Andreas Grün / Mbed 2 deprecated madplayer

MP3 Player without external hardware MP3 Player without external hardware. A software based MP3 player based on a modified version of libmad. Mono output (at the moment) via AnalogOut. Files are read from an USB drive. This is a demo program, it plays only one file at the moment. Documentation is in "main.cpp" and "config.h"

Dependencies:   mbed

layer12.cpp@2:f28cf0afd021, 2010-11-27 (annotated)

Committer:
Gruenfrosch
Date:
Sat Nov 27 17:27:33 2010 +0000
Revision:
2:f28cf0afd021
Parent:
1:7c923cbe9f1d 
Version 3:

 * moved another memory block into AHB RAM, giving more room for

 * stereo buffer.

 * moved content of decode() to main()

 * decoding	is now safe to be called multiple times (bug in older versions)

 * Output routine now fills stereo buffer, DAC output sums channels,

 * just for demonstration that stereo output could go here

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Gruenfrosch 0:7627c79db971 1 /*
Gruenfrosch 0:7627c79db971 2 * libmad - MPEG audio decoder library
Gruenfrosch 0:7627c79db971 3 * Copyright (C) 2000-2004 Underbit Technologies, Inc.
Gruenfrosch 0:7627c79db971 4 *
Gruenfrosch 0:7627c79db971 5 * This program is free software; you can redistribute it and/or modify
Gruenfrosch 0:7627c79db971 6 * it under the terms of the GNU General Public License as published by
Gruenfrosch 0:7627c79db971 7 * the Free Software Foundation; either version 2 of the License, or
Gruenfrosch 0:7627c79db971 8 * (at your option) any later version.
Gruenfrosch 0:7627c79db971 9 *
Gruenfrosch 0:7627c79db971 10 * This program is distributed in the hope that it will be useful,
Gruenfrosch 0:7627c79db971 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
Gruenfrosch 0:7627c79db971 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
Gruenfrosch 0:7627c79db971 13 * GNU General Public License for more details.
Gruenfrosch 0:7627c79db971 14 *
Gruenfrosch 0:7627c79db971 15 * You should have received a copy of the GNU General Public License
Gruenfrosch 0:7627c79db971 16 * along with this program; if not, write to the Free Software
Gruenfrosch 0:7627c79db971 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Gruenfrosch 0:7627c79db971 18 *
Gruenfrosch 0:7627c79db971 19 * $Id: layer12.c,v 1.1 2010/11/23 20:12:57 andy Exp $
Gruenfrosch 0:7627c79db971 20 */
Gruenfrosch 0:7627c79db971 21
Gruenfrosch 0:7627c79db971 22 # include "config.h"
Gruenfrosch 0:7627c79db971 23
Gruenfrosch 0:7627c79db971 24 # include "global.h"
Gruenfrosch 0:7627c79db971 25
Gruenfrosch 0:7627c79db971 26 # ifdef HAVE_LIMITS_H
Gruenfrosch 0:7627c79db971 27 # include <limits.h>
Gruenfrosch 0:7627c79db971 28 # else
Gruenfrosch 0:7627c79db971 29 # define CHAR_BIT 8
Gruenfrosch 0:7627c79db971 30 # endif
Gruenfrosch 0:7627c79db971 31
Gruenfrosch 0:7627c79db971 32 # include "fixed.h"
Gruenfrosch 0:7627c79db971 33 # include "bit.h"
Gruenfrosch 0:7627c79db971 34 # include "stream.h"
Gruenfrosch 0:7627c79db971 35 # include "frame.h"
Gruenfrosch 0:7627c79db971 36 # include "layer12.h"
Gruenfrosch 0:7627c79db971 37
Gruenfrosch 0:7627c79db971 38 /*
Gruenfrosch 0:7627c79db971 39 * scalefactor table
Gruenfrosch 0:7627c79db971 40 * used in both Layer I and Layer II decoding
Gruenfrosch 0:7627c79db971 41 */
Gruenfrosch 0:7627c79db971 42 # include "sf_table.h"
Gruenfrosch 0:7627c79db971 43
Gruenfrosch 0:7627c79db971 44 /* --- Layer I ------------------------------------------------------------- */
Gruenfrosch 0:7627c79db971 45
Gruenfrosch 0:7627c79db971 46 /* linear scaling table */
Gruenfrosch 0:7627c79db971 47 static
Gruenfrosch 0:7627c79db971 48 mad_fixed_t const linear_table[14] = {
