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sbrhfgen.c
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/* ***** BEGIN LICENSE BLOCK *****
* Source last modified: $Id: sbrhfgen.c,v 1.2 2005/05/19 20:45:20 jrecker Exp $
*
* Portions Copyright (c) 1995-2005 RealNetworks, Inc. All Rights Reserved.
*
* The contents of this file, and the files included with this file,
* are subject to the current version of the RealNetworks Public
* Source License (the "RPSL") available at
* http://www.helixcommunity.org/content/rpsl unless you have licensed
* the file under the current version of the RealNetworks Community
* Source License (the "RCSL") available at
* http://www.helixcommunity.org/content/rcsl, in which case the RCSL
* will apply. You may also obtain the license terms directly from
* RealNetworks. You may not use this file except in compliance with
* the RPSL or, if you have a valid RCSL with RealNetworks applicable
* to this file, the RCSL. Please see the applicable RPSL or RCSL for
* the rights, obligations and limitations governing use of the
* contents of the file.
*
* This file is part of the Helix DNA Technology. RealNetworks is the
* developer of the Original Code and owns the copyrights in the
* portions it created.
*
* This file, and the files included with this file, is distributed
* and made available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY
* KIND, EITHER EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS
* ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET
* ENJOYMENT OR NON-INFRINGEMENT.
*
* Technology Compatibility Kit Test Suite(s) Location:
* http://www.helixcommunity.org/content/tck
*
* Contributor(s):
*
* ***** END LICENSE BLOCK ***** */
/**************************************************************************************
* Fixed-point HE-AAC decoder
* Jon Recker ([email protected])
* February 2005
*
* sbrhfgen.c - high frequency generation for SBR
**************************************************************************************/
#include "sbr.h"
#include "assembly.h"
#define FBITS_LPCOEFS 29 /* Q29 for range of (-4, 4) */
#define MAG_16 (16 * (1 << (32 - (2*(32-FBITS_LPCOEFS))))) /* i.e. 16 in Q26 format */
#define RELAX_COEF 0x7ffff79c /* 1.0 / (1.0 + 1e-6), Q31 */
/* newBWTab[prev invfMode][curr invfMode], format = Q31 (table 4.158)
* sample file which uses all of these: al_sbr_sr_64_2_fsaac32.aac
*/
static const int newBWTab[4][4] PROGMEM = {
{0x00000000, 0x4ccccccd, 0x73333333, 0x7d70a3d7},
{0x4ccccccd, 0x60000000, 0x73333333, 0x7d70a3d7},
{0x00000000, 0x60000000, 0x73333333, 0x7d70a3d7},
{0x00000000, 0x60000000, 0x73333333, 0x7d70a3d7},
};
/**************************************************************************************
* Function: CVKernel1
*
* Description: kernel of covariance matrix calculation for p01, p11, p12, p22
*
* Inputs: buffer of low-freq samples, starting at time index = 0,
* freq index = patch subband
*
* Outputs: 64-bit accumulators for p01re, p01im, p12re, p12im, p11re, p22re
* stored in accBuf
*
* Return: none
*
* Notes: this is carefully written to be efficient on ARM
* use the assembly code version in sbrcov.s when building for ARM!
