audiostreamengine.cpp

S60_Platform_Audio_Streaming_Example 60平台下

// If EFalse, the default PCM is used. If the platform does not support AMR-NB,
// PCM will be used no matter what the argument's value is.
// ----------------------------------------------------------------------------
void CAudioStreamEngine::SetEncodingL(TBool aAmr)
	{
	// Act only if the new encoding differs from the current one
	if (iUseAMR != aAmr)
		{
		iUseAMR = aAmr;
		if (iUseAMR)
			{
			// Try to set AMR-NB encoding, this will indicate whether it is supported
			// by the platform or not.
			TRAPD(err, iInputStream->SetDataTypeL(KMMFFourCCCodeAMR));
			if (err != KErrNone)
				{
				ShowMessage(_L("AMR-NB not supported,\nusing PCM."), ETrue);	
				iCurrentEncoding = iDefaultEncoding;
				iUseAMR = EFalse;
				// We do not need to invalidate the buffer or change buffer settings, 
				// since the encoding was not changed -> just return.
				return;  
				}
			else
				{
				iCurrentEncoding = KMMFFourCCCodeAMR;
				iAudioFile.Zero();  // Empty the audio file name				
				iAudioFile.Append(KAudioFileAMR);
				iFrameCount = KFrameCountAMR;
				iFrameSize = KFrameSizeAMR;
				ShowMessage(_L("Encoding set to AMR-NB."), ETrue);	
				}
			}
		else
			{
			// If we get here, the encoding has previously been changed to AMR. Switch back to
			// PCM.
			iCurrentEncoding = iDefaultEncoding;
			iAudioFile.Zero();  // Empty the audio file name				
			iAudioFile.Append(KAudioFilePCM);
			iFrameCount = KFrameCountPCM;
			iFrameSize = KFrameSizePCM;
			ShowMessage(_L("Encoding set to PCM."), ETrue);	
			}

		// Make sure the user re-records or reloads the audio file, so that we do not 
		// accidentally try to play PCM data using AMR or vice versa.
		iBufferOK = EFalse;	
		if (iStreamBuffer) delete iStreamBuffer;
		iStreamBuffer = NULL; // In case the following NewL leaves
		iStreamBuffer = HBufC8::NewMaxL(iFrameSize * iFrameCount);
		iStreamStart=0;
		iStreamEnd=iFrameCount - 1;
		}	
	}

// ----------------------------------------------------------------------------
// CAudioStreamEngine::ShowMessage(
//     const TDesC& aMsg, TBool aReset=EFalse)
//
// displays text referenced by aMsg in the label, will append the aMsg in the 
// existing text in label if aReset is EFalse, otherwise will reset the label 
// text.
// ----------------------------------------------------------------------------
void CAudioStreamEngine::ShowMessage(const TDesC& aMsg, TBool aReset=EFalse)
	{
	if (aReset) 	// if ETrue, clear the message on the label prior to output
		iMsg.Zero();
	iMsg.Append(aMsg);
	TRAPD(error, iAppUi->GetView()->ShowMessageL(iMsg));
	PanicIfError(error);
	}

// ----------------------------------------------------------------------------
// TPtr8& CAudioStreamEngine::GetFrame(TUint aFrameIdx)
//
// Returns a modifiable pointer to a single frame inside the audio buffer 
// ----------------------------------------------------------------------------
TPtr8& CAudioStreamEngine::GetFrame(TUint aFrameIdx)
	{
	  __ASSERT_ALWAYS(aFrameIdx < iFrameCount, 
  									User::Panic(_L("AudioStreamEx"), 1));
  								
	  iFramePtr.Set((TUint8*)(iStreamBuffer->Ptr() + (aFrameIdx * iFrameSize)),
  								 iFrameSize,
  								 iFrameSize);
	  return iFramePtr;
	}

// ----------------------------------------------------------------------------
// TPtr8& CAudioStreamEngine::GetPlaybackFrames(TUint aLastFrame)
//
// Returns a modifiable pointer to the requested frames inside the audio buffer
// (from the first frame to aLastFrame). 
// ----------------------------------------------------------------------------
TPtr8& CAudioStreamEngine::GetPlaybackFrames(TUint aLastFrame)
	{
	__ASSERT_ALWAYS(aLastFrame < iFrameCount, 
  								User::Panic(_L("AudioStreamEx"), 2));
  								
	iFramePtr.Set((TUint8*)(iStreamBuffer->Ptr()),
  								 (aLastFrame + 1) * iFrameSize,
  								 (aLastFrame + 1) * iFrameSize);
  	return iFramePtr;
	}


