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) { 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 00141 s->frame_len = 1 << s->frame_len_bits; 00142 if (s->use_variable_block_len) { 00143 int nb_max, nb; 00144 nb = ((flags2 >> 3) & 3) + 1; 00145 if ((s->bit_rate / s->nb_channels) >= 32000) 00146 nb += 2; 00147 nb_max = s->frame_len_bits - BLOCK_MIN_BITS; 00148 if (nb > nb_max) 00149 nb = nb_max; 00150 s->nb_block_sizes = nb + 1; 00151 } else { 00152 s->nb_block_sizes = 1; 00153 } 00154 00155 /* init rate dependent parameters */ 00156 s->use_noise_coding = 1; 00157 high_freq = s->sample_rate * 0.5; 00158 00159 /* if version 2, then the rates are normalized */ 00160 sample_rate1 = s->sample_rate; 00161 if (s->version == 2) { 00162 if (sample_rate1 >= 44100) { 00163 sample_rate1 = 44100; 00164 } else if (sample_rate1 >= 22050) { 00165 sample_rate1 = 22050; 00166 } else if (sample_rate1 >= 16000) { 00167 sample_rate1 = 16000; 00168 } else if (sample_rate1 >= 11025) { 00169 sample_rate1 = 11025; 00170 } else if (sample_rate1 >= 8000) { 00171 sample_rate1 = 8000; 00172 } 00173 } 00174 00175 bps = (float)s->bit_rate / (float)(s->nb_channels * s->sample_rate); 00176 s->byte_offset_bits = av_log2((int)(bps * s->frame_len / 8.0 + 0.5)) + 2; 00177 00178 /* compute high frequency value and choose if noise coding should 00179 be activated */ 00180 bps1 = bps; 00181 if (s->nb_channels == 2) 00182 bps1 = bps * 1.6; 00183 if (sample_rate1 == 44100) { 00184 if (bps1 >= 0.61) { 00185 s->use_noise_coding = 0; 00186 } else { 00187 high_freq = high_freq * 0.4; 00188 } 00189 } else if (sample_rate1 == 22050) { 00190 if (bps1 >= 1.16) { 00191 s->use_noise_coding = 0; 00192 } else if (bps1 >= 0.72) { 00193 high_freq = high_freq * 0.7; 00194 } else { 00195 high_freq = high_freq * 0.6; 00196 } 00197 } else if (sample_rate1 == 16000) { 00198 if (bps > 0.5) { 00199 high_freq = high_freq * 0.5; 00200 } else { 00201 high_freq = high_freq * 0.3; 00202 } 00203 } else if (sample_rate1 == 11025) { 00204 high_freq = high_freq * 0.7; 00205 } else if (sample_rate1 == 8000) { 00206 if (bps <= 0.625) { 00207 high_freq = high_freq * 0.5; 00208 } else if (bps > 0.75) { 00209 s->use_noise_coding = 0; 00210 } else { 00211 high_freq = high_freq * 0.65; 00212 } 00213 } else { 00214 if (bps >= 0.8) { 00215 high_freq = high_freq * 0.75; 00216 } else if (bps >= 0.6) { 00217 high_freq = high_freq * 0.6; 00218 } else { 00219 high_freq = high_freq * 0.5; 00220 } 00221 } 00222 av_dlog(s->avctx, "flags2=0x%x\n", flags2); 00223 av_dlog(s->avctx, "version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n", 00224 s->version, s->nb_channels, s->sample_rate, s->bit_rate, 00225 s->block_align); 00226 av_dlog(s->avctx, "bps=%f bps1=%f high_freq=%f bitoffset=%d\n", 00227 bps, bps1, high_freq, s->byte_offset_bits); 00228 av_dlog(s->avctx, "use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n", 00229 s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes); 00230 00231 /* compute the scale factor band sizes for each MDCT block size */ 00232 { 00233 int a, b, pos, lpos, k, block_len, i, j, n; 00234 const uint8_t *table; 00235 00236 if (s->version == 1) { 00237 s->coefs_start = 3; 00238 } else { 00239 s->coefs_start = 0; 00240 } 00241 for (k = 0; k < s->nb_block_sizes; k++) { 00242 block_len = s->frame_len >> k; 00243 00244 if (s->version == 1) { 00245 lpos = 0; 00246 for (i = 0; i < 25; i++) { 