Libav 0.7.1
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00001 /* 00002 * WMA compatible codec 00003 * Copyright (c) 2002-2007 The Libav Project 00004 * 00005 * This file is part of Libav. 00006 * 00007 * Libav is free software; you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public 00009 * License as published by the Free Software Foundation; either 00010 * version 2.1 of the License, or (at your option) any later version. 00011 * 00012 * Libav is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with Libav; if not, write to the Free Software 00019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00020 */ 00021 00022 #include "avcodec.h" 00023 #include "sinewin.h" 00024 #include "wma.h" 00025 #include "wmadata.h" 00026 00027 #undef NDEBUG 00028 #include <assert.h> 00029 00030 /* XXX: use same run/length optimization as mpeg decoders */ 00031 //FIXME maybe split decode / encode or pass flag 00032 static void init_coef_vlc(VLC *vlc, uint16_t **prun_table, 00033 float **plevel_table, uint16_t **pint_table, 00034 const CoefVLCTable *vlc_table) 00035 { 00036 int n = vlc_table->n; 00037 const uint8_t *table_bits = vlc_table->huffbits; 00038 const uint32_t *table_codes = vlc_table->huffcodes; 00039 const uint16_t *levels_table = vlc_table->levels; 00040 uint16_t *run_table, *level_table, *int_table; 00041 float *flevel_table; 00042 int i, l, j, k, level; 00043 00044 init_vlc(vlc, VLCBITS, n, table_bits, 1, 1, table_codes, 4, 4, 0); 00045 00046 run_table = av_malloc(n * sizeof(uint16_t)); 00047 level_table = av_malloc(n * sizeof(uint16_t)); 00048 flevel_table= av_malloc(n * sizeof(*flevel_table)); 00049 int_table = av_malloc(n * sizeof(uint16_t)); 00050 i = 2; 00051 level = 1; 00052 k = 0; 00053 while (i < n) { 00054 int_table[k] = i; 00055 l = levels_table[k++]; 00056 for (j = 0; j < l; j++) { 00057 run_table[i] = j; 00058 level_table[i] = level; 00059 flevel_table[i]= level; 00060 i++; 00061 } 00062 level++; 00063 } 00064 *prun_table = run_table; 00065 *plevel_table = flevel_table; 00066 *pint_table = int_table; 00067 av_free(level_table); 00068 } 00069 00077 int av_cold ff_wma_get_frame_len_bits(int sample_rate, int version, 00078 unsigned int decode_flags) 00079 { 00080 00081 int frame_len_bits; 00082 00083 if (sample_rate <= 16000) { 00084 frame_len_bits = 9; 00085 } else if (sample_rate <= 22050 || 00086 (sample_rate <= 32000 && version == 1)) { 00087 frame_len_bits = 10; 00088 } else if (sample_rate <= 48000 || version < 3) { 00089 frame_len_bits = 11; 00090 } else if (sample_rate <= 96000) { 00091 frame_len_bits = 12; 00092 } else { 00093 frame_len_bits = 13; 00094 } 00095 00096 if (version == 3) { 00097 int tmp = decode_flags & 0x6; 00098 if (tmp == 0x2) { 00099 ++frame_len_bits; 00100 } else if (tmp == 0x4) { 00101 --frame_len_bits; 00102 } else if (tmp == 0x6) { 00103 frame_len_bits -= 2; 00104 } 00105 } 00106 00107 return frame_len_bits; 00108 } 00109 00110 int ff_wma_init(AVCodecContext *avctx, int flags2) 00111 { 00112 WMACodecContext *s = avctx->priv_data; 00113 int i; 00114 float bps1, high_freq; 00115 volatile float bps; 00116 int sample_rate1; 00117 int coef_vlc_table; 00118 00119 if ( avctx->sample_rate <= 0 || avctx->sample_rate > 50000 00120 || avctx->channels <= 0 || avctx->channels > 8 00121 || avctx->bit_rate <= 0) 00122 return -1; 00123 00124 s->sample_rate = avctx->sample_rate; 00125 s->nb_channels = avctx->channels; 00126 s->bit_rate = avctx->bit_rate; 00127 s->block_align = avctx->block_align; 00128 00129 dsputil_init(&s->dsp, avctx); 