audiomp3engine.cpp

封装了Symbian OS 3rd的音频播放器

/*
============================================================================
 Name        : AudioMp3Engine.cpp
 Author      : 
 Version     :
 Copyright   : Your copyright notice
 Description : CAudioMp3Engine implementation
============================================================================
*/

#include "AudioMp3Engine.h"

#include <eikenv.h>             
#include <eikapp.h>
#include <eikdef.h>
#include <e32math.h> 
#include "mp3_engine.h"
#include "MP3DecodeEngine.h"

CAudioMp3Engine::CAudioMp3Engine()
	:iVolume(KInitialVolume),
	iVolStep(0),
	iFileOK(EFalse),
	iMp3Status(EEngineNotReady),
	iPlayFile(ETrue),
	iRepeat(EFalse),
	imp3Buf(0,0),
	iStart(EFalse),
	fm(0),
	bufx(0)
	{
	
	}

CAudioMp3Engine::~CAudioMp3Engine()
	{
	delete iStream;
	delete [] aa;
	delete imp3;
	fss.Close();
	}

CAudioMp3Engine* CAudioMp3Engine::NewLC()
	{
	CAudioMp3Engine* self = new (ELeave)CAudioMp3Engine();
	CleanupStack::PushL(self);
	self->ConstructL();
	return self;
	}

CAudioMp3Engine* CAudioMp3Engine::NewL()
	{
	CAudioMp3Engine* self=CAudioMp3Engine::NewLC();
	CleanupStack::Pop(); 
	return self;
	}

void CAudioMp3Engine::ConstructL()
	{
	// get the Eikon environment
	iEnv = CEikonEnv::Static();
	imp3=CMP3DecodeEngine::NewL();

	iFileOK = EFalse;
	aa=new (ELeave) TUint16[2400];//缓冲区，存储单帧内容，大小不定，  最好设的足够大，不然会报错

	imp3Buf.Set(aa,2400,2400);


	fss.Connect();
	// create and initialize output stream          
	iStream = CMdaAudioOutputStream::NewL(*this);
	iStream->Open(&iSettings);
	}

void CAudioMp3Engine::MaoscOpenComplete( TInt aError )
	{
	if (aError==KErrNone)
		{
		// set stream properties to 16bit,8KHz mono EChannelsMono EChannelsStereo
		//因为解码后的内容为单声道，所以一定要用TMdaAudioDataSettings::EChannelsMono，
		//另外采样率要和imp3->SetResampleRate设置的一致
		iStream->SetAudioPropertiesL(TMdaAudioDataSettings::ESampleRate44100Hz, TMdaAudioDataSettings::EChannelsMono);

		// set the appropriate volume step. values for the target
		// device are scaled down to get the optimal volume level
#if defined(__WINS__)
		// for emulator (MaxVolume == 65535)
		iVolStep = iStream->MaxVolume() / KVolSliderLength;
#else
		// for target device (MaxVolume == 9)
		iVolStep = iStream->MaxVolume() / (KVolSliderLength-1);
#endif
		iStream->SetVolume(iVolStep * KInitialVolume);        

		iStream->SetPriority(EPriorityNormal, EMdaPriorityPreferenceNone);

		iMp3Status = EEngineReady;        
		}
	else        
		ShowErrorMsg(R_WAVEGEN_ERROR_OPENCOMPLETE, aError);


	//  PlayL();

	}

void CAudioMp3Engine::MaoscBufferCopied( TInt aError, const TDesC8& aBuffer )
	{
	// if a single file (buffer) is played, return immediately

	if(aError==KErrNone || aError==KErrAbort)
		{
		if(iMp3Status==EEngineToPause)
			{
			iMp3Status=EEnginePause;
			iStream->Stop();
			return;
			}

		if(iMp3Status==EEnginePause)
			{
			return;
			} 

		if(iPlayFile )
			{

			if(iMp3Status==EEnginePlaying  && iFileOK)
				{
				NextBuffer(aBuffer);
				}

			return;
			}
		}
	else
		{
		//  if(iMp3Status!=EEngineReady)
		//  {
		iMp3Status=EEnginePause;
		//   iStream->Stop();
		//  }
		//  User::Invariant();
		}


