From 2ed4439658971fd238c02102bd24906aad4caf6b Mon Sep 17 00:00:00 2001
From: Justin Ruggles <justin.ruggles@gmail.com>
Date: Wed, 30 Sep 2009 01:25:04 +0000
Subject: [PATCH] Simplify stereo rematrixing by only using one temporary
variable. It is also about 1.8% faster on my system.
Originally committed as revision 20090 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
libavcodec/ac3dec.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/libavcodec/ac3dec.c b/libavcodec/ac3dec.c
index dd97d116cd1..91b82cfa7da 100644
--- a/libavcodec/ac3dec.c
+++ b/libavcodec/ac3dec.c
@@ -604,7 +604,6 @@ static void do_rematrixing(AC3DecodeContext *s)
{
int bnd, i;
int end, bndend;
- int tmp0, tmp1;
end = FFMIN(s->end_freq[1], s->end_freq[2]);
@@ -613,10 +612,9 @@ static void do_rematrixing(AC3DecodeContext *s)
if(s->rematrixing_flags[bnd]) {
bndend = FFMIN(end, ff_ac3_rematrix_band_tab[bnd+1]);
for(; i<bndend; i++) {
- tmp0 = s->fixed_coeffs[1][i];
- tmp1 = s->fixed_coeffs[2][i];
- s->fixed_coeffs[1][i] = tmp0 + tmp1;
- s->fixed_coeffs[2][i] = tmp0 - tmp1;
+ int tmp0 = s->fixed_coeffs[1][i];
+ s->fixed_coeffs[1][i] -= s->fixed_coeffs[2][i];
+ s->fixed_coeffs[2][i] = tmp0 - s->fixed_coeffs[2][i];
}
}
}
--
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