//
// MMdaAudioInputStream callbacks (MMdaAudioInputStreamCallback)
//
// ----------------------------------------------------------------------------
// CAudioStreamEngine::MaiscOpenComplete(
//     TInt aError)
//
// called upon completion of CMdaAudioInputStream::Open(),
// if the stream was opened succesfully (aError==KErrNone), it's ready for use.
// upon succesful open, the first audio data block will be read from the input
// stream.
// ----------------------------------------------------------------------------
void CAudioStreamEngine::MaiscOpenComplete(TInt aError)
	{
	if (aError==KErrNone) 
		{
		// Input stream opened succesfully, set status
		iInputStatus = EOpen;
		// Set the data type (encoding)
		TRAPD(error, iInputStream->SetDataTypeL(iCurrentEncoding));
		PanicIfError(error);

		// set stream input gain to maximum
		iInputStream->SetGain(iInputStream->MaxGain());	
		// set stream priority to normal and time sensitive
		iInputStream->SetPriority(EPriorityNormal, EMdaPriorityPreferenceTime);				
		ShowMessage(_L("Recording..."), ETrue);
		
		// Emtpy the buffer and issue ReadL() to read the first audio data block, 
		// subsequent calls to ReadL() will be issued 
		// in MMdaAudioInputStreamCallback::MaiscBufferCopied()
		iStreamBuffer->Des().FillZ(iFrameCount * iFrameSize);
		iStreamIdx=0;
		TRAPD(error2, iInputStream->ReadL(GetFrame(iStreamIdx)));
		PanicIfError(error2);
		} 
	else 
		{
		// input stream open failed
		iInputStatus = ENotReady;
		ShowMessage(_L("Recording failed!"), ETrue);
		}
	}

// ----------------------------------------------------------------------------
// CAudioStreamEngine::MaiscBufferCopied(
//     TInt aError, const TDesC8& aBuffer)
//
// called when a block of audio data has been read and is available at the 
// buffer reference *aBuffer.  calls to ReadL() will be issued until all blocks
// in the audio data buffer (iStreamBuffer) are filled.
// ----------------------------------------------------------------------------
void CAudioStreamEngine::MaiscBufferCopied(TInt aError, const TDesC8& /*aBuffer*/)
	{
	
	if (aError==KErrNone) 
		{
		// stop recording if at the end of the buffer
		iStreamIdx++;
		if (iStreamIdx == iFrameCount)
		    {
		    ShowMessage(_L("\nRecording complete!"), EFalse);
		    iStreamEnd = iStreamIdx - 1;
	    	iBufferOK = ETrue;
			iInputStatus = ENotReady;
			// NOTE: In 2nd Edition we MUST NOT call iInputStream->Stop() here, because
			// this will cause a crash on 2nd Edition, FP1 devices.
			// Since iInputStream->Stop() is not called, the callback method
			// MaiscRecordComplete() will not be called either after exiting this method.
			// In 3rd Edition, however, iInputStream->Stop() MUST be called in order to reach
			// MaiscRecordComplete(), otherwise the stream will "hang".
			#ifdef __SERIES60_3X__
				iInputStream->Stop();
			#endif
		    return;
		  	}		
		
		// issue ReadL() for next frame		
		TRAPD(error, iInputStream->ReadL(GetFrame(iStreamIdx)));
		PanicIfError(error);
		}
	else if (aError==KErrAbort) 
		{
		// Recording was aborted, due to call to CMdaAudioInputStream::Stop()
		// This KErrAbort will occur each time the Stop() method in this class is executed.
		// Also, MaiscRecordComplete() will be called after exiting this method.
	    iStreamEnd = iStreamIdx - 1;
	    iBufferOK = ETrue;
		iInputStatus = ENotReady;
		}
	else 
		{
		ShowMessage(_L("\nError reading data \nfrom input"), EFalse);
		iInputStatus = ENotReady;
		}
	}

// ----------------------------------------------------------------------------
// CAudioStreamEngine::MaiscRecordComplete(
//     TInt aError)
//
// called when input stream is closed by CMdaAudioInputStream::Stop()
// ----------------------------------------------------------------------------
void CAudioStreamEngine::MaiscRecordComplete(TInt aError)
	{	
	iInputStatus = ENotReady;
	if (aError==KErrNone) 
		{
		// normal stream closure
		}
	else 
		{
		// completed with error(s)
		}
	}


// MMdaAudioOutputStream callbacks (MMdaAudioOutputStreamCallback)