**************************************************************************************/
#if (defined (__arm) && defined (__ARMCC_VERSION)) || (defined (_WIN32) && defined (_WIN32_WCE) && defined (ARM)) || (defined(__GNUC__) && defined(__arm__))
#ifdef __cplusplus
extern "C"
#endif
void CVKernel1(int *XBuf, int *accBuf);
#else
void CVKernel1(int *XBuf, int *accBuf)
{
U64 p01re, p01im, p12re, p12im, p11re, p22re;
int n, x0re, x0im, x1re, x1im;
x0re = XBuf[0];
x0im = XBuf[1];
XBuf += (2*64);
x1re = XBuf[0];
x1im = XBuf[1];
XBuf += (2*64);
p01re.w64 = p01im.w64 = 0;
p12re.w64 = p12im.w64 = 0;
p11re.w64 = 0;
p22re.w64 = 0;
p12re.w64 = MADD64(p12re.w64, x1re, x0re);
p12re.w64 = MADD64(p12re.w64, x1im, x0im);
p12im.w64 = MADD64(p12im.w64, x0re, x1im);
p12im.w64 = MADD64(p12im.w64, -x0im, x1re);
p22re.w64 = MADD64(p22re.w64, x0re, x0re);
p22re.w64 = MADD64(p22re.w64, x0im, x0im);
for (n = (NUM_TIME_SLOTS*SAMPLES_PER_SLOT + 6); n != 0; n--) {
/* 4 input, 3*2 acc, 1 ptr, 1 loop counter = 12 registers (use same for x0im, -x0im) */
x0re = x1re;
x0im = x1im;
x1re = XBuf[0];
x1im = XBuf[1];
p01re.w64 = MADD64(p01re.w64, x1re, x0re);
p01re.w64 = MADD64(p01re.w64, x1im, x0im);
p01im.w64 = MADD64(p01im.w64, x0re, x1im);
p01im.w64 = MADD64(p01im.w64, -x0im, x1re);
p11re.w64 = MADD64(p11re.w64, x0re, x0re);
p11re.w64 = MADD64(p11re.w64, x0im, x0im);
XBuf += (2*64);
}
/* these can be derived by slight changes to account for boundary conditions */
p12re.w64 += p01re.w64;
p12re.w64 = MADD64(p12re.w64, x1re, -x0re);
p12re.w64 = MADD64(p12re.w64, x1im, -x0im);
p12im.w64 += p01im.w64;
p12im.w64 = MADD64(p12im.w64, x0re, -x1im);
p12im.w64 = MADD64(p12im.w64, x0im, x1re);
p22re.w64 += p11re.w64;
p22re.w64 = MADD64(p22re.w64, x0re, -x0re);
p22re.w64 = MADD64(p22re.w64, x0im, -x0im);
accBuf[0] = p01re.r.lo32; accBuf[1] = p01re.r.hi32;
accBuf[2] = p01im.r.lo32; accBuf[3] = p01im.r.hi32;
accBuf[4] = p11re.r.lo32; accBuf[5] = p11re.r.hi32;
accBuf[6] = p12re.r.lo32; accBuf[7] = p12re.r.hi32;
accBuf[8] = p12im.r.lo32; accBuf[9] = p12im.r.hi32;
accBuf[10] = p22re.r.lo32; accBuf[11] = p22re.r.hi32;
}
#endif
/**************************************************************************************
* Function: CalcCovariance1
*
* Description: calculate covariance matrix for p01, p12, p11, p22 (4.6.18.6.2)
*
* Inputs: buffer of low-freq samples, starting at time index 0,
* freq index = patch subband
*
* Outputs: complex covariance elements p01re, p01im, p12re, p12im, p11re, p22re
* (p11im = p22im = 0)
* format = integer (Q0) * 2^N, with scalefactor N >= 0
*
* Return: scalefactor N
*
* Notes: outputs are normalized to have 1 GB (sign in at least top 2 bits)
**************************************************************************************/
static int CalcCovariance1(int *XBuf, int *p01reN, int *p01imN, int *p12reN, int *p12imN, int *p11reN, int *p22reN)
{
int accBuf[2*6];
int n, z, s, loShift, hiShift, gbMask;
U64 p01re, p01im, p12re, p12im, p11re, p22re;
CVKernel1(XBuf, accBuf);
