blob: 1f53c4542fa4624355c2ed8545d8f3a9d10ab6f5
| 1 | /* ***** BEGIN LICENSE BLOCK ***** |
| 2 | * Source last modified: $Id: couple.c,v 1.6 2005/04/27 19:20:50 hubbe Exp $ |
| 3 | * |
| 4 | * REALNETWORKS CONFIDENTIAL--NOT FOR DISTRIBUTION IN SOURCE CODE FORM |
| 5 | * Portions Copyright (c) 1995-2002 RealNetworks, Inc. |
| 6 | * All Rights Reserved. |
| 7 | * |
| 8 | * The contents of this file, and the files included with this file, |
| 9 | * are subject to the current version of the Real Format Source Code |
| 10 | * Porting and Optimization License, available at |
| 11 | * https://helixcommunity.org/2005/license/realformatsource (unless |
| 12 | * RealNetworks otherwise expressly agrees in writing that you are |
| 13 | * subject to a different license). You may also obtain the license |
| 14 | * terms directly from RealNetworks. You may not use this file except |
| 15 | * in compliance with the Real Format Source Code Porting and |
| 16 | * Optimization License. There are no redistribution rights for the |
| 17 | * source code of this file. Please see the Real Format Source Code |
| 18 | * Porting and Optimization License for the rights, obligations and |
| 19 | * limitations governing use of the contents of the file. |
| 20 | * |
| 21 | * RealNetworks is the developer of the Original Code and owns the |
| 22 | * copyrights in the portions it created. |
| 23 | * |
| 24 | * This file, and the files included with this file, is distributed and |
| 25 | * made available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, |
| 26 | * EITHER EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS ALL |
| 27 | * SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF |
| 28 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT |
| 29 | * OR NON-INFRINGEMENT. |
| 30 | * |
| 31 | * Technology Compatibility Kit Test Suite(s) Location: |
| 32 | * https://rarvcode-tck.helixcommunity.org |
| 33 | * |
| 34 | * Contributor(s): |
| 35 | * |
| 36 | * ***** END LICENSE BLOCK ***** */ |
| 37 | |
| 38 | /************************************************************************************** |
| 39 | * Fixed-point RealAudio 8 decoder |
| 40 | * Jon Recker (jrecker@real.com), Ken Cooke (kenc@real.com) |
| 41 | * October 2003 |
| 42 | * |
| 43 | * couple.c - joint stereo processing |
| 44 | **************************************************************************************/ |
| 45 | |
| 46 | #include "coder.h" |
| 47 | #include "assembly.h" |
| 48 | |
| 49 | /* coupling band widths, based on Zwicker critical-bandwidth */ |
| 50 | const int cplband[MAXREGNS] = { |
| 51 | 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, |
| 52 | 11, 11, |
| 53 | 12, 12, |
| 54 | 13, 13, |
| 55 | 14, 14, 14, |
| 56 | 15, 15, 15, 15, |
| 57 | 16, 16, 16, 16, 16, |
| 58 | 17, 17, 17, 17, 17, 17, |
| 59 | 18, 18, 18, 18, 18, 18, 18, |
| 60 | 19, 19, 19, 19, 19, 19, 19, 19, 19 |
| 61 | }; |
| 62 | |
| 63 | /* Lookup tables for reconstructed scaling factors - format = Q31 */ |
| 64 | static const int cplScale[3 + 7 + 15 + 31 + 63] = { |
| 65 | |
| 66 | /* cplScale2[3] */ |
| 67 | 0x79fc945f, 0x5a82799a, 0x26c59af8, |
| 68 | |
| 69 | /* cplScale3[7] */ |