00130 ff_fmt_convert_init(&s->fmt_conv, avctx); 00131 00132 if (avctx->codec->id == CODEC_ID_WMAV1) { 00133 s->version = 1; 00134 } else { 00135 s->version = 2; 00136 } 00137 00138 /* compute MDCT block size */ 00139 s->frame_len_bits = ff_wma_get_frame_len_bits(s->sample_rate, s->version, 0); 00140 s->next_block_len_bits = s->frame_len_bits; 00141 s->prev_block_len_bits = s->frame_len_bits; 00142 s->block_len_bits = s->frame_len_bits; 00143 00144 s->frame_len = 1 << s->frame_len_bits; 00145 if (s->use_variable_block_len) { 00146 int nb_max, nb; 00147 nb = ((flags2 >> 3) & 3) + 1; 00148 if ((s->bit_rate / s->nb_channels) >= 32000) 00149 nb += 2; 00150 nb_max = s->frame_len_bits - BLOCK_MIN_BITS; 00151 if (nb > nb_max) 00152 nb = nb_max; 00153 s->nb_block_sizes = nb + 1; 00154 } else { 00155 s->nb_block_sizes = 1; 00156 } 00157 00158 /* init rate dependent parameters */ 00159 s->use_noise_coding = 1; 00160 high_freq = s->sample_rate * 0.5; 00161 00162 /* if version 2, then the rates are normalized */ 00163 sample_rate1 = s->sample_rate; 00164 if (s->version == 2) { 00165 if (sample_rate1 >= 44100) { 00166 sample_rate1 = 44100; 00167 } else if (sample_rate1 >= 22050) { 00168 sample_rate1 = 22050; 00169 } else if (sample_rate1 >= 16000) { 00170 sample_rate1 = 16000; 00171 } else if (sample_rate1 >= 11025) { 00172 sample_rate1 = 11025; 00173 } else if (sample_rate1 >= 8000) { 00174 sample_rate1 = 8000; 00175 } 00176 } 00177 00178 bps = (float)s->bit_rate / (float)(s->nb_channels * s->sample_rate); 00179 s->byte_offset_bits = av_log2((int)(bps * s->frame_len / 8.0 + 0.5)) + 2; 00180 00181 /* compute high frequency value and choose if noise coding should 00182 be activated */ 00183 bps1 = bps; 00184 if (s->nb_channels == 2) 00185 bps1 = bps * 1.6; 00186 if (sample_rate1 == 44100) { 00187 if (bps1 >= 0.61) { 00188 s->use_noise_coding = 0; 00189 } else { 00190 high_freq = high_freq * 0.4; 00191 } 00192 } else if (sample_rate1 == 22050) { 00193 if (bps1 >= 1.16) { 00194 s->use_noise_coding = 0; 00195 } else if (bps1 >= 0.72) { 00196 high_freq = high_freq * 0.7; 00197 } else { 00198 high_freq = high_freq * 0.6; 00199 } 00200 } else if (sample_rate1 == 16000) { 00201 if (bps > 0.5) { 00202 high_freq = high_freq * 0.5; 00203 } else { 00204 high_freq = high_freq * 0.3; 00205 } 00206 } else if (sample_rate1 == 11025) { 00207 high_freq = high_freq * 0.7; 00208 } else if (sample_rate1 == 8000) { 00209 if (bps <= 0.625) { 00210 high_freq = high_freq * 0.5; 00211 } else if (bps > 0.75) { 00212 s->use_noise_coding = 0; 00213 } else { 00214 high_freq = high_freq * 0.65; 00215 } 00216 } else { 00217 if (bps >= 0.8) { 00218 high_freq = high_freq * 0.75; 00219 } else if (bps >= 0.6) { 00220 high_freq = high_freq * 0.6; 00221 } else { 00222 high_freq = high_freq * 0.5; 00223 } 00224 } 00225 av_dlog(s->avctx, "flags2=0x%x\n", flags2); 00226 av_dlog(s->avctx, "version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n", 00227 s->version, s->nb_channels, s->sample_rate, s->bit_rate, 00228 s->block_align); 00229 av_dlog(s->avctx, "bps=%f bps1=%f high_freq=%f bitoffset=%d\n", 00230 bps, bps1, high_freq, s->byte_offset_bits); 00231 av_dlog(s->avctx, "use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n", 00232 s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes); 00233 00234 /* compute the scale factor band sizes for each MDCT block size */ 00235 { 00236 int a, b, pos, lpos, k, block_len, i, j, n; 00237 const uint8_t *table; 00238 00239 if (s->version == 1) { 00240 