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/*
File: AUTimestampGenerator.cpp
Abstract: AUTimestampGenerator.h
Version: 1.1
Disclaimer: IMPORTANT: This Apple software is supplied to you by Apple
Inc. ("Apple") in consideration of your agreement to the following
terms, and your use, installation, modification or redistribution of
this Apple software constitutes acceptance of these terms. If you do
not agree with these terms, please do not use, install, modify or
redistribute this Apple software.
In consideration of your agreement to abide by the following terms, and
subject to these terms, Apple grants you a personal, non-exclusive
license, under Apple's copyrights in this original Apple software (the
"Apple Software"), to use, reproduce, modify and redistribute the Apple
Software, with or without modifications, in source and/or binary forms;
provided that if you redistribute the Apple Software in its entirety and
without modifications, you must retain this notice and the following
text and disclaimers in all such redistributions of the Apple Software.
Neither the name, trademarks, service marks or logos of Apple Inc. may
be used to endorse or promote products derived from the Apple Software
without specific prior written permission from Apple. Except as
expressly stated in this notice, no other rights or licenses, express or
implied, are granted by Apple herein, including but not limited to any
patent rights that may be infringed by your derivative works or by other
works in which the Apple Software may be incorporated.
The Apple Software is provided by Apple on an "AS IS" basis. APPLE
MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION
THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND
OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS.
IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL
OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION,
MODIFICATION AND/OR DISTRIBUTION OF THE APPLE SOFTWARE, HOWEVER CAUSED
AND WHETHER UNDER THEORY OF CONTRACT, TORT (INCLUDING NEGLIGENCE),
STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
Copyright (C) 2014 Apple Inc. All Rights Reserved.
*/
#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;
}
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