00247 a = ff_wma_critical_freqs[i]; 00248 b = s->sample_rate; 00249 pos = ((block_len * 2 * a) + (b >> 1)) / b; 00250 if (pos > block_len) 00251 pos = block_len; 00252 s->exponent_bands[0][i] = pos - lpos; 00253 if (pos >= block_len) { 00254 i++; 00255 break; 00256 } 00257 lpos = pos; 00258 } 00259 s->exponent_sizes[0] = i; 00260 } else { 00261 /* hardcoded tables */ 00262 table = NULL; 00263 a = s->frame_len_bits - BLOCK_MIN_BITS - k; 00264 if (a < 3) { 00265 if (s->sample_rate >= 44100) { 00266 table = exponent_band_44100[a]; 00267 } else if (s->sample_rate >= 32000) { 00268 table = exponent_band_32000[a]; 00269 } else if (s->sample_rate >= 22050) { 00270 table = exponent_band_22050[a]; 00271 } 00272 } 00273 if (table) { 00274 n = *table++; 00275 for (i = 0; i < n; i++) 00276 s->exponent_bands[k][i] = table[i]; 00277 s->exponent_sizes[k] = n; 00278 } else { 00279 j = 0; 00280 lpos = 0; 00281 for (i = 0; i < 25; i++) { 00282 a = ff_wma_critical_freqs[i]; 00283 b = s->sample_rate; 00284 pos = ((block_len * 2 * a) + (b << 1)) / (4 * b); 00285 pos <<= 2; 00286 if (pos > block_len) 00287 pos = block_len; 00288 if (pos > lpos) 00289 s->exponent_bands[k][j++] = pos - lpos; 00290 if (pos >= block_len) 00291 break; 00292 lpos = pos; 00293 } 00294 s->exponent_sizes[k] = j; 00295 } 00296 } 00297 00298 /* max number of coefs */ 00299 s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k; 00300 /* high freq computation */ 00301 s->high_band_start[k] = (int)((block_len * 2 * high_freq) / 00302 s->sample_rate + 0.5); 00303 n = s->exponent_sizes[k]; 00304 j = 0; 00305 pos = 0; 00306 for (i = 0; i < n; i++) { 00307 int start, end; 00308 start = pos; 00309 pos += s->exponent_bands[k][i]; 00310 end = pos; 00311 if (start < s->high_band_start[k]) 00312 start = s->high_band_start[k]; 00313 if (end > s->coefs_end[k]) 00314 end = s->coefs_end[k]; 00315 if (end > start) 00316 s->exponent_high_bands[k][j++] = end - start; 00317 } 00318 s->exponent_high_sizes[k] = j; 00319 #if 0 00320 tprintf(s->avctx, "%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ", 00321 s->frame_len >> k, 00322 s->coefs_end[k], 00323 s->high_band_start[k], 00324 s->exponent_high_sizes[k]); 00325 for (j = 0; j < s->exponent_high_sizes[k]; j++) 00326 tprintf(s->avctx, " %d", s->exponent_high_bands[k][j]); 00327 tprintf(s->avctx, "\n"); 00328 #endif 00329 } 00330 } 00331 00332 #ifdef TRACE 00333 { 00334 int i, j; 00335 for (i = 0; i < s->nb_block_sizes; i++) { 00336 tprintf(s->avctx, "%5d: n=%2d:", 00337 s->frame_len >> i, 00338 s->exponent_sizes[i]); 00339 for (j = 0; j < s->exponent_sizes[i]; j++) 00340 tprintf(s->avctx, " %d", s->exponent_bands[i][j]); 00341 tprintf(s->avctx, "\n"); 00342 } 00343 } 00344 #endif 00345 00346 /* init MDCT windows : simple sinus window */ 00347 for (i = 0; i < s->nb_block_sizes; i++) { 00348 ff_init_ff_sine_windows(s->frame_len_bits - i); 00349 s->windows[i] = ff_sine_windows[s->frame_len_bits - i]; 00350 } 00351 00352 s->reset_block_lengths = 1; 00353 00354 if (s->use_noise_coding) { 00355 00356 /* init the noise generator */ 00357 if (s->use_exp_vlc) { 00358 s->noise_mult = 0.02; 00359 } else { 00360 s->noise_mult = 0.04; 00361 } 00362 00363 #ifdef TRACE 00364 for (i = 0; i < NOISE_TAB_SIZE; i++) 00365 s->noise_table[i] = 1.0 * s->noise_mult; 00366 #else 00367 { 00368 unsigned int seed; 00369 float norm; 00370 seed = 1; 00371 norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult; 