ref: c75fa187fc410d777867807bc1a0f934a0e085dc
parent: 07ca5cc776a04cfbf2fd6423ca6eb78c49eb50a2
author: Jean-Marc Valin <jmvalin@jmvalin.ca>
date: Mon Jul 25 08:08:08 EDT 2016
Disabling the use of celt_fir() in silk_LPC_analysis_filter() by default
--- a/silk/LPC_analysis_filter.c
+++ b/silk/LPC_analysis_filter.c
@@ -39,6 +39,13 @@
/* first d output samples are set to zero */
/*******************************************/
+/* OPT: Using celt_fir() for this function should be faster, but it may cause
+ integer overflows in intermediate values (not final results), which the
+ current implementation silences by casting to unsigned. Enabling
+ this should be safe in pretty much all cases, even though it is not technically
+ C89-compliant. */
+#define USE_CELT_FIR 0
+
void silk_LPC_analysis_filter(
opus_int16 *out, /* O Output signal */
const opus_int16 *in, /* I Input signal */
@@ -49,7 +56,7 @@
)
{opus_int j;
-#ifdef FIXED_POINT
+#if USE_CELT_FIR
opus_int16 mem[SILK_MAX_ORDER_LPC];
opus_int16 num[SILK_MAX_ORDER_LPC];
#else
@@ -62,7 +69,7 @@
silk_assert( (d & 1) == 0 );
silk_assert( d <= len );
-#ifdef FIXED_POINT
+#if USE_CELT_FIR
silk_assert( d <= SILK_MAX_ORDER_LPC );
for ( j = 0; j < d; j++ ) {num[ j ] = -B[ j ];