diff options
author | hairball <xhairball@gmail.com> | 2014-02-08 03:21:02 +0000 |
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committer | Tim Angus <tim@ngus.net> | 2014-06-17 17:43:38 +0100 |
commit | 35064811c0ac104acddd7777e00bfd9e054c2db6 (patch) | |
tree | 4063389141542093ecc3de47e3999ed099520621 /src/opus-1.0.2/silk/A2NLSF.c | |
parent | 1778f3fb8cabe7400011c84331018b0ebf6a44b1 (diff) |
Upgrade opus 1.0.2 -> 1.1
Diffstat (limited to 'src/opus-1.0.2/silk/A2NLSF.c')
-rw-r--r-- | src/opus-1.0.2/silk/A2NLSF.c | 252 |
1 files changed, 0 insertions, 252 deletions
diff --git a/src/opus-1.0.2/silk/A2NLSF.c b/src/opus-1.0.2/silk/A2NLSF.c deleted file mode 100644 index 49d5d9d9..00000000 --- a/src/opus-1.0.2/silk/A2NLSF.c +++ /dev/null @@ -1,252 +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 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 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 ); - for( n = dd - 1; n >= 0; n-- ) { - y32 = silk_SMLAWW( p[ n ], y32, x_Q16 ); /* Q16 */ - } - return y32; -} - -static 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 */ - } - } - } -} |