00372 for (i = 0; i < NOISE_TAB_SIZE; i++) { 00373 seed = seed * 314159 + 1; 00374 s->noise_table[i] = (float)((int)seed) * norm; 00375 } 00376 } 00377 #endif 00378 } 00379 00380 /* choose the VLC tables for the coefficients */ 00381 coef_vlc_table = 2; 00382 if (s->sample_rate >= 32000) { 00383 if (bps1 < 0.72) { 00384 coef_vlc_table = 0; 00385 } else if (bps1 < 1.16) { 00386 coef_vlc_table = 1; 00387 } 00388 } 00389 s->coef_vlcs[0]= &coef_vlcs[coef_vlc_table * 2 ]; 00390 s->coef_vlcs[1]= &coef_vlcs[coef_vlc_table * 2 + 1]; 00391 init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0], &s->int_table[0], 00392 s->coef_vlcs[0]); 00393 init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1], &s->int_table[1], 00394 s->coef_vlcs[1]); 00395 00396 return 0; 00397 } 00398 00399 int ff_wma_total_gain_to_bits(int total_gain) 00400 { 00401 if (total_gain < 15) return 13; 00402 else if (total_gain < 32) return 12; 00403 else if (total_gain < 40) return 11; 00404 else if (total_gain < 45) return 10; 00405 else return 9; 00406 } 00407 00408 int ff_wma_end(AVCodecContext *avctx) 00409 { 00410 WMACodecContext *s = avctx->priv_data; 00411 int i; 00412 00413 for (i = 0; i < s->nb_block_sizes; i++) 00414 ff_mdct_end(&s->mdct_ctx[i]); 00415 00416 if (s->use_exp_vlc) { 00417 free_vlc(&s->exp_vlc); 00418 } 00419 if (s->use_noise_coding) { 00420 free_vlc(&s->hgain_vlc); 00421 } 00422 for (i = 0; i < 2; i++) { 00423 free_vlc(&s->coef_vlc[i]); 00424 av_free(s->run_table[i]); 00425 av_free(s->level_table[i]); 00426 av_free(s->int_table[i]); 00427 } 00428 00429 return 0; 00430 } 00431 00437 unsigned int ff_wma_get_large_val(GetBitContext* gb) 00438 { 00440 int n_bits = 8; 00442 if (get_bits1(gb)) { 00443 n_bits += 8; 00444 if (get_bits1(gb)) { 00445 n_bits += 8; 00446 if (get_bits1(gb)) { 00447 n_bits += 7; 00448 } 00449 } 00450 } 00451 return get_bits_long(gb, n_bits); 00452 } 00453 00470 int ff_wma_run_level_decode(AVCodecContext* avctx, GetBitContext* gb, 00471 VLC *vlc, 00472 const float *level_table, const uint16_t *run_table, 00473 int version, WMACoef *ptr, int offset, 00474 int num_coefs, int block_len, int frame_len_bits, 00475 int coef_nb_bits) 00476 { 00477 int code, level, sign; 00478 const uint32_t *ilvl = (const uint32_t*)level_table; 00479 uint32_t *iptr = (uint32_t*)ptr; 00480 const unsigned int coef_mask = block_len - 1; 00481 for (; offset < num_coefs; offset++) { 00482 code = get_vlc2(gb, vlc->table, VLCBITS, VLCMAX); 00483 if (code > 1) { 00485 offset += run_table[code]; 00486 sign = get_bits1(gb) - 1; 00487 iptr[offset & coef_mask] = ilvl[code] ^ sign<<31; 00488 } else if (code == 1) { 00490 break; 00491 } else { 00493 if (!version) { 00494 level = get_bits(gb, coef_nb_bits); 00497 offset += get_bits(gb, frame_len_bits); 00498 } else { 00499 level = ff_wma_get_large_val(gb); 00501 if (get_bits1(gb)) { 00502 if (get_bits1(gb)) { 00503 if (get_bits1(gb)) { 00504 av_log(avctx,AV_LOG_ERROR, 00505 "broken escape sequence\n"); 00506 return -1; 00507 } else 00508 offset += get_bits(gb, frame_len_bits) + 4; 00509 } else 00510 offset += get_bits(gb, 2) + 1; 00511 } 00512 } 00513 sign = get_bits1(gb) - 1; 00514 ptr[offset & coef_mask] = (level^sign) - sign; 00515 } 00516 } 00518 if (offset > num_coefs) { 00519 av_log(avctx, AV_LOG_ERROR, "overflow in spectral RLE, ignoring\n"); 00520 return -1; 00521 } 00522 00523 return 0; 00524 } 00525