Gruenfrosch 0:7627c79db971 49 MAD_F(0x15555555), /* 2^2 / (2^2 - 1) == 1.33333333333333 */
Gruenfrosch 0:7627c79db971 50 MAD_F(0x12492492), /* 2^3 / (2^3 - 1) == 1.14285714285714 */
Gruenfrosch 0:7627c79db971 51 MAD_F(0x11111111), /* 2^4 / (2^4 - 1) == 1.06666666666667 */
Gruenfrosch 0:7627c79db971 52 MAD_F(0x10842108), /* 2^5 / (2^5 - 1) == 1.03225806451613 */
Gruenfrosch 0:7627c79db971 53 MAD_F(0x10410410), /* 2^6 / (2^6 - 1) == 1.01587301587302 */
Gruenfrosch 0:7627c79db971 54 MAD_F(0x10204081), /* 2^7 / (2^7 - 1) == 1.00787401574803 */
Gruenfrosch 0:7627c79db971 55 MAD_F(0x10101010), /* 2^8 / (2^8 - 1) == 1.00392156862745 */
Gruenfrosch 0:7627c79db971 56 MAD_F(0x10080402), /* 2^9 / (2^9 - 1) == 1.00195694716243 */
Gruenfrosch 0:7627c79db971 57 MAD_F(0x10040100), /* 2^10 / (2^10 - 1) == 1.00097751710655 */
Gruenfrosch 0:7627c79db971 58 MAD_F(0x10020040), /* 2^11 / (2^11 - 1) == 1.00048851978505 */
Gruenfrosch 0:7627c79db971 59 MAD_F(0x10010010), /* 2^12 / (2^12 - 1) == 1.00024420024420 */
Gruenfrosch 0:7627c79db971 60 MAD_F(0x10008004), /* 2^13 / (2^13 - 1) == 1.00012208521548 */
Gruenfrosch 0:7627c79db971 61 MAD_F(0x10004001), /* 2^14 / (2^14 - 1) == 1.00006103888177 */
Gruenfrosch 0:7627c79db971 62 MAD_F(0x10002000) /* 2^15 / (2^15 - 1) == 1.00003051850948 */
Gruenfrosch 0:7627c79db971 63 };
Gruenfrosch 0:7627c79db971 64
Gruenfrosch 0:7627c79db971 65 /*
Gruenfrosch 0:7627c79db971 66 * NAME: I_sample()
Gruenfrosch 0:7627c79db971 67 * DESCRIPTION: decode one requantized Layer I sample from a bitstream
Gruenfrosch 0:7627c79db971 68 */
Gruenfrosch 0:7627c79db971 69 static
Gruenfrosch 0:7627c79db971 70 mad_fixed_t I_sample(struct mad_bitptr *ptr, unsigned int nb)
Gruenfrosch 0:7627c79db971 71 {
Gruenfrosch 0:7627c79db971 72 mad_fixed_t sample;
Gruenfrosch 0:7627c79db971 73
Gruenfrosch 0:7627c79db971 74 sample = mad_bit_read(ptr, nb);
Gruenfrosch 0:7627c79db971 75
Gruenfrosch 0:7627c79db971 76 /* invert most significant bit, extend sign, then scale to fixed format */
Gruenfrosch 0:7627c79db971 77
Gruenfrosch 0:7627c79db971 78 sample ^= 1 << (nb - 1);
Gruenfrosch 0:7627c79db971 79 sample |= -(sample & (1 << (nb - 1)));
Gruenfrosch 0:7627c79db971 80
Gruenfrosch 0:7627c79db971 81 sample <<= MAD_F_FRACBITS - (nb - 1);
Gruenfrosch 0:7627c79db971 82
Gruenfrosch 0:7627c79db971 83 /* requantize the sample */
Gruenfrosch 0:7627c79db971 84
Gruenfrosch 0:7627c79db971 85 /* s'' = (2^nb / (2^nb - 1)) * (s''' + 2^(-nb + 1)) */
Gruenfrosch 0:7627c79db971 86
Gruenfrosch 0:7627c79db971 87 sample += MAD_F_ONE >> (nb - 1);
Gruenfrosch 0:7627c79db971 88
Gruenfrosch 0:7627c79db971 89 return mad_f_mul(sample, linear_table[nb - 2]);
Gruenfrosch 0:7627c79db971 90
Gruenfrosch 0:7627c79db971 91 /* s' = factor * s'' */
Gruenfrosch 0:7627c79db971 92 /* (to be performed by caller) */
Gruenfrosch 0:7627c79db971 93 }
Gruenfrosch 0:7627c79db971 94
Gruenfrosch 0:7627c79db971 95 /*
Gruenfrosch 0:7627c79db971 96 * NAME: layer->I()
Gruenfrosch 0:7627c79db971 97 * DESCRIPTION: decode a single Layer I frame
Gruenfrosch 0:7627c79db971 98 */
Gruenfrosch 0:7627c79db971 99 int mad_layer_I(struct mad_stream *stream, struct mad_frame *frame)
Gruenfrosch 0:7627c79db971 100 {
Gruenfrosch 0:7627c79db971 101 struct mad_header *header = &frame->header;
Gruenfrosch 0:7627c79db971 102 unsigned int nch, bound, ch, s, sb, nb;
Gruenfrosch 0:7627c79db971 103 unsigned char allocation[2][32], scalefactor[2][32];
Gruenfrosch 0:7627c79db971 104
Gruenfrosch 0:7627c79db971 105 nch = MAD_NCHANNELS(header);
Gruenfrosch 0:7627c79db971 106
Gruenfrosch 0:7627c79db971 107 bound = 32;
Gruenfrosch 0:7627c79db971 108 if (header->mode == MAD_MODE_JOINT_STEREO) {
Gruenfrosch 0:7627c79db971 109 header->flags |= MAD_FLAG_I_STEREO;
