From 3dc666810732dcabb95a3bd1d02d4fcee0befd3f Mon Sep 17 00:00:00 2001
From: Nebuleon Fumika
Date: Wed, 6 Feb 2013 05:59:22 -0500
Subject: Raise the sound frequency from 22050 Hz to 32000 Hz, which is like
 the SNES. Use sound interpolation to make it sound even more like the SNES.

---
 source/nds/ds2sound.h | 21 ++++++++++++---------
 source/nds/entry.cpp  |  4 ++--
 2 files changed, 14 insertions(+), 11 deletions(-)

(limited to 'source')

diff --git a/source/nds/ds2sound.h b/source/nds/ds2sound.h
index f51a6e1..8c0e2bf 100644
--- a/source/nds/ds2sound.h
+++ b/source/nds/ds2sound.h
@@ -1,21 +1,24 @@
 // The sound buffer sizes used on the DS2's side, for each value of
 // Settings.SoundPlaybackRate.
+// * Don't buffer too much, otherwise audio is delayed from video.
+// * Don't go below one frame (20 milliseconds).
+// * Buffer sizes must be multiples of 128.
 #define DS2_BUFFER_SIZE_4  512 /* tested working */
-#define DS2_BUFFER_SIZE_5 1024 /* like the SNES! tested working, but slow */
-#define DS2_BUFFER_SIZE_6 1024 /* tested working, slow because of upsampling */
-#define DS2_BUFFER_SIZE_7 1024 /* tested working, slow because of upsampling */
+#define DS2_BUFFER_SIZE_5  640 /* like the SNES! tested working */
+#define DS2_BUFFER_SIZE_6  896 /* tested working */
+#define DS2_BUFFER_SIZE_7 1024 /* tested working */
 
 // The sampling rate for the sound, in Hz, for each value of
 // Settings.SoundPlaybackRate.
 #define SND_SAMPLE_RATE_1 8000
 #define SND_SAMPLE_RATE_2 11025
 #define SND_SAMPLE_RATE_3 16000
-#define SND_SAMPLE_RATE_4 22050
-#define SND_SAMPLE_RATE_5 32000
+#define SND_SAMPLE_RATE_4 22050 /* NDSSFC 1.06 - CATSFC 1.28 used this one */
+#define SND_SAMPLE_RATE_5 32000 /* like the SNES! */
 #define SND_SAMPLE_RATE_6 44100
-#define SND_SAMPLE_RATE_7 48000
+#define SND_SAMPLE_RATE_7 48000 /* CATSFC 1.25 made using this one possible */
 
 // Settings in use. The number should match in all three settings.
-#define DS2_BUFFER_SIZE   DS2_BUFFER_SIZE_4
-#define SND_SAMPLE_RATE   SND_SAMPLE_RATE_4
-#define SNES9X_SRATE_ID   4
+#define DS2_BUFFER_SIZE   DS2_BUFFER_SIZE_5
+#define SND_SAMPLE_RATE   SND_SAMPLE_RATE_5
+#define SNES9X_SRATE_ID   5
diff --git a/source/nds/entry.cpp b/source/nds/entry.cpp
index ca27249..723374c 100644
--- a/source/nds/entry.cpp
+++ b/source/nds/entry.cpp
@@ -425,7 +425,7 @@ void init_sfc_setting(void)
 	//sound settings
     Settings.APUEnabled = Settings.NextAPUEnabled = TRUE;
 	Settings.FixFrequency = 1;
-
+	Settings.InterpolatedSound = TRUE;
 
     Settings.H_Max = SNES_CYCLES_PER_SCANLINE;
     Settings.SkipFrames = AUTO_FRAMERATE;
@@ -1042,7 +1042,7 @@ void S9xGenerateSound ()
 	}
 }
 
-#define SOUND_EMISSION_INTERVAL ((unsigned int) ((((unsigned long long) DS2_BUFFER_SIZE * 1000000) / SND_SAMPLE_RATE) * 3 / 128))
+#define SOUND_EMISSION_INTERVAL ((unsigned int) ((((unsigned long long) DS2_BUFFER_SIZE * 1000000) / SND_SAMPLE_RATE) * 3 / 128) - 1) /* -1 is for roundoff errors */
 unsigned int LastSoundEmissionTime = 0;
 
 void S9xProcessSound (unsigned int)
-- 
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