ref: ba9a38b8266fd42f2bc327b7e6e60866812cbb92
dir: /src/libflac/fixed.c/
/* libFLAC - Free Lossless Audio Codec library
* Copyright (C) 2000-2009 Josh Coalson
* Copyright (C) 2011-2016 Xiph.Org Foundation
*
* 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 the Xiph.org Foundation nor the names of its
* 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 FOUNDATION 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.
*/
#include <math.h>
#include <string.h>
#include "share/compat.h"
#include "private/bitmath.h"
#include "private/fixed.h"
#include "private/macros.h"
#ifdef local_abs
#undef local_abs
#endif
#define local_abs(x) ((uint32_t)((x)<0? -(x) : (x)))
void FLAC__fixed_compute_residual(const FLAC__int32 data[], uint32_t data_len, uint32_t order, FLAC__int32 residual[])
{
const int idata_len = (int)data_len;
int i;
switch(order) {
case 0:
memcpy(residual, data, sizeof(residual[0])*data_len);
break;
case 1:
for(i = 0; i < idata_len; i++)
residual[i] = data[i] - data[i-1];
break;
case 2:
for(i = 0; i < idata_len; i++)
residual[i] = data[i] - 2*data[i-1] + data[i-2];
break;
case 3:
for(i = 0; i < idata_len; i++)
residual[i] = data[i] - 3*data[i-1] + 3*data[i-2] - data[i-3];
break;
case 4:
for(i = 0; i < idata_len; i++)
residual[i] = data[i] - 4*data[i-1] + 6*data[i-2] - 4*data[i-3] + data[i-4];
break;
default: break;
}
}
void FLAC__fixed_restore_signal(const FLAC__int32 residual[], uint32_t data_len, uint32_t order, FLAC__int32 data[])
{
int i, idata_len = (int)data_len;
switch(order) {
case 0:
memcpy(data, residual, sizeof(residual[0])*data_len);
break;
case 1:
for(i = 0; i < idata_len; i++)
data[i] = residual[i] + data[i-1];
break;
case 2:
for(i = 0; i < idata_len; i++)
data[i] = residual[i] + 2*data[i-1] - data[i-2];
break;
case 3:
for(i = 0; i < idata_len; i++)
data[i] = residual[i] + 3*data[i-1] - 3*data[i-2] + data[i-3];
break;
case 4:
for(i = 0; i < idata_len; i++)
data[i] = residual[i] + 4*data[i-1] - 6*data[i-2] + 4*data[i-3] - data[i-4];
break;
default: break;
}
}