p01re.r.lo32 = accBuf[0]; p01re.r.hi32 = accBuf[1];
p01im.r.lo32 = accBuf[2]; p01im.r.hi32 = accBuf[3];
p11re.r.lo32 = accBuf[4]; p11re.r.hi32 = accBuf[5];
p12re.r.lo32 = accBuf[6]; p12re.r.hi32 = accBuf[7];
p12im.r.lo32 = accBuf[8]; p12im.r.hi32 = accBuf[9];
p22re.r.lo32 = accBuf[10]; p22re.r.hi32 = accBuf[11];
/* 64-bit accumulators now have 2*FBITS_OUT_QMFA fraction bits
* want to scale them down to integers (32-bit signed, Q0)
* with scale factor of 2^n, n >= 0
* leave 2 GB's for calculating determinant, so take top 30 non-zero bits
*/
gbMask = ((p01re.r.hi32) ^ (p01re.r.hi32 >> 31)) | ((p01im.r.hi32) ^ (p01im.r.hi32 >> 31));
gbMask |= ((p12re.r.hi32) ^ (p12re.r.hi32 >> 31)) | ((p12im.r.hi32) ^ (p12im.r.hi32 >> 31));
gbMask |= ((p11re.r.hi32) ^ (p11re.r.hi32 >> 31)) | ((p22re.r.hi32) ^ (p22re.r.hi32 >> 31));
if (gbMask == 0) {
s = p01re.r.hi32 >> 31; gbMask = (p01re.r.lo32 ^ s) - s;
s = p01im.r.hi32 >> 31; gbMask |= (p01im.r.lo32 ^ s) - s;
s = p12re.r.hi32 >> 31; gbMask |= (p12re.r.lo32 ^ s) - s;
s = p12im.r.hi32 >> 31; gbMask |= (p12im.r.lo32 ^ s) - s;
s = p11re.r.hi32 >> 31; gbMask |= (p11re.r.lo32 ^ s) - s;
s = p22re.r.hi32 >> 31; gbMask |= (p22re.r.lo32 ^ s) - s;
z = 32 + CLZ(gbMask);
} else {
gbMask = FASTABS(p01re.r.hi32) | FASTABS(p01im.r.hi32);
gbMask |= FASTABS(p12re.r.hi32) | FASTABS(p12im.r.hi32);
gbMask |= FASTABS(p11re.r.hi32) | FASTABS(p22re.r.hi32);
z = CLZ(gbMask);
}
n = 64 - z; /* number of non-zero bits in bottom of 64-bit word */
if (n <= 30) {
loShift = (30 - n);
*p01reN = p01re.r.lo32 << loShift; *p01imN = p01im.r.lo32 << loShift;
*p12reN = p12re.r.lo32 << loShift; *p12imN = p12im.r.lo32 << loShift;
*p11reN = p11re.r.lo32 << loShift; *p22reN = p22re.r.lo32 << loShift;
return -(loShift + 2*FBITS_OUT_QMFA);
} else if (n < 32 + 30) {
loShift = (n - 30);
hiShift = 32 - loShift;
*p01reN = (p01re.r.hi32 << hiShift) | (p01re.r.lo32 >> loShift);
*p01imN = (p01im.r.hi32 << hiShift) | (p01im.r.lo32 >> loShift);
*p12reN = (p12re.r.hi32 << hiShift) | (p12re.r.lo32 >> loShift);
*p12imN = (p12im.r.hi32 << hiShift) | (p12im.r.lo32 >> loShift);
*p11reN = (p11re.r.hi32 << hiShift) | (p11re.r.lo32 >> loShift);
*p22reN = (p22re.r.hi32 << hiShift) | (p22re.r.lo32 >> loShift);
return (loShift - 2*FBITS_OUT_QMFA);
} else {
hiShift = n - (32 + 30);
*p01reN = p01re.r.hi32 >> hiShift; *p01imN = p01im.r.hi32 >> hiShift;
*p12reN = p12re.r.hi32 >> hiShift; *p12imN = p12im.r.hi32 >> hiShift;
*p11reN = p11re.r.hi32 >> hiShift; *p22reN = p22re.r.hi32 >> hiShift;
return (32 - 2*FBITS_OUT_QMFA - hiShift);
}
return 0;
}
/**************************************************************************************
* Function: CVKernel2
*
* Description: kernel of covariance matrix calculation for p02
*
* Inputs: buffer of low-freq samples, starting at time index = 0,
* freq index = patch subband
*
* Outputs: 64-bit accumulators for p02re, p02im stored in accBuf
*
* Return: none
*
* Notes: this is carefully written to be efficient on ARM
* use the assembly code version in sbrcov.s when building for ARM!
