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squeezelite-esp32/components/spotify/cspot/bell/libhelix-aac/stproc.c
Philippe G 898998efb0 big merge
2021-12-18 21:04:23 -08:00

247 lines
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C

/* ***** BEGIN LICENSE BLOCK *****
* Source last modified: $Id: stproc.c,v 1.3 2005/05/24 16:01:55 albertofloyd 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 (jrecker@real.com)
* February 2005
*
* stproc.c - mid-side and intensity stereo processing
**************************************************************************************/
#include "coder.h"
#include "assembly.h"
/* pow14[0][i] = -pow(2, i/4.0)
* pow14[1][i] = +pow(2, i/4.0)
*
* i = [0,1,2,3]
* format = Q30
*/
/**************************************************************************************
* Function: StereoProcessGroup
*
* Description: apply mid-side and intensity stereo to group of transform coefficients
*
* Inputs: dequantized transform coefficients for both channels
* pointer to appropriate scalefactor band table
* mid-side mask enabled flag
* buffer with mid-side mask (one bit for each scalefactor band)
* bit offset into mid-side mask buffer
* max coded scalefactor band
* buffer of codebook indices for right channel
* buffer of scalefactors for right channel, range = [0, 256]
*
* Outputs: updated transform coefficients in Q(FBITS_OUT_DQ_OFF)
* updated minimum guard bit count for both channels
*
* Return: none
*
* Notes: assume no guard bits in input
* gains 0 int bits
**************************************************************************************/
static void StereoProcessGroup(int *coefL, int *coefR, const /*short*/ int *sfbTab,
int msMaskPres, unsigned char *msMaskPtr, int msMaskOffset, int maxSFB,
unsigned char *cbRight, short *sfRight, int *gbCurrent)
{
//fb
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wnarrowing"
static const int pow14[2][4] PROGMEM = {
{ 0xc0000000, 0xb3e407d7, 0xa57d8666, 0x945d819b },
{ 0x40000000, 0x4c1bf829, 0x5a82799a, 0x6ba27e65 }
};
#pragma GCC diagnostic pop
int sfb, width, cbIdx, sf, cl, cr, scalef, scalei;
int gbMaskL, gbMaskR;
unsigned char msMask;
msMask = (*msMaskPtr++) >> msMaskOffset;
gbMaskL = 0;
gbMaskR = 0;
for (sfb = 0; sfb < maxSFB; sfb++) {
width = sfbTab[sfb+1] - sfbTab[sfb]; /* assume >= 0 (see sfBandTabLong/sfBandTabShort) */
cbIdx = cbRight[sfb];
if (cbIdx == 14 || cbIdx == 15) {
/* intensity stereo */
if (msMaskPres == 1 && (msMask & 0x01))
cbIdx ^= 0x01; /* invert_intensity(): 14 becomes 15, or 15 becomes 14 */
sf = -sfRight[sfb]; /* negative since we use identity 0.5^(x) = 2^(-x) (see spec) */
cbIdx &= 0x01; /* choose - or + scale factor */
scalef = pow14[cbIdx][sf & 0x03];
scalei = (sf >> 2) + 2; /* +2 to compensate for scalef = Q30 */
if (scalei > 0) {
if (scalei > 30)
scalei = 30;
do {
cr = MULSHIFT32(*coefL++, scalef);
CLIP_2N(cr, 31-scalei);
cr <<= scalei;
gbMaskR |= FASTABS(cr);
*coefR++ = cr;
} while (--width);
} else {
scalei = -scalei;
if (scalei > 31)
scalei = 31;
do {
