Mono & pan

source/engine/datastream.c

@@ -91,7 +91,7 @@ void ds_openvideo(struct datastream *ds, const char *video, const char *adriver)
     fir->in = astream_filter;
 */
 
-    first_free_bus(astream_filter);
+    //first_free_bus(astream_filter);
 
     plm_set_video_decode_callback(ds->plm, render_frame, ds);
     plm_set_audio_decode_callback(ds->plm, render_audio, ds);

source/engine/dsp.c

@@ -526,3 +526,107 @@ void dsp_reverb_fillbuf(struct dsp_reverb *r, short *out, int n)
 {
 
 }
+
+struct dsp_filter dsp_make_compressor()
+{
+    struct dsp_filter filter;
+    struct dsp_compressor new;
+
+    new.ratio = 4000;
+    new.atk = 50;
+    new.rls = 250;
+    new.target = 0.f;
+    new.threshold = -3.f;
+    new.atk_tau = tau2pole(new.atk / 3000.f);
+    new.rls_tau = tau2pole(new.rls / 3000.f);
+
+    struct dsp_compressor *c = malloc(sizeof(*c));
+    *c = new;
+
+    filter.data = c;
+    filter.filter = dsp_compressor_fillbuf;
+
+    return filter;
+}
+
+void dsp_compressor_fillbuf(struct dsp_compressor *comp, short *out, int n)
+{
+    float val;
+    float db;
+    db = comp->target * (val - comp->threshold) / comp->ratio;
+
+    for (int i = 0; i < n; i++) {
+        val = short2db(out[i*CHANNELS]);
+
+
+        if (val < comp->threshold) {
+            comp->target = comp->rls_tau * comp->target;
+
+            val += db;
+        } else {
+            comp->target = (1 - comp->atk_tau) + comp->atk_tau * comp->target; // TODO: Bake in the 1 - atk_tau
+
+            val -= db;
+        }
+
+
+
+        // Apply same compression to both channels
+        out[i*CHANNELS] = out[i*CHANNELS+1] = db2short(val) * ( out[i*CHANNELS] > 0 ? 1 : -1);
+    }
+}
+
+void dsp_pan(float *deg, short *out, int n)
+{
+    if (*deg < -100) *deg = -100.f;
+    else if (*deg > 100) *deg = 100.f;
+
+    if (*deg == 0.f) return;
+
+    float db1, db2;
+    float pct = *deg / 100.f;
+
+    if (*deg > 0) {
+        db1 = pct2db(1 - pct);
+        db2 = pct2db(pct);
+    } else {
+        db1 = pct2db(1 + pct);
+        db2 = pct2db(-1*pct);
+    }
+
+
+    for (int i = 0; i < n; i++) {
+        double pct = *deg / 100.f;
+        short L = out[i*CHANNELS];
+        short R = out[i*CHANNELS +1];
+
+
+        if (*deg > 0) {
+
+
+            out[i*CHANNELS] = short_gain(L, db1);
+            out[i*CHANNELS+1] = (R + short_gain(L, db2)) / 2;
+
+            continue;
+        }
+
+        out[i*CHANNELS+1] = short_gain(R, db1);
+        out[i*CHANNELS] = short_gain(L, db1) + short_gain(R, db2);
+
+
+
+
+    }
+
+
+}
+
+void dsp_mono(void *p, short *out, int n)
+{
+    for (int i = 0; i < n; i++) {
+        short val = (out[i*CHANNELS] + out[i*CHANNELS+1]) / 2;
+
+        for (int j = 0; j < CHANNELS; j++)
+            out[i*CHANNELS+j] = val;
+    }
+}

source/engine/dsp.h

@@ -77,7 +77,13 @@ struct dsp_ammod {
 };
 
 struct dsp_compressor {
-
+    double ratio;
+    double threshold;
+    float target;
+    unsigned int atk; /* Milliseconds */
+    double atk_tau;
+    unsigned int rls; /* MIlliseconds */
+    double rls_tau;
 };
 
 struct dsp_filter dsp_make_compressor();
@@ -137,4 +143,8 @@ struct dsp_reverb {
 struct dsp_filter make_reverb();
 void dsp_reverb_fillbuf(struct dsp_reverb *r, short *out, int n);
 
