func_volume: Accept decimal number as argument

Allow voice volume to be multiplied or divided by a floating point number.

ASTERISK-28813

Change-Id: I5b42b890ec4e1f6b0b3400cb44ff16522b021c8c

doc/CHANGES-staging/func_volume.txt

@@ -0,0 +1,3 @@
+Subject: func_volume
+
+Accept decimal number as argument.

funcs/func_volume.c

@@ -72,8 +72,8 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 
 struct volume_information {
 	struct ast_audiohook audiohook;
-	int tx_gain;
+	float tx_gain;
-	int rx_gain;
+	float rx_gain;
 	unsigned int flags;
 };
 
@@ -109,7 +109,7 @@ static int volume_callback(struct ast_audiohook *audiohook, struct ast_channel *
 {
 	struct ast_datastore *datastore = NULL;
 	struct volume_information *vi = NULL;
-	int *gain = NULL;
+	float *gain = NULL;
 
 	/* If the audiohook is stopping it means the channel is shutting down.... but we let the datastore destroy take care of it */
 	if (audiohook->status == AST_AUDIOHOOK_STATUS_DONE)
@@ -143,7 +143,7 @@ static int volume_callback(struct ast_audiohook *audiohook, struct ast_channel *
 		if (!(gain = (direction == AST_AUDIOHOOK_DIRECTION_READ) ? &vi->rx_gain : &vi->tx_gain) || !*gain)
 			return 0;
 		/* Apply gain to frame... easy as pi */
-		ast_frame_adjust_volume(frame, *gain);
+		ast_frame_adjust_volume_float(frame, *gain);
 	}
 
 	return 0;
@@ -195,9 +195,9 @@ static int volume_write(struct ast_channel *chan, const char *cmd, char *data, c
 	}
 
 	if (!strcasecmp(args.direction, "tx")) {
-		vi->tx_gain = atoi(value);
+		vi->tx_gain = atof(value);
 	} else if (!strcasecmp(args.direction, "rx")) {
-		vi->rx_gain = atoi(value);
+		vi->rx_gain = atof(value);
 	} else {
 		ast_log(LOG_ERROR, "Direction must be either RX or TX\n");
 	}

include/asterisk/frame.h

@@ -587,6 +587,14 @@ struct ast_frame *ast_frame_enqueue(struct ast_frame *head, struct ast_frame *f,
  */
 int ast_frame_adjust_volume(struct ast_frame *f, int adjustment);
 
+/*!
+  \brief Adjusts the volume of the audio samples contained in a frame.
+  \param f The frame containing the samples (must be AST_FRAME_VOICE and AST_FORMAT_SLINEAR)
+  \param adjustment The number of dB to adjust up or down.
+  \return 0 for success, non-zero for an error
+ */
+int ast_frame_adjust_volume_float(struct ast_frame *f, float adjustment);
+
 /*!
   \brief Sums two frames of audio samples.
   \param f1 The first frame (which will contain the result)

include/asterisk/utils.h

@@ -375,11 +375,35 @@ static force_inline void ast_slinear_saturated_multiply(short *input, short *val
 		*input = (short) res;
 }
 
+static force_inline void ast_slinear_saturated_multiply_float(short *input, float *value)
+{
+	float res;
+
+	res = (float) *input * *value;
+	if (res > 32767)
+		*input = 32767;
+	else if (res < -32768)
+		*input = -32768;
+	else
+		*input = (short) res;
+}
+
 static force_inline void ast_slinear_saturated_divide(short *input, short *value)
 {
 	*input /= *value;
 }
 
+static force_inline void ast_slinear_saturated_divide_float(short *input, float *value)
+{
+	float res = (float) *input / *value;
+	if (res > 32767)
+		*input = 32767;
+	else if (res < -32768)
+		*input = -32768;
+	else
+		*input = (short) res;
+}
+
 #ifdef localtime_r
 #undef localtime_r
 #endif

main/frame.c

@@ -45,6 +45,8 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include "asterisk/dsp.h"
 #include "asterisk/file.h"
 
+#include <math.h>
+
 #if !defined(LOW_MEMORY)
 static void frame_cache_cleanup(void *data);
 
@@ -695,6 +697,31 @@ int ast_frame_adjust_volume(struct ast_frame *f, int adjustment)
 	return 0;
 }
 
+int ast_frame_adjust_volume_float(struct ast_frame *f, float adjustment)
+{
+	int count;
+	short *fdata = f->data.ptr;
+	float adjust_value = fabs(adjustment);
+
+	if ((f->frametype != AST_FRAME_VOICE) || !(ast_format_cache_is_slinear(f->subclass.format))) {
+		return -1;
+	}
+
+	if (!adjustment) {
+		return 0;
+	}
+
+	for (count = 0; count < f->samples; count++) {
+		if (adjustment > 0) {
+			ast_slinear_saturated_multiply_float(&fdata[count], &adjust_value);
+		} else if (adjustment < 0) {
+			ast_slinear_saturated_divide_float(&fdata[count], &adjust_value);
+		}
+	}
+
+	return 0;
+}
+
 int ast_frame_slinear_sum(struct ast_frame *f1, struct ast_frame *f2)
 {
 	int count;