cr = MULSHIFT32(*coefL++, scalef) >> scalei;
gbMaskR |= FASTABS(cr);
*coefR++ = cr;
} while (--width);
}
} else if ( cbIdx != 13 && ((msMaskPres == 1 && (msMask & 0x01)) || msMaskPres == 2) ) {
/* mid-side stereo (assumes no GB in inputs) */
do {
cl = *coefL;
cr = *coefR;
if ( (FASTABS(cl) | FASTABS(cr)) >> 30 ) {
/* avoid overflow (rare) */
cl >>= 1;
sf = cl + (cr >> 1); CLIP_2N(sf, 30); sf <<= 1;
cl = cl - (cr >> 1); CLIP_2N(cl, 30); cl <<= 1;
} else {
/* usual case */
sf = cl + cr;
cl -= cr;
}
*coefL++ = sf;
gbMaskL |= FASTABS(sf);
*coefR++ = cl;
gbMaskR |= FASTABS(cl);
} while (--width);
} else {
/* nothing to do */
coefL += width;
coefR += width;
}
/* get next mask bit (should be branchless on ARM) */
msMask >>= 1;
if (++msMaskOffset == 8) {
msMask = *msMaskPtr++;
msMaskOffset = 0;
}
}
cl = CLZ(gbMaskL) - 1;
if (gbCurrent[0] > cl)
gbCurrent[0] = cl;
cr = CLZ(gbMaskR) - 1;
if (gbCurrent[1] > cr)
gbCurrent[1] = cr;
return;
}
/**************************************************************************************
* Function: StereoProcess
*
* Description: apply mid-side and intensity stereo, if enabled
*
* Inputs: valid AACDecInfo struct (including dequantized transform coefficients)
*
* Outputs: updated transform coefficients in Q(FBITS_OUT_DQ_OFF)
* updated minimum guard bit count for both channels
*
* Return: 0 if successful, -1 if error
**************************************************************************************/
int StereoProcess(AACDecInfo *aacDecInfo)
{
PSInfoBase *psi;
ICSInfo *icsInfo;
int gp, win, nSamps, msMaskOffset;
int *coefL, *coefR;
unsigned char *msMaskPtr;
const /*short*/ int *sfbTab;
/* validate pointers */
if (!aacDecInfo || !aacDecInfo->psInfoBase)
return -1;
psi = (PSInfoBase *)(aacDecInfo->psInfoBase);
/* mid-side and intensity stereo require common_window == 1 (see MPEG4 spec, Correction 2, 2004) */
if (psi->commonWin != 1 || aacDecInfo->currBlockID != AAC_ID_CPE)
return 0;
/* nothing to do */
if (!psi->msMaskPresent && !psi->intensityUsed[1])
return 0;
icsInfo = &(psi->icsInfo[0]);
if (icsInfo->winSequence == 2) {
sfbTab = sfBandTabShort + sfBandTabShortOffset[psi->sampRateIdx];
nSamps = NSAMPS_SHORT;
} else {
sfbTab = sfBandTabLong + sfBandTabLongOffset[psi->sampRateIdx];
nSamps = NSAMPS_LONG;
}
coefL = psi->coef[0];
coefR = psi->coef[1];
/* do fused mid-side/intensity processing for each block (one long or eight short) */
msMaskOffset = 0;
msMaskPtr = psi->msMaskBits;
for (gp = 0; gp < icsInfo->numWinGroup; gp++) {
for (win = 0; win < icsInfo->winGroupLen[gp]; win++) {
StereoProcessGroup(coefL, coefR, sfbTab, psi->msMaskPresent,
msMaskPtr, msMaskOffset, icsInfo->maxSFB, psi->sfbCodeBook[1] + gp*icsInfo->maxSFB,
psi->scaleFactors[1] + gp*icsInfo->maxSFB, psi->gbCurrent);
coefL += nSamps;
coefR += nSamps;
}
/* we use one bit per sfb, so there are maxSFB bits for each window group */
msMaskPtr += (msMaskOffset + icsInfo->maxSFB) >> 3;
msMaskOffset = (msMaskOffset + icsInfo->maxSFB) & 0x07;
}
ASSERT(coefL == psi->coef[0] + 1024);
ASSERT(coefR == psi->coef[1] + 1024);
return 0;
}