[FFmpeg-cvslog] aacpsy: correct calculation of minath in psy_3gpp_init

[Andreas Cadhalpun]

ffmpeg | branch: master | Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com> | Tue Apr 21 18:43:55 2015 +0200| [ca9849eecdf7db91d652c698018a5b096d8b78c7] | committer: Michael Niedermayer

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 at googlemail.com>
Approved-by: Claudio Freire <klaussfreire at gmail.com>
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=ca9849eecdf7db91d652c698018a5b096d8b78c7
---

 libavcodec/aacpsy.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/aacpsy.c b/libavcodec/aacpsy.c
index 7205ee3..49ff3fe 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];