michael@0: /***********************************************************************
michael@0: Copyright (c) 2006-2011, Skype Limited. All rights reserved.
michael@0: Redistribution and use in source and binary forms, with or without
michael@0: modification, are permitted provided that the following conditions
michael@0: are met:
michael@0: - Redistributions of source code must retain the above copyright notice,
michael@0: this list of conditions and the following disclaimer.
michael@0: - Redistributions in binary form must reproduce the above copyright
michael@0: notice, this list of conditions and the following disclaimer in the
michael@0: documentation and/or other materials provided with the distribution.
michael@0: - Neither the name of Internet Society, IETF or IETF Trust, nor the
michael@0: names of specific contributors, may be used to endorse or promote
michael@0: products derived from this software without specific prior written
michael@0: permission.
michael@0: THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
michael@0: AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
michael@0: IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
michael@0: ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
michael@0: LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
michael@0: CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
michael@0: SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
michael@0: INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
michael@0: CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
michael@0: ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
michael@0: POSSIBILITY OF SUCH DAMAGE.
michael@0: ***********************************************************************/
michael@0: 
michael@0: #ifdef HAVE_CONFIG_H
michael@0: #include "config.h"
michael@0: #endif
michael@0: 
michael@0: #include "main_FIX.h"
michael@0: 
michael@0: #define QC  10
michael@0: #define QS  14
michael@0: 
michael@0: /* Autocorrelations for a warped frequency axis */
michael@0: void silk_warped_autocorrelation_FIX(
michael@0:           opus_int32                *corr,                                  /* O    Result [order + 1]                                                          */
michael@0:           opus_int                  *scale,                                 /* O    Scaling of the correlation vector                                           */
michael@0:     const opus_int16                *input,                                 /* I    Input data to correlate                                                     */
michael@0:     const opus_int                  warping_Q16,                            /* I    Warping coefficient                                                         */
michael@0:     const opus_int                  length,                                 /* I    Length of input                                                             */
michael@0:     const opus_int                  order                                   /* I    Correlation order (even)                                                    */
michael@0: )
michael@0: {
michael@0:     opus_int   n, i, lsh;
michael@0:     opus_int32 tmp1_QS, tmp2_QS;
michael@0:     opus_int32 state_QS[ MAX_SHAPE_LPC_ORDER + 1 ] = { 0 };
michael@0:     opus_int64 corr_QC[  MAX_SHAPE_LPC_ORDER + 1 ] = { 0 };
michael@0: 
michael@0:     /* Order must be even */
michael@0:     silk_assert( ( order & 1 ) == 0 );
michael@0:     silk_assert( 2 * QS - QC >= 0 );
michael@0: 
michael@0:     /* Loop over samples */
michael@0:     for( n = 0; n < length; n++ ) {
michael@0:         tmp1_QS = silk_LSHIFT32( (opus_int32)input[ n ], QS );
michael@0:         /* Loop over allpass sections */
michael@0:         for( i = 0; i < order; i += 2 ) {
michael@0:             /* Output of allpass section */
michael@0:             tmp2_QS = silk_SMLAWB( state_QS[ i ], state_QS[ i + 1 ] - tmp1_QS, warping_Q16 );
michael@0:             state_QS[ i ]  = tmp1_QS;
michael@0:             corr_QC[  i ] += silk_RSHIFT64( silk_SMULL( tmp1_QS, state_QS[ 0 ] ), 2 * QS - QC );
michael@0:             /* Output of allpass section */
michael@0:             tmp1_QS = silk_SMLAWB( state_QS[ i + 1 ], state_QS[ i + 2 ] - tmp2_QS, warping_Q16 );
michael@0:             state_QS[ i + 1 ]  = tmp2_QS;
michael@0:             corr_QC[  i + 1 ] += silk_RSHIFT64( silk_SMULL( tmp2_QS, state_QS[ 0 ] ), 2 * QS - QC );
michael@0:         }
michael@0:         state_QS[ order ] = tmp1_QS;
michael@0:         corr_QC[  order ] += silk_RSHIFT64( silk_SMULL( tmp1_QS, state_QS[ 0 ] ), 2 * QS - QC );
michael@0:     }
michael@0: 
michael@0:     lsh = silk_CLZ64( corr_QC[ 0 ] ) - 35;
michael@0:     lsh = silk_LIMIT( lsh, -12 - QC, 30 - QC );
michael@0:     *scale = -( QC + lsh );
michael@0:     silk_assert( *scale >= -30 && *scale <= 12 );
michael@0:     if( lsh >= 0 ) {
michael@0:         for( i = 0; i < order + 1; i++ ) {
michael@0:             corr[ i ] = (opus_int32)silk_CHECK_FIT32( silk_LSHIFT64( corr_QC[ i ], lsh ) );
michael@0:         }
michael@0:     } else {
michael@0:         for( i = 0; i < order + 1; i++ ) {
michael@0:             corr[ i ] = (opus_int32)silk_CHECK_FIT32( silk_RSHIFT64( corr_QC[ i ], -lsh ) );
michael@0:         }
michael@0:     }
michael@0:     silk_assert( corr_QC[ 0 ] >= 0 ); /* If breaking, decrease QC*/
michael@0: }