mirror of
https://github.com/UberGames/lilium-voyager.git
synced 2024-12-15 14:40:53 +00:00
82 lines
3.4 KiB
C
82 lines
3.4 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 "main_FLP.h"
|
||
|
|
|
||
|
|
/* Apply sine window to signal vector */
|
||
|
|
/* Window types: */
|
||
|
|
/* 1 -> sine window from 0 to pi/2 */
|
||
|
|
/* 2 -> sine window from pi/2 to pi */
|
||
|
|
void silk_apply_sine_window_FLP(
|
||
|
|
silk_float px_win[], /* O Pointer to windowed signal */
|
||
|
|
const silk_float px[], /* I Pointer to input signal */
|
||
|
|
const opus_int win_type, /* I Selects a window type */
|
||
|
|
const opus_int length /* I Window length, multiple of 4 */
|
||
|
|
)
|
||
|
|
{
|
||
|
|
opus_int k;
|
||
|
|
silk_float freq, c, S0, S1;
|
||
|
|
|
||
|
|
silk_assert( win_type == 1 || win_type == 2 );
|
||
|
|
|
||
|
|
/* Length must be multiple of 4 */
|
||
|
|
silk_assert( ( length & 3 ) == 0 );
|
||
|
|
|
||
|
|
freq = PI / ( length + 1 );
|
||
|
|
|
||
|
|
/* Approximation of 2 * cos(f) */
|
||
|
|
c = 2.0f - freq * freq;
|
||
|
|
|
||
|
|
/* Initialize state */
|
||
|
|
if( win_type < 2 ) {
|
||
|
|
/* Start from 0 */
|
||
|
|
S0 = 0.0f;
|
||
|
|
/* Approximation of sin(f) */
|
||
|
|
S1 = freq;
|
||
|
|
} else {
|
||
|
|
/* Start from 1 */
|
||
|
|
S0 = 1.0f;
|
||
|
|
/* Approximation of cos(f) */
|
||
|
|
S1 = 0.5f * c;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Uses the recursive equation: sin(n*f) = 2 * cos(f) * sin((n-1)*f) - sin((n-2)*f) */
|
||
|
|
/* 4 samples at a time */
|
||
|
|
for( k = 0; k < length; k += 4 ) {
|
||
|
|
px_win[ k + 0 ] = px[ k + 0 ] * 0.5f * ( S0 + S1 );
|
||
|
|
px_win[ k + 1 ] = px[ k + 1 ] * S1;
|
||
|
|
S0 = c * S1 - S0;
|
||
|
|
px_win[ k + 2 ] = px[ k + 2 ] * 0.5f * ( S1 + S0 );
|
||
|
|
px_win[ k + 3 ] = px[ k + 3 ] * S0;
|
||
|
|
S1 = c * S0 - S1;
|
||
|
|
}
|
||
|
|
}
|