@@ -519,7 +519,7 @@ static inline int APESIGN(int32_t x) {

 static av_always_inline int predictor_update_filter(APEPredictor *p, const int decoded, const int filter, const int delayA, const int delayB, const int adaptA, const int adaptB)

 {

-    int32_t predictionA, predictionB;

+    int32_t predictionA, predictionB, sign;

     p->buf[delayA]     = p->lastA[filter];

     p->buf[adaptA]     = APESIGN(p->buf[delayA]);

@@ -547,32 +547,17 @@ static av_always_inline int predictor_update_filter(APEPredictor *p, const int d

     p->lastA[filter] = decoded + ((predictionA + (predictionB >> 1)) >> 10);

     p->filterA[filter] = p->lastA[filter] + ((p->filterA[filter] * 31) >> 5);

-    if (!decoded) // no need updating filter coefficients

-        return p->filterA[filter];

+    sign = APESIGN(decoded);

+    p->coeffsA[filter][0] += p->buf[adaptA    ] * sign;

+    p->coeffsA[filter][1] += p->buf[adaptA - 1] * sign;

+    p->coeffsA[filter][2] += p->buf[adaptA - 2] * sign;

+    p->coeffsA[filter][3] += p->buf[adaptA - 3] * sign;

+    p->coeffsB[filter][0] += p->buf[adaptB    ] * sign;

+    p->coeffsB[filter][1] += p->buf[adaptB - 1] * sign;

+    p->coeffsB[filter][2] += p->buf[adaptB - 2] * sign;

+    p->coeffsB[filter][3] += p->buf[adaptB - 3] * sign;

+    p->coeffsB[filter][4] += p->buf[adaptB - 4] * sign;

-    if (decoded > 0) {

-        p->coeffsA[filter][0] -= p->buf[adaptA    ];

-        p->coeffsA[filter][1] -= p->buf[adaptA - 1];

-        p->coeffsA[filter][2] -= p->buf[adaptA - 2];

-        p->coeffsA[filter][3] -= p->buf[adaptA - 3];

-

-        p->coeffsB[filter][0] -= p->buf[adaptB    ];

-        p->coeffsB[filter][1] -= p->buf[adaptB - 1];

-        p->coeffsB[filter][2] -= p->buf[adaptB - 2];

-        p->coeffsB[filter][3] -= p->buf[adaptB - 3];

-        p->coeffsB[filter][4] -= p->buf[adaptB - 4];

-    } else {

-        p->coeffsA[filter][0] += p->buf[adaptA    ];

-        p->coeffsA[filter][1] += p->buf[adaptA - 1];

-        p->coeffsA[filter][2] += p->buf[adaptA - 2];

-        p->coeffsA[filter][3] += p->buf[adaptA - 3];

-

-        p->coeffsB[filter][0] += p->buf[adaptB    ];

-        p->coeffsB[filter][1] += p->buf[adaptB - 1];

-        p->coeffsB[filter][2] += p->buf[adaptB - 2];

-        p->coeffsB[filter][3] += p->buf[adaptB - 3];

-        p->coeffsB[filter][4] += p->buf[adaptB - 4];

-    }

     return p->filterA[filter];

 }

@@ -604,7 +589,7 @@ static void predictor_decode_mono(APEContext * ctx, int count)

 {

     APEPredictor *p = &ctx->predictor;

     int32_t *decoded0 = ctx->decoded0;

-    int32_t predictionA, currentA, A;

+    int32_t predictionA, currentA, A, sign;

     currentA = p->lastA[0];

@@ -624,17 +609,11 @@ static void predictor_decode_mono(APEContext * ctx, int count)

         p->buf[YADAPTCOEFFSA]     = APESIGN(p->buf[YDELAYA    ]);

         p->buf[YADAPTCOEFFSA - 1] = APESIGN(p->buf[YDELAYA - 1]);

-        if (A > 0) {

-            p->coeffsA[0][0] -= p->buf[YADAPTCOEFFSA    ];

-            p->coeffsA[0][1] -= p->buf[YADAPTCOEFFSA - 1];

-            p->coeffsA[0][2] -= p->buf[YADAPTCOEFFSA - 2];

-            p->coeffsA[0][3] -= p->buf[YADAPTCOEFFSA - 3];

-        } else if (A < 0) {

-            p->coeffsA[0][0] += p->buf[YADAPTCOEFFSA    ];

-            p->coeffsA[0][1] += p->buf[YADAPTCOEFFSA - 1];

-            p->coeffsA[0][2] += p->buf[YADAPTCOEFFSA - 2];

-            p->coeffsA[0][3] += p->buf[YADAPTCOEFFSA - 3];

-        }

+        sign = APESIGN(A);

+        p->coeffsA[0][0] += p->buf[YADAPTCOEFFSA    ] * sign;

+        p->coeffsA[0][1] += p->buf[YADAPTCOEFFSA - 1] * sign;

+        p->coeffsA[0][2] += p->buf[YADAPTCOEFFSA - 2] * sign;

+        p->coeffsA[0][3] += p->buf[YADAPTCOEFFSA - 3] * sign;

         p->buf++;