| 70 | 0x7d9a93a4, 0x77ef8978, 0x701e9f27, 0x5a82799a, |
| 71 | 0x3dc04491, 0x2cb7094c, 0x18a6b4ed, |
| 72 | |
| 73 | /* cplScale4[15] */ |
| 74 | 0x7ee90962, 0x7c936c4f, 0x79fc9465, 0x770e9d8f, |
| 75 | 0x73a45b28, 0x6f749c4e, 0x69c04836, 0x5a82799a, |
| 76 | 0x481dac45, 0x3ef11955, 0x36df3415, 0x2f011d16, |
| 77 | 0x26c59ae8, 0x1d688afa, 0x10aaa6fd, |
| 78 | |
| 79 | /* cplScale5[31] */ |
| 80 | 0x7f7a8410, 0x7e66f9cf, 0x7d46e886, 0x7c18c36e, |
| 81 | 0x7adaa745, 0x798a3db9, 0x78249362, 0x76a5d7e1, |
| 82 | 0x7508f83e, 0x7346f452, 0x7155abbc, 0x6f257fbd, |
| 83 | 0x6c9c00f0, 0x6985577e, 0x655acbf3, 0x5a82799a, |
| 84 | 0x4e2ca29a, 0x4873cee8, 0x43bc1a9b, 0x3f7c6426, |
| 85 | 0x3b7ddcf1, 0x37a26159, 0x33d59802, 0x30072e43, |
| 86 | 0x2c27c13f, 0x28266a5d, 0x23edbab6, 0x1f5e6927, |
| 87 | 0x1a42fec7, 0x14294028, 0x0b8ab0db, |
| 88 | |
| 89 | /* cplScale6[63] */ |
| 90 | 0x7fbea8be, 0x7f39f9ab, 0x7eb28121, 0x7e281805, |
| 91 | 0x7d9a93a8, 0x7d09c543, 0x7c75796f, 0x7bdd7778, |
| 92 | 0x7b418090, 0x7aa14ee1, 0x79fc9466, 0x7952f983, |
| 93 | 0x78a41b51, 0x77ef897b, 0x7734c38d, 0x76733593, |
| 94 | 0x75aa33b1, 0x74d8f46c, 0x73fe8908, 0x7319d333, |
| 95 | 0x722976ad, 0x712bc4eb, 0x701e9f29, 0x6eff48fd, |
| 96 | 0x6dca2025, 0x6c7a2377, 0x6b081945, 0x6968e250, |
| 97 | 0x6789b6cc, 0x6545d976, 0x623e1923, 0x5a82799a, |
| 98 | 0x520d1a91, 0x4e47c3aa, 0x4b4243b5, 0x489d2fc3, |
| 99 | 0x46338b6a, 0x43f2498b, 0x41cdfe96, 0x3fbf1c82, |
| 100 | 0x3dc0448d, 0x3bcd6c20, 0x39e361f6, 0x37ff83c3, |
| 101 | 0x361f8e06, 0x34417ac7, 0x326368ee, 0x3083887b, |
| 102 | 0x2ea0091f, 0x2cb70944, 0x2ac683d0, 0x28cc3a99, |
| 103 | 0x26c59ae4, 0x24af97f2, 0x22867502, 0x20457311, |
| 104 | 0x1de64c41, 0x1b604f6f, 0x18a6b4dc, 0x15a521e0, |
| 105 | 0x1237205d, 0x0e0d0479, 0x08144f82 |
| 106 | }; |
| 107 | |
| 108 | static const int cplScaleOffset[7] = { 0, 0, 0, 3, 10, 25, 56}; |
| 109 | |
| 110 | |
| 111 | /************************************************************************************** |
| 112 | * Function: DecodeCoupleInfo |
| 113 | * |
| 114 | * Description: decode indices for joint stereo scale factors |
| 115 | * |
| 116 | * Inputs: pointer to initialized Gecko2Info struct |
| 117 | * number of bits remaining in bitstream for this frame |
| 118 | * |
| 119 | * Outputs: filled-in cplindex[] buffer, with one index per coupling band |
| 120 | * |
| 121 | * Return: number of bits remaining in bitstream, -1 if out-of-bits |
| 122 | * |
| 123 | * Notes: couple index info can either be direct-coded or Huffman-coded |
| 124 | **************************************************************************************/ |
| 125 | int DecodeCoupleInfo(Gecko2Info *gi, int availbits) |
| 126 | { |
| 127 | int bandstart = cplband[gi->cplStart]; |
| 128 | int bandend = cplband[gi->nRegions - 1]; |
| 129 | int hufmode, nbits, b, cache; |
| 130 | int *cplindex = gi->db.cplindex; |
| 131 | BitStreamInfo *bsi = &(gi->bsi); |
| 132 | |
| 133 | if (availbits < 1) { |
| 134 | return -1; |
| 135 | } |
| 136 | |
| 137 | /* one-bit flag indicating Huffman or direct coding */ |
| 138 | hufmode = GetBits(bsi, 1, 1); |
| 139 | availbits--; |
| 140 | |
| 141 | if (hufmode) { |
