/* ***** BEGIN LICENSE BLOCK ***** * Source last modified: $Id: dequant.c,v 1.2 2005/05/20 18:05:41 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), Ken Cooke (kenc@real.com) * February 2005 * * dequant.c - transform coefficient dequantization and short-block deinterleaving **************************************************************************************/ #include "coder.h" #include "assembly.h" #define SF_OFFSET 100 /* pow(2, i/4.0) for i = [0,1,2,3], format = Q30 */ static const int pow14[4] PROGMEM = { 0x40000000, 0x4c1bf829, 0x5a82799a, 0x6ba27e65 }; /* pow(2, i/4.0) * pow(j, 4.0/3.0) for i = [0,1,2,3], j = [0,1,2,...,15] * format = Q28 for j = [0-3], Q25 for j = [4-15] */ static const int pow43_14[4][16] PROGMEM = { { 0x00000000, 0x10000000, 0x285145f3, 0x453a5cdb, /* Q28 */ 0x0cb2ff53, 0x111989d6, 0x15ce31c8, 0x1ac7f203, /* Q25 */ 0x20000000, 0x257106b9, 0x2b16b4a3, 0x30ed74b4, /* Q25 */ 0x36f23fa5, 0x3d227bd3, 0x437be656, 0x49fc823c, /* Q25 */ }, { 0x00000000, 0x1306fe0a, 0x2ff221af, 0x52538f52, 0x0f1a1bf4, 0x1455ccc2, 0x19ee62a8, 0x1fd92396, 0x260dfc14, 0x2c8694d8, 0x333dcb29, 0x3a2f5c7a, 0x4157aed5, 0x48b3aaa3, 0x50409f76, 0x57fc3010, }, { 0x00000000, 0x16a09e66, 0x39047c0f, 0x61e734aa, 0x11f59ac4, 0x182ec633, 0x1ed66a45, 0x25dfc55a, 0x2d413ccd, 0x34f3462d, 0x3cefc603, 0x4531ab69, 0x4db4adf8, 0x56752054, 0x5f6fcfcd, 0x68a1eca1, }, { 0x00000000, 0x1ae89f99, 0x43ce3e4b, 0x746d57b2, 0x155b8109, 0x1cc21cdc, 0x24ac1839, 0x2d0a479e, 0x35d13f33, 0x3ef80748, 0x48775c93, 0x524938cd, 0x5c68841d, 0x66d0df0a, 0x717e7bfe, 0x7c6e0305, }, }; /* pow(j, 4.0 / 3.0) for j = [16,17,18,...,63], format = Q23 */ static const int pow43[48] PROGMEM = { 0x1428a2fa, 0x15db1bd6, 0x1796302c, 0x19598d85, 0x1b24e8bb, 0x1cf7fcfa, 0x1ed28af2, 0x20b4582a, 0x229d2e6e, 0x248cdb55, 0x26832fda, 0x28800000, 0x2a832287, 0x2c8c70a8, 0x2e9bc5d8, 0x30b0ff99, 0x32cbfd4a, 0x34eca001, 0x3712ca62, 0x393e6088, 0x3b6f47e0, 0x3da56717, 0x3fe0a5fc, 0x4220ed72, 0x44662758, 0x46b03e7c, 0x48ff1e87, 0x4b52b3f3, 0x4daaebfd, 0x5007b497, 0x5268fc62, 0x54ceb29c, 0x5738c721, 0x59a72a59, 0x5c19cd35, 0x5e90a129, 0x610b9821, 0x638aa47f, 0x660db90f, 0x6894c90b, 0x6b1fc80c, 0x6daeaa0d, 0x70416360, 0x72d7e8b0, 0x75722ef9, 0x78102b85, 0x7ab1d3ec, 0x7d571e09, }; /* sqrt(0.5), format = Q31 */ #define SQRTHALF 0x5a82799a /* Minimax polynomial approximation to pow(x, 4/3), over the range * poly43lo: x = [0.5, 0.7071] * poly43hi: x = [0.7071, 1.0] * * Relative error < 1E-7 * Coefs are scaled by 4, 2, 1, 0.5, 0.25 */ //fb #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Wnarrowing" static const int poly43lo[5] PROGMEM = { 0x29a0bda9, 0xb02e4828, 0x5957aa1b, 0x236c498d, 0xff581859 }; static const int poly43hi[5] PROGMEM = { 0x10852163, 0xd333f6a4, 0x46e9408b, 0x27c2cef0, 0xfef577b4 }; #pragma GCC diagnostic pop /* pow2exp[i] = pow(2, i*4/3) exponent */ static const int pow2exp[8] PROGMEM = { 14, 13, 11, 10, 9, 7, 6, 5 }; /* pow2exp[i] = pow(2, i*4/3) fraction */ static const int pow2frac[8] PROGMEM = { 0x6597fa94, 0x50a28be6, 0x7fffffff, 0x6597fa94, 0x50a28be6, 0x7fffffff, 0x6597fa94, 0x50a28be6 }; /************************************************************************************** * Function: