545 files changed, 230976 insertions, 0 deletions
diff --git a/audio_codec/libfaad/helixaac/pns_helix.c b/audio_codec/libfaad/helixaac/pns_helix.c new file mode 100644 index 0000000..2384593 --- a/dev/null +++ b/audio_codec/libfaad/helixaac/pns_helix.c @@ -0,0 +1,371 @@ +/* ***** BEGIN LICENSE BLOCK ***** + * Source last modified: $Id: pns.c,v 1.2 2005/03/10 17:01:56 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 (jrecker@real.com) + * February 2005 + * + * pns.c - perceptual noise substitution + **************************************************************************************/ + +#include "coder.h" +#ifndef __MW__ +#include "assembly.h" +#else +#include "assembly_mw.h" +#endif /* __MW__ */ + +/************************************************************************************** + * Function: Get32BitVal + * + * Description: generate 32-bit unsigned random number + * + * Inputs: last number calculated (seed, first time through) + * + * Outputs: new number, saved in *last + * + * Return: 32-bit number, uniformly distributed between [0, 2^32) + * + * Notes: uses simple linear congruential generator + **************************************************************************************/ +static unsigned int Get32BitVal(unsigned int *last) +{ + unsigned int r = *last; + + /* use same coefs as MPEG reference code (classic LCG) + * use unsigned multiply to force reliable wraparound behavior in C (mod 2^32) + */ + r = (1664525U * r) + 1013904223U; + *last = r; + + return r; +} + +/* pow(2, i/4.0) for i = [0,1,2,3], format = Q30 */ +static const int pow14[4] = { + 0x40000000, 0x4c1bf829, 0x5a82799a, 0x6ba27e65 +}; + +#define NUM_ITER_INVSQRT 4 + +#define X0_COEF_2 0xc0000000 /* Q29: -2.0 */ +#define X0_OFF_2 0x60000000 /* Q29: 3.0 */ +#define Q26_3 0x0c000000 /* Q26: 3.0 */ + +/************************************************************************************** + * Function: InvRootR + * + * Description: use Newton's method to solve for x = 1/sqrt(r) + * + * Inputs: r in Q30 format, range = [0.25, 1] (normalize inputs to this range) + * + * Outputs: none + * + * Return: x = Q29, range = (1, 2) + * + * Notes: guaranteed to converge and not overflow for any r in this range + * + * xn+1 = xn - f(xn)/f'(xn) + * f(x) = 1/sqrt(r) - x = 0 (find root) + * = 1/x^2 - r + * f'(x) = -2/x^3 + * + * so xn+1 = xn/2 * (3 - r*xn^2) + * + * NUM_ITER_INVSQRT = 3, maxDiff = 1.3747e-02 + * NUM_ITER_INVSQRT = 4, maxDiff = 3.9832e-04 + **************************************************************************************/ +static int InvRootR(int r) +{ + int i, xn, t; + + /* use linear equation for initial guess + * x0 = -2*r + 3 (so x0 always >= correct answer in range [0.25, 1)) + * xn = Q29 (at every step) + */ + xn = (MULSHIFT32(r, X0_COEF_2) << 2) + X0_OFF_2; + + for (i = 0; i < NUM_ITER_INVSQRT; i++) { + t = MULSHIFT32(xn, xn); /* Q26 = Q29*Q29 */ + t = Q26_3 - (MULSHIFT32(r, t) << 2); /* Q26 = Q26 - (Q31*Q26 << 1) */ + xn = MULSHIFT32(xn, t) << (6 - 1); /* Q29 = (Q29*Q26 << 6), and -1 for division by 2 */ + } + + /* clip to range (1.0, 2.0) + * (because of rounding, this can converge to xn slightly > 2.0 when r is near 0.25) + */ + if (xn >> 30) { + xn = (1 << 30) - 1; + } + + return xn; +} + +/************************************************************************************** + * Function: ScaleNoiseVector + * + * Description: apply scaling to vector of noise coefficients for one scalefactor band + * + * Inputs: unscaled coefficients + * number of coefficients in vector (one scalefactor band of coefs) + * scalefactor for this band (i.e. noise energy) + * + * Outputs: nVals coefficients in Q(FBITS_OUT_DQ_OFF) + * + * Return: guard bit mask (OR of abs value of all noise coefs) + **************************************************************************************/ +static int ScaleNoiseVector(int *coef, int nVals, int sf) +{ + int i, c, spec, energy, sq, scalef, scalei, invSqrtEnergy, z, gbMask; + + energy = 0; + for (i = 0; i < nVals; i++) { + spec = coef[i]; + + /* max nVals = max SFB width = 96, so energy can gain < 2^7 bits in accumulation */ + sq = (spec * spec) >> 8; /* spec*spec range = (-2^30, 2^30) */ + energy += sq; + } + + /* unless nVals == 1 (or the number generator is broken...), this should not happen */ + if (energy == 0) { + return 0; /* coef[i] must = 0 for i = [0, nVals-1], so gbMask = 0 */ + } + + /* pow(2, sf/4) * pow(2, FBITS_OUT_DQ_OFF) */ + scalef = pow14[sf & 0x3]; + scalei = (sf >> 2) + FBITS_OUT_DQ_OFF; + + /* energy has implied factor of 2^-8 since we shifted the accumulator + * normalize energy to range [0.25, 1.0), calculate 1/sqrt(1), and denormalize + * i.e. divide input by 2^(30-z) and convert to Q30 + * output of 1/sqrt(i) now has extra factor of 2^((30-z)/2) + * for energy > 0, z is an even number between 0 and 28 + * final scaling of invSqrtEnergy: + * 2^(15 - z/2) to compensate for implicit 2^(30-z) factor in input + * +4 to compensate for implicit 2^-8 factor in input + */ + z = CLZ(energy) - 2; /* energy has at least 2 leading zeros (see acc loop) */ + z &= 0xfffffffe; /* force even */ + invSqrtEnergy = InvRootR(energy << z); /* energy << z must be in range [0x10000000, 0x40000000] */ + scalei -= (15 - z / 2 + 4); /* nInt = 1/sqrt(energy) in Q29 */ + + /* normalize for final scaling */ + z = CLZ(invSqrtEnergy) - 1; + invSqrtEnergy <<= z; + scalei -= (z - 3 - 2); /* -2 for scalef, z-3 for invSqrtEnergy */ + scalef = MULSHIFT32(scalef, invSqrtEnergy); /* scalef (input) = Q30, invSqrtEnergy = Q29 * 2^z */ + gbMask = 0; + + if (scalei < 0) { + scalei = -scalei; + if (scalei > 31) { + scalei = 31; + } + for (i = 0; i < nVals; i++) { + c = MULSHIFT32(coef[i], scalef) >> scalei; + gbMask |= FASTABS(c); + coef[i] = c; + } + } else { + /* for scalei <= 16, no clipping possible (coef[i] is < 2^15 before scaling) + * for scalei > 16, just saturate exponent (rare) + * scalef is close to full-scale (since we normalized invSqrtEnergy) + * remember, we are just producing noise here + */ + if (scalei > 16) { + scalei = 16; + } + for (i = 0; i < nVals; i++) { + c = MULSHIFT32(coef[i] << scalei, scalef); + coef[i] = c; + gbMask |= FASTABS(c); + } + } + + return gbMask; +} + +/************************************************************************************** + * Function: GenerateNoiseVector + * + * Description: create vector of noise coefficients for one scalefactor band + * + * Inputs: seed for number generator + * number of coefficients to generate + * + * Outputs: buffer of nVals coefficients, range = [-2^15, 2^15) + * updated seed for number generator + * + * Return: none + **************************************************************************************/ +static void GenerateNoiseVector(int *coef, int *last, int nVals) +{ + int i; + + for (i = 0; i < nVals; i++) { + coef[i] = ((signed int)Get32BitVal((unsigned int *)last)) >> 16; + } +} + +/************************************************************************************** + * Function: CopyNoiseVector + * + * Description: copy vector of noise coefficients for one scalefactor band from L to R + * + * Inputs: buffer of left coefficients + * number of coefficients to