зеркало из https://github.com/mozilla/gecko-dev.git
142 строки
6.0 KiB
C
142 строки
6.0 KiB
C
/***********************************************************************
|
|
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.
|
|
***********************************************************************/
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
#include "config.h"
|
|
#endif
|
|
|
|
#include "SigProc_FIX.h"
|
|
#include "define.h"
|
|
|
|
#define QA 24
|
|
#define A_LIMIT SILK_FIX_CONST( 0.99975, QA )
|
|
|
|
#define MUL32_FRAC_Q(a32, b32, Q) ((opus_int32)(silk_RSHIFT_ROUND64(silk_SMULL(a32, b32), Q)))
|
|
|
|
/* Compute inverse of LPC prediction gain, and */
|
|
/* test if LPC coefficients are stable (all poles within unit circle) */
|
|
static opus_int32 LPC_inverse_pred_gain_QA_c( /* O Returns inverse prediction gain in energy domain, Q30 */
|
|
opus_int32 A_QA[ SILK_MAX_ORDER_LPC ], /* I Prediction coefficients */
|
|
const opus_int order /* I Prediction order */
|
|
)
|
|
{
|
|
opus_int k, n, mult2Q;
|
|
opus_int32 invGain_Q30, rc_Q31, rc_mult1_Q30, rc_mult2, tmp1, tmp2;
|
|
|
|
invGain_Q30 = SILK_FIX_CONST( 1, 30 );
|
|
for( k = order - 1; k > 0; k-- ) {
|
|
/* Check for stability */
|
|
if( ( A_QA[ k ] > A_LIMIT ) || ( A_QA[ k ] < -A_LIMIT ) ) {
|
|
return 0;
|
|
}
|
|
|
|
/* Set RC equal to negated AR coef */
|
|
rc_Q31 = -silk_LSHIFT( A_QA[ k ], 31 - QA );
|
|
|
|
/* rc_mult1_Q30 range: [ 1 : 2^30 ] */
|
|
rc_mult1_Q30 = silk_SUB32( SILK_FIX_CONST( 1, 30 ), silk_SMMUL( rc_Q31, rc_Q31 ) );
|
|
silk_assert( rc_mult1_Q30 > ( 1 << 15 ) ); /* reduce A_LIMIT if fails */
|
|
silk_assert( rc_mult1_Q30 <= ( 1 << 30 ) );
|
|
|
|
/* Update inverse gain */
|
|
/* invGain_Q30 range: [ 0 : 2^30 ] */
|
|
invGain_Q30 = silk_LSHIFT( silk_SMMUL( invGain_Q30, rc_mult1_Q30 ), 2 );
|
|
silk_assert( invGain_Q30 >= 0 );
|
|
silk_assert( invGain_Q30 <= ( 1 << 30 ) );
|
|
if( invGain_Q30 < SILK_FIX_CONST( 1.0f / MAX_PREDICTION_POWER_GAIN, 30 ) ) {
|
|
return 0;
|
|
}
|
|
|
|
/* rc_mult2 range: [ 2^30 : silk_int32_MAX ] */
|
|
mult2Q = 32 - silk_CLZ32( silk_abs( rc_mult1_Q30 ) );
|
|
rc_mult2 = silk_INVERSE32_varQ( rc_mult1_Q30, mult2Q + 30 );
|
|
|
|
/* Update AR coefficient */
|
|
for( n = 0; n < (k + 1) >> 1; n++ ) {
|
|
opus_int64 tmp64;
|
|
tmp1 = A_QA[ n ];
|
|
tmp2 = A_QA[ k - n - 1 ];
|
|
tmp64 = silk_RSHIFT_ROUND64( silk_SMULL( silk_SUB_SAT32(tmp1,
|
|
MUL32_FRAC_Q( tmp2, rc_Q31, 31 ) ), rc_mult2 ), mult2Q);
|
|
if( tmp64 > silk_int32_MAX || tmp64 < silk_int32_MIN ) {
|
|
return 0;
|
|
}
|
|
A_QA[ n ] = ( opus_int32 )tmp64;
|
|
tmp64 = silk_RSHIFT_ROUND64( silk_SMULL( silk_SUB_SAT32(tmp2,
|
|
MUL32_FRAC_Q( tmp1, rc_Q31, 31 ) ), rc_mult2), mult2Q);
|
|
if( tmp64 > silk_int32_MAX || tmp64 < silk_int32_MIN ) {
|
|
return 0;
|
|
}
|
|
A_QA[ k - n - 1 ] = ( opus_int32 )tmp64;
|
|
}
|
|
}
|
|
|
|
/* Check for stability */
|
|
if( ( A_QA[ k ] > A_LIMIT ) || ( A_QA[ k ] < -A_LIMIT ) ) {
|
|
return 0;
|
|
}
|
|
|
|
/* Set RC equal to negated AR coef */
|
|
rc_Q31 = -silk_LSHIFT( A_QA[ 0 ], 31 - QA );
|
|
|
|
/* Range: [ 1 : 2^30 ] */
|
|
rc_mult1_Q30 = silk_SUB32( SILK_FIX_CONST( 1, 30 ), silk_SMMUL( rc_Q31, rc_Q31 ) );
|
|
|
|
/* Update inverse gain */
|
|
/* Range: [ 0 : 2^30 ] */
|
|
invGain_Q30 = silk_LSHIFT( silk_SMMUL( invGain_Q30, rc_mult1_Q30 ), 2 );
|
|
silk_assert( invGain_Q30 >= 0 );
|
|
silk_assert( invGain_Q30 <= ( 1 << 30 ) );
|
|
if( invGain_Q30 < SILK_FIX_CONST( 1.0f / MAX_PREDICTION_POWER_GAIN, 30 ) ) {
|
|
return 0;
|
|
}
|
|
|
|
return invGain_Q30;
|
|
}
|
|
|
|
/* For input in Q12 domain */
|
|
opus_int32 silk_LPC_inverse_pred_gain_c( /* O Returns inverse prediction gain in energy domain, Q30 */
|
|
const opus_int16 *A_Q12, /* I Prediction coefficients, Q12 [order] */
|
|
const opus_int order /* I Prediction order */
|
|
)
|
|
{
|
|
opus_int k;
|
|
opus_int32 Atmp_QA[ SILK_MAX_ORDER_LPC ];
|
|
opus_int32 DC_resp = 0;
|
|
|
|
/* Increase Q domain of the AR coefficients */
|
|
for( k = 0; k < order; k++ ) {
|
|
DC_resp += (opus_int32)A_Q12[ k ];
|
|
Atmp_QA[ k ] = silk_LSHIFT32( (opus_int32)A_Q12[ k ], QA - 12 );
|
|
}
|
|
/* If the DC is unstable, we don't even need to do the full calculations */
|
|
if( DC_resp >= 4096 ) {
|
|
return 0;
|
|
}
|
|
return LPC_inverse_pred_gain_QA_c( Atmp_QA, order );
|
|
}
|