New attack and release behavior for a-comp

Details in http://tracker.ardour.org/view.php?id=7439

1 files changed, 71 insertions, 64 deletions

diff --git a/libs/plugins/a-comp.lv2/a-comp.c b/libs/plugins/a-comp.lv2/a-comp.c
index 89bd5c9270..a77893782b 100644
--- a/libs/plugins/a-comp.lv2/a-comp.c
+++ b/libs/plugins/a-comp.lv2/a-comp.c
@@ -78,9 +78,8 @@ typedef struct {
 	float* output1;
 
 	float srate;
-	float old_yl;
-	float old_y1;
-	float old_yg;
+
+	float old_in_peak_db;
 
 	float makeup_gain;
 
@@ -100,8 +99,6 @@ typedef struct {
 	float v_thresdb;
 	float v_gainr;
 	float v_makeup;
-	float v_lvl;
-	float v_lv1;
 	float v_lvl_in;
 	float v_lvl_out;
 #endif
@@ -124,7 +121,6 @@ instantiate(const LV2_Descriptor* descriptor,
 	}
 
 	acomp->srate = rate;
-	acomp->old_yl=acomp->old_y1=acomp->old_yg=0.f;
 	acomp->makeup_gain = 1.f;
 #ifdef LV2_EXTENDED
 	acomp->need_expose = true;
@@ -134,7 +130,6 @@ instantiate(const LV2_Descriptor* descriptor,
 	return (LV2_Handle)acomp;
 }
 
-
 static void
 connect_port(LV2_Handle instance,
              uint32_t port,
@@ -256,7 +251,7 @@ activate(LV2_Handle instance)
 
 	*(acomp->gainr) = 0.0f;
 	*(acomp->outlevel) = -45.0f;
-	acomp->old_yl=acomp->old_y1=acomp->old_yg=0.f;
+	acomp->old_in_peak_db = -160.0f;
 }
 
 static void
@@ -270,14 +265,16 @@ run_mono(LV2_Handle instance, uint32_t n_samples)
 
 	float srate = acomp->srate;
 	float width = (6.f * *(acomp->knee)) + 0.01;
-	float cdb=0.f;
 	float attack_coeff = exp(-1000.f/(*(acomp->attack) * srate));
 	float release_coeff = exp(-1000.f/(*(acomp->release) * srate));
 
 	float max = 0.f;
 	float lgaininp = 0.f;
 	float Lgain = 1.f;
-	float Lxg, Lxl, Lyg, Lyl, Ly1;
+	float Lxg, Lyg;
+	float current_gainr;
+	float old_gainr = *acomp->gainr;
+
 	int usesidechain = (*(acomp->sidechain) <= 0.f) ? 0 : 1;
 	uint32_t i;
 	float ingain;
@@ -333,7 +330,6 @@ run_mono(LV2_Handle instance, uint32_t n_samples)
 		Lxg = (ingain==0.f) ? -160.f : to_dB(ingain);
 		Lxg = sanitize_denormal(Lxg);
 
-
 		if (2.f*(Lxg-thresdb) < -width) {
 			Lyg = Lxg;
 		} else if (2.f*(Lxg-thresdb) > width) {
@@ -343,21 +339,23 @@ run_mono(LV2_Handle instance, uint32_t n_samples)
 			Lyg = Lxg + (1.f/ratio-1.f)*(Lxg-thresdb+width/2.f)*(Lxg-thresdb+width/2.f)/(2.f*width);
 		}
 
-		Lxl = Lxg - Lyg;
+		current_gainr = Lxg - Lyg;
+
+		if (current_gainr < old_gainr) {
+			current_gainr = release_coeff*old_gainr + (1.f-release_coeff)*current_gainr;
+		} else if (current_gainr > old_gainr) {
+			current_gainr = attack_coeff*old_gainr + (1.f-attack_coeff)*current_gainr;
+		}
+
+		current_gainr = sanitize_denormal(current_gainr);
 
-		acomp->old_y1 = sanitize_denormal(acomp->old_y1);
-		acomp->old_yl = sanitize_denormal(acomp->old_yl);
-		Ly1 = fmaxf(Lxl, release_coeff * acomp->old_y1+(1.f-release_coeff)*Lxl);
-		Lyl = attack_coeff * acomp->old_yl+(1.f-attack_coeff)*Ly1;
-		Ly1 = sanitize_denormal(Ly1);
-		Lyl = sanitize_denormal(Lyl);
+		Lgain = from_dB(-current_gainr);
 
-		cdb = -Lyl;
-		Lgain = from_dB(cdb);
+		old_gainr = current_gainr;
 
