Add analysis_level property to sox filter.

[mlt] / src / modules / sox / filter_sox.c

diff --git a/src/modules/sox/filter_sox.c b/src/modules/sox/filter_sox.c
index 004c2be8a83c21818044e91599dc0b3e4b4f884a..bc4ff44da4e660d690a6b33ca11c3dc2983a7fde 100644 (file)
--- 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 );