copy + * + * Outputs: buffer of right coefficients + * + * Return: none + **************************************************************************************/ +static void CopyNoiseVector(int *coefL, int *coefR, int nVals) +{ + int i; + + for (i = 0; i < nVals; i++) { + coefR[i] = coefL[i]; + } +} + +/************************************************************************************** + * Function: PNS + * + * Description: apply perceptual noise substitution, if enabled (MPEG-4 only) + * + * Inputs: valid AACDecInfo struct + * index of current channel + * + * Outputs: shaped noise in scalefactor bands where PNS is active + * updated minimum guard bit count for this channel + * + * Return: 0 if successful, -1 if error + **************************************************************************************/ +int PNS(AACDecInfo *aacDecInfo, int ch) +{ + int gp, sfb, win, width, nSamps, gb, gbMask; + int *coef; + const short *sfbTab; + unsigned char *sfbCodeBook; + short *scaleFactors; + int msMaskOffset, checkCorr, genNew; + unsigned char msMask; + unsigned char *msMaskPtr; + PSInfoBase *psi; + ICSInfo *icsInfo; + + /* validate pointers */ + if (!aacDecInfo || !aacDecInfo->psInfoBase) { + return -1; + } + psi = (PSInfoBase *)(aacDecInfo->psInfoBase); + icsInfo = (ch == 1 && psi->commonWin == 1) ? &(psi->icsInfo[0]) : &(psi->icsInfo[ch]); + + if (!psi->pnsUsed[ch]) { + return 0; + } + + if (icsInfo->winSequence == 2) { + sfbTab = sfBandTabShort + sfBandTabShortOffset[psi->sampRateIdx]; + nSamps = NSAMPS_SHORT; + } else { + sfbTab = sfBandTabLong + sfBandTabLongOffset[psi->sampRateIdx]; + nSamps = NSAMPS_LONG; + } + coef = psi->coef[ch]; + sfbCodeBook = psi->sfbCodeBook[ch]; + scaleFactors = psi->scaleFactors[ch]; + checkCorr = (aacDecInfo->currBlockID == AAC_ID_CPE && psi->commonWin == 1 ? 1 : 0); + + gbMask = 0; + for (gp = 0; gp < icsInfo->numWinGroup; gp++) { + for (win = 0; win < icsInfo->winGroupLen[gp]; win++) { + msMaskPtr = psi->msMaskBits + ((gp * icsInfo->maxSFB) >> 3); + msMaskOffset = ((gp * icsInfo->maxSFB) & 0x07); + msMask = (*msMaskPtr++) >> msMaskOffset; + + for (sfb = 0; sfb < icsInfo->maxSFB; sfb++) { + width = sfbTab[sfb + 1] - sfbTab[sfb]; + if (sfbCodeBook[sfb] == 13) { + if (ch == 0) { + /* generate new vector, copy into ch 1 if it's possible that the channels will be correlated + * if ch 1 has PNS enabled for this SFB but it's uncorrelated (i.e. ms_used == 0), + * the copied values will be overwritten when we process ch 1 + */ + GenerateNoiseVector(coef, &psi->pnsLastVal, width); + if (checkCorr && psi->sfbCodeBook[1][gp * icsInfo->maxSFB + sfb] == 13) { + CopyNoiseVector(coef, psi->coef[1] + (coef - psi->coef[0]), width); + } + } else { + /* generate new vector if no correlation between channels */ + genNew = 1; + if (checkCorr && psi->sfbCodeBook[0][gp * icsInfo->maxSFB + sfb] == 13) { + if ((psi->msMaskPresent == 1 && (msMask & 0x01)) || psi->msMaskPresent == 2) { + genNew = 0; + } + } + if (genNew) { + GenerateNoiseVector(coef, &psi->pnsLastVal, width); + } + } + gbMask |= ScaleNoiseVector(coef, width, psi->scaleFactors[ch][gp * icsInfo->maxSFB + sfb]); + } + coef += width; + + /* get next mask bit (should be branchless on ARM) */ + msMask >>= 1; + if (++msMaskOffset == 8) { + msMask = *msMaskPtr++; + msMaskOffset = 0; + } + } + coef += (nSamps - sfbTab[icsInfo->maxSFB]); + } + sfbCodeBook += icsInfo->maxSFB; + scaleFactors += icsInfo->maxSFB; + } + + /* update guard bit count if necessary */ + gb = CLZ(gbMask) - 1; + if (psi->gbCurrent[ch] > gb) { + psi->gbCurrent[ch] = gb; + } + + return 0; +} |