-		*(acomp->gainr) = Lyl;
-		if (Lyl > max_gainr) {
-			max_gainr = Lyl;
+		*(acomp->gainr) = current_gainr;
+		if (current_gainr > max_gainr) {
+			max_gainr = current_gainr;
 		}
 
 		lgaininp = in0 * Lgain;
@@ -365,12 +363,6 @@ run_mono(LV2_Handle instance, uint32_t n_samples)
 		output[i] = lgaininp * makeup_gain;
 
 		max = (fabsf(output[i]) > max) ? fabsf(output[i]) : sanitize_denormal(max);
-
-		// TODO re-use local variables on stack
-		// store values back to acomp at the end of the inner-loop
-		acomp->old_yl = Lyl;
-		acomp->old_y1 = Ly1;
-		acomp->old_yg = Lyg;
 	}
 
 	if ( fabsf(makeup_target - makeup_gain) < 1e-6 ) {
@@ -385,17 +377,25 @@ run_mono(LV2_Handle instance, uint32_t n_samples)
 #ifdef LV2_EXTENDED
 	acomp->v_gainr = max_gainr;
 
-	const float old_v_lv1 = acomp->v_lv1;
-	const float old_v_lvl = acomp->v_lvl;
+	float in_peak_db = to_dB(in_peak);
+
+	if (!isfinite_local (in_peak_db)) {
+		in_peak_db = -160.0f;
+	}
 	const float tot_rel_c = exp(-1000.f/(*(acomp->release) * srate) * n_samples);
 	const float tot_atk_c = exp(-1000.f/(*(acomp->attack) * srate) * n_samples);
-	acomp->v_lv1 = fmaxf (in_peak, tot_rel_c*old_v_lv1 + (1.f-tot_rel_c)*in_peak);
-	acomp->v_lvl = tot_atk_c*old_v_lvl + (1.f-tot_atk_c)*acomp->v_lv1;
 
-	if (!isfinite_local (acomp->v_lvl)) {
-		acomp->v_lvl = 0.f;
+	const float old_in_peak_db = acomp->old_in_peak_db;
+
+	if (in_peak_db < old_in_peak_db && in_peak_db < thresdb) {
+		in_peak_db = tot_rel_c*old_in_peak_db + (1.f-tot_rel_c)*in_peak_db;
+	} else if (in_peak_db > acomp->old_in_peak_db && in_peak_db > thresdb) {
+		in_peak_db = tot_atk_c*old_in_peak_db+ (1.f*tot_atk_c)*in_peak_db;
 	}
-	const float v_lvl_in = (acomp->v_lvl < 0.001f) ? -60.f : to_dB(acomp->v_lvl);
+
+	acomp->old_in_peak_db = in_peak_db;
+
+	const float v_lvl_in = in_peak_db;
 	const float v_lvl_out = (max < 0.001f) ? -60.f : to_dB(max);
 	if (fabsf (acomp->v_lvl_out - v_lvl_out) >= 1 || fabsf (acomp->v_lvl_in - v_lvl_in) >= 1) {
 		// >= 1dB difference
@@ -424,7 +424,6 @@ run_stereo(LV2_Handle instance, uint32_t n_samples)
 
 	float srate = acomp->srate;
 	float width = (6.f * *(acomp->knee)) + 0.01;
-	float cdb=0.f;
 	float attack_coeff = exp(-1000.f/(*(acomp->attack) * srate));
 	float release_coeff = exp(-1000.f/(*(acomp->release) * srate));
 
@@ -432,7 +431,10 @@ run_stereo(LV2_Handle instance, uint32_t n_samples)
 	float lgaininp = 0.f;
 	float rgaininp = 0.f;
 	float Lgain = 1.f;
-	float Lxg, Lxl, Lyg, Lyl, Ly1;
+	float Lxg, Lyg;
+	float current_gainr;
+	float old_gainr = *acomp->gainr;
+
 	int usesidechain = (*(acomp->sidechain) <= 0.f) ? 0 : 1;
 	uint32_t i;
 	float ingain;
@@ -492,7 +494,6 @@ run_stereo(LV2_Handle instance, uint32_t n_samples)
 		Lxg = (ingain==0.f) ? -160.f : to_dB(ingain);
 		Lxg = sanitize_denormal(Lxg);
 
