Mercurial > hg > sonic-visualiser
changeset 23:a2ad974b0c8c
...
author | Chris Cannam |
---|---|
date | Fri, 15 Sep 2006 13:46:45 +0000 |
parents | 80126455d169 |
children | ae0731ba8e67 |
files | audioio/PhaseVocoderTimeStretcher.h |
diffstat | 1 files changed, 29 insertions(+), 24 deletions(-) [+] |
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--- a/audioio/PhaseVocoderTimeStretcher.h Fri Sep 15 13:35:37 2006 +0000 +++ b/audioio/PhaseVocoderTimeStretcher.h Fri Sep 15 13:46:45 2006 +0000 @@ -49,10 +49,11 @@ * samples (on each channel); the output must have space for * lrintf(samples * m_ratio). * - * This should work correctly for some ratios, e.g. small powers - * of two. For other ratios it may drop samples -- use putInput - * in a loop followed by getOutput (when getAvailableOutputSamples - * reports enough) instead. + * This function isn't really recommended, and I may yet remove it. + * It should work correctly for some ratios, e.g. small powers of + * two, if transient sharpening is off. For other ratios it may + * drop samples -- use putInput in a loop followed by getOutput + * (when getAvailableOutputSamples reports enough) instead. * * Do not mix process calls with putInput/getOutput calls. */ @@ -62,6 +63,7 @@ * Return the number of samples that would need to be added via * putInput in order to provoke the time stretcher into doing some * time stretching and making more output samples available. + * This will be an estimate, if transient sharpening is on. */ size_t getRequiredInputSamples() const; @@ -72,8 +74,14 @@ */ void putInput(float **input, size_t samples); + /** + * Get the number of processed samples ready for reading. + */ size_t getAvailableOutputSamples() const; + /** + * Get some processed samples. + */ void getOutput(float **output, size_t samples); //!!! and reset? @@ -94,11 +102,6 @@ size_t getWindowSize() const { return m_wlen; } /** - * Get the window type. - */ -// WindowType getWindowType() const { return m_window->getType(); } - - /** * Get the stretch ratio. */ float getRatio() const { return float(m_n2) / float(m_n1); } @@ -110,29 +113,31 @@ /** * Get the latency added by the time stretcher, in sample frames. + * This will be exact if transient sharpening is off, or approximate + * if it is on. */ size_t getProcessingLatency() const; protected: /** - * Process a single phase vocoder frame. - * - * Take m_wlen time-domain source samples from in, perform an FFT, - * phase shift, and IFFT, and add the results to out (presumably - * overlapping parts of existing data from prior frames). - * - * Also add to the modulation output the results of windowing a - * set of 1s with the resynthesis window -- this can then be used - * to ensure the output has the correct magnitude in cases where - * the window overlap varies or otherwise results in something - * other than a flat sum. + * Process a single phase vocoder frame from "in" into + * m_freq[channel]. */ - + void analyseBlock(size_t channel, float *in); // into m_freq[channel] - void analyseBlock(size_t channel, float *in); // into m_freq[channel] - - bool isTransient(); // operates on m_freq[0..m_channels-1] + /** + * Examine m_freq[0..m_channels-1] and return whether a percussive + * transient is found. + */ + bool isTransient(); + /** + * Resynthesise from m_freq[channel] adding in to "out", + * adjusting phases on the basis of a prior step size of lastStep. + * Also add the window shape in to the modulation array (if + * present) -- for use in ensuring the output has the correct + * magnitude afterwards. + */ void synthesiseBlock(size_t channel, float *out, float *modulation, size_t lastStep);