diff options
Diffstat (limited to 'libs/libopus/silk/LPC_analysis_filter.c')
| -rw-r--r-- | libs/libopus/silk/LPC_analysis_filter.c | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/libs/libopus/silk/LPC_analysis_filter.c b/libs/libopus/silk/LPC_analysis_filter.c index 20906673f..d34b5eb70 100644 --- a/libs/libopus/silk/LPC_analysis_filter.c +++ b/libs/libopus/silk/LPC_analysis_filter.c @@ -39,6 +39,13 @@ POSSIBILITY OF SUCH DAMAGE. /* 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 */ @@ -49,8 +56,7 @@ void silk_LPC_analysis_filter( ) { opus_int j; -#ifdef FIXED_POINT - opus_int16 mem[SILK_MAX_ORDER_LPC]; +#if defined(FIXED_POINT) && USE_CELT_FIR opus_int16 num[SILK_MAX_ORDER_LPC]; #else int ix; @@ -58,19 +64,16 @@ void silk_LPC_analysis_filter( const opus_int16 *in_ptr; #endif - silk_assert( d >= 6 ); - silk_assert( (d & 1) == 0 ); - silk_assert( d <= len ); + celt_assert( d >= 6 ); + celt_assert( (d & 1) == 0 ); + celt_assert( d <= len ); -#ifdef FIXED_POINT - silk_assert( d <= SILK_MAX_ORDER_LPC ); +#if defined(FIXED_POINT) && USE_CELT_FIR + celt_assert( d <= SILK_MAX_ORDER_LPC ); for ( j = 0; j < d; j++ ) { num[ j ] = -B[ j ]; } - for (j=0;j<d;j++) { - mem[ j ] = in[ d - j - 1 ]; - } - celt_fir( in + d, num, out + d, len - d, d, mem, arch ); + celt_fir( in + d, num, out + d, len - d, d, arch ); for ( j = 0; j < d; j++ ) { out[ j ] = 0; } |