DequantBlock * * Description: dequantize one block of transform coefficients (in-place) * * Inputs: quantized transform coefficients, range = [0, 8191] * number of samples to dequantize * scalefactor for this block of data, range = [0, 256] * * Outputs: dequantized transform coefficients in Q(FBITS_OUT_DQ_OFF) * * Return: guard bit mask (OR of abs value of all dequantized coefs) * * Notes: applies dequant formula y = pow(x, 4.0/3.0) * pow(2, (scale - 100)/4.0) * * pow(2, FBITS_OUT_DQ_OFF) * clips outputs to Q(FBITS_OUT_DQ_OFF) * output has no minimum number of guard bits **************************************************************************************/ static int DequantBlock(int *inbuf, int nSamps, int scale) { int iSamp, scalef, scalei, x, y, gbMask, shift, tab4[4]; const int *tab16, *coef; if (nSamps <= 0) return 0; scale -= SF_OFFSET; /* new range = [-100, 156] */ /* with two's complement numbers, scalei/scalef factorization works for pos and neg values of scale: * [+4...+7] >> 2 = +1, [ 0...+3] >> 2 = 0, [-4...-1] >> 2 = -1, [-8...-5] >> 2 = -2 ... * (-1 & 0x3) = 3, (-2 & 0x3) = 2, (-3 & 0x3) = 1, (0 & 0x3) = 0 * * Example: 2^(-5/4) = 2^(-1) * 2^(-1/4) = 2^-2 * 2^(3/4) */ tab16 = pow43_14[scale & 0x3]; scalef = pow14[scale & 0x3]; scalei = (scale >> 2) + FBITS_OUT_DQ_OFF; /* cache first 4 values: * tab16[j] = Q28 for j = [0,3] * tab4[x] = x^(4.0/3.0) * 2^(0.25*scale), Q(FBITS_OUT_DQ_OFF) */ shift = 28 - scalei; if (shift > 31) { tab4[0] = tab4[1] = tab4[2] = tab4[3] = 0; } else if (shift <= 0) { shift = -shift; if (shift > 31) shift = 31; for (x = 0; x < 4; x++) { y = tab16[x]; if (y > (0x7fffffff >> shift)) y = 0x7fffffff; /* clip (rare) */ else y <<= shift; tab4[x] = y; } } else { tab4[0] = 0; tab4[1] = tab16[1] >> shift; tab4[2] = tab16[2] >> shift; tab4[3] = tab16[3] >> shift; } gbMask = 0; do { iSamp = *inbuf; x = FASTABS(iSamp); if (x < 4) { y = tab4[x]; } else { if (x < 16) { /* result: y = Q25 (tab16 = Q25) */ y = tab16[x]; shift = 25 - scalei; } else if (x < 64) { /* result: y = Q21 (pow43tab[j] = Q23, scalef = Q30) */ y = pow43[x-16]; shift = 21 - scalei; y = MULSHIFT32(y, scalef); } else { /* normalize to [0x40000000, 0x7fffffff] * input x = [64, 8191] = [64, 2^13-1] * ranges: * shift = 7: 64 - 127 * shift = 6: 128 - 255 * shift = 5: 256 - 511 * shift = 4: 512 - 1023 * shift = 3: 1024 - 2047 * shift = 2: 2048 - 4095 * shift = 1: 4096 - 8191 */ x <<= 17; shift = 0; if (x < 0x08000000) x <<= 4, shift += 4; if (x < 0x20000000) x <<= 2, shift += 2; if (x < 0x40000000) x <<= 1, shift += 1; coef = (x < SQRTHALF) ? poly43lo : poly43hi; /* polynomial */ y = coef[0]; y = MULSHIFT32(y, x) + coef[1]; y = MULSHIFT32(y, x) + coef[2]; y = MULSHIFT32(y, x) + coef[3]; y = MULSHIFT32(y, x) + coef[4]; y = MULSHIFT32(y, pow2frac[shift]) << 3; /* fractional scale * result: y = Q21 (pow43tab[j] = Q23, scalef = Q30) */ y = MULSHIFT32(y, scalef); /* now y is Q24 */ shift = 24 - scalei - pow2exp[shift]; } /* integer scale */ if (shift <= 0) { shift = -shift; if (shift > 31) shift = 31; if (y > (0x7fffffff >> shift)) y = 0x7fffffff; /* clip (rare) */ else y <<= shift; } else { if (shift > 31) shift = 31; y >>= shift; } } /* sign and store (gbMask used to count GB's) */ gbMask |= y; /* apply sign */ iSamp >>= 31; y ^= iSamp; y -= iSamp; *inbuf++ = y; } while (--nSamps); return gbMask; } /************************************************************************************** * Function: Dequantize * * Description: dequantize all transform coefficients for one channel * * Inputs: valid AACDecInfo struct (including unpacked, quantized coefficients) * index of current channel * * Outputs: dequantized coefficients, including short-block deinterleaving * flags indicating if intensity and/or PNS is active * minimum guard bit count for dequantized coefficients * * Return: 0 if successful, error code (< 0) if error **************************************************************************************/ int Dequantize(AACDecInfo *aacDecInfo, int ch) { int gp, cb, sfb, win, width, nSamps, gbMask; int *coef; const int /*short*/ *sfbTab; unsigned char *sfbCodeBook; short *scaleFactors; PSInfoBase *psi; ICSInfo *icsInfo; /* validate pointers */ if (!aacDecInfo || !aacDecInfo->psInfoBase) return ERR_AAC_NULL_POINTER; psi = (PSInfoBase *)(aacDecInfo->psInfoBase); icsInfo = (ch == 1 && psi->commonWin == 1) ? &(psi->icsInfo[0]) : &(psi->icsInfo[ch]); 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]; psi->intensityUsed[ch] = 0; psi->pnsUsed[ch] = 0; gbMask = 0; for (gp = 0; gp < icsInfo->numWinGroup; gp++) { for (win = 0; win < icsInfo->winGroupLen[gp]; win++) { for (sfb = 0; sfb < icsInfo->maxSFB; sfb++) { /* dequantize one scalefactor band (not necessary if codebook is intensity or PNS) * for zero codebook, still run dequantizer in case non-zero pulse data was added */ cb = (int)(sfbCodeBook[sfb]); width = sfbTab[sfb+1] - sfbTab[sfb]; if (cb >= 0 && cb <= 11) gbMask |= DequantBlock(coef, width, scaleFactors[sfb]); else if (cb == 13) psi->pnsUsed[ch] = 1; else if (cb == 14 || cb == 15) psi->intensityUsed[ch] = 1; /* should only happen if ch == 1 */ coef += width; } coef += (nSamps - sfbTab[icsInfo->maxSFB]); } sfbCodeBook += icsInfo->maxSFB; scaleFactors += icsInfo->maxSFB; } aacDecInfo->pnsUsed |= psi->pnsUsed[ch]; /* set flag if PNS used for any channel */ /* calculate number of guard bits in dequantized data */ psi->gbCurrent[ch] = CLZ(gbMask) - 1; return ERR_AAC_NONE; } /************************************************************************************** * Function: DeinterleaveShortBlocks * * Description: deinterleave transform coefficients in short blocks for one channel * * Inputs: valid AACDecInfo struct (including unpacked, quantized coefficients) * index of current channel * * Outputs: deinterleaved coefficients (window groups into 8 separate windows) * * Return: 0 if successful, error code (< 0) if error * * Notes: only necessary if deinterleaving not part of Huffman decoding **************************************************************************************/ int DeinterleaveShortBlocks(AACDecInfo *aacDecInfo, int ch) { (void)aacDecInfo; (void)ch; /* not used for this implementation - short block deinterleaving performed during Huffman decoding */ return ERR_AAC_NONE; }