summaryrefslogtreecommitdiff
path: root/thirdparty/opus/silk/A2NLSF.c
diff options
context:
space:
mode:
Diffstat (limited to 'thirdparty/opus/silk/A2NLSF.c')
-rw-r--r--thirdparty/opus/silk/A2NLSF.c267
1 files changed, 0 insertions, 267 deletions
diff --git a/thirdparty/opus/silk/A2NLSF.c b/thirdparty/opus/silk/A2NLSF.c
deleted file mode 100644
index b6e9e5ffcc..0000000000
--- a/thirdparty/opus/silk/A2NLSF.c
+++ /dev/null
@@ -1,267 +0,0 @@
-/***********************************************************************
-Copyright (c) 2006-2011, Skype Limited. All rights reserved.
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions
-are met:
-- Redistributions of source code must retain the above copyright notice,
-this list of conditions and the following disclaimer.
-- Redistributions in binary form must reproduce the above copyright
-notice, this list of conditions and the following disclaimer in the
-documentation and/or other materials provided with the distribution.
-- Neither the name of Internet Society, IETF or IETF Trust, nor the
-names of specific contributors, may be used to endorse or promote
-products derived from this software without specific prior written
-permission.
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
-LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
-CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
-SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
-INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
-CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
-ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
-POSSIBILITY OF SUCH DAMAGE.
-***********************************************************************/
-
-/* Conversion between prediction filter coefficients and NLSFs */
-/* Requires the order to be an even number */
-/* A piecewise linear approximation maps LSF <-> cos(LSF) */
-/* Therefore the result is not accurate NLSFs, but the two */
-/* functions are accurate inverses of each other */
-
-#ifdef HAVE_CONFIG_H
-#include "config.h"
-#endif
-
-#include "SigProc_FIX.h"
-#include "tables.h"
-
-/* Number of binary divisions, when not in low complexity mode */
-#define BIN_DIV_STEPS_A2NLSF_FIX 3 /* must be no higher than 16 - log2( LSF_COS_TAB_SZ_FIX ) */
-#define MAX_ITERATIONS_A2NLSF_FIX 30
-
-/* Helper function for A2NLSF(..) */
-/* Transforms polynomials from cos(n*f) to cos(f)^n */
-static OPUS_INLINE void silk_A2NLSF_trans_poly(
- opus_int32 *p, /* I/O Polynomial */
- const opus_int dd /* I Polynomial order (= filter order / 2 ) */
-)
-{
- opus_int k, n;
-
- for( k = 2; k <= dd; k++ ) {
- for( n = dd; n > k; n-- ) {
- p[ n - 2 ] -= p[ n ];
- }
- p[ k - 2 ] -= silk_LSHIFT( p[ k ], 1 );
- }
-}
-/* Helper function for A2NLSF(..) */
-/* Polynomial evaluation */
-static OPUS_INLINE opus_int32 silk_A2NLSF_eval_poly( /* return the polynomial evaluation, in Q16 */
