From 57848ef3c6a135caeb1f8034cadc157a38947009 Mon Sep 17 00:00:00 2001
From: Rostislav Pehlivanov <atomnuker@gmail.com>
Date: Thu, 2 Jul 2015 19:13:02 +0100
Subject: [PATCH] aaccoder: fix M/S coding
There were some mistakes in the code for M/S stereo, this commit fixes them.
The start variable was not being reset for every window and every access to
the coefficients was incorrect as well. This fixes that by properly
addressing the coefficients using both windows and setting the start on every window to zero.
Reviewed-by: Claudio Freire <klaussfreire@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
---
libavcodec/aaccoder.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/libavcodec/aaccoder.c b/libavcodec/aaccoder.c
index cd996b24307..aaf70d53729 100644
--- a/libavcodec/aaccoder.c
+++ b/libavcodec/aaccoder.c
@@ -1166,6 +1166,7 @@ static void search_for_ms(AACEncContext *s, ChannelElement *cpe,
if (!cpe->common_window)
return;
for (w = 0; w < sce0->ics.num_windows; w += sce0->ics.group_len[w]) {
+ start = 0;
for (g = 0; g < sce0->ics.num_swb; g++) {
if (!cpe->ch[0].zeroes[w*16+g] && !cpe->ch[1].zeroes[w*16+g]) {
float dist1 = 0.0f, dist2 = 0.0f;
@@ -1175,22 +1176,22 @@ static void search_for_ms(AACEncContext *s, ChannelElement *cpe,
float minthr = FFMIN(band0->threshold, band1->threshold);
float maxthr = FFMAX(band0->threshold, band1->threshold);
for (i = 0; i < sce0->ics.swb_sizes[g]; i++) {
- M[i] = (sce0->pcoeffs[start+w2*128+i]
- + sce1->pcoeffs[start+w2*128+i]) * 0.5;
+ M[i] = (sce0->pcoeffs[start+(w+w2)*128+i]
+ + sce1->pcoeffs[start+(w+w2)*128+i]) * 0.5;
S[i] = M[i]
- - sce1->pcoeffs[start+w2*128+i];
+ - sce1->pcoeffs[start+(w+w2)*128+i];
}
- abs_pow34_v(L34, sce0->coeffs+start+w2*128, sce0->ics.swb_sizes[g]);
- abs_pow34_v(R34, sce1->coeffs+start+w2*128, sce0->ics.swb_sizes[g]);
+ abs_pow34_v(L34, sce0->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]);
+ abs_pow34_v(R34, sce1->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]);
abs_pow34_v(M34, M, sce0->ics.swb_sizes[g]);
abs_pow34_v(S34, S, sce0->ics.swb_sizes[g]);
- dist1 += quantize_band_cost(s, sce0->coeffs + start + w2*128,
+ dist1 += quantize_band_cost(s, sce0->coeffs + start + (w+w2)*128,
L34,
sce0->ics.swb_sizes[g],
sce0->sf_idx[(w+w2)*16+g],
sce0->band_type[(w+w2)*16+g],
lambda / band0->threshold, INFINITY, NULL);
- dist1 += quantize_band_cost(s, sce1->coeffs + start + w2*128,
+ dist1 += quantize_band_cost(s, sce1->coeffs + start + (w+w2)*128,
R34,
sce1->ics.swb_sizes[g],
sce1->sf_idx[(w+w2)*16+g],
--
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