**************************************************************************************/
#if (defined (__arm) && defined (__ARMCC_VERSION)) || (defined (_WIN32) && defined (_WIN32_WCE) && defined (ARM)) || (defined(__GNUC__) && defined(__arm__))
#ifdef __cplusplus
extern "C"
#endif
void CVKernel2(int *XBuf, int *accBuf);
#else
void CVKernel2(int *XBuf, int *accBuf)
{
U64 p02re, p02im;
int n, x0re, x0im, x1re, x1im, x2re, x2im;
p02re.w64 = p02im.w64 = 0;
x0re = XBuf[0];
x0im = XBuf[1];
XBuf += (2*64);
x1re = XBuf[0];
x1im = XBuf[1];
XBuf += (2*64);
for (n = (NUM_TIME_SLOTS*SAMPLES_PER_SLOT + 6); n != 0; n--) {
/* 6 input, 2*2 acc, 1 ptr, 1 loop counter = 12 registers (use same for x0im, -x0im) */
x2re = XBuf[0];
x2im = XBuf[1];
p02re.w64 = MADD64(p02re.w64, x2re, x0re);
p02re.w64 = MADD64(p02re.w64, x2im, x0im);
p02im.w64 = MADD64(p02im.w64, x0re, x2im);
p02im.w64 = MADD64(p02im.w64, -x0im, x2re);
x0re = x1re;
x0im = x1im;
x1re = x2re;
x1im = x2im;
XBuf += (2*64);
}
accBuf[0] = p02re.r.lo32;
accBuf[1] = p02re.r.hi32;
accBuf[2] = p02im.r.lo32;
accBuf[3] = p02im.r.hi32;
}
#endif
/**************************************************************************************
* Function: CalcCovariance2
*
* Description: calculate covariance matrix for p02 (4.6.18.6.2)
*
* Inputs: buffer of low-freq samples, starting at time index = 0,
* freq index = patch subband
*
* Outputs: complex covariance element p02re, p02im
* format = integer (Q0) * 2^N, with scalefactor N >= 0
*
* Return: scalefactor N
*
* Notes: outputs are normalized to have 1 GB (sign in at least top 2 bits)
**************************************************************************************/
static int CalcCovariance2(int *XBuf, int *p02reN, int *p02imN)
{
U64 p02re, p02im;
int n, z, s, loShift, hiShift, gbMask;
int accBuf[2*2];
CVKernel2(XBuf, accBuf);
p02re.r.lo32 = accBuf[0];
p02re.r.hi32 = accBuf[1];
p02im.r.lo32 = accBuf[2];
p02im.r.hi32 = accBuf[3];
/* 64-bit accumulators now have 2*FBITS_OUT_QMFA fraction bits
* want to scale them down to integers (32-bit signed, Q0)
* with scale factor of 2^n, n >= 0
* leave 1 GB for calculating determinant, so take top 30 non-zero bits
*/
gbMask = ((p02re.r.hi32) ^ (p02re.r.hi32 >> 31)) | ((p02im.r.hi32) ^ (p02im.r.hi32 >> 31));
if (gbMask == 0) {
s = p02re.r.hi32 >> 31; gbMask = (p02re.r.lo32 ^ s) - s;
s = p02im.r.hi32 >> 31; gbMask |= (p02im.r.lo32 ^ s) - s;
z = 32 + CLZ(gbMask);
} else {
gbMask = FASTABS(p02re.r.hi32) | FASTABS(p02im.r.hi32);
z = CLZ(gbMask);
}
n = 64 - z; /* number of non-zero bits in bottom of 64-bit word */
if (n <= 30) {
loShift = (30 - n);
*p02reN = p02re.r.lo32 << loShift;
*p02imN = p02im.r.lo32 << loShift;
return -(loShift + 2*FBITS_OUT_QMFA);
} else if (n < 32 + 30) {
loShift = (n - 30);
hiShift = 32 - loShift;
*p02reN = (p02re.r.hi32 << hiShift) | (p02re.r.lo32 >> loShift);
*p02imN = (p02im.r.hi32 << hiShift) | (p02im.r.lo32 >> loShift);