// ----------------------------------------------------------------------------
// CAudioStreamEngine::MaoscOpenComplete(
//     TInt aError)
//
// called upon completion of CMdaAudioOutputStream::Open(),
// if the stream was opened succesfully (aError==KErrNone), it's ready for use.
// upon succesful open, the first audio data block will be written to the 
// output stream.
// ----------------------------------------------------------------------------
void CAudioStreamEngine::MaoscOpenComplete(TInt aError)
	{
	if (aError==KErrNone) 
		{
		// output stream opened succesfully, set status
		iOutputStatus = EOpen;
		// Set the data type (encoding). Should not fail, since we already
		// have tested support for this encoding in SetEncodingL with the 
		// corresponding input stream!
		TRAPD(error, iOutputStream->SetDataTypeL(iCurrentEncoding));
		PanicIfError(error);
		
		// set volume to 1/4th of stream max volume
		iOutputStream->SetVolume(iOutputStream->MaxVolume()/4);
		// set stream priority to normal and time sensitive
		iOutputStream->SetPriority(EPriorityNormal, 
			EMdaPriorityPreferenceTime);				
		ShowMessage(_L("Playing "), ETrue);

		if (iUseAMR)
			{
			// In case of AMR, the whole recorded/loaded buffer is played back at once, not frame by frame. 
			// The buffer might not be fully recorded, so we will only play back the part
			// that is filled with data.
			iStreamIdx = iStreamEnd;
			TRAPD(error2, iOutputStream->WriteL(GetPlaybackFrames(iStreamEnd)));
			PanicIfError(error2);
			}
		else
			{
			// PCM needs to be played back frame by frame, otherwise some older devices might
			// run into buffer overflow situations.
			iStreamIdx = 0;
			TRAPD(error3, iOutputStream->WriteL(GetFrame(iStreamIdx)));
			PanicIfError(error3);
			}
		}
	else 
		{
		// output stream open failed
		iOutputStatus = ENotReady;
		ShowMessage(_L("Playback failed!"), ETrue);
		}		
	}

// ----------------------------------------------------------------------------
// CAudioStreamEngine::MaoscBufferCopied(
//     TInt aError, const TDesC8& aBuffer)
//
// called when a block of audio data has been written to MMF. calls to WriteL() 
// will be issued until all blocks in the audio data buffer (iStreamBuffer) are 
// written.
// ----------------------------------------------------------------------------
void CAudioStreamEngine::MaoscBufferCopied(TInt aError, const TDesC8& /*aBuffer*/)
	{	
	if (aError==KErrNone) 
		{
		if (iStreamIdx==iStreamEnd)
			{
			ShowMessage(_L("\nPlayback complete!"), EFalse);
			iOutputStatus = ENotReady;
			// NOTE: In 2nd Edition we MUST NOT call iOutputStream->Stop() here, because
			// this will cause a crash on 2nd Edition, FP1 devices.
			// Since iOutputStream->Stop() is not called, the callback method
			// MaiscRecordComplete() will not be called either after exiting this method.
			// In 3rd Edition, however, iOutputStream->Stop() MUST be called in order to reach
			// MaiscRecordComplete(), otherwise the stream will "hang".
			#ifdef __SERIES60_3X__
				iOutputStream->Stop();
			#endif
			}
		else 
			{
			iStreamIdx++;
			TRAPD(error, iOutputStream->WriteL(GetFrame(iStreamIdx)));	
			PanicIfError(error);
			}
		}
	else if (aError==KErrAbort) 
		{
		// Playing was aborted, due to call to CMdaAudioOutputStream::Stop().
		// MaoscRecordComplete() will be called after exiting this method.
		iOutputStatus = ENotReady;
		}
	else 
		{
		ShowMessage(_L("\nError writing data \nto output"), EFalse);			
		iOutputStatus = ENotReady;
		}
	}


// ----------------------------------------------------------------------------
// CAudioStreamEngine::MaoscPlayComplete(
//     TInt aError)
//
// called when output stream is closed by CMdaAudioOutputStream::Stop() or if 
// end of audio data has been reached, in this case KErrUnderflow will be 
// returned.
// ----------------------------------------------------------------------------
void CAudioStreamEngine::MaoscPlayComplete(TInt aError)
	{
	iOutputStatus = ENotReady;
	if (aError==KErrNone) 
		{
		// normal stream closure
		}	
	else if (aError==KErrUnderflow) 
		{
		// end of audio data stream was reached because of stream underflow,
		}
	else 
		{
		// completed with error(s)
		}	
	}

// END OF FILE