- opus_int32 *p, /* I Polynomial, Q16 */
- const opus_int32 x, /* I Evaluation point, Q12 */
- const opus_int dd /* I Order */
-)
-{
- opus_int n;
- opus_int32 x_Q16, y32;
-
- y32 = p[ dd ]; /* Q16 */
- x_Q16 = silk_LSHIFT( x, 4 );
-
- if ( opus_likely( 8 == dd ) )
- {
- y32 = silk_SMLAWW( p[ 7 ], y32, x_Q16 );
- y32 = silk_SMLAWW( p[ 6 ], y32, x_Q16 );
- y32 = silk_SMLAWW( p[ 5 ], y32, x_Q16 );
- y32 = silk_SMLAWW( p[ 4 ], y32, x_Q16 );
- y32 = silk_SMLAWW( p[ 3 ], y32, x_Q16 );
- y32 = silk_SMLAWW( p[ 2 ], y32, x_Q16 );
- y32 = silk_SMLAWW( p[ 1 ], y32, x_Q16 );
- y32 = silk_SMLAWW( p[ 0 ], y32, x_Q16 );
- }
- else
- {
- for( n = dd - 1; n >= 0; n-- ) {
- y32 = silk_SMLAWW( p[ n ], y32, x_Q16 ); /* Q16 */
- }
- }
- return y32;
-}
-
-static OPUS_INLINE void silk_A2NLSF_init(
- const opus_int32 *a_Q16,
- opus_int32 *P,
- opus_int32 *Q,
- const opus_int dd
-)
-{
- opus_int k;
-
- /* Convert filter coefs to even and odd polynomials */
- P[dd] = silk_LSHIFT( 1, 16 );
- Q[dd] = silk_LSHIFT( 1, 16 );
- for( k = 0; k < dd; k++ ) {
- P[ k ] = -a_Q16[ dd - k - 1 ] - a_Q16[ dd + k ]; /* Q16 */
- Q[ k ] = -a_Q16[ dd - k - 1 ] + a_Q16[ dd + k ]; /* Q16 */
- }
-
- /* Divide out zeros as we have that for even filter orders, */
- /* z = 1 is always a root in Q, and */
- /* z = -1 is always a root in P */
- for( k = dd; k > 0; k-- ) {
- P[ k - 1 ] -= P[ k ];
- Q[ k - 1 ] += Q[ k ];
- }
-
- /* Transform polynomials from cos(n*f) to cos(f)^n */
- silk_A2NLSF_trans_poly( P, dd );
- silk_A2NLSF_trans_poly( Q, dd );
-}
-
-/* Compute Normalized Line Spectral Frequencies (NLSFs) from whitening filter coefficients */
-/* If not all roots are found, the a_Q16 coefficients are bandwidth expanded until convergence. */
-void silk_A2NLSF(
- opus_int16 *NLSF, /* O Normalized Line Spectral Frequencies in Q15 (0..2^15-1) [d] */
- opus_int32 *a_Q16, /* I/O Monic whitening filter coefficients in Q16 [d] */
- const opus_int d /* I Filter order (must be even) */
-)
-{
- opus_int i, k, m, dd, root_ix, ffrac;
- opus_int32 xlo, xhi, xmid;
- opus_int32 ylo, yhi, ymid, thr;
- opus_int32 nom, den;
- opus_int32 P[ SILK_MAX_ORDER_LPC / 2 + 1 ];
- opus_int32 Q[ SILK_MAX_ORDER_LPC / 2 + 1 ];
- opus_int32 *PQ[ 2 ];
- opus_int32 *p;
-
- /* Store pointers to array */
- PQ[ 0 ] = P;
- PQ[ 1 ] = Q;
-
- dd = silk_RSHIFT( d, 1 );
-
- silk_A2NLSF_init( a_Q16, P, Q, dd );
-
- /* Find roots, alternating between P and Q */
- p = P; /* Pointer to polynomial */
-
- xlo = silk_LSFCosTab_FIX_Q12[ 0 ]; /* Q12*/
- ylo = silk_A2NLSF_eval_poly( p, xlo, dd );
-
- if( ylo < 0 ) {
- /* Set the first NLSF to zero and move on to the next */
- NLSF[ 0 ] = 0;
- p = Q; /* Pointer to polynomial */
- ylo = silk_A2NLSF_eval_poly( p, xlo, dd );
- root_ix = 1; /* Index of current root */
- } else {
- root_ix = 0; /* Index of current root */
- }
- k = 1; /* Loop counter */
- i = 0; /* Counter for bandwidth expansions applied */
