[FFmpeg-devel] [PATCH] avcodec/tak: reset filter buffers

[James Almer]

Zeroing them allows us to use scalarproduct_int16 even if the length of vectors is not multiple of 16.

Signed-off-by: James Almer <jamrial at gmail.com>
---
 libavcodec/takdec.c | 28 +++++-----------------------
 1 file changed, 5 insertions(+), 23 deletions(-)

diff --git a/libavcodec/takdec.c b/libavcodec/takdec.c
index 2f0155d..0f808e0 100644
--- a/libavcodec/takdec.c
+++ b/libavcodec/takdec.c
@@ -451,6 +451,7 @@ static int decode_subframe(TAKDecContext *s, int32_t *decoded,
         s->filter[j] = x - ((tfilter[i] + y) >> (15 - filter_quant));
         s->filter[i] = x - ((tfilter[j] + y) >> (15 - filter_quant));
     }
+    memset(s->filter + filter_order, 0, sizeof(s->filter) - filter_order*2);
 
     if ((ret = decode_residues(s, &decoded[filter_order],
                                subframe_size - filter_order)) < 0)
@@ -467,15 +468,8 @@ static int decode_subframe(TAKDecContext *s, int32_t *decoded,
         for (i = 0; i < tmp; i++) {
             int v = 1 << (filter_quant - 1);
 
-            if (filter_order & -16)
-                v += s->adsp.scalarproduct_int16(&s->residues[i], s->filter,
-                                                 filter_order & -16);
-            for (j = filter_order & -16; j < filter_order; j += 4) {
-                v += s->residues[i + j + 3] * s->filter[j + 3] +
-                     s->residues[i + j + 2] * s->filter[j + 2] +
-                     s->residues[i + j + 1] * s->filter[j + 1] +
-                     s->residues[i + j    ] * s->filter[j    ];
-            }
+            v += s->adsp.scalarproduct_int16(&s->residues[i], s->filter,
+                                             FFALIGN(filter_order, 16));
             v = (av_clip(v >> filter_quant, -8192, 8191) << dshift) - *decoded;
             *decoded++ = v;
             s->residues[filter_order + i] = v >> dshift;
@@ -601,6 +595,7 @@ static int decorrelate(TAKDecContext *s, int c1, int c2, int length)
                 code_size = 14 - get_bits(gb, 3);
             s->filter[i] = get_sbits(gb, code_size);
         }
+        memset(s->filter + filter_order, 0, sizeof(s->filter) - filter_order*2);
 
         order_half = filter_order / 2;
         length2    = length - (filter_order - 1);
@@ -638,20 +633,7 @@ static int decorrelate(TAKDecContext *s, int c1, int c2, int length)
             for (i = 0; i < tmp; i++) {
                 int v = 1 << 9;
 
-                if (filter_order == 16) {
-                    v += s->adsp.scalarproduct_int16(&s->residues[i], s->filter,
-                                                     filter_order);
-                } else {
-                    v += s->residues[i + 7] * s->filter[7] +
-                         s->residues[i + 6] * s->filter[6] +
-                         s->residues[i + 5] * s->filter[5] +
-                         s->residues[i + 4] * s->filter[4] +
-                         s->residues[i + 3] * s->filter[3] +
-                         s->residues[i + 2] * s->filter[2] +
-                         s->residues[i + 1] * s->filter[1] +
-                         s->residues[i    ] * s->filter[0];
-                }
-
+                v += s->adsp.scalarproduct_int16(&s->residues[i], s->filter, 16);
                 v = (av_clip(v >> 10, -8192, 8191) << dshift) - *p1;
                 *p1++ = v;
             }
-- 
2.3.0