Gruenfrosch 0:7627c79db971 110 bound = 4 + header->mode_extension * 4;
Gruenfrosch 0:7627c79db971 111 }
Gruenfrosch 0:7627c79db971 112
Gruenfrosch 0:7627c79db971 113 /* check CRC word */
Gruenfrosch 0:7627c79db971 114
Gruenfrosch 0:7627c79db971 115 if (header->flags & MAD_FLAG_PROTECTION) {
Gruenfrosch 0:7627c79db971 116 header->crc_check =
Gruenfrosch 0:7627c79db971 117 mad_bit_crc(stream->ptr, 4 * (bound * nch + (32 - bound)),
Gruenfrosch 0:7627c79db971 118 header->crc_check);
Gruenfrosch 0:7627c79db971 119
Gruenfrosch 0:7627c79db971 120 if (header->crc_check != header->crc_target &&
Gruenfrosch 0:7627c79db971 121 !(frame->options & MAD_OPTION_IGNORECRC)) {
Gruenfrosch 0:7627c79db971 122 stream->error = MAD_ERROR_BADCRC;
Gruenfrosch 0:7627c79db971 123 return -1;
Gruenfrosch 0:7627c79db971 124 }
Gruenfrosch 0:7627c79db971 125 }
Gruenfrosch 0:7627c79db971 126
Gruenfrosch 0:7627c79db971 127 /* decode bit allocations */
Gruenfrosch 0:7627c79db971 128
Gruenfrosch 0:7627c79db971 129 for (sb = 0; sb < bound; ++sb) {
Gruenfrosch 0:7627c79db971 130 for (ch = 0; ch < nch; ++ch) {
Gruenfrosch 0:7627c79db971 131 nb = mad_bit_read(&stream->ptr, 4);
Gruenfrosch 0:7627c79db971 132
Gruenfrosch 0:7627c79db971 133 if (nb == 15) {
Gruenfrosch 0:7627c79db971 134 stream->error = MAD_ERROR_BADBITALLOC;
Gruenfrosch 0:7627c79db971 135 return -1;
Gruenfrosch 0:7627c79db971 136 }
Gruenfrosch 0:7627c79db971 137
Gruenfrosch 0:7627c79db971 138 allocation[ch][sb] = nb ? nb + 1 : 0;
Gruenfrosch 0:7627c79db971 139 }
Gruenfrosch 0:7627c79db971 140 }
Gruenfrosch 0:7627c79db971 141
Gruenfrosch 0:7627c79db971 142 for (sb = bound; sb < 32; ++sb) {
Gruenfrosch 0:7627c79db971 143 nb = mad_bit_read(&stream->ptr, 4);
Gruenfrosch 0:7627c79db971 144
Gruenfrosch 0:7627c79db971 145 if (nb == 15) {
Gruenfrosch 0:7627c79db971 146 stream->error = MAD_ERROR_BADBITALLOC;
Gruenfrosch 0:7627c79db971 147 return -1;
Gruenfrosch 0:7627c79db971 148 }
Gruenfrosch 0:7627c79db971 149
Gruenfrosch 0:7627c79db971 150 allocation[0][sb] =
Gruenfrosch 0:7627c79db971 151 allocation[1][sb] = nb ? nb + 1 : 0;
Gruenfrosch 0:7627c79db971 152 }
Gruenfrosch 0:7627c79db971 153
Gruenfrosch 0:7627c79db971 154 /* decode scalefactors */
Gruenfrosch 0:7627c79db971 155
Gruenfrosch 0:7627c79db971 156 for (sb = 0; sb < 32; ++sb) {
Gruenfrosch 0:7627c79db971 157 for (ch = 0; ch < nch; ++ch) {
Gruenfrosch 0:7627c79db971 158 if (allocation[ch][sb]) {
Gruenfrosch 0:7627c79db971 159 scalefactor[ch][sb] = mad_bit_read(&stream->ptr, 6);
Gruenfrosch 0:7627c79db971 160
Gruenfrosch 0:7627c79db971 161 # if defined(OPT_STRICT)
Gruenfrosch 0:7627c79db971 162 /*
Gruenfrosch 0:7627c79db971 163 * Scalefactor index 63 does not appear in Table B.1 of
Gruenfrosch 0:7627c79db971 164 * ISO/IEC 11172-3. Nonetheless, other implementations accept it,
Gruenfrosch 0:7627c79db971 165 * so we only reject it if OPT_STRICT is defined.
Gruenfrosch 0:7627c79db971 166 */
Gruenfrosch 0:7627c79db971 167 if (scalefactor[ch][sb] == 63) {
Gruenfrosch 0:7627c79db971 168 stream->error = MAD_ERROR_BADSCALEFACTOR;
Gruenfrosch 0:7627c79db971 169 return -1;
Gruenfrosch 0:7627c79db971 170 }
Gruenfrosch 0:7627c79db971 171 # endif
Gruenfrosch 0:7627c79db971 172 }
Gruenfrosch 0:7627c79db971 173 }
Gruenfrosch 0:7627c79db971 174 }
Gruenfrosch 0:7627c79db971 175
Gruenfrosch 0:7627c79db971 176 /* decode samples */
Gruenfrosch 0:7627c79db971 177
Gruenfrosch 0:7627c79db971 178 for (s = 0; s < 12; ++s) {
Gruenfrosch 0:7627c79db971 179 for (sb = 0; sb < bound; ++sb) {
Gruenfrosch 0:7627c79db971 180 for (ch = 0; ch < nch; ++ch) {
Gruenfrosch 0:7627c79db971 181 nb = allocation[ch][sb];
Gruenfrosch 0:7627c79db971 182 frame->sbsample[ch][s][sb] = nb ?