	}

void CAudioMp3Engine::MaoscPlayComplete( TInt aError )
	{
	if (aError==KErrNone || aError==KErrCancel)
		{
		if(iMp3Status == EEnginePlaying)
			{
			bufx=0;
			iFileOK=EFalse;
			iStart=EFalse;
			iMp3Status = EEngineReady;

			imp3->CloseFile();
			iBufList[0].SetLength(0);
			iBufList[1].SetLength(0);
			}
		}
	else
		{
		iMp3Status=EEnginePause;
		//  if(iMp3Status == EEnginePlaying)
		//  {
		//   iMp3Status=EEnginePause;
		//   iStream->Stop();
		//  }
		//  User::Invariant();
		}
	}

void CAudioMp3Engine::PlayL()
	{

	if(iMp3Status == EEngineReady || iMp3Status == EEnginePause)
		{
		iMp3Status = EEnginePlaying;
		if( !iFileOK )
			{
			imp3->OpenFile(fss,tFullFileName);
			imp3->SetResampleRate(44100);
			imp3->DecodeStart();
			iFileOK=ETrue;
			}
		if( !iStart )
			{
			imp3->DecodeOneFrame(imp3Buf);
			iBufList[0].Copy( (TUint8*)imp3Buf.Ptr(), imp3Buf.Length()*2 );
			imp3->DecodeOneFrame(imp3Buf);    
			iBufList[1].Copy( (TUint8*)imp3Buf.Ptr(), imp3Buf.Length()*2 );
			}
		else
			{
			imp3->DecodeOneFrame(imp3Buf);    
			iBufList[1].Copy( (TUint8*)imp3Buf.Ptr(),imp3Buf.Length()*2 );
			}

		iStream->WriteL(iBufList[bufx]);
		if(bufx==0)
			bufx=1;
		else
			bufx=0;

		iStart=ETrue;
		if(imp3->GetFilePosition()==imp3->GetFileLength())
			{
			imp3->CloseFile();
			if(iRepeat)
				{
				imp3->OpenFile(fss,tFullFileName);
				imp3->SetResampleRate(44100);
				imp3->DecodeStart();
				}
			else
				{
				iFileOK=EFalse;
				}
			}
		}
	}

void CAudioMp3Engine::Pause()
	{
	iMp3Status = EEngineToPause;
	}
void CAudioMp3Engine::StopL()
	{
	bufx=0;
	iFileOK=EFalse;
	iStart=EFalse;
	iMp3Status = EEngineReady;

	iStream->Stop();
	imp3->CloseFile();
	iBufList[0].SetLength(0);
	iBufList[1].SetLength(0);
	}

void CAudioMp3Engine::SetRepeat( TBool aRepeat )
	{
	iRepeat=aRepeat;
	}

void CAudioMp3Engine::OpenL(TFileName  aFileName)
	{

	if(iMp3Status == EEnginePlaying || iMp3Status == EEnginePause)
		{
		StopL();
		}

	tFullFileName = aFileName;
	PlayL();
	}


void CAudioMp3Engine::SetVolume(TInt aVol)
	{ 
	iVolume = aVol;

	// if value has changed, pass it directly to audiostream object. 
	if((iVolume * iVolStep) != iStream->Volume())        
		iStream->SetVolume(iVolume * iVolStep);

	}

void CAudioMp3Engine::ShowErrorMsg(TInt aResourceBuf, TInt aError)
	{
	TBuf<16> errorNum;
	TBuf<128> rDes;
	errorNum.Num(aError);

	iEnv->ReadResource(rDes, aResourceBuf);
	rDes.Append(errorNum);

	CAudioMp3Engine* dlg = new(ELeave)CAknInformationNote();
	dlg->ExecuteLD(rDes); 
	}



void CAudioMp3Engine::NextBuffer(const TDesC8& aBuffer)
	{
	//assume the buffer is already there!
	iStream->WriteL(iBufList[bufx]);
	if(bufx==0)
		bufx=1;
	else
		bufx=0;

	if(imp3->GetFilePosition()==imp3->GetFileLength())
		{
		imp3->CloseFile();
		if(iRepeat)
			{
			imp3->OpenFile(fss,tFullFileName);
			imp3->SetResampleRate(44100);
			imp3->DecodeStart();
			}
		else
			{
			iFileOK=EFalse;
			}
		}


	ASSERT(iBufList[bufx]==aBuffer);
	iBufList[bufx].SetLength(0);
	imp3->DecodeOneFrame(imp3Buf);    
	iBufList[bufx].Copy((TUint8*)imp3Buf.Ptr(),imp3Buf.Length()*2);

	}