s->coefs_start = 3; 00241 } else { 00242 s->coefs_start = 0; 00243 } 00244 for (k = 0; k < s->nb_block_sizes; k++) { 00245 block_len = s->frame_len >> k; 00246 00247 if (s->version == 1) { 00248 lpos = 0; 00249 for (i = 0; i < 25; i++) { 00250 a = ff_wma_critical_freqs[i]; 00251 b = s->sample_rate; 00252 pos = ((block_len * 2 * a) + (b >> 1)) / b; 00253 if (pos > block_len) 00254 pos = block_len; 00255 s->exponent_bands[0][i] = pos - lpos; 00256 if (pos >= block_len) { 00257 i++; 00258 break; 00259 } 00260 lpos = pos; 00261 } 00262 s->exponent_sizes[0] = i; 00263 } else { 00264 /* hardcoded tables */ 00265 table = NULL; 00266 a = s->frame_len_bits - BLOCK_MIN_BITS - k; 00267 if (a < 3) { 00268 if (s->sample_rate >= 44100) { 00269 table = exponent_band_44100[a]; 00270 } else if (s->sample_rate >= 32000) { 00271 table = exponent_band_32000[a]; 00272 } else if (s->sample_rate >= 22050) { 00273 table = exponent_band_22050[a]; 00274 } 00275 } 00276 if (table) { 00277 n = *table++; 00278 for (i = 0; i < n; i++) 00279 s->exponent_bands[k][i] = table[i]; 00280 s->exponent_sizes[k] = n; 00281 } else { 00282 j = 0; 00283 lpos = 0; 00284 for (i = 0; i < 25; i++) { 00285 a = ff_wma_critical_freqs[i]; 00286 b = s->sample_rate; 00287 pos = ((block_len * 2 * a) + (b << 1)) / (4 * b); 00288 pos <<= 2; 00289 if (pos > block_len) 00290 pos = block_len; 00291 if (pos > lpos) 00292 s->exponent_bands[k][j++] = pos - lpos; 00293 if (pos >= block_len) 00294 break; 00295 lpos = pos; 00296 } 00297 s->exponent_sizes[k] = j; 00298 } 00299 } 00300 00301 /* max number of coefs */ 00302 s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k; 00303 /* high freq computation */ 00304 s->high_band_start[k] = (int)((block_len * 2 * high_freq) / 00305 s->sample_rate + 0.5); 00306 n = s->exponent_sizes[k]; 00307 j = 0; 00308 pos = 0; 00309 for (i = 0; i < n; i++) { 00310 int start, end; 00311 start = pos; 00312 pos += s->exponent_bands[k][i]; 00313 end = pos; 00314 if (start < s->high_band_start[k]) 00315 start = s->high_band_start[k]; 00316 if (end > s->coefs_end[k]) 00317 end = s->coefs_end[k]; 00318 if (end > start) 00319 s->exponent_high_bands[k][j++] = end - start; 00320 } 00321 s->exponent_high_sizes[k] = j; 00322 #if 0 00323 tprintf(s->avctx, "%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ", 00324 s->frame_len >> k, 00325 s->coefs_end[k], 00326 s->high_band_start[k], 00327 s->exponent_high_sizes[k]); 00328 for (j = 0; j < s->exponent_high_sizes[k]; j++) 00329 tprintf(s->avctx, " %d", s->exponent_high_bands[k][j]); 00330 tprintf(s->avctx, "\n"); 00331 #endif 00332 } 00333 } 00334 00335 #ifdef TRACE 00336 { 00337 int i, j; 00338 for (i = 0; i < s->nb_block_sizes; i++) { 00339 tprintf(s->avctx, "%5d: n=%2d:", 00340 s->frame_len >> i, 00341 s->exponent_sizes[i]); 00342 for (j = 0; j < s->exponent_sizes[i]; j++) 00343 tprintf(s->avctx, " %d", s->exponent_bands[i][j]); 00344 tprintf(s->avctx, "\n"); 00345 } 00346 } 00347 #endif 00348 00349 /* init MDCT windows : simple sinus window */ 00350 for (i = 0; i < s->nb_block_sizes; i++) { 00351 ff_init_ff_sine_windows(s->frame_len_bits - i); 00352 s->windows[i] = ff_sine_windows[s->frame_len_bits - i]; 00353 } 00354 00355 s->reset_block_lengths = 1; 00356 00357 if (s->use_noise_coding) { 00358 00359 /* init the noise generator */ 00360 if (s->use_exp_vlc) { 00361 s->noise_mult = 0.02; 00362 } else { 00363 s->noise_mult = 0.04; 00364 } 00365 00366 #ifdef TRACE 00367 for (i = 0; i < NOISE_TAB_SIZE; i++) 00368 s->noise_table[i] = 1.0 * s->noise_mult; 00369 #else 00370 { 00371 unsigned int seed; 00372 float norm; 00373 seed = 1; 00374 norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult; 00375 for (i = 0; i < NOISE_TAB_SIZE; i++) { 00376 seed = seed * 314159 + 1; 00377 s->noise_table[i] = (float)((int)seed) * norm; 00378 } 00379 } 00380 #endif 00381 } 00382 00383 /* choose the VLC tables for the coefficients */ 00384 coef_vlc_table = 2; 00385 if (s->sample_rate >= 32000) { 00386 if (bps1 < 0.72) { 00387 coef_vlc_table = 0; 00388 } else if (bps1 < 1.16) { 00389 coef_vlc_table = 1; 00390 } 00391 } 00392 s->coef_vlcs[0]= &coef_vlcs[coef_vlc_table * 2 ]; 00393 s->coef_vlcs[1]= &coef_vlcs[coef_vlc_table * 2 + 1]; 00394 init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0], &s->int_table[0], 00395 s->coef_vlcs[0]); 00396 init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1], &s->int_table[1], 00397 s->coef_vlcs[1]); 00398 00399 return 0; 00400 } 00401 00402 int ff_wma_total_gain_to_bits(int total_gain) 00403 { 00404 if (total_gain < 15) return 13; 00405 else if (total_gain < 32) return 12; 00406 else if (total_gain < 40) return 11; 00407 else if (total_gain < 45) return 10; 00408 else return 9; 00409 } 00410 00411 int ff_wma_end(AVCodecContext *avctx) 00412 { 00413 WMACodecContext *s = avctx->priv_data; 00414 int i; 00415 00416 for (i = 0; i < s->nb_block_sizes; i++) 00417 ff_mdct_end(&s->mdct_ctx[i]); 00418 00419 if (s->use_exp_vlc) { 00420 free_vlc(&s->exp_vlc); 00421 } 00422 if (s->use_noise_coding) { 00423 free_vlc(&s->hgain_vlc); 00424 } 00425 for (i = 0; i < 2; i++) { 00426 free_vlc(&s->coef_vlc[i]); 00427 av_free(s->run_table[i]); 00428 av_free(s->level_table[i]); 00429 av_free(s->int_table[i]); 00430 } 00431 00432 return 0; 00433 } 00434 00440 unsigned int ff_wma_get_large_val(GetBitContext* gb) 00441 { 00443 int n_bits = 8; 00445 if (get_bits1(gb)) { 00446 n_bits += 8; 00447 if (get_bits1(gb)) { 00448 n_bits += 8; 00449 if (get_bits1(gb)) { 00450 n_bits += 7; 00451 } 00452 } 00453 } 00454 return get_bits_long(gb, n_bits); 00455 } 00456 00473 int ff_wma_run_level_decode(AVCodecContext* avctx, GetBitContext* gb, 00474 VLC *vlc, 00475 const float *level_table, const uint16_t *run_table, 00476 int version, WMACoef *ptr, int offset, 00477 int num_coefs, int block_len, int frame_len_bits, 00478 int coef_nb_bits) 00479 { 00480 int code, level, sign; 00481 const uint32_t *ilvl = (const uint32_t*)level_table; 00482 uint32_t *iptr = (uint32_t*)ptr; 00483 const unsigned int coef_mask = block_len - 1; 00484 for (; offset < num_coefs; offset++) { 00485 code = get_vlc2(gb, vlc->table, VLCBITS, VLCMAX); 00486 if (code > 1) { 00488 offset += run_table[code]; 00489 sign = get_bits1(gb) - 1; 00490 iptr[offset & coef_mask] = ilvl[code] ^ sign<<31; 00491 } else if (code == 1) { 00493 break; 00494 } else { 00496 if (!version) { 00497 level = get_bits(gb, coef_nb_bits); 00500 offset += get_bits(gb, frame_len_bits); 00501 } else { 00502 level = ff_wma_get_large_val(gb); 00504 if (get_bits1(gb)) { 00505 if (get_bits1(gb)) { 00506 if (get_bits1(gb)) { 00507 av_log(avctx,AV_LOG_ERROR, 00508 "broken escape sequence\n"); 00509 return -1; 00510 } else 00511 offset += get_bits(gb, frame_len_bits) + 4; 00512 } else 00513 offset += get_bits(gb, 2) + 1; 00514 } 00515 } 00516 sign = get_bits1(gb) - 1; 00517 ptr[offset & coef_mask] = (level^sign) - sign; 00518 } 00519 } 00521 if (offset > num_coefs) { 00522 av_log(avctx, AV_LOG_ERROR, "overflow in spectral RLE, ignoring\n"); 00523 return -1; 00524 } 00525 00526 return 0; 00527 } 00528