mirror of
https://github.com/Relintai/pandemonium_engine.git
synced 2024-11-22 17:07:20 +01:00
104 lines
4.7 KiB
C
104 lines
4.7 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 "resampler_private.h"
|
|
#include "stack_alloc.h"
|
|
|
|
#define ORDER_FIR 4
|
|
|
|
/* Downsample by a factor 2/3, low quality */
|
|
void silk_resampler_down2_3(
|
|
opus_int32 *S, /* I/O State vector [ 6 ] */
|
|
opus_int16 *out, /* O Output signal [ floor(2*inLen/3) ] */
|
|
const opus_int16 *in, /* I Input signal [ inLen ] */
|
|
opus_int32 inLen /* I Number of input samples */
|
|
)
|
|
{
|
|
opus_int32 nSamplesIn, counter, res_Q6;
|
|
VARDECL( opus_int32, buf );
|
|
opus_int32 *buf_ptr;
|
|
SAVE_STACK;
|
|
|
|
ALLOC( buf, RESAMPLER_MAX_BATCH_SIZE_IN + ORDER_FIR, opus_int32 );
|
|
|
|
/* Copy buffered samples to start of buffer */
|
|
silk_memcpy( buf, S, ORDER_FIR * sizeof( opus_int32 ) );
|
|
|
|
/* Iterate over blocks of frameSizeIn input samples */
|
|
while( 1 ) {
|
|
nSamplesIn = silk_min( inLen, RESAMPLER_MAX_BATCH_SIZE_IN );
|
|
|
|
/* Second-order AR filter (output in Q8) */
|
|
silk_resampler_private_AR2( &S[ ORDER_FIR ], &buf[ ORDER_FIR ], in,
|
|
silk_Resampler_2_3_COEFS_LQ, nSamplesIn );
|
|
|
|
/* Interpolate filtered signal */
|
|
buf_ptr = buf;
|
|
counter = nSamplesIn;
|
|
while( counter > 2 ) {
|
|
/* Inner product */
|
|
res_Q6 = silk_SMULWB( buf_ptr[ 0 ], silk_Resampler_2_3_COEFS_LQ[ 2 ] );
|
|
res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 1 ], silk_Resampler_2_3_COEFS_LQ[ 3 ] );
|
|
res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 2 ], silk_Resampler_2_3_COEFS_LQ[ 5 ] );
|
|
res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 3 ], silk_Resampler_2_3_COEFS_LQ[ 4 ] );
|
|
|
|
/* Scale down, saturate and store in output array */
|
|
*out++ = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( res_Q6, 6 ) );
|
|
|
|
res_Q6 = silk_SMULWB( buf_ptr[ 1 ], silk_Resampler_2_3_COEFS_LQ[ 4 ] );
|
|
res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 2 ], silk_Resampler_2_3_COEFS_LQ[ 5 ] );
|
|
res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 3 ], silk_Resampler_2_3_COEFS_LQ[ 3 ] );
|
|
res_Q6 = silk_SMLAWB( res_Q6, buf_ptr[ 4 ], silk_Resampler_2_3_COEFS_LQ[ 2 ] );
|
|
|
|
/* Scale down, saturate and store in output array */
|
|
*out++ = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( res_Q6, 6 ) );
|
|
|
|
buf_ptr += 3;
|
|
counter -= 3;
|
|
}
|
|
|
|
in += nSamplesIn;
|
|
inLen -= nSamplesIn;
|
|
|
|
if( inLen > 0 ) {
|
|
/* More iterations to do; copy last part of filtered signal to beginning of buffer */
|
|
silk_memcpy( buf, &buf[ nSamplesIn ], ORDER_FIR * sizeof( opus_int32 ) );
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Copy last part of filtered signal to the state for the next call */
|
|
silk_memcpy( S, &buf[ nSamplesIn ], ORDER_FIR * sizeof( opus_int32 ) );
|
|
RESTORE_STACK;
|
|
}
|