shithub: opus

Download patch

ref: b1fe4f60e6366bb100515150073d07397047e8a4
parent: d74c851febda06d0cc783adc8dded6c971b7d556
author: Jean-Marc Valin <[email protected]>
date: Wed Sep 29 14:05:20 EDT 2010 

Fixes a fixed-point overflow on 16-bit architectures


--- a/libcelt/quant_bands.c
+++ b/libcelt/quant_bands.c
@@ -287,7 +287,7 @@
             q2 = 0;
          ec_enc_bits(enc, q2, fine_quant[i]);
 #ifdef FIXED_POINT
-         offset = SUB16(SHR16(SHL16(q2,DB_SHIFT)+QCONST16(.5,DB_SHIFT),fine_quant[i]),QCONST16(.5f,DB_SHIFT));
+         offset = SUB16(SHR32(SHL32(EXTEND32(q2),DB_SHIFT)+QCONST16(.5,DB_SHIFT),fine_quant[i]),QCONST16(.5f,DB_SHIFT));
 #else
          offset = (q2+.5f)*(1<<(14-fine_quant[i]))*(1.f/16384) - .5f;
 #endif
@@ -377,7 +377,7 @@
          celt_word16 offset;
          q2 = ec_dec_bits(dec, fine_quant[i]);
 #ifdef FIXED_POINT
-         offset = SUB16(SHR16(SHL16(q2,DB_SHIFT)+QCONST16(.5,DB_SHIFT),fine_quant[i]),QCONST16(.5f,DB_SHIFT));
+         offset = SUB16(SHR32(SHL32(EXTEND32(q2),DB_SHIFT)+QCONST16(.5,DB_SHIFT),fine_quant[i]),QCONST16(.5f,DB_SHIFT));
 #else
          offset = (q2+.5f)*(1<<(14-fine_quant[i]))*(1.f/16384) - .5f;
 #endif