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More minor spectrogram drawing changes...

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... Removed an unnecessary zero-filling, added comments, removed a duplication
with a loop.
This commit is contained in:
Paul Licameli 2015-06-07 17:35:58 -04:00
parent 2b2183ae63
commit bb42f6e7c0
1 changed files with 16 additions and 13 deletions
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29
src/WaveClip.cpp
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@ -850,14 +850,18 @@ void SpecCache::CalculateOneSpectrum
sampleCount len = windowSize; sampleCount len = windowSize;
if (start <= 0 || start >= numSamples) { if (start <= 0 || start >= numSamples) {
// Pixel column is out of bounds of the clip! Should not happen.
std::fill(results, results + half, 0.0f); std::fill(results, results + half, 0.0f);
} }
else { else {
bool copy = !autocorrelation || (padding > 0); bool copy = !autocorrelation || (padding > 0);
float *useBuffer = 0; float *useBuffer = 0;
float *adj = scratch + padding; float *adj = scratch + padding;
// Take a window of the track centered at this sample.
start -= windowSize >> 1; start -= windowSize >> 1;
if (start < 0) { if (start < 0) {
// Near the start of the clip, pad left with zeroes as needed.
for (sampleCount ii = start; ii < 0; ++ii) for (sampleCount ii = start; ii < 0; ++ii)
*adj++ = 0; *adj++ = 0;
len += start; len += start;
@ -874,6 +878,7 @@ void SpecCache::CalculateOneSpectrum
} }
#else //!EXPERIMENTAL_FFT_SKIP_POINTS #else //!EXPERIMENTAL_FFT_SKIP_POINTS
if (start + len > numSamples) { if (start + len > numSamples) {
// Near the end of the clip, pad right with zeroes as needed.
int newlen = numSamples - start; int newlen = numSamples - start;
for (sampleCount ii = newlen; ii < (sampleCount)len; ++ii) for (sampleCount ii = newlen; ii < (sampleCount)len; ++ii)
adj[ii] = 0; adj[ii] = 0;
@ -883,6 +888,7 @@ void SpecCache::CalculateOneSpectrum
#endif //EXPERIMENTAL_FFT_SKIP_POINTS #endif //EXPERIMENTAL_FFT_SKIP_POINTS
if (len > 0) { if (len > 0) {
// Copy samples out of the track.
#ifdef EXPERIMENTAL_FFT_SKIP_POINTS #ifdef EXPERIMENTAL_FFT_SKIP_POINTS
useBuffer = (float*)(waveTrackCache.Get(floatSample, useBuffer = (float*)(waveTrackCache.Get(floatSample,
floor(0.5 + start + offset * rate), len*fftSkipPoints1)); floor(0.5 + start + offset * rate), len*fftSkipPoints1));
@ -912,6 +918,10 @@ void SpecCache::CalculateOneSpectrum
rate, results, rate, results,
autocorrelation, settings.windowType); autocorrelation, settings.windowType);
else else
// Do the FFT. Note that scratch is multiplied by the window,
// and the window is initialized with leading and trailing zeroes
// when there is padding. Therefore we did not need to reinitialize
// the part of scratch in the padding zones.
ComputeSpectrumUsingRealFFTf ComputeSpectrumUsingRealFFTf
(useBuffer, settings.hFFT, settings.window, fftLen, results); (useBuffer, settings.hFFT, settings.window, fftLen, results);
#else // EXPERIMENTAL_USE_REALFFTF #else // EXPERIMENTAL_USE_REALFFTF
@ -964,26 +974,19 @@ void SpecCache::Populate
#endif //EXPERIMENTAL_FFT_SKIP_POINTS #endif //EXPERIMENTAL_FFT_SKIP_POINTS
); );
// Initialize zero padding in the buffer
for (int ii = 0; ii < padding; ++ii) {
buffer[ii] = 0.0;
buffer[fftLen - ii - 1] = 0.0;
}
std::vector<float> gainFactors; std::vector<float> gainFactors;
ComputeSpectrogramGainFactors(fftLen, rate, frequencyGain, gainFactors); ComputeSpectrogramGainFactors(fftLen, rate, frequencyGain, gainFactors);
// Loop over the ranges before and after the copied portion and compute anew. // Loop over the ranges before and after the copied portion and compute anew.
// One of the ranges may be empty. // One of the ranges may be empty.
for (sampleCount xx = 0; xx < copyBegin; ++xx) for (int jj = 0; jj < 2; ++jj) {
CalculateOneSpectrum( const int lowerBoundX = jj == 0 ? 0 : copyEnd;
settings, waveTrackCache, xx, numSamples, const int upperBoundX = jj == 0 ? copyBegin : numPixels;
offset, rate, autocorrelation, gainFactors, &buffer[0]); for (sampleCount xx = lowerBoundX; xx < upperBoundX; ++xx)
CalculateOneSpectrum(
for (sampleCount xx = copyEnd; xx < numPixels; ++xx)
CalculateOneSpectrum(
settings, waveTrackCache, xx, numSamples, settings, waveTrackCache, xx, numSamples,
offset, rate, autocorrelation, gainFactors, &buffer[0]); offset, rate, autocorrelation, gainFactors, &buffer[0]);
}
} }
bool WaveClip::GetSpectrogram(WaveTrackCache &waveTrackCache, bool WaveClip::GetSpectrogram(WaveTrackCache &waveTrackCache,