+void dsp_pan(float *deg, short *out, int n);
+
+void dsp_mono(void *p, short *out, int n);
+
 #endif

source/engine/mix.c

@@ -19,14 +19,10 @@ struct bus *first_free_bus(struct dsp_filter in) {
 }
 
 void bus_fill_buffers(short *master, int n) {
-    //clock_t sa = clock();
     for (int i = 0; i < 256; i++) {
         if (bus[i].on != 1) continue;
         dsp_run(bus[i].in, bus[i].buf, BUF_FRAMES);
     }
-    //printf("DSP run took %f.\n", (double)(clock() - sa)/CLOCKS_PER_SEC);
-
-    //sa = clock();
 
     memset(master, 0, BUF_FRAMES*CHANNELS*sizeof(short));
 
@@ -36,6 +32,4 @@ void bus_fill_buffers(short *master, int n) {
                 master[i] += bus[j].buf[i];
             }
         }
-
-    //printf("Mix took %f.\n", (double)(clock() - sa)/CLOCKS_PER_SEC);
 }

source/engine/mix.h

@@ -12,6 +12,12 @@ struct bus {
     short buf[BUF_FRAMES*CHANNELS];
 };
 
+struct listener {
+    float x;
+    float y;
+    float z;
+};
+
 extern short mastermix[BUF_FRAMES*CHANNELS];
 
 struct bus *first_free_bus(struct dsp_filter in);

source/engine/music.c

@@ -11,6 +11,8 @@
 struct dsp_filter cursong;
 struct dsp_midi_song gsong;
 
+float music_pan = 0.f;
+
 void dsp_midi_fillbuf(struct dsp_midi_song *song, void *out, int n)
 {
     short *o = (short*)out;
@@ -54,12 +56,14 @@ void dsp_midi_fillbuf(struct dsp_midi_song *song, void *out, int n)
     }
 
     song->midi = midi;
+
+    dsp_pan(&music_pan, out, n);
 }
 
 void play_song(const char *midi, const char *sf)
 {
-    gsong.midi = tml_load_filename("sounds/littlewonder.mid");
+    gsong.midi = tml_load_filename("sounds/one-winged-angel.mid");
-    gsong.sf = tsf_load_filename("sounds/ff7.sf2");
+    gsong.sf = tsf_load_filename("sounds/mario.sf2");
     gsong.time = 0.f;
 
     tsf_set_output(gsong.sf, TSF_STEREO_INTERLEAVED, SAMPLERATE, 0.f);

source/engine/music.h

@@ -11,6 +11,8 @@ struct dsp_midi_song {
     tml_message *midi;
 };
 
+extern float music_pan;
+
 void play_song(const char *midi, const char *sf);
 void dsp_midi_fillbuf(struct dsp_midi_song *song, void *out, int n);
 

source/engine/sound.c

@@ -91,7 +91,7 @@ static PaStream *stream_def;
 
 void normalize_gain(struct wav *w, double lv)
 {
-    short tarmax = pow(10, lv/20.f) * SHRT_MAX;
+    short tarmax = db2short(lv);
     short max = 0;
     short *s = w->data;
     for (int i = 0; i < w->frames; i++) {
@@ -180,7 +180,7 @@ void sound_init()
     dspammod.ina = s600;
     dspammod.inb = s20;
 
-   // first_free_bus(am_filter);
+   //first_free_bus(am_filter);
 
     struct dsp_filter wn;
     wn.filter = gen_pinknoise;
@@ -227,7 +227,7 @@ void sound_init()
 
 
 
-    //play_song("", "");
+    play_song("", "");
 }
 
 void audio_open(const char *device)
@@ -381,3 +381,24 @@ void soundstream_fillbuf(struct soundstream *s, short *buf, int n)
     }
 }
 
+float short2db(short val)
+{
+    return 20*log10(abs((double)val) / SHRT_MAX);
+}
+
+short db2short(float db)
+{
+    return pow(10, db/20.f) * SHRT_MAX;
+}
+
+short short_gain(short val, float db)
+{
+    return (short)(pow(10, db/20.f) * val);
+}
+
+float pct2db(float pct)
+{
+    if (pct <= 0) return -72.f;
+
+    return 10*log2(pct);
+}

source/engine/sound.h

@@ -67,6 +67,13 @@ void soundstream_fillbuf(struct soundstream *stream, short *buf, int n);
 void close_audio_device(int device);
 int open_device(const char *adriver);
 
+float short2db(short val);
+short db2short(float db);
+float pct2db(float pct);
+short short_gain(short val, float db);
+
 void audio_init();
 
+
+
 #endif