blob: 852fefab58455e75087ed110591e001599c477e5
| 1 | /* ***** BEGIN LICENSE BLOCK ***** |
| 2 | * Source last modified: $Id: stproc.c,v 1.3 2005/05/24 16:01:55 albertofloyd Exp $ |
| 3 | * |
| 4 | * Portions Copyright (c) 1995-2005 RealNetworks, Inc. All Rights Reserved. |
| 5 | * |
| 6 | * The contents of this file, and the files included with this file, |
| 7 | * are subject to the current version of the RealNetworks Public |
| 8 | * Source License (the "RPSL") available at |
| 9 | * http://www.helixcommunity.org/content/rpsl unless you have licensed |
| 10 | * the file under the current version of the RealNetworks Community |
| 11 | * Source License (the "RCSL") available at |
| 12 | * http://www.helixcommunity.org/content/rcsl, in which case the RCSL |
| 13 | * will apply. You may also obtain the license terms directly from |
| 14 | * RealNetworks. You may not use this file except in compliance with |
| 15 | * the RPSL or, if you have a valid RCSL with RealNetworks applicable |
| 16 | * to this file, the RCSL. Please see the applicable RPSL or RCSL for |
| 17 | * the rights, obligations and limitations governing use of the |
| 18 | * contents of the file. |
| 19 | * |
| 20 | * This file is part of the Helix DNA Technology. RealNetworks is the |
| 21 | * developer of the Original Code and owns the copyrights in the |
| 22 | * portions it created. |
| 23 | * |
| 24 | * This file, and the files included with this file, is distributed |
| 25 | * and made available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY |
| 26 | * KIND, EITHER EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS |
| 27 | * ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES |
| 28 | * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET |
| 29 | * ENJOYMENT OR NON-INFRINGEMENT. |
| 30 | * |
| 31 | * Technology Compatibility Kit Test Suite(s) Location: |
| 32 | * http://www.helixcommunity.org/content/tck |
| 33 | * |
| 34 | * Contributor(s): |
| 35 | * |
| 36 | * ***** END LICENSE BLOCK ***** */ |
| 37 | |
| 38 | /************************************************************************************** |
| 39 | * Fixed-point HE-AAC decoder |
| 40 | * Jon Recker (jrecker@real.com) |
| 41 | * February 2005 |
| 42 | * |
| 43 | * stproc.c - mid-side and intensity stereo processing |
| 44 | **************************************************************************************/ |
| 45 | |
| 46 | #include "coder.h" |
| 47 | #include "assembly.h" |
| 48 | |
| 49 | /* pow14[0][i] = -pow(2, i/4.0) |
| 50 | * pow14[1][i] = +pow(2, i/4.0) |
| 51 | * |
| 52 | * i = [0,1,2,3] |
| 53 | * format = Q30 |
| 54 | */ |
| 55 | static const int pow14[2][4] = { |
| 56 | { 0xc0000000, 0xb3e407d7, 0xa57d8666, 0x945d819b }, |
| 57 | { 0x40000000, 0x4c1bf829, 0x5a82799a, 0x6ba27e65 } |
| 58 | }; |
| 59 | |
| 60 | /************************************************************************************** |
| 61 | * Function: StereoProcessGroup |
| 62 | * |
| 63 | * Description: apply mid-side and intensity stereo to group of transform coefficients |
| 64 | * |
| 65 | * Inputs: dequantized transform coefficients for both channels |
| 66 | * pointer to appropriate scalefactor band table |
| 67 | * mid-side mask enabled flag |
| 68 | * buffer with mid-side mask (one bit for each scalefactor band) |