Gruenfrosch 0:7627c79db971 183 mad_f_mul(I_sample(&stream->ptr, nb),
Gruenfrosch 0:7627c79db971 184 sf_table[scalefactor[ch][sb]]) : 0;
Gruenfrosch 0:7627c79db971 185 }
Gruenfrosch 0:7627c79db971 186 }
Gruenfrosch 0:7627c79db971 187
Gruenfrosch 0:7627c79db971 188 for (sb = bound; sb < 32; ++sb) {
Gruenfrosch 0:7627c79db971 189 if ((nb = allocation[0][sb]) != 0) {
Gruenfrosch 0:7627c79db971 190 mad_fixed_t sample;
Gruenfrosch 0:7627c79db971 191
Gruenfrosch 0:7627c79db971 192 sample = I_sample(&stream->ptr, nb);
Gruenfrosch 0:7627c79db971 193
Gruenfrosch 0:7627c79db971 194 for (ch = 0; ch < nch; ++ch) {
Gruenfrosch 0:7627c79db971 195 frame->sbsample[ch][s][sb] =
Gruenfrosch 0:7627c79db971 196 mad_f_mul(sample, sf_table[scalefactor[ch][sb]]);
Gruenfrosch 0:7627c79db971 197 }
Gruenfrosch 0:7627c79db971 198 }
Gruenfrosch 0:7627c79db971 199 else {
Gruenfrosch 0:7627c79db971 200 for (ch = 0; ch < nch; ++ch)
Gruenfrosch 0:7627c79db971 201 frame->sbsample[ch][s][sb] = 0;
Gruenfrosch 0:7627c79db971 202 }
Gruenfrosch 0:7627c79db971 203 }
Gruenfrosch 0:7627c79db971 204 }
Gruenfrosch 0:7627c79db971 205
Gruenfrosch 0:7627c79db971 206 return 0;
Gruenfrosch 0:7627c79db971 207 }
Gruenfrosch 0:7627c79db971 208
Gruenfrosch 0:7627c79db971 209 /* --- Layer II ------------------------------------------------------------ */
Gruenfrosch 0:7627c79db971 210
Gruenfrosch 0:7627c79db971 211 /* possible quantization per subband table */
Gruenfrosch 0:7627c79db971 212 static
Gruenfrosch 1:7c923cbe9f1d 213 const struct {
Gruenfrosch 0:7627c79db971 214 unsigned int sblimit;
Gruenfrosch 1:7c923cbe9f1d 215 unsigned char offsets[30];
Gruenfrosch 1:7c923cbe9f1d 216 } sbquant_table[5] = {
Gruenfrosch 0:7627c79db971 217 /* ISO/IEC 11172-3 Table B.2a */
Gruenfrosch 0:7627c79db971 218 { 27, { 7, 7, 7, 6, 6, 6, 6, 6, 6, 6, 6, 3, 3, 3, 3, 3, /* 0 */
Gruenfrosch 0:7627c79db971 219 3, 3, 3, 3, 3, 3, 3, 0, 0, 0, 0 } },
Gruenfrosch 0:7627c79db971 220 /* ISO/IEC 11172-3 Table B.2b */
Gruenfrosch 0:7627c79db971 221 { 30, { 7, 7, 7, 6, 6, 6, 6, 6, 6, 6, 6, 3, 3, 3, 3, 3, /* 1 */
Gruenfrosch 0:7627c79db971 222 3, 3, 3, 3, 3, 3, 3, 0, 0, 0, 0, 0, 0, 0 } },
Gruenfrosch 0:7627c79db971 223 /* ISO/IEC 11172-3 Table B.2c */
Gruenfrosch 0:7627c79db971 224 { 8, { 5, 5, 2, 2, 2, 2, 2, 2 } }, /* 2 */
Gruenfrosch 0:7627c79db971 225 /* ISO/IEC 11172-3 Table B.2d */
Gruenfrosch 0:7627c79db971 226 { 12, { 5, 5, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 } }, /* 3 */
Gruenfrosch 0:7627c79db971 227 /* ISO/IEC 13818-3 Table B.1 */
Gruenfrosch 0:7627c79db971 228 { 30, { 4, 4, 4, 4, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, /* 4 */
Gruenfrosch 0:7627c79db971 229 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 } }
Gruenfrosch 0:7627c79db971 230 };
Gruenfrosch 0:7627c79db971 231
Gruenfrosch 0:7627c79db971 232 /* bit allocation table */
Gruenfrosch 0:7627c79db971 233 static
Gruenfrosch 0:7627c79db971 234 struct {
Gruenfrosch 0:7627c79db971 235 unsigned short nbal;
Gruenfrosch 0:7627c79db971 236 unsigned short offset;
Gruenfrosch 0:7627c79db971 237 } const bitalloc_table[8] = {
Gruenfrosch 0:7627c79db971 238 { 2, 0 }, /* 0 */
Gruenfrosch 0:7627c79db971 239 { 2, 3 }, /* 1 */
Gruenfrosch 0:7627c79db971 240 { 3, 3 }, /* 2 */
Gruenfrosch 0:7627c79db971 241 { 3, 1 }, /* 3 */
Gruenfrosch 0:7627c79db971 242 { 4, 2 }, /* 4 */
Gruenfrosch 0:7627c79db971 243 { 4, 3 }, /* 5 */
Gruenfrosch 0:7627c79db971 244 { 4, 4 }, /* 6 */
Gruenfrosch 0:7627c79db971 245 { 4, 5 } /* 7 */
Gruenfrosch 0:7627c79db971 246 };
Gruenfrosch 0:7627c79db971 247
Gruenfrosch 0:7627c79db971 248 /* offsets into quantization class table */
Gruenfrosch 0:7627c79db971 249 static
Gruenfrosch 0:7627c79db971 250 unsigned char const offset_table[6][15] = {
Gruenfrosch 0:7627c79db971 251 { 0, 1, 16 }, /* 0 */
