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authorPaul Davis <paul@linuxaudiosystems.com>2016-09-27 15:42:26 -0500
committerPaul Davis <paul@linuxaudiosystems.com>2016-09-27 15:42:26 -0500
commita6d4bb0432d12b72aa9d556a07e30c9acfc8d0b1 (patch)
treeee6db0022205afb1bcaa85781baf580cde2cfa5c /libs/ardour/ardour/logmeter.h
parentbbc410dae87a2b80796aabccc9ff36ffb9139613 (diff)
add missing/moved files from push2 merge
Diffstat (limited to 'libs/ardour/ardour/logmeter.h')
-rw-r--r--libs/ardour/ardour/logmeter.h172
1 files changed, 172 insertions, 0 deletions
diff --git a/libs/ardour/ardour/logmeter.h b/libs/ardour/ardour/logmeter.h
new file mode 100644
index 0000000000..6846af1f69
--- /dev/null
+++ b/libs/ardour/ardour/logmeter.h
@@ -0,0 +1,172 @@
+/*
+ Copyright (C) 2000-2007 Paul Davis
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#ifndef __ardour_gtk_log_meter_h__
+#define __ardour_gtk_log_meter_h__
+
+#include "ardour/dB.h"
+
+#if 1
+static inline float
+_log_meter (float power, double lower_db, double upper_db, double non_linearity)
+{
+ return (power < lower_db ? 0.0 : pow((power-lower_db)/(upper_db-lower_db), non_linearity));
+}
+
+static inline float
+alt_log_meter (float power)
+{
+ return _log_meter (power, -192.0, 0.0, 8.0);
+}
+#endif
+
+/* prototypes - avoid compiler warning */
+static inline float log_meter (float db);
+static inline float meter_deflect_ppm (float);
+static inline float meter_deflect_din (float);
+static inline float meter_deflect_nordic (float);
+static inline float meter_deflect_vu (float);
+static inline float meter_deflect_k (float, float);
+
+
+
+static inline float
+log_meter (float db)
+{
+ float def = 0.0f; /* Meter deflection %age */
+
+ if (db < -70.0f) {
+ def = 0.0f;
+ } else if (db < -60.0f) {
+ def = (db + 70.0f) * 0.25f;
+ } else if (db < -50.0f) {
+ def = (db + 60.0f) * 0.5f + 2.5f;
+ } else if (db < -40.0f) {
+ def = (db + 50.0f) * 0.75f + 7.5f;
+ } else if (db < -30.0f) {
+ def = (db + 40.0f) * 1.5f + 15.0f;
+ } else if (db < -20.0f) {
+ def = (db + 30.0f) * 2.0f + 30.0f;
+ } else if (db < 6.0f) {
+ def = (db + 20.0f) * 2.5f + 50.0f;
+ } else {
+ def = 115.0f;
+ }
+
+ /* 115 is the deflection %age that would be
+ when db=6.0. this is an arbitrary
+ endpoint for our scaling.
+ */
+
+ return def/115.0f;
+}
+
+static inline float
+log_meter0dB (float db)
+{
+ float def = 0.0f; /* Meter deflection %age */
+
+ if (db < -70.0f) {
+ def = 0.0f;
+ } else if (db < -60.0f) {
+ def = (db + 70.0f) * 0.25f;
+ } else if (db < -50.0f) {
+ def = (db + 60.0f) * 0.5f + 2.5f;
+ } else if (db < -40.0f) {
+ def = (db + 50.0f) * 0.75f + 7.5f;
+ } else if (db < -30.0f) {
+ def = (db + 40.0f) * 1.5f + 15.0f;
+ } else if (db < -20.0f) {
+ def = (db + 30.0f) * 2.0f + 30.0f;
+ } else if (db < 0.0f) {
+ def = (db + 20.0f) * 2.5f + 50.0f;
+ } else {
+ def = 100.0f;
+ }
+ return def/100.0f;
+}
+
+static inline float
+meter_deflect_ppm (float db)
+{
+ if (db < -30) {
+ // 2.258 == ((-30 + 32.0)/ 28.0) / 10^(-30 / 20);
+ return (dB_to_coefficient(db) * 2.258769757f);
+ } else {
+ const float rv = (db + 32.0f) / 28.0f;
+ if (rv < 1.0) {
+ return rv;
+ } else {
+ return 1.0;
+ }
+ }
+}
+
+static inline float
+meter_deflect_din (float db)
+{
+ float rv = dB_to_coefficient(db);
+ rv = sqrtf (sqrtf (2.3676f * rv)) - 0.1803f;
+ if (rv >= 1.0) {
+ return 1.0;
+ } else {
+ return (rv > 0 ? rv : 0.0);
+ }
+}
+
+static inline float
+meter_deflect_nordic (float db)
+{
+ if (db < -60) {
+ return 0.0;
+ } else {
+ const float rv = (db + 60.0f) / 54.0f;
+ if (rv < 1.0) {
+ return rv;
+ } else {
+ return 1.0;
+ }
+ }
+}
+
+static inline float
+meter_deflect_vu (float db)
+{
+ const float rv = 6.77165f * dB_to_coefficient(db);
+ if (rv > 1.0) return 1.0;
+ return rv;
+}
+
+static inline float
+meter_deflect_k (float db, float krange)
+{
+ db+=krange;
+ if (db < -40.0f) {
+ return (dB_to_coefficient(db) * 500.0f / (krange + 45.0f));
+ } else {
+ const float rv = (db + 45.0f) / (krange + 45.0f);
+ if (rv < 1.0) {
+ return rv;
+ } else {
+ return 1.0;
+ }
+ }
+}
+
+#endif /* __ardour_gtk_log_meter_h__ */