| 69 | * bit offset into mid-side mask buffer |
| 70 | * max coded scalefactor band |
| 71 | * buffer of codebook indices for right channel |
| 72 | * buffer of scalefactors for right channel, range = [0, 256] |
| 73 | * |
| 74 | * Outputs: updated transform coefficients in Q(FBITS_OUT_DQ_OFF) |
| 75 | * updated minimum guard bit count for both channels |
| 76 | * |
| 77 | * Return: none |
| 78 | * |
| 79 | * Notes: assume no guard bits in input |
| 80 | * gains 0 int bits |
| 81 | **************************************************************************************/ |
| 82 | static void StereoProcessGroup(int *coefL, int *coefR, const short *sfbTab, |
| 83 | int msMaskPres, unsigned char *msMaskPtr, int msMaskOffset, int maxSFB, |
| 84 | unsigned char *cbRight, short *sfRight, int *gbCurrent) |
| 85 | { |
| 86 | int sfb, width, cbIdx, sf, cl, cr, scalef, scalei; |
| 87 | int gbMaskL, gbMaskR; |
| 88 | unsigned char msMask; |
| 89 | |
| 90 | msMask = (*msMaskPtr++) >> msMaskOffset; |
| 91 | gbMaskL = 0; |
| 92 | gbMaskR = 0; |
| 93 | |
| 94 | for (sfb = 0; sfb < maxSFB; sfb++) { |
| 95 | width = sfbTab[sfb + 1] - sfbTab[sfb]; /* assume >= 0 (see sfBandTabLong/sfBandTabShort) */ |
| 96 | cbIdx = cbRight[sfb]; |
| 97 | |
| 98 | if (cbIdx == 14 || cbIdx == 15) { |
| 99 | /* intensity stereo */ |
| 100 | if (msMaskPres == 1 && (msMask & 0x01)) { |
| 101 | cbIdx ^= 0x01; /* invert_intensity(): 14 becomes 15, or 15 becomes 14 */ |
| 102 | } |
| 103 | sf = -sfRight[sfb]; /* negative since we use identity 0.5^(x) = 2^(-x) (see spec) */ |
| 104 | cbIdx &= 0x01; /* choose - or + scale factor */ |
| 105 | scalef = pow14[cbIdx][sf & 0x03]; |
| 106 | scalei = (sf >> 2) + 2; /* +2 to compensate for scalef = Q30 */ |
| 107 | |
| 108 | if (scalei > 0) { |
| 109 | if (scalei > 30) { |
| 110 | scalei = 30; |
| 111 | } |
| 112 | do { |
| 113 | cr = MULSHIFT32(*coefL++, scalef); |
| 114 | CLIP_2N(cr, 31 - scalei); |
| 115 | cr <<= scalei; |
| 116 | gbMaskR |= FASTABS(cr); |
| 117 | *coefR++ = cr; |
| 118 | } while (--width > 0); |
| 119 | } else { |
| 120 | scalei = -scalei; |
| 121 | if (scalei > 31) { |
| 122 | scalei = 31; |
| 123 | } |
| 124 | do { |
| 125 | cr = MULSHIFT32(*coefL++, scalef) >> scalei; |
| 126 | gbMaskR |= FASTABS(cr); |
| 127 | *coefR++ = cr; |
| 128 | } while (--width > 0); |
| 129 | } |
| 130 | } else if (cbIdx != 13 && ((msMaskPres == 1 && (msMask & 0x01)) || msMaskPres == 2)) { |
| 131 | /* mid-side stereo (assumes no GB in inputs) */ |
| 132 | do { |
| 133 | cl = *coefL; |
| 134 | cr = *coefR; |
| 135 | |
| 136 | if ((FASTABS(cl) | FASTABS(cr)) >> 30) { |
| 137 | /* avoid overflow (rare) */ |
| 138 | cl >>= 1; |
| 139 | sf = cl + (cr >> 1); |
| 140 | CLIP_2N(sf, 30); |
| 141 | sf <<= 1; |
| 142 | cl = cl - (cr >> 1); |
| 143 | CLIP_2N(cl, 30); |
| 144 | cl <<= 1; |
| 145 | } else { |
| 146 | /* usual case */ |
| 147 | sf = cl + cr; |
| 148 | cl -= cr; |
| 149 | } |
| 150 | |
| 151 | *coefL++ = sf; |
| 152 | gbMaskL |= FASTABS(sf); |
| 153 | *coefR++ = cl; |
| 154 | gbMaskR |= FASTABS(cl); |
| 155 | } while (--width > 0); |
| 156 | |
| 157 | } else { |
| 158 | /* nothing to do */ |
| 159 | coefL += width; |
| 160 | coefR += width; |
| 161 | } |
| 162 | |
| 163 | /* get next mask bit (should be branchless on ARM) */ |
| 164 | msMask >>= 1; |
| 165 | if (++msMaskOffset == 8) { |
