ardour/livetrax
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tweak spectrum logscale

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This commit is contained in:
Robin Gareus 2016-02-11 16:09:34 +01:00
parent 6723f075d6
commit f9e526dab8
1 changed files with 13 additions and 10 deletions
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23
libs/audiographer/src/general/analyser.cc
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@ -86,9 +86,9 @@ Analyser::Analyser (float sample_rate, unsigned int channels, framecnt_t bufsize
const float nyquist = (sample_rate * .5);
#if 0 // linear
#define YPOS(FREQ) ceil (height * (1.0 - FREQ / nyquist))
#define YPOS(FREQ) rint (height * (1.0 - FREQ / nyquist))
#else
#define YPOS(FREQ) ceil (height * (1 - logf (1.f + .1f * _fft_data_size * FREQ / nyquist) / logf (1.f + .1f * _fft_data_size)))
#define YPOS(FREQ) rint (height * (1 - logf (1.f + .1f * _fft_data_size * FREQ / nyquist) / logf (1.f + .1f * _fft_data_size)))
#endif
_result.freq[0] = YPOS (50);
@ -197,21 +197,24 @@ Analyser::process (ProcessContext<float> const & c)
if (x0 == x1) x1 = x0 + 1;
const float range = 80; // dB
for (uint32_t i = 1; i < _fft_data_size - 1; ++i) {
for (uint32_t i = 0; i < _fft_data_size - 1; ++i) {
const float level = fft_power_at_bin (i, i);
if (level < -range) continue;
const float pk = level > 0.0 ? 1.0 : (range + level) / range;
#if 0 // linear
const uint32_t y0 = height - ceil (i * (float) height / _fft_data_size);
uint32_t y1= height - ceil (i * (float) height / _fft_data_size);
const uint32_t y0 = floor (i * (float) height / _fft_data_size);
uint32_t y1 = ceil ((i + 1.0) * (float) height / _fft_data_size);
#else // logscale
const uint32_t y0 = height - ceilf (height * logf (1.f + .1f * i) / logf (1.f + .1f * _fft_data_size));
uint32_t y1 = height - ceilf (height * logf (1.f + .1f * (i + 1.f)) / logf (1.f + .1f * _fft_data_size));
const uint32_t y0 = floor (height * logf (1.f + .1f * i) / logf (1.f + .1f * _fft_data_size));
uint32_t y1 = ceilf (height * logf (1.f + .1f * (i + 1.f)) / logf (1.f + .1f * _fft_data_size));
#endif
if (y0 == y1 && y0 > 0) y1 = y0 - 1;
assert (y0 < height);
assert (y1 > 0 && y1 <= height);
if (y0 == y1) y1 = y0 + 1;
for (int x = x0; x < x1; ++x) {
for (uint32_t y = y0; y > y1; --y) {
if (_result.spectrum[x][y] < pk) { _result.spectrum[x][y] = pk; }
for (uint32_t y = y0; y < y1 && y < height; ++y) {
uint32_t yy = height - 1 - y;
if (_result.spectrum[x][yy] < pk) { _result.spectrum[x][yy] = pk; }
}
}
}