Backed out changeset 9524b1df278e (bug 908669)

This commit is contained in:
Ed Morley 2013-09-17 17:14:58 +01:00
parent e41d9b2e38
commit 00f3b24a4a

View File

@ -36,39 +36,6 @@ NS_INTERFACE_MAP_END_INHERITING(AudioNode)
NS_IMPL_ADDREF_INHERITED(OscillatorNode, AudioNode)
NS_IMPL_RELEASE_INHERITED(OscillatorNode, AudioNode)
static const float sLeak = 0.995;
class DCBlocker
{
public:
// These are sane defauts when the initial mPhase is zero
DCBlocker(float aLastInput = 0.0f,
float aLastOutput = 0.0f,
float aPole = 0.995)
:mLastInput(aLastInput),
mLastOutput(aLastOutput),
mPole(aPole)
{
MOZ_ASSERT(aPole > 0);
}
inline float Process(float aInput)
{
float out;
out = mLastOutput * mPole + aInput - mLastInput;
mLastOutput = out;
mLastInput = aInput;
return out;
}
private:
float mLastInput;
float mLastOutput;
float mPole;
};
class OscillatorNodeEngine : public AudioNodeEngine
{
public:
@ -83,16 +50,6 @@ public:
, mDetune(0.f)
, mType(OscillatorType::Sine)
, mPhase(0.)
, mFinalFrequency(0.0)
, mNumberOfHarmonics(0)
, mSignalPeriod(0.0)
, mAmplitudeAtZero(0.0)
, mPhaseIncrement(0.0)
, mSquare(0.0)
, mTriangle(0.0)
, mSaw(0.0)
, mPhaseWrap(0.0)
, mRecomputeFrequency(true)
{
}
@ -113,7 +70,6 @@ public:
const AudioParamTimeline& aValue,
TrackRate aSampleRate) MOZ_OVERRIDE
{
mRecomputeFrequency = true;
switch (aIndex) {
case FREQUENCY:
MOZ_ASSERT(mSource && mDestination);
@ -129,7 +85,6 @@ public:
NS_ERROR("Bad OscillatorNodeEngine TimelineParameter");
}
}
virtual void SetStreamTimeParameter(uint32_t aIndex, TrackTicks aParam)
{
switch (aIndex) {
@ -139,95 +94,29 @@ public:
NS_ERROR("Bad OscillatorNodeEngine StreamTimeParameter");
}
}
virtual void SetInt32Parameter(uint32_t aIndex, int32_t aParam)
{
mType = static_cast<OscillatorType>(aParam);
// Set the new type, and update integrators with the new initial conditions.
switch (mType) {
case OscillatorType::Sine:
mPhase = 0.0;
break;
case OscillatorType::Square:
mPhase = 0.0;
// Initial integration condition is -0.5, because our square has 50%
// duty cycle.
mSquare = -0.5;
break;
case OscillatorType::Triangle:
// Initial mPhase and related integration condition so the triangle is
// in the middle of the first upward slope.
// XXX actually do the maths and put the right number here.
mPhase = M_PI / 2;
mSquare = 0.5;
mTriangle = 0.0;
break;
case OscillatorType::Sawtooth:
/* initial mPhase so the oscillator start at the middle
* of the ramp, per spec */
mPhase = M_PI / 2;
/* mSaw = 0 when mPhase = pi/2 */
mSaw = 0.0;
break;
default:
NS_ERROR("Bad OscillatorNodeEngine Int32Parameter.");
};
}
void IncrementPhase()
{
mPhase += mPhaseIncrement;
if (mPhase > mPhaseWrap) {
mPhase -= mPhaseWrap;
switch (aIndex) {
case TYPE: mType = static_cast<OscillatorType>(aParam); break;
default:
NS_ERROR("Bad OscillatorNodeEngine Int32Parameter");
}
}
// Square and triangle are using a bipolar band-limited impulse train, saw is
// using a normal band-limited impulse train.
bool UsesBipolarBLIT() {
return mType == OscillatorType::Square || mType == OscillatorType::Triangle;
}
void UpdateFrequencyIfNeeded(TrackTicks ticks, size_t count)
double ComputeFrequency(TrackTicks ticks, size_t count)
{
double frequency, detune;
bool simpleFrequency = mFrequency.HasSimpleValue();
bool simpleDetune = mDetune.HasSimpleValue();
// Shortcut if frequency-related AudioParam are not automated, and we
// already have computed the frequency information and related parameters.
