avcodec/adpcm: use av_clip_intp2()

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/adpcm.c

@@ -269,7 +269,7 @@ static inline short adpcm_ima_oki_expand_nibble(ADPCMChannelStatus *c, int nibbl
     if (sign) predictor -= diff;
     else predictor += diff;
 
-    c->predictor = av_clip(predictor, -2048, 2047);
+    c->predictor = av_clip_intp2(predictor, 11);
     c->step_index = step_index;
 
     return c->predictor << 4;

libavcodec/adpcmenc.c

@@ -227,7 +227,7 @@ static inline uint8_t adpcm_ms_compress_sample(ADPCMChannelStatus *c,
         bias = -c->idelta / 2;
 
     nibble = (nibble + bias) / c->idelta;
-    nibble = av_clip(nibble, -8, 7) & 0x0F;
+    nibble = av_clip_intp2(nibble, 3) & 0x0F;
 
     predictor += ((nibble & 0x08) ? (nibble - 0x10) : nibble) * c->idelta;