/*

     File: AUTimestampGenerator.cpp

 Abstract: AUTimestampGenerator.h

  Version: 1.1

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*/

#include "AUTimestampGenerator.h"

#include "CAMath.h"

#if DEBUG

static double DebugHostTime(const AudioTimeStamp &ts)

{

    static UInt64 baseHostTime = 0;

    if (!(ts.mFlags & kAudioTimeStampHostTimeValid))

        return -1.;

    if (baseHostTime == 0)

        baseHostTime = ts.mHostTime;

    return double(SInt64(ts.mHostTime) - SInt64(baseHostTime)) * CAHostTimeBase::GetInverseFrequency();

}

#endif

void    AUTimestampGenerator::AddOutputTime(const AudioTimeStamp &inTimeStamp, Float64 expectedDeltaFrames, double outputSampleRate, double rateScalarAdj)

{

    mState.mRateScalarAdj = rateScalarAdj;

    mState.mLastOutputTime = mState.mCurrentOutputTime;

    mState.mInputSampleTimeForOutputPull = mState.mNextInputSampleTime;

    mState.mCurrentOutputTime = inTimeStamp;

    if (mState.mBypassed)

        return;

    if (mState.mHostTimeDiscontinuityCorrection && !(mState.mCurrentOutputTime.mFlags & kAudioTimeStampHostTimeValid) && (mState.mLastOutputTime.mFlags & kAudioTimeStampHostTimeValid)) {

        // no host time here but we had one last time, interpolate one

        double rateScalar = (mState.mCurrentOutputTime.mFlags & kAudioTimeStampRateScalarValid) ? mState.mCurrentOutputTime.mRateScalar : 1.0;

        Float64 deltaSamples = mState.mCurrentOutputTime.mSampleTime - mState.mLastOutputTime.mSampleTime;

        mState.mCurrentOutputTime.mHostTime = mState.mLastOutputTime.mHostTime + 

            UInt64(CAHostTimeBase::GetFrequency() * deltaSamples * rateScalar / outputSampleRate);

        mState.mCurrentOutputTime.mFlags |= kAudioTimeStampHostTimeValid;

#if DEBUG

        if (mVerbosity > 1)

            printf("synthesized host time: %.3f (%.3f + %.f smp @ %.f Hz, rs %.3f\n", DebugHostTime(mState.mCurrentOutputTime), DebugHostTime(mState.mLastOutputTime), deltaSamples, outputSampleRate, rateScalar);

#endif

    }

    // copy rate scalar

    if (rateScalarAdj != 1.0) {

        if (mState.mCurrentOutputTime.mFlags & kAudioTimeStampRateScalarValid)

            mState.mCurrentOutputTime.mRateScalar *= rateScalarAdj;

        else {

            mState.mCurrentOutputTime.mRateScalar = rateScalarAdj;

            mState.mCurrentOutputTime.mFlags |= kAudioTimeStampRateScalarValid;

        }

    }

    if (mFirstTime) {

        mFirstTime = false;

        mState.mDiscontinuous = false;

        mState.mDiscontinuityDeltaSamples = 0.;

        if (!mState.mStartInputAtZero) {

            mState.mNextInputSampleTime = mState.mCurrentOutputTime.mSampleTime;

            mState.mInputSampleTimeForOutputPull = mState.mNextInputSampleTime;

        }

    } else {

        mState.mDiscontinuous = fnotequal(mState.mCurrentOutputTime.mSampleTime, mState.mNextOutputSampleTime);

        mState.mDiscontinuityDeltaSamples = mState.mCurrentOutputTime.mSampleTime - mState.mNextOutputSampleTime;

        // time should never go backwards...

        if (mState.mDiscontinuityDeltaSamples < 0.)

            mState.mDiscontinuityDeltaSamples = 0.;

#if DEBUG

        if (mVerbosity > 1)

            if (mState.mDiscontinuous)

                printf("%-20.20s: *** DISCONTINUOUS, got " TSGFMT ", expected " TSGFMT "\n", mDebugName, (SInt64)mState.mCurrentOutputTime.mSampleTime, (SInt64)mState.mNextOutputSampleTime);

#endif

    }

    mState.mNextOutputSampleTime = mState.mCurrentOutputTime.mSampleTime + expectedDeltaFrames;

}

const AudioTimeStamp &  AUTimestampGenerator::GenerateInputTime(Float64 framesToAdvance, double inputSampleRate, bool advanceHostTime)

{

    if (mState.mBypassed)

        return mState.mCurrentOutputTime;

    double inputSampleTime;

    mState.mCurrentInputTime.mFlags = kAudioTimeStampSampleTimeValid;

    double rateScalar = 1.0;

