Change DFT window size

Closes #97.

.gitignore

@@ -1,4 +1,5 @@
 *.a
+*.core
 *.exe
 *.msi
 *.o

MANUAL.md

@@ -53,6 +53,9 @@ On OS X use the Command key instead of Ctrl.
 `Ctrl-Shift-up`, `Ctrl-Shift-down`
 :   Change the upper limit of the dynamic range in dBFS.
 
+`s`, `S`
+:   Change the DFT window size.
+
 # FILES
 
 *~/.config/spek/preferences*

src/spek-pipeline.cc

@@ -325,7 +325,7 @@ static void * reader_func(void *pp)
     pthread_join(p->worker_thread, NULL);
 
     // Notify the client.
-    p->cb(-1, NULL, p->cb_data);
+    p->cb(p->fft->get_output_size(), -1, NULL, p->cb_data);
     return NULL;
 }
 
@@ -422,7 +422,7 @@ static void * worker_func(void *pp)
                 }
 
                 if (sample == p->samples) break;
-                p->cb(sample++, p->output, p->cb_data);
+                p->cb(p->fft->get_output_size(), sample++, p->output, p->cb_data);
 
                 memset(p->output, 0, sizeof(float) * p->fft->get_output_size());
                 frames = 0;

src/spek-pipeline.h

@@ -26,7 +26,7 @@ class AudioFile;
 class FFTPlan;
 struct spek_pipeline;
 
-typedef void (*spek_pipeline_cb)(int sample, float *values, void *cb_data);
+typedef void (*spek_pipeline_cb)(int bands, int sample, float *values, void *cb_data);
 
 struct spek_pipeline * spek_pipeline_open(
     std::unique_ptr<AudioFile> file,

src/spek-spectrogram.cc

@@ -40,12 +40,13 @@ END_EVENT_TABLE()
 
 enum
 {
-    MAX_RANGE = 0,
     MIN_RANGE = -140,
+    MAX_RANGE = 0,
     URANGE = -20,
     LRANGE = -120,
     FFT_BITS = 11,
-    BANDS = (1 << (FFT_BITS - 1)) + 1,
+    MIN_FFT_BITS = 8,
+    MAX_FFT_BITS = 14,
     LPAD = 60,
     TPAD = 60,
     RPAD = 90,
@@ -56,6 +57,7 @@ enum
 
 // Forward declarations.
 static wxString trim(wxDC& dc, const wxString& s, int length, bool trim_end);
+static int bits_to_bands(int bits);
 
 SpekSpectrogram::SpekSpectrogram(wxFrame *parent) :
     wxWindow(
@@ -67,25 +69,17 @@ SpekSpectrogram::SpekSpectrogram(wxFrame *parent) :
     pipeline(NULL),
     duration(0.0),
     sample_rate(0),
-    palette(RULER, BANDS),
+    palette(),
     image(1, 1),
     prev_width(-1),
+    fft_bits(FFT_BITS),
     urange(URANGE),
     lrange(LRANGE)
 {
+    this->create_palette();
+
     SetBackgroundStyle(wxBG_STYLE_CUSTOM);
     SetFocus();
-
-    // Pre-draw the palette.
-    for (int y = 0; y < BANDS; y++) {
-        uint32_t color = spek_palette_spectrum(y / (double) BANDS);
-        this->palette.SetRGB(
-            wxRect(0, BANDS - y - 1, RULER, 1),
-            color >> 16,
-            (color >> 8) & 0xFF,
-            color & 0xFF
-        );
-    }
 }
 
 SpekSpectrogram::~SpekSpectrogram()
@@ -111,19 +105,27 @@ void SpekSpectrogram::save(const wxString& path)
 
 void SpekSpectrogram::on_char(wxKeyEvent& evt)
 {
+    bool N = evt.GetModifiers() == wxMOD_NONE;
     bool C = evt.GetModifiers() == wxMOD_CONTROL;
+    bool S = evt.GetModifiers() == wxMOD_SHIFT;
     bool CS = evt.GetModifiers() == (wxMOD_CONTROL | wxMOD_SHIFT);
-    bool dn = evt.GetKeyCode() == WXK_DOWN;
-    bool up = evt.GetKeyCode() == WXK_UP;
+    bool U = evt.GetKeyCode() == WXK_UP;
+    bool D = evt.GetKeyCode() == WXK_DOWN;
 