Gruenfrosch 0:7627c79db971 252 { 0, 1, 2, 3, 4, 5, 16 }, /* 1 */
Gruenfrosch 0:7627c79db971 253 { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 }, /* 2 */
Gruenfrosch 0:7627c79db971 254 { 0, 1, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 }, /* 3 */
Gruenfrosch 0:7627c79db971 255 { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 16 }, /* 4 */
Gruenfrosch 0:7627c79db971 256 { 0, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 } /* 5 */
Gruenfrosch 0:7627c79db971 257 };
Gruenfrosch 0:7627c79db971 258
Gruenfrosch 0:7627c79db971 259 /* quantization class table */
Gruenfrosch 0:7627c79db971 260 static
Gruenfrosch 0:7627c79db971 261 struct quantclass {
Gruenfrosch 0:7627c79db971 262 unsigned short nlevels;
Gruenfrosch 0:7627c79db971 263 unsigned char group;
Gruenfrosch 0:7627c79db971 264 unsigned char bits;
Gruenfrosch 0:7627c79db971 265 mad_fixed_t C;
Gruenfrosch 0:7627c79db971 266 mad_fixed_t D;
Gruenfrosch 0:7627c79db971 267 } const qc_table[17] = {
Gruenfrosch 0:7627c79db971 268 # include "qc_table.h"
Gruenfrosch 0:7627c79db971 269 };
Gruenfrosch 0:7627c79db971 270
Gruenfrosch 0:7627c79db971 271 /*
Gruenfrosch 0:7627c79db971 272 * NAME: II_samples()
Gruenfrosch 0:7627c79db971 273 * DESCRIPTION: decode three requantized Layer II samples from a bitstream
Gruenfrosch 0:7627c79db971 274 */
Gruenfrosch 0:7627c79db971 275 static
Gruenfrosch 0:7627c79db971 276 void II_samples(struct mad_bitptr *ptr,
Gruenfrosch 0:7627c79db971 277 struct quantclass const *quantclass,
Gruenfrosch 0:7627c79db971 278 mad_fixed_t output[3])
Gruenfrosch 0:7627c79db971 279 {
Gruenfrosch 0:7627c79db971 280 unsigned int nb, s, sample[3];
Gruenfrosch 0:7627c79db971 281
Gruenfrosch 0:7627c79db971 282 if ((nb = quantclass->group) != 0) {
Gruenfrosch 0:7627c79db971 283 unsigned int c, nlevels;
Gruenfrosch 0:7627c79db971 284
Gruenfrosch 0:7627c79db971 285 /* degrouping */
Gruenfrosch 0:7627c79db971 286 c = mad_bit_read(ptr, quantclass->bits);
Gruenfrosch 0:7627c79db971 287 nlevels = quantclass->nlevels;
Gruenfrosch 0:7627c79db971 288
Gruenfrosch 0:7627c79db971 289 for (s = 0; s < 3; ++s) {
Gruenfrosch 0:7627c79db971 290 sample[s] = c % nlevels;
Gruenfrosch 0:7627c79db971 291 c /= nlevels;
Gruenfrosch 0:7627c79db971 292 }
Gruenfrosch 0:7627c79db971 293 }
Gruenfrosch 0:7627c79db971 294 else {
Gruenfrosch 0:7627c79db971 295 nb = quantclass->bits;
Gruenfrosch 0:7627c79db971 296
Gruenfrosch 0:7627c79db971 297 for (s = 0; s < 3; ++s)
Gruenfrosch 0:7627c79db971 298 sample[s] = mad_bit_read(ptr, nb);
Gruenfrosch 0:7627c79db971 299 }
Gruenfrosch 0:7627c79db971 300
Gruenfrosch 0:7627c79db971 301 for (s = 0; s < 3; ++s) {
Gruenfrosch 0:7627c79db971 302 mad_fixed_t requantized;
Gruenfrosch 0:7627c79db971 303
Gruenfrosch 0:7627c79db971 304 /* invert most significant bit, extend sign, then scale to fixed format */
Gruenfrosch 0:7627c79db971 305
Gruenfrosch 0:7627c79db971 306 requantized = sample[s] ^ (1 << (nb - 1));
Gruenfrosch 0:7627c79db971 307 requantized |= -(requantized & (1 << (nb - 1)));
Gruenfrosch 0:7627c79db971 308
Gruenfrosch 0:7627c79db971 309 requantized <<= MAD_F_FRACBITS - (nb - 1);
Gruenfrosch 0:7627c79db971 310
Gruenfrosch 0:7627c79db971 311 /* requantize the sample */
Gruenfrosch 0:7627c79db971 312
Gruenfrosch 0:7627c79db971 313 /* s'' = C * (s''' + D) */
Gruenfrosch 0:7627c79db971 314
Gruenfrosch 0:7627c79db971 315 output[s] = mad_f_mul(requantized + quantclass->D, quantclass->C);
Gruenfrosch 0:7627c79db971 316
Gruenfrosch 0:7627c79db971 317 /* s' = factor * s'' */
Gruenfrosch 0:7627c79db971 318 /* (to be performed by caller) */
Gruenfrosch 0:7627c79db971 319 }
Gruenfrosch 0:7627c79db971 320 }
Gruenfrosch 0:7627c79db971 321
Gruenfrosch 0:7627c79db971 322 /*
Gruenfrosch 0:7627c79db971 323 * NAME: layer->II()
