From 8287d597a2b0c9a51a49cc7c6124b4d59663deea Mon Sep 17 00:00:00 2001
From: r5 <Inbox is full>
Date: Wed, 20 Sep 2017 19:24:52 +0100
Subject: [PATCH 1/3] (libretro) Expose stereo/mono core option

---
 libretro/libretro.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/libretro/libretro.c b/libretro/libretro.c
index e264117..262c5c7 100644
--- a/libretro/libretro.c
+++ b/libretro/libretro.c
@@ -514,7 +514,7 @@ static void config_default(void)
    config.hg             = 100.0;
    config.dac_bits       = 14; /* MAX DEPTH */ 
    config.ym2413         = 2; /* AUTO */
-   config.mono           = 0; /* STEREO output */
+   config.mono           = 1; /* MONO output */
 
    /* system options */
    config.system         = 0; /* AUTO */
@@ -1032,7 +1032,16 @@ static void check_variables(void)
       }
     }
   }
-	
+
+  var.key = "genesis_plus_gx_sound_output";
+  environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var);
+  {
+    if (!strcmp(var.value, "mono"))
+      config.mono = 1;
+    else if (!strcmp(var.value, "stereo"))
+      config.mono = 0; 
+  }
+
   var.key = "genesis_plus_gx_audio_filter";
   environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var);
   {
@@ -1628,6 +1637,7 @@ void retro_set_environment(retro_environment_t cb)
       { "genesis_plus_gx_lock_on", "Cartridge lock-on; disabled|game genie|action replay (pro)|sonic & knuckles" },
       { "genesis_plus_gx_ym2413", "Master System FM; auto|disabled|enabled" },
       { "genesis_plus_gx_dac_bits", "YM2612 DAC quantization; disabled|enabled" },
+      { "genesis_plus_gx_sound_output", "Sound output; mono|stereo" }, 
       { "genesis_plus_gx_audio_filter", "Audio filter; disabled|Lowpass" },
       { "genesis_plus_gx_lowpass_range", "Low-pass filter %; 60|65|70|75|80|85|90|95|5|10|15|20|25|30|35|40|45|50|55"},
       

From f0fe9307c9ccd3b8eb6f9b25c410c477ef4141d1 Mon Sep 17 00:00:00 2001
From: r5 <Inbox is full>
Date: Thu, 21 Sep 2017 14:38:22 +0100
Subject: [PATCH 2/3] (libretro) Revert default sound output to 'stereo'

---
 libretro/libretro.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libretro/libretro.c b/libretro/libretro.c
index 262c5c7..4998366 100644
--- a/libretro/libretro.c
+++ b/libretro/libretro.c
@@ -514,7 +514,7 @@ static void config_default(void)
    config.hg             = 100.0;
    config.dac_bits       = 14; /* MAX DEPTH */ 
    config.ym2413         = 2; /* AUTO */
-   config.mono           = 1; /* MONO output */
+   config.mono           = 0; /* STEREO output */
 
    /* system options */
    config.system         = 0; /* AUTO */
@@ -1637,7 +1637,7 @@ void retro_set_environment(retro_environment_t cb)
       { "genesis_plus_gx_lock_on", "Cartridge lock-on; disabled|game genie|action replay (pro)|sonic & knuckles" },
       { "genesis_plus_gx_ym2413", "Master System FM; auto|disabled|enabled" },
       { "genesis_plus_gx_dac_bits", "YM2612 DAC quantization; disabled|enabled" },
-      { "genesis_plus_gx_sound_output", "Sound output; mono|stereo" }, 
+      { "genesis_plus_gx_sound_output", "Sound output; stereo|mono" }, 
       { "genesis_plus_gx_audio_filter", "Audio filter; disabled|Lowpass" },
       { "genesis_plus_gx_lowpass_range", "Low-pass filter %; 60|65|70|75|80|85|90|95|5|10|15|20|25|30|35|40|45|50|55"},
       

From 5cd8f6e7d39aa2e17d5d73fd4f21746fbccbdcbe Mon Sep 17 00:00:00 2001
From: LodanZark <lodan.zark@hotmail.com>
Date: Thu, 21 Sep 2017 15:13:17 +0100
Subject: [PATCH 3/3] change the Lowpass core option to lowercase

change the Lowpass core option to lowercase for better consistence with other options
---
 libretro/libretro.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libretro/libretro.c b/libretro/libretro.c
index 262c5c7..a1adb2b 100644
--- a/libretro/libretro.c
+++ b/libretro/libretro.c
@@ -1045,7 +1045,7 @@ static void check_variables(void)
   var.key = "genesis_plus_gx_audio_filter";
   environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var);
   {
-    if (!strcmp(var.value, "Lowpass"))
+    if (!strcmp(var.value, "lowpass"))
       config.filter = 1;
 
     #if HAVE_EQ 
@@ -1638,7 +1638,7 @@ void retro_set_environment(retro_environment_t cb)
       { "genesis_plus_gx_ym2413", "Master System FM; auto|disabled|enabled" },
       { "genesis_plus_gx_dac_bits", "YM2612 DAC quantization; disabled|enabled" },
       { "genesis_plus_gx_sound_output", "Sound output; mono|stereo" }, 
-      { "genesis_plus_gx_audio_filter", "Audio filter; disabled|Lowpass" },
+      { "genesis_plus_gx_audio_filter", "Audio filter; disabled|lowpass" },
       { "genesis_plus_gx_lowpass_range", "Low-pass filter %; 60|65|70|75|80|85|90|95|5|10|15|20|25|30|35|40|45|50|55"},
       
       #if HAVE_EQ