audio: don't cast to double in SDL_ConvertStereoToMono().

It's expensive and (hopefully) unnecessary. If this becomes an overflow problem, we could multiply both values by 0.5f before adding them, but let's see if we can get by without the extra multiplication first.
libsdl-org · Jan 23, 2017 · a7f86f2 · a7f86f2
1 parent 83454c8
commit a7f86f2
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/src/audio/SDL_audiocvt.c b/src/audio/SDL_audiocvt.c
@@ -41,7 +41,7 @@ SDL_ConvertStereoToMono(SDL_AudioCVT * cvt, SDL_AudioFormat format)
     SDL_assert(format == AUDIO_F32SYS);
 
     for (i = cvt->len_cvt / 8; i; --i, src += 2) {
-        *(dst++) = (float) ((((double) src[0]) + ((double) src[1])) * 0.5);
+        *(dst++) = (src[0] + src[1]) * 0.5f;
     }
 
     cvt->len_cvt /= 2;