Gruenfrosch 0:7627c79db971 324 * DESCRIPTION: decode a single Layer II frame
Gruenfrosch 0:7627c79db971 325 */
Gruenfrosch 0:7627c79db971 326 int mad_layer_II(struct mad_stream *stream, struct mad_frame *frame)
Gruenfrosch 0:7627c79db971 327 {
Gruenfrosch 0:7627c79db971 328 struct mad_header *header = &frame->header;
Gruenfrosch 0:7627c79db971 329 struct mad_bitptr start;
Gruenfrosch 0:7627c79db971 330 unsigned int index, sblimit, nbal, nch, bound, gr, ch, s, sb;
Gruenfrosch 0:7627c79db971 331 unsigned char const *offsets;
Gruenfrosch 0:7627c79db971 332 unsigned char allocation[2][32], scfsi[2][32], scalefactor[2][32][3];
Gruenfrosch 0:7627c79db971 333 mad_fixed_t samples[3];
Gruenfrosch 0:7627c79db971 334
Gruenfrosch 0:7627c79db971 335 nch = MAD_NCHANNELS(header);
Gruenfrosch 0:7627c79db971 336
Gruenfrosch 0:7627c79db971 337 if (header->flags & MAD_FLAG_LSF_EXT)
Gruenfrosch 0:7627c79db971 338 index = 4;
Gruenfrosch 0:7627c79db971 339 else if (header->flags & MAD_FLAG_FREEFORMAT)
Gruenfrosch 0:7627c79db971 340 goto freeformat;
Gruenfrosch 0:7627c79db971 341 else {
Gruenfrosch 0:7627c79db971 342 unsigned long bitrate_per_channel;
Gruenfrosch 0:7627c79db971 343
Gruenfrosch 0:7627c79db971 344 bitrate_per_channel = header->bitrate;
Gruenfrosch 0:7627c79db971 345 if (nch == 2) {
Gruenfrosch 0:7627c79db971 346 bitrate_per_channel /= 2;
Gruenfrosch 0:7627c79db971 347
Gruenfrosch 0:7627c79db971 348 # if defined(OPT_STRICT)
Gruenfrosch 0:7627c79db971 349 /*
Gruenfrosch 0:7627c79db971 350 * ISO/IEC 11172-3 allows only single channel mode for 32, 48, 56, and
Gruenfrosch 0:7627c79db971 351 * 80 kbps bitrates in Layer II, but some encoders ignore this
Gruenfrosch 0:7627c79db971 352 * restriction. We enforce it if OPT_STRICT is defined.
Gruenfrosch 0:7627c79db971 353 */
Gruenfrosch 0:7627c79db971 354 if (bitrate_per_channel <= 28000 || bitrate_per_channel == 40000) {
Gruenfrosch 0:7627c79db971 355 stream->error = MAD_ERROR_BADMODE;
Gruenfrosch 0:7627c79db971 356 return -1;
Gruenfrosch 0:7627c79db971 357 }
Gruenfrosch 0:7627c79db971 358 # endif
Gruenfrosch 0:7627c79db971 359 }
Gruenfrosch 0:7627c79db971 360 else { /* nch == 1 */
Gruenfrosch 0:7627c79db971 361 if (bitrate_per_channel > 192000) {
Gruenfrosch 0:7627c79db971 362 /*
Gruenfrosch 0:7627c79db971 363 * ISO/IEC 11172-3 does not allow single channel mode for 224, 256,
Gruenfrosch 0:7627c79db971 364 * 320, or 384 kbps bitrates in Layer II.
Gruenfrosch 0:7627c79db971 365 */
Gruenfrosch 0:7627c79db971 366 stream->error = MAD_ERROR_BADMODE;
Gruenfrosch 0:7627c79db971 367 return -1;
Gruenfrosch 0:7627c79db971 368 }
Gruenfrosch 0:7627c79db971 369 }
Gruenfrosch 0:7627c79db971 370
Gruenfrosch 0:7627c79db971 371 if (bitrate_per_channel <= 48000)
Gruenfrosch 0:7627c79db971 372 index = (header->samplerate == 32000) ? 3 : 2;
Gruenfrosch 0:7627c79db971 373 else if (bitrate_per_channel <= 80000)
Gruenfrosch 0:7627c79db971 374 index = 0;
Gruenfrosch 0:7627c79db971 375 else {
Gruenfrosch 0:7627c79db971 376 freeformat:
Gruenfrosch 0:7627c79db971 377 index = (header->samplerate == 48000) ? 0 : 1;
Gruenfrosch 0:7627c79db971 378 }
Gruenfrosch 0:7627c79db971 379 }
Gruenfrosch 0:7627c79db971 380
Gruenfrosch 0:7627c79db971 381 sblimit = sbquant_table[index].sblimit;
Gruenfrosch 0:7627c79db971 382 offsets = sbquant_table[index].offsets;
Gruenfrosch 0:7627c79db971 383
Gruenfrosch 0:7627c79db971 384 bound = 32;
Gruenfrosch 0:7627c79db971 385 if (header->mode == MAD_MODE_JOINT_STEREO) {
Gruenfrosch 0:7627c79db971 386 header->flags |= MAD_FLAG_I_STEREO;
Gruenfrosch 0:7627c79db971 387 bound = 4 + header->mode_extension * 4;
Gruenfrosch 0:7627c79db971 388 }
Gruenfrosch 0:7627c79db971 389
Gruenfrosch 0:7627c79db971 390 if (bound > sblimit)
Gruenfrosch 0:7627c79db971 391 bound = sblimit;
Gruenfrosch 0:7627c79db971 392