| 166 | msMask = *msMaskPtr++; |
| 167 | msMaskOffset = 0; |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | cl = CLZ(gbMaskL) - 1; |
| 172 | if (gbCurrent[0] > cl) { |
| 173 | gbCurrent[0] = cl; |
| 174 | } |
| 175 | |
| 176 | cr = CLZ(gbMaskR) - 1; |
| 177 | if (gbCurrent[1] > cr) { |
| 178 | gbCurrent[1] = cr; |
| 179 | } |
| 180 | |
| 181 | return; |
| 182 | } |
| 183 | |
| 184 | /************************************************************************************** |
| 185 | * Function: StereoProcess |
| 186 | * |
| 187 | * Description: apply mid-side and intensity stereo, if enabled |
| 188 | * |
| 189 | * Inputs: valid AACDecInfo struct (including dequantized transform coefficients) |
| 190 | * |
| 191 | * Outputs: updated transform coefficients in Q(FBITS_OUT_DQ_OFF) |
| 192 | * updated minimum guard bit count for both channels |
| 193 | * |
| 194 | * Return: 0 if successful, -1 if error |
| 195 | **************************************************************************************/ |
| 196 | int StereoProcess(AACDecInfo *aacDecInfo) |
| 197 | { |
| 198 | PSInfoBase *psi; |
| 199 | ICSInfo *icsInfo; |
| 200 | int gp, win, nSamps, msMaskOffset; |
| 201 | int *coefL, *coefR; |
| 202 | unsigned char *msMaskPtr; |
| 203 | const short *sfbTab; |
| 204 | |
| 205 | /* validate pointers */ |
| 206 | if (!aacDecInfo || !aacDecInfo->psInfoBase) { |
| 207 | return ERR_AAC_NULL_POINTER; |
| 208 | } |
| 209 | psi = (PSInfoBase *)(aacDecInfo->psInfoBase); |
| 210 | |
| 211 | /* mid-side and intensity stereo require common_window == 1 (see MPEG4 spec, Correction 2, 2004) */ |
| 212 | if (psi->commonWin != 1 || aacDecInfo->currBlockID != AAC_ID_CPE) { |
| 213 | return ERR_AAC_NONE; |
| 214 | } |
| 215 | |
| 216 | /* nothing to do */ |
| 217 | if (!psi->msMaskPresent && !psi->intensityUsed[1]) { |
| 218 | return ERR_AAC_NONE; |
| 219 | } |
| 220 | |
| 221 | icsInfo = &(psi->icsInfo[0]); |
| 222 | if (icsInfo->winSequence == 2) { |
| 223 | sfbTab = sfBandTabShort + sfBandTabShortOffset[psi->sampRateIdx]; |
| 224 | nSamps = NSAMPS_SHORT; |
| 225 | } else { |
| 226 | sfbTab = sfBandTabLong + sfBandTabLongOffset[psi->sampRateIdx]; |
| 227 | nSamps = NSAMPS_LONG; |
| 228 | } |
| 229 | coefL = psi->coef[0]; |
| 230 | coefR = psi->coef[1]; |
| 231 | |
| 232 | /* do fused mid-side/intensity processing for each block (one long or eight short) */ |
| 233 | msMaskOffset = 0; |
| 234 | msMaskPtr = psi->msMaskBits; |
| 235 | for (gp = 0; gp < icsInfo->numWinGroup; gp++) { |
| 236 | for (win = 0; win < icsInfo->winGroupLen[gp]; win++) { |
| 237 | StereoProcessGroup(coefL, coefR, sfbTab, psi->msMaskPresent, |
| 238 | msMaskPtr, msMaskOffset, icsInfo->maxSFB, psi->sfbCodeBook[1] + gp * icsInfo->maxSFB, |
| 239 | psi->scaleFactors[1] + gp * icsInfo->maxSFB, psi->gbCurrent); |
| 240 | coefL += nSamps; |
| 241 | coefR += nSamps; |
| 242 | } |
| 243 | /* we use one bit per sfb, so there are maxSFB bits for each window group */ |
| 244 | msMaskPtr += (msMaskOffset + icsInfo->maxSFB) >> 3; |
| 245 | msMaskOffset = (msMaskOffset + icsInfo->maxSFB) & 0x07; |
| 246 | } |
| 247 | |
| 248 | ASSERT(coefL == psi->coef[0] + 1024, ERR_AAC_COFF_EXCEED_RANGE); |
| 249 | ASSERT(coefR == psi->coef[1] + 1024, ERR_AAC_COFF_EXCEED_RANGE); |
| 250 | return ERR_AAC_NONE; |
| 251 | } |
| 252 |