1 files changed, 23 insertions, 0 deletions
diff --git a/src/libultra_code_O2/osAiSetFrequency.c b/src/libultra_code_O2/osAiSetFrequency.c
new file mode 100644
index 000000000..f0606809e
--- /dev/null
+++ b/src/libultra_code_O2/osAiSetFrequency.c
@@ -0,0 +1,23 @@
+#include "global.h"
+
+s32 osAiSetFrequency(u32 frequency) {
+    u32 dacRate;
+    u8 bitrate;
+    f32 dacRateF;
+
+    dacRateF = ((f32)osViClock / frequency) + 0.5f;
+    dacRate = dacRateF;
+
+    if (dacRate < 132) {
+        return -1;
+    }
+
+    bitrate = (dacRate / 66);
+    if (bitrate > 16) {
+        bitrate = 16;
+    }
+
+    HW_REG(AI_DACRATE_REG, u32) = dacRate - 1;
+    HW_REG(AI_BITRATE_REG, u32) = bitrate - 1;
+    return osViClock / (s32)dacRate;
+}