From 71a4e8ed1348293efc867c40b321ab040500fced Mon Sep 17 00:00:00 2001
From: Sam Lantinga <slouken@libsdl.org>
Date: Thu, 23 Feb 2017 12:10:02 -0800
Subject: [PATCH] Stop CoreAudio from doing expensive audio rate conversion

---
 src/audio/coreaudio/SDL_coreaudio.m | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/audio/coreaudio/SDL_coreaudio.m b/src/audio/coreaudio/SDL_coreaudio.m
index 515df99339cdf..485d86d164e1b 100644
--- a/src/audio/coreaudio/SDL_coreaudio.m
+++ b/src/audio/coreaudio/SDL_coreaudio.m
@@ -734,6 +734,13 @@ static BOOL update_audio_session(_THIS, SDL_bool open)
     if (!update_audio_session(this, SDL_TRUE)) {
         return -1;
     }
+
+    /* Stop CoreAudio from doing expensive audio rate conversion */
+    @autoreleasepool {
+        AVAudioSession* session = [AVAudioSession sharedInstance];
+        [session setPreferredSampleRate:this->spec.freq error:nil];
+        this->spec.freq = (int)session.sampleRate;
+    }
 #endif
 
     /* Setup a AudioStreamBasicDescription with the requested format */