- thr = 0;
- while( 1 ) {
- /* Evaluate polynomial */
- xhi = silk_LSFCosTab_FIX_Q12[ k ]; /* Q12 */
- yhi = silk_A2NLSF_eval_poly( p, xhi, dd );
-
- /* Detect zero crossing */
- if( ( ylo <= 0 && yhi >= thr ) || ( ylo >= 0 && yhi <= -thr ) ) {
- if( yhi == 0 ) {
- /* If the root lies exactly at the end of the current */
- /* interval, look for the next root in the next interval */
- thr = 1;
- } else {
- thr = 0;
- }
- /* Binary division */
- ffrac = -256;
- for( m = 0; m < BIN_DIV_STEPS_A2NLSF_FIX; m++ ) {
- /* Evaluate polynomial */
- xmid = silk_RSHIFT_ROUND( xlo + xhi, 1 );
- ymid = silk_A2NLSF_eval_poly( p, xmid, dd );
-
- /* Detect zero crossing */
- if( ( ylo <= 0 && ymid >= 0 ) || ( ylo >= 0 && ymid <= 0 ) ) {
- /* Reduce frequency */
- xhi = xmid;
- yhi = ymid;
- } else {
- /* Increase frequency */
- xlo = xmid;
- ylo = ymid;
- ffrac = silk_ADD_RSHIFT( ffrac, 128, m );
- }
- }
-
- /* Interpolate */
- if( silk_abs( ylo ) < 65536 ) {
- /* Avoid dividing by zero */
- den = ylo - yhi;
- nom = silk_LSHIFT( ylo, 8 - BIN_DIV_STEPS_A2NLSF_FIX ) + silk_RSHIFT( den, 1 );
- if( den != 0 ) {
- ffrac += silk_DIV32( nom, den );
- }
- } else {
- /* No risk of dividing by zero because abs(ylo - yhi) >= abs(ylo) >= 65536 */
- ffrac += silk_DIV32( ylo, silk_RSHIFT( ylo - yhi, 8 - BIN_DIV_STEPS_A2NLSF_FIX ) );
- }
- NLSF[ root_ix ] = (opus_int16)silk_min_32( silk_LSHIFT( (opus_int32)k, 8 ) + ffrac, silk_int16_MAX );
-
- silk_assert( NLSF[ root_ix ] >= 0 );
-
- root_ix++; /* Next root */
- if( root_ix >= d ) {
- /* Found all roots */
- break;
- }
- /* Alternate pointer to polynomial */
- p = PQ[ root_ix & 1 ];
-
- /* Evaluate polynomial */
- xlo = silk_LSFCosTab_FIX_Q12[ k - 1 ]; /* Q12*/
- ylo = silk_LSHIFT( 1 - ( root_ix & 2 ), 12 );
- } else {
- /* Increment loop counter */
- k++;
- xlo = xhi;
- ylo = yhi;
- thr = 0;
-
- if( k > LSF_COS_TAB_SZ_FIX ) {
- i++;
- if( i > MAX_ITERATIONS_A2NLSF_FIX ) {
- /* Set NLSFs to white spectrum and exit */
- NLSF[ 0 ] = (opus_int16)silk_DIV32_16( 1 << 15, d + 1 );
- for( k = 1; k < d; k++ ) {
- NLSF[ k ] = (opus_int16)silk_SMULBB( k + 1, NLSF[ 0 ] );
- }
- return;
- }
-
- /* Error: Apply progressively more bandwidth expansion and run again */
- silk_bwexpander_32( a_Q16, d, 65536 - silk_SMULBB( 10 + i, i ) ); /* 10_Q16 = 0.00015*/
-
- silk_A2NLSF_init( a_Q16, P, Q, dd );
- p = P; /* Pointer to polynomial */
- xlo = silk_LSFCosTab_FIX_Q12[ 0 ]; /* Q12*/
- ylo = silk_A2NLSF_eval_poly( p, xlo, dd );
- if( ylo < 0 ) {
- /* Set the first NLSF to zero and move on to the next */
- NLSF[ 0 ] = 0;
- p = Q; /* Pointer to polynomial */
- ylo = silk_A2NLSF_eval_poly( p, xlo, dd );
- root_ix = 1; /* Index of current root */
- } else {
- root_ix = 0; /* Index of current root */
- }
- k = 1; /* Reset loop counter */
- }
- }
- }
-}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-19 23:47:40 +0000