 9801449
http://www.codeproject.com/wtl/mix_wtl_mfc.asp

This is a slightly akward example, but if you can get around the odd coding since it is a WTL to MFC conversion example, check out the project files, and then open the scrollwindow.cpp and .h for example in implementing the OnDraw method.  ScrollWindow subclasses CStatic (and does a lot of other stuff).

I was actually looking at that for something else so it's the reason I'm giving it as the example.  Hope it helps more than confuses.
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Author Comment

by:georgiek50
ID: 9801879
I have already subclassed the window to process the WM_PAINT message.  I thought of doing something along the lines like you suggested, keep a track of the current frame and just paint it in when needed.  I just wanted to see if this was the "proper" way to handle this situation because reading through MSDN it states that Directshow will handle the painting.
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Accepted Solution

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_corey_ earned 300 total points
ID: 9803126
It will, but the CStatic window might not repaint correctly?  I've seen this error too.

I think just implementing OnDraw will work instead of trying to trap WM_PAINT manually.
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Expert Comment

by:tinchos
ID: 10249343
No comment has been added lately, so it's time to clean up this TA.
I will leave the following recommendation for this question in the Cleanup topic area:

Accept: _corey_ {http:#9803126}

Please leave any comments here within the next seven days.
PLEASE DO NOT ACCEPT THIS COMMENT AS AN ANSWER!

Tinchos
EE Cleanup Volunteer
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Expert Comment

by:_corey_
ID: 10252929
All you have to do is check for a DEVICELOST return value, and then re-create the device the video is being displayed on.  Or something like that.
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