-
 		if (2.f*(Lxg-thresdb) < -width) {
 			Lyg = Lxg;
 		} else if (2.f*(Lxg-thresdb) > width) {
@@ -502,21 +503,23 @@ run_stereo(LV2_Handle instance, uint32_t n_samples)
 			Lyg = Lxg + (1.f/ratio-1.f)*(Lxg-thresdb+width/2.f)*(Lxg-thresdb+width/2.f)/(2.f*width);
 		}
 
-		Lxl = Lxg - Lyg;
+		current_gainr = Lxg - Lyg;
+
+		if (current_gainr < old_gainr) {
+			current_gainr = release_coeff*old_gainr + (1.f-release_coeff)*current_gainr;
+		} else if (current_gainr > old_gainr) {
+			current_gainr = attack_coeff*old_gainr + (1.f-attack_coeff)*current_gainr;
+		}
 
-		acomp->old_y1 = sanitize_denormal(acomp->old_y1);
-		acomp->old_yl = sanitize_denormal(acomp->old_yl);
-		Ly1 = fmaxf(Lxl, release_coeff * acomp->old_y1+(1.f-release_coeff)*Lxl);
-		Lyl = attack_coeff * acomp->old_yl+(1.f-attack_coeff)*Ly1;
-		Ly1 = sanitize_denormal(Ly1);
-		Lyl = sanitize_denormal(Lyl);
+		current_gainr = sanitize_denormal(current_gainr);
 
-		cdb = -Lyl;
-		Lgain = from_dB(cdb);
+		Lgain = from_dB(-current_gainr);
 
-		*(acomp->gainr) = Lyl;
-		if (Lyl > max_gainr) {
-			max_gainr = Lyl;
+		old_gainr = current_gainr;
+
+		*(acomp->gainr) = current_gainr;
+		if (current_gainr > max_gainr) {
+			max_gainr = current_gainr;
 		}
 
 		lgaininp = in0 * Lgain;
@@ -526,12 +529,6 @@ run_stereo(LV2_Handle instance, uint32_t n_samples)
 		output1[i] = rgaininp * makeup_gain;
 
 		max = (fmaxf(fabs(output0[i]), fabs(output1[i])) > max) ? fmaxf(fabs(output0[i]), fabs(output1[i])) : sanitize_denormal(max);
-
-		// TODO re-use local variables on stack
-		// store values back to acomp at the end of the inner-loop
-		acomp->old_yl = Lyl;
-		acomp->old_y1 = Ly1;
-		acomp->old_yg = Lyg;
 	}
 
 	if ( fabsf(makeup_target - makeup_gain) < 1e-6 ) {
@@ -546,16 +543,26 @@ run_stereo(LV2_Handle instance, uint32_t n_samples)
 #ifdef LV2_EXTENDED
 	acomp->v_gainr = max_gainr;
 
-	const float old_v_lv1 = acomp->v_lv1;
-	const float old_v_lvl = acomp->v_lvl;
+	float in_peak_db = to_dB(in_peak);
+
+	if (!isfinite_local (in_peak_db)) {
+		in_peak_db = -160.0f;
+	}
+
 	const float tot_rel_c = exp(-1000.f/(*(acomp->release) * srate) * n_samples);
 	const float tot_atk_c = exp(-1000.f/(*(acomp->attack) * srate) * n_samples);
-	acomp->v_lv1 = fmaxf (in_peak, tot_rel_c*old_v_lv1 + (1.f-tot_rel_c)*in_peak);
-	acomp->v_lvl = tot_atk_c*old_v_lvl + (1.f-tot_atk_c)*acomp->v_lv1;
-	if (!isfinite_local (acomp->v_lvl)) {
-		acomp->v_lvl = 0.f;
+
+	const float old_in_peak_db = acomp->old_in_peak_db;
+
+	if (in_peak_db < old_in_peak_db && in_peak_db < thresdb) {
+		in_peak_db = tot_rel_c*old_in_peak_db + (1.f-tot_rel_c)*in_peak_db;
+	} else if (in_peak_db > acomp->old_in_peak_db && in_peak_db > thresdb) {
+		in_peak_db = tot_atk_c*old_in_peak_db+ (1.f*tot_atk_c)*in_peak_db;
 	}
-	const float v_lvl_in = (acomp->v_lvl < 0.001f) ? -60.f : to_dB(acomp->v_lvl);
+
+	acomp->old_in_peak_db = in_peak_db;
+
+	const float v_lvl_in = in_peak_db;
 	const float v_lvl_out = (max < 0.001f) ? -60.f : to_dB(max);
 	if (fabsf (acomp->v_lvl_out - v_lvl_out) >= 1 || fabsf (acomp->v_lvl_in - v_lvl_in) >= 1) {
 		// >= 1dB difference