return (loShift - 2*FBITS_OUT_QMFA);
} else {
hiShift = n - (32 + 30);
*p02reN = p02re.r.hi32 >> hiShift;
*p02imN = p02im.r.hi32 >> hiShift;
return (32 - 2*FBITS_OUT_QMFA - hiShift);
}
return 0;
}
/**************************************************************************************
* Function: CalcLPCoefs
*
* Description: calculate linear prediction coefficients for one subband (4.6.18.6.2)
*
* Inputs: buffer of low-freq samples, starting at time index = 0,
* freq index = patch subband
* number of guard bits in input sample buffer
*
* Outputs: complex LP coefficients a0re, a0im, a1re, a1im, format = Q29
*
* Return: none
*
* Notes: output coefficients (a0re, a0im, a1re, a1im) clipped to range (-4, 4)
* if the comples coefficients have magnitude >= 4.0, they are all
* set to 0 (see spec)
**************************************************************************************/
static void CalcLPCoefs(int *XBuf, int *a0re, int *a0im, int *a1re, int *a1im, int gb)
{
int zFlag, n1, n2, nd, d, dInv, tre, tim;
int p01re, p01im, p02re, p02im, p12re, p12im, p11re, p22re;
/* pre-scale to avoid overflow - probably never happens in practice (see QMFA)
* max bit growth per accumulator = 38*2 = 76 mul-adds (X * X)
* using 64-bit MADD, so if X has n guard bits, X*X has 2n+1 guard bits
* gain 1 extra sign bit per multiply, so ensure ceil(log2(76/2) / 2) = 3 guard bits on inputs
*/
if (gb < 3) {
nd = 3 - gb;
for (n1 = (NUM_TIME_SLOTS*SAMPLES_PER_SLOT + 6 + 2); n1 != 0; n1--) {
XBuf[0] >>= nd; XBuf[1] >>= nd;
XBuf += (2*64);
}
XBuf -= (2*64*(NUM_TIME_SLOTS*SAMPLES_PER_SLOT + 6 + 2));
}
/* calculate covariance elements */
n1 = CalcCovariance1(XBuf, &p01re, &p01im, &p12re, &p12im, &p11re, &p22re);
n2 = CalcCovariance2(XBuf, &p02re, &p02im);
/* normalize everything to larger power of 2 scalefactor, call it n1 */
if (n1 < n2) {
nd = MIN(n2 - n1, 31);
p01re >>= nd; p01im >>= nd;
p12re >>= nd; p12im >>= nd;
p11re >>= nd; p22re >>= nd;
n1 = n2;
} else if (n1 > n2) {
nd = MIN(n1 - n2, 31);
p02re >>= nd; p02im >>= nd;
}
/* calculate determinant of covariance matrix (at least 1 GB in pXX) */
d = MULSHIFT32(p12re, p12re) + MULSHIFT32(p12im, p12im);
d = MULSHIFT32(d, RELAX_COEF) << 1;
d = MULSHIFT32(p11re, p22re) - d;
ASSERT(d >= 0); /* should never be < 0 */
zFlag = 0;
*a0re = *a0im = 0;
*a1re = *a1im = 0;
if (d > 0) {
/* input = Q31 d = Q(-2*n1 - 32 + nd) = Q31 * 2^(31 + 2*n1 + 32 - nd)
* inverse = Q29 dInv = Q29 * 2^(-31 - 2*n1 - 32 + nd) = Q(29 + 31 + 2*n1 + 32 - nd)
*
* numerator has same Q format as d, since it's sum of normalized squares
* so num * inverse = Q(-2*n1 - 32) * Q(29 + 31 + 2*n1 + 32 - nd)
* = Q(29 + 31 - nd), drop low 32 in MULSHIFT32
* = Q(29 + 31 - 32 - nd) = Q(28 - nd)
*/
nd = CLZ(d) - 1;
d <<= nd;
dInv = InvRNormalized(d);
/* 1 GB in pXX */
tre = MULSHIFT32(p01re, p12re) - MULSHIFT32(p01im, p12im) - MULSHIFT32(p02re, p11re);
tre = MULSHIFT32(tre, dInv);