if (simpleFrequency && simpleDetune && !mRecomputeFrequency) {
return;
}
if (simpleFrequency) {
if (mFrequency.HasSimpleValue()) {
frequency = mFrequency.GetValue();
} else {
frequency = mFrequency.GetValueAtTime(ticks, count);
}
if (simpleDetune) {
if (mDetune.HasSimpleValue()) {
detune = mDetune.GetValue();
} else {
detune = mDetune.GetValueAtTime(ticks, count);
}
mFinalFrequency = frequency * pow(2., detune / 1200.);
mRecomputeFrequency = false;
// When using bipolar BLIT, we divide the signal period by two, because we
// are using two BLIT out of phase.
mSignalPeriod = UsesBipolarBLIT() ? 0.5 * mSource->SampleRate() / mFinalFrequency
: mSource->SampleRate() / mFinalFrequency;
// Wrap the phase accordingly:
mPhaseWrap = UsesBipolarBLIT() || mType == OscillatorType::Sine ? 2 * M_PI
: M_PI;
// Even number of harmonics for bipolar blit, odd otherwise.
mNumberOfHarmonics = UsesBipolarBLIT() ? 2 * floor(0.5 * mSignalPeriod)
: 2 * floor(0.5 * mSignalPeriod) + 1;
mPhaseIncrement = mType == OscillatorType::Sine ? 2 * M_PI / mSignalPeriod
: M_PI / mSignalPeriod;
mAmplitudeAtZero = mNumberOfHarmonics / mSignalPeriod;
return frequency * pow(2., detune / 1200.);
}
void FillBounds(float* output, TrackTicks ticks,
@ -252,98 +141,95 @@ public:
}
}
float BipolarBLIT()
void ComputeSine(AudioChunk *aOutput)
{
float blit;
float denom = sin(mPhase);
AllocateAudioBlock(1, aOutput);
float* output = static_cast<float*>(const_cast<void*>(aOutput->mChannelData[0]));
if (fabs(denom) < std::numeric_limits<float>::epsilon()) {
if (mPhase < 0.1f || mPhase > 2 * M_PI - 0.1f) {
blit = mAmplitudeAtZero;
} else {
blit = -mAmplitudeAtZero;
TrackTicks ticks = mSource->GetCurrentPosition();
uint32_t start, end;
FillBounds(output, ticks, start, end);
double rate = 2.*M_PI / mSource->SampleRate();
double phase = mPhase;
for (uint32_t i = start; i < end; ++i) {
phase += ComputeFrequency(ticks, i) * rate;
output[i] = sin(phase);
}
mPhase = phase;
while (mPhase > 2.0*M_PI) {
// Rescale to avoid precision reductions on long runs.
mPhase -= 2.0*M_PI;
}
}
void ComputeSquare(AudioChunk *aOutput)
{
AllocateAudioBlock(1, aOutput);
float* output = static_cast<float*>(const_cast<void*>(aOutput->mChannelData[0]));
TrackTicks ticks = mSource->GetCurrentPosition();
uint32_t start, end;
FillBounds(output, ticks, start, end);
double rate = 1.0 / mSource->SampleRate();
double phase = mPhase;
for (uint32_t i = start; i < end; ++i) {
phase += ComputeFrequency(ticks, i) * rate;
if (phase > 1.0) {
phase -= 1.0;
}
} else {
blit = sin(mNumberOfHarmonics * mPhase);
blit /= mSignalPeriod * denom;
output[i] = phase < 0.5 ? 1.0 : -1.0;
}
return blit;
mPhase = phase;
}
float UnipolarBLIT()
void ComputeSawtooth(AudioChunk *aOutput)
{
float blit;
float denom = sin(mPhase);
AllocateAudioBlock(1, aOutput);
float* output = static_cast<float*>(const_cast<void*>(aOutput->mChannelData[0]));
if (fabs(denom) <= std::numeric_limits<float>::epsilon()) {
blit = mAmplitudeAtZero;
} else {
blit = sin(mNumberOfHarmonics * mPhase);
blit /= mSignalPeriod * denom;
TrackTicks ticks = mSource->GetCurrentPosition();
uint32_t start, end;
FillBounds(output, ticks, start, end);
double rate = 1.0 / mSource->SampleRate();
double phase = mPhase;
for (uint32_t i = start; i < end; ++i) {
phase += ComputeFrequency(ticks, i) * rate;
if (phase > 1.0) {
phase -= 1.0;
}
output[i] = phase < 0.5 ? 2.0*phase : 2.0*(phase - 1.0);
}
return blit;
mPhase = phase;
}
void ComputeSine(float * aOutput, TrackTicks ticks, uint32_t aStart, uint32_t aEnd)
void ComputeTriangle(AudioChunk *aOutput)
{
for (uint32_t i = aStart; i < aEnd; ++i) {
UpdateFrequencyIfNeeded(ticks, i);
AllocateAudioBlock(1, aOutput);
float* output = static_cast<float*>(const_cast<void*>(aOutput->mChannelData[0]));
aOutput[i] = sin(mPhase);
TrackTicks ticks = mSource->GetCurrentPosition();
uint32_t start, end;
FillBounds(output, ticks, start, end);
IncrementPhase();
}
}
void ComputeSquare(float * aOutput, TrackTicks ticks, uint32_t aStart, uint32_t aEnd)
{
for (uint32_t i = aStart; i < aEnd; ++i) {
UpdateFrequencyIfNeeded(ticks, i);
// Integration to get us a square. It turns out we can have a
// pure integrator here.
