1 /* ------------------------------------------------------------------ 2 * Copyright (C) 1998-2009 PacketVideo 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either 13 * express or implied. 14 * See the License for the specific language governing permissions 15 * and limitations under the License. 16 * ------------------------------------------------------------------- 17 */ 18 19 /* 20 ------------------------------------------------------------------------------ 21 22 PacketVideo Corp. 23 MP3 Decoder Library 24 25 Filename: pvmp3_huffman_decoding.cpp 26 27 Funtions: 28 pvmp3_huffman_quad_decoding 29 pvmp3_huffman_pair_decoding 30 pvmp3_huffman_pair_decoding_linbits 31 32 Date: 09/21/2007 33 34 ------------------------------------------------------------------------------ 35 REVISION HISTORY 36 37 38 Description: 39 40 ------------------------------------------------------------------------------ 41 INPUT AND OUTPUT DEFINITIONS 42 43 Inputs: 44 int32 is[], 45 granuleInfo *grInfo, information for the given channel and granule 46 tmp3dec_file *pVars, decoder state structure 47 int32 part2_start, index to beginning of part 2 data 48 mp3Header *info mp3 header info 49 50 Outputs: 51 int32 is[], uncompressed data 52 53 Return: 54 non zero frequency lines 55 56 ------------------------------------------------------------------------------ 57 FUNCTION DESCRIPTION 58 59 These functions are used to decode huffman codewords from the input 60 bitstream using combined binary search and look-up table approach. 61 62 ------------------------------------------------------------------------------ 63 REQUIREMENTS 64 65 66 ------------------------------------------------------------------------------ 67 REFERENCES 68 [1] ISO MPEG Audio Subgroup Software Simulation Group (1996) 69 ISO 13818-3 MPEG-2 Audio Decoder - Lower Sampling Frequency Extension 70 71 72 ------------------------------------------------------------------------------ 73 PSEUDO-CODE 74 75 ------------------------------------------------------------------------------ 76 */ 77 78 79 /*---------------------------------------------------------------------------- 80 ; INCLUDES 81 ----------------------------------------------------------------------------*/ 82 #include "pv_mp3_huffman.h" 83 #include "s_mp3bits.h" 84 #include "mp3_mem_funcs.h" 85 #include "pvmp3_tables.h" 86 87 88 /*---------------------------------------------------------------------------- 89 ; MACROS 90 ; Define module specific macros here 91 ----------------------------------------------------------------------------*/ 92 93 94 /*---------------------------------------------------------------------------- 95 ; DEFINES 96 ; Include all pre-processor statements here. Include conditional 97 ; compile variables also. 98 ----------------------------------------------------------------------------*/ 99 100 101 /*---------------------------------------------------------------------------- 102 ; LOCAL FUNCTION DEFINITIONS 103 ; Function Prototype declaration 104 ----------------------------------------------------------------------------*/ 105 106 /*---------------------------------------------------------------------------- 107 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS 108 ; Variable declaration - defined here and used outside this module 109 ----------------------------------------------------------------------------*/ 110 111 /*---------------------------------------------------------------------------- 112 ; EXTERNAL FUNCTION REFERENCES 113 ; Declare functions defined elsewhere and referenced in this module 114 ----------------------------------------------------------------------------*/ 115 116 /*---------------------------------------------------------------------------- 117 ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES 118 ; Declare variables used in this module but defined elsewhere 119 ----------------------------------------------------------------------------*/ 120 121 /*---------------------------------------------------------------------------- 122 ; FUNCTION CODE 123 ----------------------------------------------------------------------------*/ 124 125 int32 pvmp3_huffman_parsing(int32 is[SUBBANDS_NUMBER*FILTERBANK_BANDS], 126 granuleInfo *grInfo, 127 tmp3dec_file *pVars, 128 int32 