tim = MULSHIFT32(p01re, p12im) + MULSHIFT32(p01im, p12re) - MULSHIFT32(p02im, p11re);
tim = MULSHIFT32(tim, dInv);
/* if d is extremely small, just set coefs to 0 (would have poor precision anyway) */
if (nd > 28 || (FASTABS(tre) >> (28 - nd)) >= 4 || (FASTABS(tim) >> (28 - nd)) >= 4) {
zFlag = 1;
} else {
*a1re = tre << (FBITS_LPCOEFS - 28 + nd); /* i.e. convert Q(28 - nd) to Q(29) */
*a1im = tim << (FBITS_LPCOEFS - 28 + nd);
}
}
if (p11re) {
/* input = Q31 p11re = Q(-n1 + nd) = Q31 * 2^(31 + n1 - nd)
* inverse = Q29 dInv = Q29 * 2^(-31 - n1 + nd) = Q(29 + 31 + n1 - nd)
*
* numerator is Q(-n1 - 3)
* so num * inverse = Q(-n1 - 3) * Q(29 + 31 + n1 - nd)
* = Q(29 + 31 - 3 - nd), drop low 32 in MULSHIFT32
* = Q(29 + 31 - 3 - 32 - nd) = Q(25 - nd)
*/
nd = CLZ(p11re) - 1; /* assume positive */
p11re <<= nd;
dInv = InvRNormalized(p11re);
/* a1re, a1im = Q29, so scaled by (n1 + 3) */
tre = (p01re >> 3) + MULSHIFT32(p12re, *a1re) + MULSHIFT32(p12im, *a1im);
tre = -MULSHIFT32(tre, dInv);
tim = (p01im >> 3) - MULSHIFT32(p12im, *a1re) + MULSHIFT32(p12re, *a1im);
tim = -MULSHIFT32(tim, dInv);
if (nd > 25 || (FASTABS(tre) >> (25 - nd)) >= 4 || (FASTABS(tim) >> (25 - nd)) >= 4) {
zFlag = 1;
} else {
*a0re = tre << (FBITS_LPCOEFS - 25 + nd); /* i.e. convert Q(25 - nd) to Q(29) */
*a0im = tim << (FBITS_LPCOEFS - 25 + nd);
}
}
/* see 4.6.18.6.2 - if magnitude of a0 or a1 >= 4 then a0 = a1 = 0
* i.e. a0re < 4, a0im < 4, a1re < 4, a1im < 4
* Q29*Q29 = Q26
*/
if (zFlag || MULSHIFT32(*a0re, *a0re) + MULSHIFT32(*a0im, *a0im) >= MAG_16 || MULSHIFT32(*a1re, *a1re) + MULSHIFT32(*a1im, *a1im) >= MAG_16) {
*a0re = *a0im = 0;
*a1re = *a1im = 0;
}
/* no need to clip - we never changed the XBuf data, just used it to calculate a0 and a1 */
if (gb < 3) {
nd = 3 - gb;
for (n1 = (NUM_TIME_SLOTS*SAMPLES_PER_SLOT + 6 + 2); n1 != 0; n1--) {
XBuf[0] <<= nd; XBuf[1] <<= nd;
XBuf += (2*64);
}
}
}
/**************************************************************************************
* Function: GenerateHighFreq
*
* Description: generate high frequencies with SBR (4.6.18.6)
*
* Inputs: initialized PSInfoSBR struct
* initialized SBRGrid struct for this channel
* initialized SBRFreq struct for this SCE/CPE block
* initialized SBRChan struct for this channel
* index of current channel (0 for SCE, 0 or 1 for CPE)
*
* Outputs: new high frequency samples starting at frequency kStart
*
* Return: none
**************************************************************************************/
void GenerateHighFreq(PSInfoSBR *psi, SBRGrid *sbrGrid, SBRFreq *sbrFreq, SBRChan *sbrChan, int ch)
{
int band, newBW, c, t, gb, gbMask, gbIdx;
int currPatch, p, x, k, g, i, iStart, iEnd, bw, bwsq;
int a0re, a0im, a1re, a1im;
int x1re, x1im, x2re, x2im;
int ACCre, ACCim;
int *XBufLo, *XBufHi;
(void) ch;
/* calculate array of chirp factors */
for (band = 0; band < sbrFreq->numNoiseFloorBands; band++) {
c = sbrChan->chirpFact[band]; /* previous (bwArray') */
