2014-02-09 Christophe Gisquet <christophe.gisq...@gmail.com>:
> And another patch that can be applied on top to make the default
> implementation a bit more optimized.
Same patch, more explicit stride (sizeof instead of magical number 32).
--
Christophe
From 5252f163665031bcd851ee71ea02b29be2534877 Mon Sep 17 00:00:00 2001
From: Christophe Gisquet <christophe.gisq...@gmail.com>
Date: Sat, 8 Feb 2014 18:12:56 +0100
Subject: [PATCH 9/9] dcadsp: perform linear access with offset
This seems to simplify noticeably the addressing. Timings before/after
for respectively win32 and win64 are 260/222 and 242/231.
---
libavcodec/dcadsp.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/libavcodec/dcadsp.c b/libavcodec/dcadsp.c
index 1e09bd3..ea4ae03 100644
--- a/libavcodec/dcadsp.c
+++ b/libavcodec/dcadsp.c
@@ -30,14 +30,17 @@ static void decode_hf_c(float dst[DCA_SUBBANDS][8],
int32_t scale[DCA_SUBBANDS][2],
intptr_t start, intptr_t end)
{
- int l;
+ int i, l;
+ const int8_t *pvq = hf_vq[0] + vq_offset;
for (l = start; l < end; l++) {
/* 1 vector -> 32 samples but we only need the 8 samples
* for this subsubframe. */
- int i, hfvq = vq_num[l];
+ const int8_t *ptr = pvq + vq_num[l]*sizeof(hf_vq[0]);
float fscale = scale[l][0] / 16.0;
- for (i = 0; i < 8; i++)
- dst[l][i] = hf_vq[hfvq][vq_offset + i] * fscale;
+ for (i = 0; i < 8; i++) {
+ // hf_vq[hfvq][vq_offset + i] * fscale
+ dst[l][i] = ptr[i] * fscale;
+ }
}
}
--
1.8.0.msysgit.0
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