From: Dan Dennedy <dan@dennedy.org>
Date: Wed, 6 Nov 2013 06:35:51 +0000 (-0800)
Subject: Add analysis_level property to sox filter.
X-Git-Url: https://git.sesse.net/?a=commitdiff_plain;h=847b05150117315546f683b63ece888c9dc61170;p=mlt

Add analysis_level property to sox filter.

For normalization analysis when not use_peak, sets the target amplitude.
---

diff --git a/src/modules/sox/filter_sox.c b/src/modules/sox/filter_sox.c
index 004c2be8..bc4ff44d 100644
--- a/src/modules/sox/filter_sox.c
+++ b/src/modules/sox/filter_sox.c
@@ -57,6 +57,7 @@
 #define BUFFER_LEN 8192
 #define AMPLITUDE_NORM 0.2511886431509580 /* -12dBFS */
 #define AMPLITUDE_MIN 0.00001
+#define DBFSTOAMP(x) pow(10,(x)/20.0)
 
 /** Compute the mean of a set of doubles skipping unset values flagged as -1
 */
@@ -311,7 +312,17 @@ static int filter_get_audio( mlt_frame frame, void **buffer, mlt_audio_format *f
 					if ( use_peak )
 						normalised_gain = ST_SSIZE_MIN / -peak;
 					else
-						normalised_gain = AMPLITUDE_NORM / rms;
+					{
+						double gain = DBFSTOAMP(-12); // default -12 dBFS
+						char *p = mlt_properties_get( filter_properties, "analysis_level" );
+						if (p)
+						{
+							gain = mlt_properties_get_double( filter_properties, "analysis_level" );
+							if ( strstr( p, "dB" ) )
+								gain = DBFSTOAMP( gain );
+						}
+						normalised_gain = gain / rms;
+					}
 
 					// Set properties for serialization
 					snprintf( effect, sizeof(effect), "vol %f", normalised_gain );
diff --git a/src/modules/sox/filter_sox.yml b/src/modules/sox/filter_sox.yml
index e425281a..a70c4fd2 100644
--- a/src/modules/sox/filter_sox.yml
+++ b/src/modules/sox/filter_sox.yml
@@ -16,7 +16,8 @@ bugs:
   - Some effects have a temporal side-effect that do not work well.
 
 parameters:
-  - identifier: argument
+  - identifier: effect
+    argument: yes
     title: Effect name and options
     type: string
     format: effect [options]
@@ -26,6 +27,17 @@ parameters:
       The results are put into the level, peak, and gain properties as well
       as this effect property as the parameter to the vol effect.
 
+  - identifier: analysis_level
+    title: Normalization level
+    type: string
+    default: -12dBFS
+    description: >
+      Normalize the volume to the specified amplitude.
+      The normalization may be indicated as a floating point value of the
+      relative volume with 1.0 being maximum.
+      The normalization may also be indicated as a numeric value with the
+      suffix "dB" to set the amplitude in decibels.
+
   - identifier: level
     title: Signal power level (RMS)
     type: float