newBW = newBWTab[sbrChan->invfMode[0][band]][sbrChan->invfMode[1][band]];
/* weighted average of new and old (can't overflow - total gain = 1.0) */
if (newBW < c)
t = MULSHIFT32(newBW, 0x60000000) + MULSHIFT32(0x20000000, c); /* new is smaller: 0.75*new + 0.25*old */
else
t = MULSHIFT32(newBW, 0x74000000) + MULSHIFT32(0x0c000000, c); /* new is larger: 0.90625*new + 0.09375*old */
t <<= 1;
if (t < 0x02000000) /* below 0.015625, clip to 0 */
t = 0;
if (t > 0x7f800000) /* clip to 0.99609375 */
t = 0x7f800000;
/* save curr as prev for next time */
sbrChan->chirpFact[band] = t;
sbrChan->invfMode[0][band] = sbrChan->invfMode[1][band];
}
iStart = sbrGrid->envTimeBorder[0] + HF_ADJ;
iEnd = sbrGrid->envTimeBorder[sbrGrid->numEnv] + HF_ADJ;
/* generate new high freqs from low freqs, patches, and chirp factors */
k = sbrFreq->kStart;
g = 0;
bw = sbrChan->chirpFact[g];
bwsq = MULSHIFT32(bw, bw) << 1;
gbMask = (sbrChan->gbMask[0] | sbrChan->gbMask[1]); /* older 32 | newer 8 */
gb = CLZ(gbMask) - 1;
for (currPatch = 0; currPatch < sbrFreq->numPatches; currPatch++) {
for (x = 0; x < sbrFreq->patchNumSubbands[currPatch]; x++) {
/* map k to corresponding noise floor band */
if (k >= sbrFreq->freqNoise[g+1]) {
g++;
bw = sbrChan->chirpFact[g]; /* Q31 */
bwsq = MULSHIFT32(bw, bw) << 1; /* Q31 */
}
p = sbrFreq->patchStartSubband[currPatch] + x; /* low QMF band */
XBufHi = psi->XBuf[iStart][k];
if (bw) {
CalcLPCoefs(psi->XBuf[0][p], &a0re, &a0im, &a1re, &a1im, gb);
a0re = MULSHIFT32(bw, a0re); /* Q31 * Q29 = Q28 */
a0im = MULSHIFT32(bw, a0im);
a1re = MULSHIFT32(bwsq, a1re);
a1im = MULSHIFT32(bwsq, a1im);
XBufLo = psi->XBuf[iStart-2][p];
x2re = XBufLo[0]; /* RE{XBuf[n-2]} */
x2im = XBufLo[1]; /* IM{XBuf[n-2]} */
XBufLo += (64*2);
x1re = XBufLo[0]; /* RE{XBuf[n-1]} */
x1im = XBufLo[1]; /* IM{XBuf[n-1]} */
XBufLo += (64*2);
for (i = iStart; i < iEnd; i++) {
/* a0re/im, a1re/im are Q28 with at least 1 GB,
* so the summing for AACre/im is fine (1 GB in, plus 1 from MULSHIFT32)
*/
ACCre = MULSHIFT32(x2re, a1re) - MULSHIFT32(x2im, a1im);
ACCim = MULSHIFT32(x2re, a1im) + MULSHIFT32(x2im, a1re);
x2re = x1re;
x2im = x1im;
ACCre += MULSHIFT32(x1re, a0re) - MULSHIFT32(x1im, a0im);
ACCim += MULSHIFT32(x1re, a0im) + MULSHIFT32(x1im, a0re);
x1re = XBufLo[0]; /* RE{XBuf[n]} */
x1im = XBufLo[1]; /* IM{XBuf[n]} */
XBufLo += (64*2);
/* lost 4 fbits when scaling by a0re/im, a1re/im (Q28) */
CLIP_2N_SHIFT30(ACCre, 4);
ACCre += x1re;
CLIP_2N_SHIFT30(ACCim, 4);
ACCim += x1im;
XBufHi[0] = ACCre;
XBufHi[1] = ACCim;
XBufHi += (64*2);
/* update guard bit masks */
gbMask = FASTABS(ACCre);
gbMask |= FASTABS(ACCim);
gbIdx = (i >> 5) & 0x01; /* 0 if i < 32, 1 if i >= 32 */
sbrChan->gbMask[gbIdx] |= gbMask;
}
} else {
XBufLo = (int *)psi->XBuf[iStart][p];
for (i = iStart; i < iEnd; i++) {
XBufHi[0] = XBufLo[0];
XBufHi[1] = XBufLo[1];
XBufLo += (64*2);
XBufHi += (64*2);
}
}
k++; /* high QMF band */
}
}
}