Gruenfrosch 0:7627c79db971 393 start = stream->ptr;
Gruenfrosch 0:7627c79db971 394
Gruenfrosch 0:7627c79db971 395 /* decode bit allocations */
Gruenfrosch 0:7627c79db971 396
Gruenfrosch 0:7627c79db971 397 for (sb = 0; sb < bound; ++sb) {
Gruenfrosch 0:7627c79db971 398 nbal = bitalloc_table[offsets[sb]].nbal;
Gruenfrosch 0:7627c79db971 399
Gruenfrosch 0:7627c79db971 400 for (ch = 0; ch < nch; ++ch)
Gruenfrosch 0:7627c79db971 401 allocation[ch][sb] = mad_bit_read(&stream->ptr, nbal);
Gruenfrosch 0:7627c79db971 402 }
Gruenfrosch 0:7627c79db971 403
Gruenfrosch 0:7627c79db971 404 for (sb = bound; sb < sblimit; ++sb) {
Gruenfrosch 0:7627c79db971 405 nbal = bitalloc_table[offsets[sb]].nbal;
Gruenfrosch 0:7627c79db971 406
Gruenfrosch 0:7627c79db971 407 allocation[0][sb] =
Gruenfrosch 0:7627c79db971 408 allocation[1][sb] = mad_bit_read(&stream->ptr, nbal);
Gruenfrosch 0:7627c79db971 409 }
Gruenfrosch 0:7627c79db971 410
Gruenfrosch 0:7627c79db971 411 /* decode scalefactor selection info */
Gruenfrosch 0:7627c79db971 412
Gruenfrosch 0:7627c79db971 413 for (sb = 0; sb < sblimit; ++sb) {
Gruenfrosch 0:7627c79db971 414 for (ch = 0; ch < nch; ++ch) {
Gruenfrosch 0:7627c79db971 415 if (allocation[ch][sb])
Gruenfrosch 0:7627c79db971 416 scfsi[ch][sb] = mad_bit_read(&stream->ptr, 2);
Gruenfrosch 0:7627c79db971 417 }
Gruenfrosch 0:7627c79db971 418 }
Gruenfrosch 0:7627c79db971 419
Gruenfrosch 0:7627c79db971 420 /* check CRC word */
Gruenfrosch 0:7627c79db971 421
Gruenfrosch 0:7627c79db971 422 if (header->flags & MAD_FLAG_PROTECTION) {
Gruenfrosch 0:7627c79db971 423 header->crc_check =
Gruenfrosch 0:7627c79db971 424 mad_bit_crc(start, mad_bit_length(&start, &stream->ptr),
Gruenfrosch 0:7627c79db971 425 header->crc_check);
Gruenfrosch 0:7627c79db971 426
Gruenfrosch 0:7627c79db971 427 if (header->crc_check != header->crc_target &&
Gruenfrosch 0:7627c79db971 428 !(frame->options & MAD_OPTION_IGNORECRC)) {
Gruenfrosch 0:7627c79db971 429 stream->error = MAD_ERROR_BADCRC;
Gruenfrosch 0:7627c79db971 430 return -1;
Gruenfrosch 0:7627c79db971 431 }
Gruenfrosch 0:7627c79db971 432 }
Gruenfrosch 0:7627c79db971 433
Gruenfrosch 0:7627c79db971 434 /* decode scalefactors */
Gruenfrosch 0:7627c79db971 435
Gruenfrosch 0:7627c79db971 436 for (sb = 0; sb < sblimit; ++sb) {
Gruenfrosch 0:7627c79db971 437 for (ch = 0; ch < nch; ++ch) {
Gruenfrosch 0:7627c79db971 438 if (allocation[ch][sb]) {
Gruenfrosch 0:7627c79db971 439 scalefactor[ch][sb][0] = mad_bit_read(&stream->ptr, 6);
Gruenfrosch 0:7627c79db971 440
Gruenfrosch 0:7627c79db971 441 switch (scfsi[ch][sb]) {
Gruenfrosch 0:7627c79db971 442 case 2:
Gruenfrosch 0:7627c79db971 443 scalefactor[ch][sb][2] =
Gruenfrosch 0:7627c79db971 444 scalefactor[ch][sb][1] =
Gruenfrosch 0:7627c79db971 445 scalefactor[ch][sb][0];
Gruenfrosch 0:7627c79db971 446 break;
Gruenfrosch 0:7627c79db971 447
Gruenfrosch 0:7627c79db971 448 case 0:
Gruenfrosch 0:7627c79db971 449 scalefactor[ch][sb][1] = mad_bit_read(&stream->ptr, 6);
Gruenfrosch 0:7627c79db971 450 /* fall through */
Gruenfrosch 0:7627c79db971 451
Gruenfrosch 0:7627c79db971 452 case 1:
Gruenfrosch 0:7627c79db971 453 case 3:
Gruenfrosch 0:7627c79db971 454 scalefactor[ch][sb][2] = mad_bit_read(&stream->ptr, 6);
Gruenfrosch 0:7627c79db971 455 }
Gruenfrosch 0:7627c79db971 456
Gruenfrosch 0:7627c79db971 457 if (scfsi[ch][sb] & 1)
Gruenfrosch 0:7627c79db971 458 scalefactor[ch][sb][1] = scalefactor[ch][sb][scfsi[ch][sb] - 1];
Gruenfrosch 0:7627c79db971 459
Gruenfrosch 0:7627c79db971 460 # if defined(OPT_STRICT)
Gruenfrosch 0:7627c79db971 461 /*
Gruenfrosch 0:7627c79db971 462 * Scalefactor index 63 does not appear in Table B.1 of
Gruenfrosch 0:7627c79db971 463 * ISO/IEC 11172-3. Nonetheless, other implementations accept it,
Gruenfrosch 0:7627c79db971 464 * so we only reject it if OPT_STRICT is defined.
