mirror of
https://github.com/UberGames/ioef.git
synced 2024-12-01 00:21:19 +00:00
188 lines
7.1 KiB
C
188 lines
7.1 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.
|
|
***********************************************************************/
|
|
|
|
/*! \file silk_Inlines.h
|
|
* \brief silk_Inlines.h defines inline signal processing functions.
|
|
*/
|
|
|
|
#ifndef SILK_FIX_INLINES_H
|
|
#define SILK_FIX_INLINES_H
|
|
|
|
#ifdef __cplusplus
|
|
extern "C"
|
|
{
|
|
#endif
|
|
|
|
/* count leading zeros of opus_int64 */
|
|
static inline opus_int32 silk_CLZ64( opus_int64 in )
|
|
{
|
|
opus_int32 in_upper;
|
|
|
|
in_upper = (opus_int32)silk_RSHIFT64(in, 32);
|
|
if (in_upper == 0) {
|
|
/* Search in the lower 32 bits */
|
|
return 32 + silk_CLZ32( (opus_int32) in );
|
|
} else {
|
|
/* Search in the upper 32 bits */
|
|
return silk_CLZ32( in_upper );
|
|
}
|
|
}
|
|
|
|
/* get number of leading zeros and fractional part (the bits right after the leading one */
|
|
static inline void silk_CLZ_FRAC(
|
|
opus_int32 in, /* I input */
|
|
opus_int32 *lz, /* O number of leading zeros */
|
|
opus_int32 *frac_Q7 /* O the 7 bits right after the leading one */
|
|
)
|
|
{
|
|
opus_int32 lzeros = silk_CLZ32(in);
|
|
|
|
* lz = lzeros;
|
|
* frac_Q7 = silk_ROR32(in, 24 - lzeros) & 0x7f;
|
|
}
|
|
|
|
/* Approximation of square root */
|
|
/* Accuracy: < +/- 10% for output values > 15 */
|
|
/* < +/- 2.5% for output values > 120 */
|
|
static inline opus_int32 silk_SQRT_APPROX( opus_int32 x )
|
|
{
|
|
opus_int32 y, lz, frac_Q7;
|
|
|
|
if( x <= 0 ) {
|
|
return 0;
|
|
}
|
|
|
|
silk_CLZ_FRAC(x, &lz, &frac_Q7);
|
|
|
|
if( lz & 1 ) {
|
|
y = 32768;
|
|
} else {
|
|
y = 46214; /* 46214 = sqrt(2) * 32768 */
|
|
}
|
|
|
|
/* get scaling right */
|
|
y >>= silk_RSHIFT(lz, 1);
|
|
|
|
/* increment using fractional part of input */
|
|
y = silk_SMLAWB(y, y, silk_SMULBB(213, frac_Q7));
|
|
|
|
return y;
|
|
}
|
|
|
|
/* Divide two int32 values and return result as int32 in a given Q-domain */
|
|
static inline opus_int32 silk_DIV32_varQ( /* O returns a good approximation of "(a32 << Qres) / b32" */
|
|
const opus_int32 a32, /* I numerator (Q0) */
|
|
const opus_int32 b32, /* I denominator (Q0) */
|
|
const opus_int Qres /* I Q-domain of result (>= 0) */
|
|
)
|
|
{
|
|
opus_int a_headrm, b_headrm, lshift;
|
|
opus_int32 b32_inv, a32_nrm, b32_nrm, result;
|
|
|
|
silk_assert( b32 != 0 );
|
|
silk_assert( Qres >= 0 );
|
|
|
|
/* Compute number of bits head room and normalize inputs */
|
|
a_headrm = silk_CLZ32( silk_abs(a32) ) - 1;
|
|
a32_nrm = silk_LSHIFT(a32, a_headrm); /* Q: a_headrm */
|
|
b_headrm = silk_CLZ32( silk_abs(b32) ) - 1;
|
|
b32_nrm = silk_LSHIFT(b32, b_headrm); /* Q: b_headrm */
|
|
|
|
/* Inverse of b32, with 14 bits of precision */
|
|
b32_inv = silk_DIV32_16( silk_int32_MAX >> 2, silk_RSHIFT(b32_nrm, 16) ); /* Q: 29 + 16 - b_headrm */
|
|
|
|
/* First approximation */
|
|
result = silk_SMULWB(a32_nrm, b32_inv); /* Q: 29 + a_headrm - b_headrm */
|
|
|
|
/* Compute residual by subtracting product of denominator and first approximation */
|
|
/* It's OK to overflow because the final value of a32_nrm should always be small */
|
|
a32_nrm = silk_SUB32_ovflw(a32_nrm, silk_LSHIFT_ovflw( silk_SMMUL(b32_nrm, result), 3 )); /* Q: a_headrm */
|
|
|
|
/* Refinement */
|
|
result = silk_SMLAWB(result, a32_nrm, b32_inv); /* Q: 29 + a_headrm - b_headrm */
|
|
|
|
/* Convert to Qres domain */
|
|
lshift = 29 + a_headrm - b_headrm - Qres;
|
|
if( lshift < 0 ) {
|
|
return silk_LSHIFT_SAT32(result, -lshift);
|
|
} else {
|
|
if( lshift < 32){
|
|
return silk_RSHIFT(result, lshift);
|
|
} else {
|
|
/* Avoid undefined result */
|
|
return 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Invert int32 value and return result as int32 in a given Q-domain */
|
|
static inline opus_int32 silk_INVERSE32_varQ( /* O returns a good approximation of "(1 << Qres) / b32" */
|
|
const opus_int32 b32, /* I denominator (Q0) */
|
|
const opus_int Qres /* I Q-domain of result (> 0) */
|
|
)
|
|
{
|
|
opus_int b_headrm, lshift;
|
|
opus_int32 b32_inv, b32_nrm, err_Q32, result;
|
|
|
|
silk_assert( b32 != 0 );
|
|
silk_assert( Qres > 0 );
|
|
|
|
/* Compute number of bits head room and normalize input */
|
|
b_headrm = silk_CLZ32( silk_abs(b32) ) - 1;
|
|
b32_nrm = silk_LSHIFT(b32, b_headrm); /* Q: b_headrm */
|
|
|
|
/* Inverse of b32, with 14 bits of precision */
|
|
b32_inv = silk_DIV32_16( silk_int32_MAX >> 2, silk_RSHIFT(b32_nrm, 16) ); /* Q: 29 + 16 - b_headrm */
|
|
|
|
/* First approximation */
|
|
result = silk_LSHIFT(b32_inv, 16); /* Q: 61 - b_headrm */
|
|
|
|
/* Compute residual by subtracting product of denominator and first approximation from one */
|
|
err_Q32 = silk_LSHIFT( ((opus_int32)1<<29) - silk_SMULWB(b32_nrm, b32_inv), 3 ); /* Q32 */
|
|
|
|
/* Refinement */
|
|
result = silk_SMLAWW(result, err_Q32, b32_inv); /* Q: 61 - b_headrm */
|
|
|
|
/* Convert to Qres domain */
|
|
lshift = 61 - b_headrm - Qres;
|
|
if( lshift <= 0 ) {
|
|
return silk_LSHIFT_SAT32(result, -lshift);
|
|
} else {
|
|
if( lshift < 32){
|
|
return silk_RSHIFT(result, lshift);
|
|
}else{
|
|
/* Avoid undefined result */
|
|
return 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* SILK_FIX_INLINES_H */
|