| 142 | /* HUFFMAN */ |
| 143 | for (b = bandstart; b <= bandend; b++) { |
| 144 | cache = GetBits(bsi, MAX_HUFF_BITS, 0); |
| 145 | nbits = DecodeHuffmanScalar(huffTabCouple, &huffTabCoupleInfo[gi->cplQbits - HUFFTAB_COUPLE_OFFSET], cache, cplindex + b); |
| 146 | if (nbits > availbits) { |
| 147 | return -1; |
| 148 | } |
| 149 | availbits -= nbits; |
| 150 | AdvanceBitstream(bsi, nbits); |
| 151 | } |
| 152 | } else { |
| 153 | /* DIRECT */ |
| 154 | if (availbits < gi->cplQbits * (bandend - bandstart + 1)) { |
| 155 | return -1; |
| 156 | } |
| 157 | for (b = bandstart; b <= bandend; b++) { |
| 158 | cplindex[b] = GetBits(bsi, gi->cplQbits, 1); |
| 159 | availbits -= gi->cplQbits; |
| 160 | } |
| 161 | } |
| 162 | |
| 163 | return availbits; |
| 164 | } |
| 165 | |
| 166 | /************************************************************************************** |
| 167 | * Function: JointDecodeMLT |
| 168 | * |
| 169 | * Description: decode the jointly-coded MLT |
| 170 | * |
| 171 | * Inputs: pointer to initialized Gecko2Info struct |
| 172 | * mltleft[0, ... , cplStart-1] has non-coupled coefficients for left |
| 173 | * mltrght[0, ... , cplStart-1] has non-coupled coefficients for right |
| 174 | * mltleft[cplStart, ... , cRegions] has coupled coefficients |
| 175 | * |
| 176 | * Outputs: mltleft[0, ... , nRegions-1] has reconstructed coefficients for left |
| 177 | * mltrght[0, ... , nRegions-1] has reconstructed coefficients for right |
| 178 | * |
| 179 | * Return: none |
| 180 | **************************************************************************************/ |
| 181 | void JointDecodeMLT(Gecko2Info *gi, int *mltleft, int *mltrght) |
| 182 | { |
| 183 | int scaleleft, scalerght; |
| 184 | int i, r, q; |
| 185 | int cplquant, cploffset; |
| 186 | int *cplindex = gi->db.cplindex; |
| 187 | |
| 188 | cplquant = (1 << gi->cplQbits) - 1; /* quant levels */ |
| 189 | cploffset = cplScaleOffset[gi->cplQbits]; |
| 190 | |
| 191 | /* reconstruct the stereo channels */ |
| 192 | for (r = gi->cplStart; r < gi->nRegions; r++) { |
| 193 | |
| 194 | /* |
| 195 | * dequantize the expanded coupling ratio |
| 196 | * expand = (q - (cplquant>>1)) * (2.0f/cplquant); |
| 197 | * |
| 198 | * square-law compression |
| 199 | * ratio = sqrt(fabs(expand)); |
| 200 | * if (expand < 0.0f) ratio = -ratio; |
| 201 | * |
| 202 | * reconstruct the scaling factors |
| 203 | * scaleleft = sqrt(0.5f - 0.5f * ratio); |
| 204 | * scalerght = sqrt(0.5f + 0.5f * ratio); |
| 205 | */ |
| 206 | q = cplindex[cplband[r]]; |
| 207 | scaleleft = cplScale[cploffset + q]; |
| 208 | scalerght = cplScale[cploffset + cplquant - 1 - q]; |
| 209 | |
| 210 | /* drop extra sign bit (max gain = 0.998) */ |
| 211 | for (i = 0; i < NBINS; i++) { |
| 212 | mltrght[NBINS * r + i] = MULSHIFT32(scalerght, mltleft[NBINS * r + i]) << 1; |
| 213 | mltleft[NBINS * r + i] = MULSHIFT32(scaleleft, mltleft[NBINS * r + i]) << 1; |
| 214 | } |
| 215 | } |
| 216 | |
| 217 | /* set non-coded regions to zero */ |
| 218 | for (i = gi->nRegions * NBINS; i < gi->nSamples; i++) { |
| 219 | mltleft[i] = 0; |
| 220 | mltrght[i] = 0; |
| 221 | } |
| 222 | |
| 223 | return; |
| 224 | } |
| 225 |