part2_start, 129 mp3Header *info) 130 131 132 { 133 int32 i; 134 int32 region1Start; 135 int32 region2Start; 136 int32 sfreq; 137 uint32 grBits; 138 void(*pt_huff)(struct huffcodetab *, int32 *, tmp3Bits *); 139 struct huffcodetab *h; 140 141 tmp3Bits *pMainData = &pVars->mainDataStream; 142 143 144 /*int32 bt = (*si).ch[ch].gr[gr].window_switching_flag && ((*si).ch[ch].gr[gr].block_type == 2);*/ 145 146 sfreq = info->sampling_frequency + info->version_x + (info->version_x << 1); 147 148 /* Find region boundary for short block case. */ 149 150 151 if ((grInfo->window_switching_flag) && (grInfo->block_type == 2)) 152 { 153 if (info->version_x == MPEG_1) 154 { 155 /* Region2. */ 156 region1Start = 12; 157 } 158 else 159 { 160 /* Region2. */ 161 i = grInfo->region0_count + 1; 162 region1Start = mp3_sfBandIndex[sfreq].s[i/3]; 163 } 164 165 region1Start += region1Start << 1; 166 region2Start = 576; /* No Region2 for short block case. */ 167 } 168 else 169 { /* Find region boundary for long block case. */ 170 i = grInfo->region0_count + 1; 171 region1Start = mp3_sfBandIndex[sfreq].l[i]; 172 region2Start = mp3_sfBandIndex[sfreq].l[i + grInfo->region1_count + 1]; 173 } 174 175 /* Read bigvalues area. */ 176 177 178 if (grInfo->big_values > (FILTERBANK_BANDS*SUBBANDS_NUMBER >> 1)) 179 { 180 grInfo->big_values = (FILTERBANK_BANDS * SUBBANDS_NUMBER >> 1); 181 } 182 183 if ((grInfo->big_values << 1) > (uint32)region2Start) 184 { 185 h = &(pVars->ht[grInfo->table_select[0]]); 186 if (h->linbits) 187 { 188 pt_huff = pvmp3_huffman_pair_decoding_linbits; 189 } 190 else 191 { 192 pt_huff = pvmp3_huffman_pair_decoding; 193 } 194 195 for (i = 0; i < region1Start; i += 2) 196 { 197 (*pt_huff)(h, &is[i], pMainData); 198 } 199 200 h = &(pVars->ht[grInfo->table_select[1]]); 201 if (h->linbits) 202 { 203 pt_huff = pvmp3_huffman_pair_decoding_linbits; 204 } 205 else 206 { 207 pt_huff = pvmp3_huffman_pair_decoding; 208 } 209 210 for (; i < region2Start; i += 2) 211 { 212 (*pt_huff)(h, &is[i], pMainData); 213 } 214 215 h = &(pVars->ht[grInfo->table_select[2]]); 216 if (h->linbits) 217 { 218 pt_huff = pvmp3_huffman_pair_decoding_linbits; 219 } 220 else 221 { 222 pt_huff = pvmp3_huffman_pair_decoding; 223 } 224 225 for (; (uint32)i < (grInfo->big_values << 1); i += 2) 226 { 227 (*pt_huff)(h, &is[i], pMainData); 228 } 229 } 230 else if ((grInfo->big_values << 1) > (uint32)region1Start) 231 { 232 h = &(pVars->ht[grInfo->table_select[0]]); 233 if (h->linbits) 234 { 235 pt_huff = pvmp3_huffman_pair_decoding_linbits; 236 } 237 else 238 { 239 pt_huff = pvmp3_huffman_pair_decoding; 240 } 241 for (i = 0; i < region1Start; i += 2) 242 { 243 (*pt_huff)(h, &is[i], pMainData); 244 } 245 246 h = &(pVars->ht[grInfo->table_select[1]]); 247 if (h->linbits) 248 { 249 pt_huff = pvmp3_huffman_pair_decoding_linbits; 250 } 251 else 252 { 253 pt_huff = pvmp3_huffman_pair_decoding; 254 } 255 for (; (uint32)i < (grInfo->big_values << 1); i += 2) 256 { 257 (*pt_huff)(h, &is[i], pMainData); 258 } 259 } 260 else 261 { 262 h = &(pVars->ht[grInfo->table_select[0]]); 263 if (h->linbits) 264 { 265 pt_huff = pvmp3_huffman_pair_decoding_linbits; 266 } 267 else 268 { 269 pt_huff = pvmp3_huffman_pair_decoding; 270 } 271 272 for (i = 0; (uint32)i < (grInfo->big_values << 1); i += 2) 273 { 274 (*pt_huff)(h, &is[i], pMainData); 275 } 276 } 277 278 279 280 /* Read count1 area. */ 281 h = &(pVars->ht[grInfo->count1table_select+32]); 282 283 grBits = part2_start + grInfo->part2_3_length; 284 285 while ((pMainData->usedBits < grBits) && 286 (i < FILTERBANK_BANDS*SUBBANDS_NUMBER - 4)) 287 { 288 pvmp3_huffman_quad_decoding(h, &is[i], pMainData); 289 i += 4; 290 } 291 292 if ((pMainData->usedBits < grBits) && 293 (i < FILTERBANK_BANDS*SUBBANDS_NUMBER)) 294 { 295 pvmp3_huffman_quad_decoding(h, &is[i], pMainData); 296 i += 4; 297 298 if ((i - 2) >= FILTERBANK_BANDS*SUBBANDS_NUMBER) 299 { 300 i -= 2; 301 is[i] = 0; 302 is[(i+1)] = 0; 303 } 304 } 305 306 if (pMainData->usedBits > grBits) 307 { 308 i -= 4; 309 310 if (i < 0 || i > FILTERBANK_BANDS*SUBBANDS_NUMBER - 4) 311 { 312 /* illegal parameters may cause invalid access, set i to 0 */ 313 i = 0; 314 } 315 316 is[i] = 0; 317 is[(i+1)] = 0; 318 is[(i+2)] = 0; 319 is[(i+3)] = 0; 320 321 } 322 323 pMainData->usedBits = grBits; 324 325 return (i); 326 327 } 328 329