mSquare += BipolarBLIT();
aOutput[i] = mSquare;
// maybe we want to apply a gain, the wg has not decided yet
aOutput[i] *= 1.5;
IncrementPhase();
}
}
void ComputeSawtooth(float * aOutput, TrackTicks ticks, uint32_t aStart, uint32_t aEnd)
{
float dcoffset;
for (uint32_t i = aStart; i < aEnd; ++i) {
UpdateFrequencyIfNeeded(ticks, i);
// DC offset so the Saw does not ramp up to infinity when integrating.
dcoffset = mFinalFrequency / mSource->SampleRate();
// Integrate and offset so we get mAmplitudeAtZero sawtooth. We have a
// very low frequency component somewhere here, but I'm not sure where.
mSaw += UnipolarBLIT() - dcoffset;
// reverse the saw so we are spec compliant
aOutput[i] = -mSaw * 1.5;
IncrementPhase();
}
}
void ComputeTriangle(float * aOutput, TrackTicks ticks, uint32_t aStart, uint32_t aEnd)
{
for (uint32_t i = aStart; i < aEnd; ++i) {
UpdateFrequencyIfNeeded(ticks, i);
// Integrate to get a square
mSquare += BipolarBLIT();
// Leaky integrate to get a triangle. We get too much dc offset if we don't
// leaky integrate here.
// C6 = k0 / period
// (period is samplingrate / frequency, k0 = (PI/2)/(2*PI)) = 0.25
float C6 = 0.25 / (mSource->SampleRate() / mFinalFrequency);
mTriangle = mTriangle * sLeak + mSquare + C6;
// DC Block, and scale back to [-1.0; 1.0]
aOutput[i] = mDCBlocker.Process(mTriangle) / (mSignalPeriod/2) * 1.5;
IncrementPhase();
double rate = 1.0 / mSource->SampleRate();
double phase = mPhase;
for (uint32_t i = start; i < end; ++i) {
phase += ComputeFrequency(ticks, i) * rate;
if (phase > 1.0) {
phase -= 1.0;
}
if (phase < 0.25) {
output[i] = 4.0*phase;
} else if (phase < 0.75) {
output[i] = 1.0 - 4.0*(phase - 0.25);
} else {
output[i] = 4.0*(phase - 0.75) - 1.0;
}
}
mPhase = phase;
}
void ComputeSilence(AudioChunk *aOutput)
@ -375,35 +261,25 @@ public:
*aFinished = true;
return;
}
AllocateAudioBlock(1, aOutput);
float* output = static_cast<float*>(
const_cast<void*>(aOutput->mChannelData[0]));
uint32_t start, end;
FillBounds(output, ticks, start, end);
// Synthesize the correct waveform.
switch(mType) {
switch (mType) {
case OscillatorType::Sine:
ComputeSine(output, ticks, start, end);
ComputeSine(aOutput);
break;
case OscillatorType::Square:
ComputeSquare(output, ticks, start, end);
break;
case OscillatorType::Triangle:
ComputeTriangle(output, ticks, start, end);
ComputeSquare(aOutput);
break;
case OscillatorType::Sawtooth:
ComputeSawtooth(output, ticks, start, end);
ComputeSawtooth(aOutput);
break;
case OscillatorType::Triangle:
ComputeTriangle(aOutput);
break;
default:
ComputeSilence(aOutput);
};
}
}
DCBlocker mDCBlocker;
AudioNodeStream* mSource;
AudioNodeStream* mDestination;
TrackTicks mStart;
@ -411,17 +287,7 @@ public:
AudioParamTimeline mFrequency;
AudioParamTimeline mDetune;
OscillatorType mType;
float mPhase;
float mFinalFrequency;
uint32_t mNumberOfHarmonics;
float mSignalPeriod;
float mAmplitudeAtZero;
float mPhaseIncrement;
float mSquare;
float mTriangle;
float mSaw;
float mPhaseWrap;
bool mRecomputeFrequency;
double mPhase;
};
OscillatorNode::OscillatorNode(AudioContext* aContext)