From ca9849eecdf7db91d652c698018a5b096d8b78c7 Mon Sep 17 00:00:00 2001
From: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Date: Tue, 21 Apr 2015 18:43:55 +0200
Subject: [PATCH] aacpsy: correct calculation of minath in psy_3gpp_init
The minimum of the ath(x, ATH_ADD) function depends on ATH_ADD.
This patch uses the first order approximation to determine it.
For ATH_ADD = 4 this results in the value at 3407.06812 (-5.24241638)
not the one at 3410 (-5.24237967).
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Approved-by: Claudio Freire <klaussfreire@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
---
libavcodec/aacpsy.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libavcodec/aacpsy.c b/libavcodec/aacpsy.c
index 7205ee3bdb8..49ff3fe139a 100644
--- a/libavcodec/aacpsy.c
+++ b/libavcodec/aacpsy.c
@@ -313,7 +313,7 @@ static av_cold int psy_3gpp_init(FFPsyContext *ctx) {
ctx->bitres.size = 6144 - pctx->frame_bits;
ctx->bitres.size -= ctx->bitres.size % 8;
pctx->fill_level = ctx->bitres.size;
- minath = ath(3410, ATH_ADD);
+ minath = ath(3410 - 0.733 * ATH_ADD, ATH_ADD);
for (j = 0; j < 2; j++) {
AacPsyCoeffs *coeffs = pctx->psy_coef[j];
const uint8_t *band_sizes = ctx->bands[j];
--
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