From 617cac672b997ffde087caafbbbf54f7a6c46714 Mon Sep 17 00:00:00 2001
From: XANTRONIX Development
Date: Mon, 31 Jan 2022 23:33:12 -0500
Subject: Ensure gain is factored into mixer input sources

---
 src/mixer.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/src/mixer.c b/src/mixer.c
index 001c765..0f3b5b1 100644
--- a/src/mixer.c
+++ b/src/mixer.c
@@ -10,50 +10,54 @@
 static void mixer_apply_mono_to_mono(int16_t *dest,
                                      int16_t *src,
                                      size_t count,
+                                     float gain,
                                      float bias_l,
                                      float bias_r) {
     size_t i;
 
     for (i=0; i<count; i++) {
-        dest[i] += src[i];
+        dest[i] += gain * src[i];
     }
 }
 
 static void mixer_apply_mono_to_stereo(int16_t *dest,
                                        int16_t *src,
                                        size_t count,
+                                       float gain,
                                        float bias_l,
                                        float bias_r) {
     size_t i;
 
     for (i=0; i<count; i++) {
-        dest[i*2]   += bias_l * src[i];
-        dest[i*2+1] += bias_r * src[i];
+        dest[i*2]   += gain * bias_l * src[i];
+        dest[i*2+1] += gain * bias_r * src[i];
     }
 }
 
 static void mixer_apply_stereo_to_stereo(int16_t *dest,
                                          int16_t *src,
                                          size_t count,
+                                         float gain,
                                          float bias_l,
                                          float bias_r) {
     size_t i;
 
     for (i=0; i<count; i++) {
-        dest[i*2]   += bias_l * src[i*2];
-        dest[i*2+1] += bias_r * src[i*2+1];
+        dest[i*2]   += gain * bias_l * src[i*2];
+        dest[i*2+1] += gain * bias_r * src[i*2+1];
     }
 }
 
 static void mixer_apply_stereo_to_mono(int16_t *dest,
                                        int16_t *src,
                                        size_t count,
+                                       float gain,
                                        float bias_l,
                                        float bias_r) {
     size_t i;
 
     for (i=0; i<count; i++) {
-        dest[i] += (src[i*2] + src[i*2+1]) / 2;
+        dest[i] += gain * ((src[i*2] + src[i*2+1]) / 2);
     }
 }
 
@@ -74,6 +78,7 @@ static ssize_t mixer_fill(xas_mixer *mixer,
                             int16_t *,
                             size_t,
                             float,
+                            float,
                             float);
 
         xas_mixer_input *next = input->next;
@@ -102,6 +107,7 @@ static ssize_t mixer_fill(xas_mixer *mixer,
         mixer_apply((int16_t *)(mixer->buf),
                     buf,
                     readlen,
+                    input->gain,
                     input->bias_l,
                     input->bias_r);
 
-- 
cgit v1.2.3