From 7deeb6d2faa38402640ba1083b576a89b3841390 Mon Sep 17 00:00:00 2001
From: Dwedit <danweiss@gmail.com>
Date: Fri, 23 Mar 2018 14:12:05 -0500
Subject: [PATCH] Functions to enable and disable audio and video, and an
 environment function to query status of audio and video enables

---
 audio/audio_driver.c               | 28 ++++++++++++++++++++++++++++
 audio/audio_driver.h               |  8 ++++++++
 dynamic.c                          | 19 +++++++++++++++++++
 gfx/video_driver.c                 | 10 ++++++++++
 gfx/video_driver.h                 |  2 ++
 libretro-common/include/libretro.h |  1 +
 6 files changed, 68 insertions(+)

diff --git a/audio/audio_driver.c b/audio/audio_driver.c
index bc2231c76e..9f4999f304 100644
--- a/audio/audio_driver.c
+++ b/audio/audio_driver.c
@@ -183,6 +183,8 @@ static void *audio_driver_resampler_data                 = NULL;
 static const audio_driver_t *current_audio               = NULL;
 static void *audio_driver_context_audio_data             = NULL;
 
+static bool audio_suspended                              = false;
+
 enum resampler_quality audio_driver_get_resampler_quality(void)
 {
    settings_t *settings = config_get_ptr();
@@ -559,6 +561,9 @@ void audio_driver_set_nonblocking_state(bool enable)
  **/
 static void audio_driver_flush(const int16_t *data, size_t samples)
 {
+   if (audio_suspended)
+      return;
+
    struct resampler_data src_data;
    bool is_perfcnt_enable                               = false;
    bool is_paused                                       = false;
@@ -696,6 +701,9 @@ static void audio_driver_flush(const int16_t *data, size_t samples)
  **/
 void audio_driver_sample(int16_t left, int16_t right)
 {
+   if (audio_suspended)
+      return;
+
    audio_driver_output_samples_conv_buf[audio_driver_data_ptr++] = left;
    audio_driver_output_samples_conv_buf[audio_driver_data_ptr++] = right;
 
@@ -1286,11 +1294,31 @@ bool audio_driver_owns_driver(void)
    return audio_driver_data_own;
 }
 
+void audio_driver_suspend(void)
+{
+   audio_suspended = true;
+}
+
+bool audio_driver_is_suspended(void)
+{
+   return audio_suspended;
+}
+
+void audio_driver_resume(void)
+{
+   audio_suspended = false;
+}
+
 void audio_driver_set_active(void)
 {
    audio_driver_active = true;
 }
 
+bool audio_driver_is_active(void)
+{
+   return audio_driver_active;
+}
+
 void audio_driver_destroy(void)
 {
    audio_driver_active   = false;
diff --git a/audio/audio_driver.h b/audio/audio_driver.h
index 9e050de794..0054050184 100644
--- a/audio/audio_driver.h
+++ b/audio/audio_driver.h
@@ -152,8 +152,16 @@ void audio_driver_set_own_driver(void);
 
 void audio_driver_unset_own_driver(void);
 
+void audio_driver_suspend(void);
+
+bool audio_driver_is_suspended(void);
+
+void audio_driver_resume(void);
+
 void audio_driver_set_active(void);
 
+bool audio_driver_is_active(void);
+
 void audio_driver_destroy(void);
 
 void audio_driver_deinit_resampler(void);
diff --git a/dynamic.c b/dynamic.c
index 9c09c2fc96..6a8ede407d 100644
--- a/dynamic.c
+++ b/dynamic.c
@@ -1692,6 +1692,25 @@ bool rarch_environment_cb(unsigned cmd, void *data)
             ledintf->set_led_state = led_driver_set_led;
       }
       break;
+
+      case RETRO_ENVIRONMENT_GET_AUDIO_VIDEO_ENABLE:
+      {
+         int result = 0;
+         if (!audio_driver_is_suspended() && audio_driver_is_active())
+         {
+            result |= 2;
+         }
+         if (video_driver_is_active() && !video_driver_is_stub_frame())
+         {
+            result |= 1;
+         }
+         if (data != NULL)
+         {
+            int* result_p = (int*)data;
+            *result_p = result;
+         }
+      }
+      break;
       
       default:
          RARCH_LOG("Environ UNSUPPORTED (#%u).\n", cmd);
diff --git a/gfx/video_driver.c b/gfx/video_driver.c
index e953666ebd..f8051f02bf 100644
--- a/gfx/video_driver.c
+++ b/gfx/video_driver.c
@@ -1585,6 +1585,11 @@ void video_driver_unset_stub_frame(void)
    frame_bak = NULL;
 }
 
+bool video_driver_is_stub_frame(void)
+{
+   return current_video->frame == video_null.frame;
+}
+
 bool video_driver_supports_recording(void)
 {
    settings_t *settings = config_get_ptr();
@@ -2146,6 +2151,11 @@ void video_driver_set_active(void)
    video_driver_active = true;
 }
 
+void video_driver_unset_active(void)
+{
+   video_driver_active = false;
+}
+
 bool video_driver_is_active(void)
 {
    return video_driver_active;
diff --git a/gfx/video_driver.h b/gfx/video_driver.h
index 8a09fea33c..ca3401953b 100644
--- a/gfx/video_driver.h
+++ b/gfx/video_driver.h
@@ -905,6 +905,7 @@ void video_driver_destroy(void);
 void video_driver_set_cached_frame_ptr(const void *data);
 void video_driver_set_stub_frame(void);
 void video_driver_unset_stub_frame(void);
+bool video_driver_is_stub_frame(void);
 bool video_driver_supports_recording(void);
 bool video_driver_supports_viewport_read(void);
 bool video_driver_supports_read_frame_raw(void);
@@ -949,6 +950,7 @@ bool video_driver_is_video_cache_context(void);
 void video_driver_set_video_cache_context_ack(void);
 bool video_driver_is_video_cache_context_ack(void);
 void video_driver_set_active(void);
+void video_driver_unset_active(void);
 bool video_driver_is_active(void);
 bool video_driver_gpu_record_init(unsigned size);
 void video_driver_gpu_record_deinit(void);
diff --git a/libretro-common/include/libretro.h b/libretro-common/include/libretro.h
index e15403d8b6..7d0cf19a20 100644
--- a/libretro-common/include/libretro.h
+++ b/libretro-common/include/libretro.h
@@ -1113,6 +1113,7 @@ struct retro_led_interface
     retro_set_led_state_t set_led_state;
 };
 
+#define RETRO_ENVIRONMENT_GET_AUDIO_VIDEO_ENABLE (47 | RETRO_ENVIRONMENT_EXPERIMENTAL)
 
 #define RETRO_ENVIRONMENT_GET_HW_RENDER_INTERFACE (41 | RETRO_ENVIRONMENT_EXPERIMENTAL)
                                            /* const struct retro_hw_render_interface ** --