diff options
| author | Robin Gareus <robin@gareus.org> | 2016-02-11 16:09:34 +0100 |
|---|---|---|
| committer | Robin Gareus <robin@gareus.org> | 2016-02-11 16:09:34 +0100 |
| commit | f9e526dab811dd792888022dfa779e0e773c1c38 (patch) | |
| tree | 87cf19c5865bc3e01cccf8ffd41d5485c3b8c4d3 /libs/audiographer | |
| parent | 6723f075d69a1e4fdaae3086051cada3dd15254e (diff) | |
tweak spectrum logscale
Diffstat (limited to 'libs/audiographer')
| -rw-r--r-- | libs/audiographer/src/general/analyser.cc | 23 |
1 files changed, 13 insertions, 10 deletions
diff --git a/libs/audiographer/src/general/analyser.cc b/libs/audiographer/src/general/analyser.cc index 726fb1bc2d..833fbcb2f9 100644 --- a/libs/audiographer/src/general/analyser.cc +++ b/libs/audiographer/src/general/analyser.cc @@ -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; } } } } |