    // propagate rate scalar

    if (mState.mCurrentOutputTime.mFlags & kAudioTimeStampRateScalarValid) {

        mState.mCurrentInputTime.mFlags |= kAudioTimeStampRateScalarValid;

        mState.mCurrentInputTime.mRateScalar = rateScalar = mState.mCurrentOutputTime.mRateScalar;

    }

    // propagate host time and sample time

    if (mState.mCurrentOutputTime.mFlags & kAudioTimeStampHostTimeValid) {

        mState.mCurrentInputTime.mFlags |= kAudioTimeStampHostTimeValid;

        if (advanceHostTime) {

            Float64 deltaSamples = mState.mNextInputSampleTime - mState.mInputSampleTimeForOutputPull;

            Float64 deltaSeconds = (deltaSamples / inputSampleRate) * mState.mRateScalarAdj;

            UInt64 deltaHostTime = (UInt64)(deltaSeconds * CAHostTimeBase::GetFrequency());

            mState.mCurrentInputTime.mHostTime = mState.mCurrentOutputTime.mHostTime + deltaHostTime;

        } else {

            mState.mCurrentInputTime.mHostTime = mState.mCurrentOutputTime.mHostTime;

        }

        if (mState.mHostTimeDiscontinuityCorrection && mState.mDiscontinuous && (mState.mLastOutputTime.mFlags & kAudioTimeStampHostTimeValid)) {

            // we had a discontinuous output time, need to resync by interpolating 

            // a sample time that is appropriate to the host time

            UInt64 deltaHostTime = mState.mCurrentOutputTime.mHostTime - mState.mLastOutputTime.mHostTime;

            double deltaSeconds = double(deltaHostTime) * CAHostTimeBase::GetInverseFrequency();

            // samples/second * seconds = samples

            double deltaSamples = floor(inputSampleRate / rateScalar * deltaSeconds + 0.5);

            double lastInputSampleTime = mState.mCurrentInputTime.mSampleTime;

            inputSampleTime = lastInputSampleTime + deltaSamples;

#if DEBUG

            if (mVerbosity > 1)

                printf("%-20.20s: adjusted input time: " TSGFMT " -> " TSGFMT " (SR=%.3f, rs=%.3f)\n", mDebugName, (SInt64)lastInputSampleTime, (SInt64)inputSampleTime, inputSampleRate, rateScalar);

#endif

            mState.mDiscontinuous = false;

        } else {

            inputSampleTime = mState.mNextInputSampleTime;

        }

    } else {

        // we don't know the host time, so we can't do much

        inputSampleTime = mState.mNextInputSampleTime;

    }

    if (!mState.mHostTimeDiscontinuityCorrection && fnonzero(mState.mDiscontinuityDeltaSamples))

    {

        // we had a discontinuous output time, need to resync by propagating the

        // detected discontinuity, taking the rate scalar adjustment into account

        inputSampleTime += floor(mState.mDiscontinuityDeltaSamples / mState.mRateScalarAdj + 0.5);

#if DEBUG

        if (mVerbosity > 1)

            printf("%-20.20s: adjusted input time: %.0f -> %.0f (SR=%.3f, rs=%.3f, delta=%.0f)\n", mDebugName, mState.mNextInputSampleTime, inputSampleTime, inputSampleRate, mState.mRateScalarAdj, mState.mDiscontinuityDeltaSamples);

#endif

        mState.mDiscontinuityDeltaSamples = 0.;

    }

    // propagate word clock

    if (mState.mCurrentOutputTime.mFlags & kAudioTimeStampWordClockTimeValid) {

        mState.mCurrentInputTime.mFlags |= kAudioTimeStampWordClockTimeValid;

        mState.mCurrentInputTime.mWordClockTime = mState.mCurrentOutputTime.mWordClockTime;

    }

    // propagate SMPTE time

    if (mState.mCurrentOutputTime.mFlags & kAudioTimeStampSMPTETimeValid) {

        mState.mCurrentInputTime.mFlags |= kAudioTimeStampSMPTETimeValid;

        mState.mCurrentInputTime.mSMPTETime = mState.mCurrentOutputTime.mSMPTETime;

    }

    // store the input sample time and expected next input time

    mState.mCurrentInputTime.mSampleTime = inputSampleTime;

    mState.mNextInputSampleTime = inputSampleTime + framesToAdvance;

#if DEBUG

    if (mVerbosity > 0) {

        printf("%-20.20s: out = " TSGFMT " (%10.3fs)  in = " TSGFMT "  (%10.3fs)  delta = " TSGFMT "  advance = " TSGFMT "\n", mDebugName, (SInt64)mState.mCurrentOutputTime.mSampleTime, DebugHostTime(mState.mCurrentOutputTime), (SInt64)inputSampleTime, DebugHostTime(mState.mCurrentInputTime), (SInt64)(mState.mCurrentOutputTime.mSampleTime - inputSampleTime), (SInt64)framesToAdvance);

    }

#endif

    return mState.mCurrentInputTime;

}