CoreAudio/AudioUnits/AUPublic/Utility/AUInputFormatConverter.h
/* |
File: AUInputFormatConverter.h |
Abstract: Part of CoreAudio Utility Classes |
Version: 1.1 |
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*/ |
#ifndef __AUInputFormatConverter_h__ |
#define __AUInputFormatConverter_h__ |
#include "FormatConverterClient.h" |
#include "AUTimestampGenerator.h" |
// ____________________________________________________________________________ |
// AUInputFormatConverter |
// |
// Subclass of FormatConverterClient that applies a format conversion |
// to an input of an AudioUnit. |
/*! @class AUInputFormatConverter */ |
class AUInputFormatConverter : public FormatConverterClient { |
public: |
/*! @ctor AUInputFormatConverter */ |
AUInputFormatConverter(AUBase *hostAU, int inputBus) : |
mHost(hostAU), |
mHostBus(inputBus), |
mPreviousSilentFrames(0x1000) |
{ |
#if DEBUG |
mTimestampGenerator.mVerbosity = 0; |
strcpy(mTimestampGenerator.mDebugName, "AUConverter"); |
#endif |
} |
// need to subsequently call Initialize, with the desired formats |
/*! @dtor ~AUInputFormatConverter */ |
~AUInputFormatConverter() |
{ |
} |
virtual OSStatus Initialize(const AudioStreamBasicDescription &src, const AudioStreamBasicDescription &dest) |
{ |
OSStatus err = FormatConverterClient::Initialize(src, dest); |
if (err) return err; |
mIsPCMToPCM = (src.mFormatID == kAudioFormatLinearPCM) && (dest.mFormatID == kAudioFormatLinearPCM); |
mHasSRC = (fnonzero(src.mSampleRate) && fnonzero(dest.mSampleRate) && fnotequal(src.mSampleRate, dest.mSampleRate)); |
return ca_noErr; |
} |
virtual OSStatus Reset() |
{ |
mPreviousSilentFrames = 0x1000; |
mTimestampGenerator.Reset(); |
return FormatConverterClient::Reset(); |
} |
void SetStartInputTimeAtZero(bool b) |
{ |
mTimestampGenerator.SetStartInputAtZero(b); |
} |
/*! @method FillComplexBuffer */ |
OSStatus AUFillComplexBuffer(const AudioTimeStamp & inTimeStamp, |
UInt32 & ioOutputDataPacketSize, |
AudioBufferList & outOutputData, |
AudioStreamPacketDescription* outPacketDescription, |
bool& outSilence) |
{ |
mTimestampGenerator.AddOutputTime(inTimeStamp, ioOutputDataPacketSize, mOutputFormat.mSampleRate); |
mSilentOutput = true; |
OSStatus err = FillComplexBuffer(ioOutputDataPacketSize, outOutputData, outPacketDescription); |
if (mSilentOutput) { |
if (!mIsPCMToPCM || (mHasSRC && mPreviousSilentFrames < 32)) |
mSilentOutput = false; |
mPreviousSilentFrames += ioOutputDataPacketSize; |
} else |
mPreviousSilentFrames = 0; |
outSilence = mSilentOutput; |
return err; |
} |
/*! @method FormatConverterInputProc */ |
virtual OSStatus FormatConverterInputProc( |
UInt32 & ioNumberDataPackets, |
AudioBufferList & ioData, |
AudioStreamPacketDescription** outDataPacketDescription) |
{ |
OSStatus err = ca_noErr; |
AudioUnitRenderActionFlags actionFlags = 0; |
AUInputElement *input = mHost->GetInput(mHostBus); |
*ioNumberDataPackets = std::min(*ioNumberDataPackets, This->mHost->GetMaxFramesPerSlice()); |
const AudioTimeStamp &inputTime = mTimestampGenerator.GenerateInputTime(ioNumberDataPackets, mInputFormat.mSampleRate); |
err = input->PullInput(actionFlags, inputTime, mHostBus, ioNumberDataPackets); |
if (!err) { |
input->CopyBufferListTo(ioData); |
if (!(actionFlags & kAudioUnitRenderAction_OutputIsSilence)) |
mSilentOutput = false; |
} |
return err; |
} |
protected: |
/*! @var mHost */ |
AUBase * mHost; |
/*! @var mHostBus */ |
int mHostBus; |
AUTimestampGenerator mTimestampGenerator; |
bool mIsPCMToPCM; |
bool mHasSRC; |
bool mSilentOutput; |
UInt32 mPreviousSilentFrames; |
}; |
#endif // __AUInputFormatConverter_h__ |
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