From 3a504820125363717399058dd025e3c74188d31a Mon Sep 17 00:00:00 2001
From: sonninnos <tony@pihaus.org>
Date: Wed, 18 Sep 2024 07:16:33 +0300
Subject: [PATCH 1/2] Libretro audio buffer and fps timing correction

---
 .../audio_libretro/audio_backend_libretro.c   | 12 ++--
 libretro/libretro.c                           | 60 ++++++++++++++++++-
 2 files changed, 63 insertions(+), 9 deletions(-)

diff --git a/custom/mupen64plus-core/plugin/audio_libretro/audio_backend_libretro.c b/custom/mupen64plus-core/plugin/audio_libretro/audio_backend_libretro.c
index c31542082..575883db2 100644
--- a/custom/mupen64plus-core/plugin/audio_libretro/audio_backend_libretro.c
+++ b/custom/mupen64plus-core/plugin/audio_libretro/audio_backend_libretro.c
@@ -40,7 +40,7 @@
 #include <audio/conversion/s16_to_float.h>
 #include <audio/audio_resampler.h>
 
-extern retro_audio_sample_batch_t audio_batch_cb;
+extern void retro_audio_queue(const int16_t *data, int32_t samples);
 
 static unsigned MAX_AUDIO_FRAMES = 2048;
 
@@ -162,14 +162,10 @@ static void aiLenChanged(void* user_data, const void* buffer, size_t size)
    resampler->process(resampler_audio_data, &data);
    convert_float_to_s16(audio_out_buffer_s16, audio_out_buffer_float, data.output_frames * 2);
 
-   out                    = audio_out_buffer_s16;
+   out               = audio_out_buffer_s16;
+
+   retro_audio_queue(out, data.output_frames * 2);
 
-   while (data.output_frames)
-   {
-      size_t ret          = audio_batch_cb(out, data.output_frames);
-      data.output_frames -= ret;
-      out                += ret * 2;
-   }
    if (remain_frames)
    {
       raw_data = raw_data + frames * 2;
diff --git a/libretro/libretro.c b/libretro/libretro.c
index 0147d9558..ae1cbb478 100644
--- a/libretro/libretro.c
+++ b/libretro/libretro.c
@@ -223,6 +223,57 @@ extern struct cheat_ctx g_cheat_ctx;
 static bool emuThreadRunning = false;
 static pthread_t emuThread;
 
+/* Audio output buffer */
+static struct {
+   int16_t *data;
+   int32_t size;
+   int32_t capacity;
+} output_audio_buffer = {NULL, 0, 0};
+
+static void ensure_output_audio_buffer_capacity(int32_t capacity)
+{
+   if (capacity <= output_audio_buffer.capacity) {
+      return;
+   }
+
+   output_audio_buffer.data = realloc(output_audio_buffer.data, capacity * sizeof(*output_audio_buffer.data));
+   output_audio_buffer.capacity = capacity;
+   log_cb(RETRO_LOG_DEBUG, "Output audio buffer capacity set to %d\n", capacity);
+}
+
+static void init_output_audio_buffer(int32_t capacity)
+{
+   output_audio_buffer.data = NULL;
+   output_audio_buffer.size = 0;
+   output_audio_buffer.capacity = 0;
+   ensure_output_audio_buffer_capacity(capacity);
+}
+
+static void free_output_audio_buffer()
+{
+   free(output_audio_buffer.data);
+   output_audio_buffer.data = NULL;
+   output_audio_buffer.size = 0;
+   output_audio_buffer.capacity = 0;
+}
+
+static void upload_output_audio_buffer()
+{
+   audio_batch_cb(output_audio_buffer.data, output_audio_buffer.size / 2);
+   output_audio_buffer.size = 0;
+}
+
+void retro_audio_queue(const int16_t *data, int32_t samples)
+{
+   if ((samples < 1) || !emu_initialized)
+      return;
+
+   if (output_audio_buffer.capacity - output_audio_buffer.size < samples)
+      ensure_output_audio_buffer_capacity((output_audio_buffer.capacity + samples) * 1.5);
+   memcpy(output_audio_buffer.data + output_audio_buffer.size, data, samples * sizeof(*output_audio_buffer.data));
+   output_audio_buffer.size += samples;
+}
+
 // after the controller's CONTROL* member has been assigned we can update
 // them straight from here...
 extern struct
@@ -665,8 +716,10 @@ void retro_get_system_av_info(struct retro_system_av_info *info)
     if (current_rdp_type == RDP_PLUGIN_PARALLEL)
         parallel_get_geometry(&info->geometry);
 #endif
-    info->timing.fps = vi_expected_refresh_rate_from_tv_standard(ROM_PARAMS.systemtype);
     info->timing.sample_rate = 44100.0;
+    info->timing.fps = (ROM_PARAMS.systemtype == SYSTEM_PAL)
+          ? info->timing.sample_rate / 882
+          : info->timing.sample_rate / 736;
 }
 
 unsigned retro_get_region (void)
@@ -725,6 +778,8 @@ void retro_init(void)
     m64p_error ret = CoreStartup(FRONTEND_API_VERSION, ".", ".", NULL, n64DebugCallback, 0, n64StateCallback);
     if(ret && log_cb)
         log_cb(RETRO_LOG_ERROR, CORE_NAME ": failed to initialize core (err=%i)\n", ret);
+
+    init_output_audio_buffer(2048);
 }
 
 void retro_deinit(void)
@@ -742,6 +797,7 @@ void retro_deinit(void)
 
     CoreShutdown();
     deinit_audio_libretro();
+    free_output_audio_buffer();
 
     if (perf_cb.perf_log)
         perf_cb.perf_log();
@@ -2056,6 +2112,8 @@ void retro_run (void)
         // screen_pitch will be 0 for GLN
         video_cb(NULL, retro_screen_width, retro_screen_height, screen_pitch);
     }
+
+    upload_output_audio_buffer();
 }
 
 void retro_reset (void)

From 0a6e9b2a2846d66c922708c4c8e04b2d7102aeec Mon Sep 17 00:00:00 2001
From: sonninnos <tony@pihaus.org>
Date: Wed, 18 Sep 2024 07:24:13 +0300
Subject: [PATCH 2/2] Buildfix copied from interrupt.c

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

diff --git a/libretro/libretro.c b/libretro/libretro.c
index ae1cbb478..f4419039c 100644
--- a/libretro/libretro.c
+++ b/libretro/libretro.c
@@ -18,6 +18,10 @@
  *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.          *
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
+#ifdef __MINGW32__
+#define _CRT_RAND_S
+#endif
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>