-    if (C && up) {
+    if (C && U) {
         this->lrange = spek_min(this->lrange + 1, this->urange - 1);
-    } else if (C && dn) {
+    } else if (C && D) {
         this->lrange = spek_max(this->lrange - 1, MIN_RANGE);
-    } else if (CS && up) {
+    } else if (CS && U) {
         this->urange = spek_min(this->urange + 1, MAX_RANGE);
-    } else if (CS && dn) {
+    } else if (CS && D) {
         this->urange = spek_max(this->urange - 1, this->lrange + 1);
+    } else if (S && evt.GetKeyCode() == 'S') {
+        this->fft_bits = spek_min(this->fft_bits + 1, MAX_FFT_BITS);
+        this->create_palette();
+    } else if (N && evt.GetKeyCode() == 's') {
+        this->fft_bits = spek_max(this->fft_bits - 1, MIN_FFT_BITS);
+        this->create_palette();
     } else {
         evt.Skip();
         return;
@@ -343,9 +345,9 @@ void SpekSpectrogram::render(wxDC& dc)
     }
 }
 
-static void pipeline_cb(int sample, float *values, void *cb_data)
+static void pipeline_cb(int bands, int sample, float *values, void *cb_data)
 {
-    SpekHaveSampleEvent event(BANDS, sample, values, false);
+    SpekHaveSampleEvent event(bands, sample, values, false);
     SpekSpectrogram *s = (SpekSpectrogram *)cb_data;
     wxPostEvent(s, event);
 }
@@ -364,10 +366,10 @@ void SpekSpectrogram::start()
     wxSize size = GetClientSize();
     int samples = size.GetWidth() - LPAD - RPAD;
     if (samples > 0) {
-        this->image.Create(samples, BANDS);
+        this->image.Create(samples, bits_to_bands(this->fft_bits));
         this->pipeline = spek_pipeline_open(
             this->audio->open(std::string(this->path.utf8_str())),
-            this->fft->create(FFT_BITS),
+            this->fft->create(this->fft_bits),
             samples,
             pipeline_cb,
             this
@@ -393,6 +395,20 @@ void SpekSpectrogram::stop()
     }
 }
 
+void SpekSpectrogram::create_palette()
+{
+    this->palette.Create(RULER, bits_to_bands(this->fft_bits));
+    for (int y = 0; y < bits_to_bands(this->fft_bits); y++) {
+        uint32_t color = spek_palette_spectrum(y / (double)bits_to_bands(this->fft_bits));
+        this->palette.SetRGB(
+            wxRect(0, bits_to_bands(this->fft_bits) - y - 1, RULER, 1),
+            color >> 16,
+            (color >> 8) & 0xFF,
+            color & 0xFF
+        );
+    }
+}
+
 // Trim `s` so that it fits into `length`.
 static wxString trim(wxDC& dc, const wxString& s, int length, bool trim_end)
 {
@@ -422,3 +438,8 @@ static wxString trim(wxDC& dc, const wxString& s, int length, bool trim_end)
 
     return trim_end ? s.substr(0, i) + fix : fix + s.substr(k);
 }
+
+// TODO: test
+static int bits_to_bands(int bits) {
+    return (1 << (bits - 1)) + 1;
+}

src/spek-spectrogram.h

@@ -46,6 +46,8 @@ private:
     void start();
     void stop();
 
+    void create_palette();
+
     std::unique_ptr<Audio> audio;
     std::unique_ptr<FFT> fft;
     spek_pipeline *pipeline;
@@ -56,6 +58,7 @@ private:
     wxImage palette;
     wxImage image;
     int prev_width;
+    int fft_bits;
     int urange;
     int lrange;