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freeswitch/libs/silk/src/SKP_Silk_resample_2_3_coarsest.c
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Brian West 5bb9d2062e bring the code up to the release tarball 
git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@17026 d0543943-73ff-0310-b7d9-9358b9ac24b2
2010-03-17 16:16:27 +00:00

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/***********************************************************************
Copyright (c) 2006-2010, Skype Limited. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, (subject to the limitations in the disclaimer below)
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 Skype Limited, nor the names of specific
contributors, may be used to endorse or promote products derived from
this software without specific prior written permission.
NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE GRANTED
BY THIS LICENSE. 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.
***********************************************************************/
/* *
* File Name: SKP_Silk_resample_2_3_coarsest.c *
* *
* Description: Linear phase FIR polyphase implementation of resampling *
* *
* Copyright 2009 (c), Skype Limited *
* All rights reserved. *
* *
* Date: 090423 *
* */
#include "SKP_Silk_SigProc_FIX.h"
#include "SKP_Silk_resample_rom.h"
/* Resamples input data with a factor 2/3 */
void SKP_Silk_resample_2_3_coarsest(
SKP_int16 *out, /* O: Output signal */
SKP_int16 *S, /* I/O: Resampler state [ SigProc_Resample_2_3_coarsest_NUM_FIR_COEFS - 1 ] */
const SKP_int16 *in, /* I: Input signal */
const SKP_int frameLenIn, /* I: Number of input samples */
SKP_int16 *scratch /* I: Scratch memory [ frameLenIn + SigProc_Resample_2_3_coarsest_NUM_FIR_COEFS - 1 ] */
)
{
SKP_int32 n, ind, interpol_ind, tmp, index_Q16;
SKP_int16 *in_ptr;
SKP_int frameLenOut;
const SKP_int16 *interpol_ptr;
#if ( EMBEDDED_ARM>=6 ) && defined (__GNUC__)
SKP_int32 in_val, interpol_val;
#endif
/* Copy buffered samples to start of scratch */
SKP_memcpy( scratch, S, ( SigProc_Resample_2_3_coarsest_NUM_FIR_COEFS - 1 ) * sizeof( SKP_int16 ) );
/* Then append by the input signal */
SKP_memcpy( &scratch[ SigProc_Resample_2_3_coarsest_NUM_FIR_COEFS - 1 ], in, frameLenIn * sizeof( SKP_int16 ) );
frameLenOut = SKP_SMULWB( SKP_LSHIFT( (SKP_int32)frameLenIn, 1 ), 21846 ); // 21846_Q15 = (2/3)_Q0 rounded _up_
index_Q16 = 0;
SKP_assert( frameLenIn == ( ( frameLenOut * 3 ) / 2 ) );
/* Interpolate */
for( n = frameLenOut; n > 0; n-- ) {
/* Integer part */
ind = SKP_RSHIFT( index_Q16, 16 );
/* Pointer to buffered input */
in_ptr = scratch + ind;
/* Fractional part */
interpol_ind = ( SKP_SMULWB( index_Q16, SigProc_Resample_2_3_coarsest_NUM_INTERPOLATORS ) &
( SigProc_Resample_2_3_coarsest_NUM_INTERPOLATORS - 1 ) );
/* Pointer to FIR taps */
interpol_ptr = SigProc_Resample_2_3_coarsest_INTERPOL[ interpol_ind ];
/* Interpolate: Hardcoded for 10 FIR taps */
#if ( EMBEDDED_ARM>=6 ) && defined (__GNUC__) /*It doesn't improve efficiency on iphone.*/
/*tmp = SKP_SMUAD( *((SKP_int32 *)interpol_ptr)++, *((SKP_int32 *)in_ptr)++);
tmp = SKP_SMLAD( tmp, *((SKP_int32 *)interpol_ptr)++, *((SKP_int32 *)in_ptr)++);
tmp = SKP_SMLAD( tmp, *((SKP_int32 *)interpol_ptr), *((SKP_int32 *)in_ptr) );*/
__asm__ __volatile__ ( "ldr %1, [%3], #4 \n\t"
"ldr %2, [%4], #4 \n\t"
"smuad %0, %1, %2 \n\t"
"ldr %1, [%3], #4 \n\t"
"ldr %2, [%4], #4 \n\t"
"smlad %0, %1, %2, %0\n\t"
"ldr %1, [%3], #4 \n\t"
"ldr %2, [%4], #4 \n\t"
"smlad %0, %1, %2, %0\n\t"
"ldr %1, [%3], #4 \n\t"
"ldr %2, [%4], #4 \n\t"
"smlad %0, %1, %2, %0\n\t"
"ldr %1, [%3] \n\t"
"ldr %2, [%4] \n\t"
"smlad %0, %1, %2, %0\n\t"
: "=r" (tmp), "=r" (interpol_val), "=r" (in_val), "=r" (interpol_ptr), "=r" (in_ptr)
: "3" (interpol_ptr), "4" (in_ptr));
#else
SKP_assert( SigProc_Resample_2_3_coarsest_NUM_FIR_COEFS == 10 );
tmp = SKP_SMULBB( interpol_ptr[ 0 ], in_ptr[ 0 ] );
tmp = SKP_SMLABB( tmp, interpol_ptr[ 1 ], in_ptr[ 1 ] );
tmp = SKP_SMLABB( tmp, interpol_ptr[ 2 ], in_ptr[ 2 ] );
tmp = SKP_SMLABB( tmp, interpol_ptr[ 3 ], in_ptr[ 3 ] );
tmp = SKP_SMLABB( tmp, interpol_ptr[ 4 ], in_ptr[ 4 ] );
tmp = SKP_SMLABB( tmp, interpol_ptr[ 5 ], in_ptr[ 5 ] );
tmp = SKP_SMLABB( tmp, interpol_ptr[ 6 ], in_ptr[ 6 ] );
tmp = SKP_SMLABB( tmp, interpol_ptr[ 7 ], in_ptr[ 7 ] );
tmp = SKP_SMLABB( tmp, interpol_ptr[ 8 ], in_ptr[ 8 ] );
tmp = SKP_SMLABB( tmp, interpol_ptr[ 9 ], in_ptr[ 9 ] );
#endif
/* Round, saturate and store to output array */
*out++ = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( tmp, 15 ) );
/* Update index */
index_Q16 += ( ( 1 << 16 ) + ( 1 << 15 ) ); // (3/2)_Q0;
}
/* Move last part of input signal to the sample buffer to prepare for the next call */
SKP_memcpy( S, &in[ frameLenIn - ( SigProc_Resample_2_3_coarsest_NUM_FIR_COEFS - 1 ) ],
( SigProc_Resample_2_3_coarsest_NUM_FIR_COEFS - 1 ) * sizeof( SKP_int16 ) );
}
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