for (unsigned i = 0; i < m_numberOfChannels; ++i) { // Set pre-filter zero and pole to create an emphasis filter.
ZeroPole& preFilter = m_preFilterPacks[i]->filters[stageIndex];
preFilter.setZero(r1);
preFilter.setPole(r2);
// Set post-filter with zero and pole reversed to create the de-emphasis // filter. If there were no compressor kernel in between, they would cancel // each other out (allpass filter).
ZeroPole& postFilter = m_postFilterPacks[i]->filters[stageIndex];
postFilter.setZero(r2);
postFilter.setPole(r1);
}
}
void DynamicsCompressor::setEmphasisParameters(float gain, float anchorFreq, float filterStageRatio) {
setEmphasisStageParameters(0, gain, anchorFreq);
setEmphasisStageParameters(1, gain, anchorFreq / filterStageRatio);
setEmphasisStageParameters( 2, gain, anchorFreq / (filterStageRatio * filterStageRatio));
setEmphasisStageParameters( 3, gain,
anchorFreq / (filterStageRatio * filterStageRatio * filterStageRatio));
}
void DynamicsCompressor::process(const AudioBlock* sourceChunk,
AudioBlock* destinationChunk, unsigned framesToProcess) { // Though numberOfChannels is retrived from destinationBus, we still name it // numberOfChannels instead of numberOfDestinationChannels. It's because we // internally match sourceChannels's size to destinationBus by channel up/down // mix. Thus we need numberOfChannels to do the loop work for both // m_sourceChannels and m_destinationChannels.
if (numberOfSourceChannels > 1)
m_sourceChannels[1] =
static_cast<constfloat*>(sourceChunk->mChannelData[1]); else // Simply duplicate mono channel input data to right channel for stereo // processing.
m_sourceChannels[1] = m_sourceChannels[0];
for (unsigned i = 0; i < numberOfChannels; ++i)
m_destinationChannels[i] = const_cast<float*>(
static_cast<constfloat*>(destinationChunk->mChannelData[i]));
// Apply pre-emphasis filter. // Note that the final three stages are computed in-place in the destination // buffer. for (unsigned i = 0; i < numberOfChannels; ++i) { constfloat* sourceData; if (sourceChunk->mVolume == 1.0f) { // Fast path, the volume scale doesn't need to get taken into account
sourceData = m_sourceChannels[i];
} else {
AudioBlockCopyChannelWithScale(m_sourceChannels[i], sourceChunk->mVolume,
alignedSourceWithVolume);
sourceData = alignedSourceWithVolume;
}
// This is effectively a master volume on the compressed signal // (pre-blending). float dbPostGain = parameterValue(ParamPostGain);
// Linear blending value from dry to completely processed (0 -> 1) // 0 means the signal is completely unprocessed. // 1 mixes in only the compressed signal. float effectBlend = parameterValue(ParamEffectBlend);
// Apply compression to the pre-filtered signal. // The processing is performed in place.
m_compressor.process(m_destinationChannels.get(), m_destinationChannels.get(),
numberOfChannels, framesToProcess,
Die Informationen auf dieser Webseite wurden
nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit,
noch Qualität der bereit gestellten Informationen zugesichert.
Bemerkung:
Die farbliche Syntaxdarstellung und die Messung sind noch experimentell.