From 0e3cec9f7d9353b01ef7af0d67a39a66c4ec899c Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michaelni@gmx.at>
Date: Sun, 3 Jun 2012 01:46:05 +0200
Subject: [PATCH] aacsbr: optimize sine level addition
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Based-on commit by Måns Rullgård <mans@mansr.com>
original: 1424 decicycles in phi, 1024 runs, 0 skips
mans code: 1104 decicycles in phi, 1024 runs, 0 skips
this change: 734 decicycles in phi, 1024 runs, 0 skips
mans code: 1 file changed, 20 insertions(+), 10 deletions(-)
this change: 1 file changed, 10 insertions(+), 6 deletions(-)
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
---
libavcodec/aacsbr.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/libavcodec/aacsbr.c b/libavcodec/aacsbr.c
index 40ee8f5127a..9ba3754beff 100644
--- a/libavcodec/aacsbr.c
+++ b/libavcodec/aacsbr.c
@@ -1635,13 +1635,17 @@ static void sbr_hf_assemble(float Y1[38][64][2],
q_filt, indexnoise,
kx, m_max);
} else {
- for (m = 0; m < m_max; m++) {
- Y1[i][m + kx][0] +=
- sbr->s_m[e][m] * phi[0][indexsine];
- Y1[i][m + kx][1] +=
- sbr->s_m[e][m] * (phi[1][indexsine] * phi_sign);
- phi_sign = -phi_sign;
+ int idx = indexsine&1;
+ int A = (1-((indexsine+(kx & 1))&2));
+ int B = (A^(-idx)) + idx;
+ float *out = &Y1[i][kx][idx];
+ float *in = sbr->s_m[e];
+ for (m = 0; m+1 < m_max; m+=2) {
+ out[2*m ] += in[m ] * A;
+ out[2*m+2] += in[m+1] * B;
}
+ if(m_max&1)
+ out[2*m ] += in[m ] * A;
}
indexnoise = (indexnoise + m_max) & 0x1ff;
indexsine = (indexsine + 1) & 3;
--
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