Gruenfrosch 0:7627c79db971 465 */
Gruenfrosch 0:7627c79db971 466 if (scalefactor[ch][sb][0] == 63 ||
Gruenfrosch 0:7627c79db971 467 scalefactor[ch][sb][1] == 63 ||
Gruenfrosch 0:7627c79db971 468 scalefactor[ch][sb][2] == 63) {
Gruenfrosch 0:7627c79db971 469 stream->error = MAD_ERROR_BADSCALEFACTOR;
Gruenfrosch 0:7627c79db971 470 return -1;
Gruenfrosch 0:7627c79db971 471 }
Gruenfrosch 0:7627c79db971 472 # endif
Gruenfrosch 0:7627c79db971 473 }
Gruenfrosch 0:7627c79db971 474 }
Gruenfrosch 0:7627c79db971 475 }
Gruenfrosch 0:7627c79db971 476
Gruenfrosch 0:7627c79db971 477 /* decode samples */
Gruenfrosch 0:7627c79db971 478
Gruenfrosch 0:7627c79db971 479 for (gr = 0; gr < 12; ++gr) {
Gruenfrosch 0:7627c79db971 480 for (sb = 0; sb < bound; ++sb) {
Gruenfrosch 0:7627c79db971 481 for (ch = 0; ch < nch; ++ch) {
Gruenfrosch 0:7627c79db971 482 if ((index = allocation[ch][sb]) != 0) {
Gruenfrosch 0:7627c79db971 483 index = offset_table[bitalloc_table[offsets[sb]].offset][index - 1];
Gruenfrosch 0:7627c79db971 484
Gruenfrosch 0:7627c79db971 485 II_samples(&stream->ptr, &qc_table[index], samples);
Gruenfrosch 0:7627c79db971 486
Gruenfrosch 0:7627c79db971 487 for (s = 0; s < 3; ++s) {
Gruenfrosch 0:7627c79db971 488 frame->sbsample[ch][3 * gr + s][sb] =
Gruenfrosch 0:7627c79db971 489 mad_f_mul(samples[s], sf_table[scalefactor[ch][sb][gr / 4]]);
Gruenfrosch 0:7627c79db971 490 }
Gruenfrosch 0:7627c79db971 491 }
Gruenfrosch 0:7627c79db971 492 else {
Gruenfrosch 0:7627c79db971 493 for (s = 0; s < 3; ++s)
Gruenfrosch 0:7627c79db971 494 frame->sbsample[ch][3 * gr + s][sb] = 0;
Gruenfrosch 0:7627c79db971 495 }
Gruenfrosch 0:7627c79db971 496 }
Gruenfrosch 0:7627c79db971 497 }
Gruenfrosch 0:7627c79db971 498
Gruenfrosch 0:7627c79db971 499 for (sb = bound; sb < sblimit; ++sb) {
Gruenfrosch 0:7627c79db971 500 if ((index = allocation[0][sb])!= 0) {
Gruenfrosch 0:7627c79db971 501 index = offset_table[bitalloc_table[offsets[sb]].offset][index - 1];
Gruenfrosch 0:7627c79db971 502
Gruenfrosch 0:7627c79db971 503 II_samples(&stream->ptr, &qc_table[index], samples);
Gruenfrosch 0:7627c79db971 504
Gruenfrosch 0:7627c79db971 505 for (ch = 0; ch < nch; ++ch) {
Gruenfrosch 0:7627c79db971 506 for (s = 0; s < 3; ++s) {
Gruenfrosch 0:7627c79db971 507 frame->sbsample[ch][3 * gr + s][sb] =
Gruenfrosch 0:7627c79db971 508 mad_f_mul(samples[s], sf_table[scalefactor[ch][sb][gr / 4]]);
Gruenfrosch 0:7627c79db971 509 }
Gruenfrosch 0:7627c79db971 510 }
Gruenfrosch 0:7627c79db971 511 }
Gruenfrosch 0:7627c79db971 512 else {
Gruenfrosch 0:7627c79db971 513 for (ch = 0; ch < nch; ++ch) {
Gruenfrosch 0:7627c79db971 514 for (s = 0; s < 3; ++s)
Gruenfrosch 0:7627c79db971 515 frame->sbsample[ch][3 * gr + s][sb] = 0;
Gruenfrosch 0:7627c79db971 516 }
Gruenfrosch 0:7627c79db971 517 }
Gruenfrosch 0:7627c79db971 518 }
Gruenfrosch 0:7627c79db971 519
Gruenfrosch 0:7627c79db971 520 for (ch = 0; ch < nch; ++ch) {
Gruenfrosch 0:7627c79db971 521 for (s = 0; s < 3; ++s) {
Gruenfrosch 0:7627c79db971 522 for (sb = sblimit; sb < 32; ++sb)
Gruenfrosch 0:7627c79db971 523 frame->sbsample[ch][3 * gr + s][sb] = 0;
Gruenfrosch 0:7627c79db971 524 }
Gruenfrosch 0:7627c79db971 525 }
Gruenfrosch 0:7627c79db971 526 }
Gruenfrosch 0:7627c79db971 527
Gruenfrosch 0:7627c79db971 528 return 0;
Gruenfrosch 0:7627c79db971 529 }