vrexviewfinder.cpp

一个symbian下的播放器的例子 适合研究视频相关的源码

/*
* ============================================================================
*  Name     : CVideoViewFinder from VRexViewFinder.cpp
*  Part of  : Video Example
*  Created  : 30/08/2006 by Forum  Nokia
*  Implementation notes:
*  Version  : 2.0
*  Copyright: Nokia Corporation, 2006
* ============================================================================
*/

// INCLUDE FILES
#include <eikenv.h> // CEikonEnv

#include "VRexViewFinder.h"

/*
-----------------------------------------------------------------------------

	CVideoViewFinder::CVideoViewFinder()

	Description: C++ default constructor can NOT contain any code, that
				 might leave.
	Comments   :

    Return values: N/A

-----------------------------------------------------------------------------
*/
CVideoViewFinder::CVideoViewFinder()
	: iState(EFinderInactive)
    {
    }

/*
-----------------------------------------------------------------------------

	CVideoViewFinder::~CVideoViewFinder()

	Description: Destructor.
	Comments   :

    Return values: N/A

-----------------------------------------------------------------------------
*/
CVideoViewFinder::~CVideoViewFinder()
    {
    if(iCamera)
	    {
	    Stop();
	    delete iCamera;
	    iCamera = NULL;
	    }
    }

/*
-----------------------------------------------------------------------------

	void CVideoViewFinder::ConstructL(TInt aCameraHandle)

	Description: Second phase constructor.
	Comments   :

    Return values: N/A

-----------------------------------------------------------------------------
*/
void CVideoViewFinder::ConstructL(TInt aCameraHandle)
	{

	if ( !CCamera::CamerasAvailable() )
		{
	    //Handle KErrHardwareNotAvailable error here
	    return;
	   	}
	iCamera = CCamera::NewL(*this, aCameraHandle);

	}

/*
-----------------------------------------------------------------------------

	void CVideoViewFinder::StartL()

	Description: This method starts video view finder.
	Comments   :

    Return values: N/A

-----------------------------------------------------------------------------
*/
void CVideoViewFinder::StartL()
	{
	if(!iCamera)
		{
		User::Leave(KErrNotReady);
		}

	iState = EFinderInitializing;
	iCamera->Reserve();

	ActivateL();
	DrawDeferred();
	}

/*
-----------------------------------------------------------------------------

	void CVideoViewFinder::Stop()

	Description: This method stops video view finder.
	Comments   :

    Return values: N/A

-----------------------------------------------------------------------------
*/
void CVideoViewFinder::Stop()
	{
	if(iState==EFinderActive)
		{
		iCamera->PowerOff();
		iCamera->Release();
		}
	iState = EFinderInactive;
	}

/*
-----------------------------------------------------------------------------

	void CVideoViewFinder::ReserveComplete(TInt aError)

	Description: This method informs that camera reservation is complete.
	Comments   : Called asynchronously when CCamera::Reserve() completes.

    Return values: N/A

-----------------------------------------------------------------------------
*/
void CVideoViewFinder::ReserveComplete(TInt aError)
	{
	if(aError==KErrNone)
		{
		iCamera->PowerOn();
		}
	else
		{
		iState = EFinderFailed;
		}
	}

/*
-----------------------------------------------------------------------------

	void CVideoViewFinder::PowerOnComplete(TInt aError)

	Description: This method indicates camera power on is complete.
	Comments   : Called on completion of CCamera:PowerOn().

    Return values: N/A

-----------------------------------------------------------------------------
*/
void CVideoViewFinder::PowerOnComplete(TInt aError)
	{
	if(aError==KErrNone)
		{
		TSize finderSize = Size();
		// Start view finder. On return, finderSize contains the finder size
		TRAPD(ignored, iCamera->StartViewFinderBitmapsL(finderSize));

		TRect rect = Rect();

		// Calculate position for finder bitmaps (centered on component)
		// iFinderPosition is the top-left coordinate for bitmap
		iFinderPosition = rect.iTl;
		iFinderPosition.iX += (rect.Size().iWidth - finderSize.iWidth)/2;
		iFinderPosition.iY += (rect.Size().iHeight - finderSize.iHeight)/2;

		iState = EFinderActive;
		}
	else
		{
		iCamera->Release();
		iState = EFinderFailed;
		}
	}

/*
-----------------------------------------------------------------------------

	void CVideoViewFinder::ViewFinderFrameReady(CFbsBitmap& aFrame)

	Description: This method tests whether transfer of view finder data has completed.
	Comments   : Called periodically in response to the use of
				 CCamera::StartViewFinderBitmapsL().

    Return values: N/A

-----------------------------------------------------------------------------
*/
void CVideoViewFinder::ViewFinderFrameReady(CFbsBitmap& aFrame)
	{
	// Keep backlight on while finder is active
    User::ResetInactivityTime();

  	// Get graphics context
    CWindowGc &gc = SystemGc();

    // Graphics context must be activated, because we are not in Draw()
	gc.Activate(Window());

	// Draw finder frame to screen; BitBlt is much faster than DrawBitmap
	gc.BitBlt(iFinderPosition, &aFrame);

	// Deactivate graphics context
    gc.Deactivate();
	}

/*
-----------------------------------------------------------------------------

	void CVideoViewFinder::ImageReady(CFbsBitmap* aBitmap, HBufC8* aData, TInt aError)

	Description: This method transfers the current image from the camera to the client.
	Comments   : Called asynchronously when CCamera::CaptureImage() completes.

    Return values: N/A

-----------------------------------------------------------------------------
*/
void CVideoViewFinder::ImageReady(CFbsBitmap* /*aBitmap*/, HBufC8* /*aData*/, TInt /*aError*/)
	{
	}

/*
-----------------------------------------------------------------------------

	void CVideoViewFinder::FrameBufferReady(MFrameBuffer* aFrameBuffer, TInt aError)

	Description: This method passes a filled frame buffer to the client.
	Comments   : Called asynchronously, when a buffer has been filled with the
				 required number of video frames by CCamera::StartVideoCapture().

    Return values: N/A

-----------------------------------------------------------------------------
*/
void CVideoViewFinder::FrameBufferReady(MFrameBuffer* /*aFrameBuffer*/, TInt /*aError*/)
	{
	}

/*
-----------------------------------------------------------------------------

	void CVideoViewFinder::Draw(const TRect& aRect) const

	Description: This method is called by the framework, draws the view.
	Comments   :

    Return values: N/A

-----------------------------------------------------------------------------
*/
void CVideoViewFinder::Draw(const TRect& aRect) const
    {
    // Draw the background of finder
    CWindowGc &gc = SystemGc();

    gc.SetBrushStyle(CGraphicsContext::ESolidBrush);
   	gc.SetBrushColor(KRgbWhite);

	gc.DrawRect(aRect);
    }

/*
-----------------------------------------------------------------------------

	CVideoViewFinder::TFinderState CVideoViewFinder::State() const

	Description: This method returns the state of video view finder.
	Comments   :

    Return values: Video view finder state

-----------------------------------------------------------------------------
*/
CVideoViewFinder::TFinderState CVideoViewFinder::State() const
	{
	return iState;
	}

/*
-----------------------------------------------------------------------------

	TInt CVideoViewFinder::CameraHandle()

	Description: This method returns camera handle.
	Comments   :

    Return values: Handle to camera object

-----------------------------------------------------------------------------
*/
TInt CVideoViewFinder::CameraHandle()
	{
	return iCamera->Handle();
	}

// End of file