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libavcodec/wma.c

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00001 /*
00002  * WMA compatible codec
00003  * Copyright (c) 2002-2007 The FFmpeg Project
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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     if (s->byte_offset_bits + 3 > MIN_CACHE_BITS) {
00181         av_log(avctx, AV_LOG_ERROR, "byte_offset_bits %d is too large\n", s->byte_offset_bits);
00182         return AVERROR_PATCHWELCOME;
00183     }
00184 
00185     /* compute high frequency value and choose if noise coding should
00186        be activated */
00187     bps1 = bps;
00188     if (s->nb_channels == 2)
00189         bps1 = bps * 1.6;
00190     if (sample_rate1 == 44100) {
00191         if (bps1 >= 0.61) {
00192             s->use_noise_coding = 0;
00193         } else {
00194             high_freq = high_freq * 0.4;
00195         }
00196     } else if (sample_rate1 == 22050) {
00197         if (bps1 >= 1.16) {
00198             s->use_noise_coding = 0;
00199         } else if (bps1 >= 0.72) {
00200             high_freq = high_freq * 0.7;
00201         } else {
00202             high_freq = high_freq * 0.6;
00203         }
00204     } else if (sample_rate1 == 16000) {
00205         if (bps > 0.5) {
00206             high_freq = high_freq * 0.5;
00207         } else {
00208             high_freq = high_freq * 0.3;
00209         }
00210     } else if (sample_rate1 == 11025) {
00211         high_freq = high_freq * 0.7;
00212     } else if (sample_rate1 == 8000) {
00213         if (bps <= 0.625) {
00214             high_freq = high_freq * 0.5;
00215         } else if (bps > 0.75) {
00216             s->use_noise_coding = 0;
00217         } else {
00218             high_freq = high_freq * 0.65;
00219         }
00220     } else {
00221         if (bps >= 0.8) {
00222             high_freq = high_freq * 0.75;
00223         } else if (bps >= 0.6) {
00224             high_freq = high_freq * 0.6;
00225         } else {
00226             high_freq = high_freq * 0.5;
00227         }
00228     }
00229     av_dlog(s->avctx, "flags2=0x%x\n", flags2);
00230     av_dlog(s->avctx, "version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n",
00231             s->version, s->nb_channels, s->sample_rate, s->bit_rate,
00232             s->block_align);
00233     av_dlog(s->avctx, "bps=%f bps1=%f high_freq=%f bitoffset=%d\n",
00234             bps, bps1, high_freq, s->byte_offset_bits);
00235     av_dlog(s->avctx, "use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
00236             s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);
00237 
00238     /* compute the scale factor band sizes for each MDCT block size */
00239     {
00240         int a, b, pos, lpos, k, block_len, i, j, n;
00241         const uint8_t *table;
00242 
00243         if (s->version == 1) {
00244             s->coefs_start = 3;
00245         } else {
00246             s->coefs_start = 0;
00247         }
00248         for (k = 0; k < s->nb_block_sizes; k++) {
00249             block_len = s->frame_len >> k;
00250 
00251             if (s->version == 1) {
00252                 lpos = 0;
00253                 for (i = 0; i < 25; i++) {
00254                     a = ff_wma_critical_freqs[i];
00255                     b = s->sample_rate;
00256                     pos = ((block_len * 2 * a) + (b >> 1)) / b;
00257                     if (pos > block_len)
00258                         pos = block_len;
00259                     s->exponent_bands[0][i] = pos - lpos;
00260                     if (pos >= block_len) {
00261                         i++;
00262                         break;
00263                     }
00264                     lpos = pos;
00265                 }
00266                 s->exponent_sizes[0] = i;
00267             } else {
00268                 /* hardcoded tables */
00269                 table = NULL;
00270                 a = s->frame_len_bits - BLOCK_MIN_BITS - k;
00271                 if (a < 3) {
00272                     if (s->sample_rate >= 44100) {
00273                         table = exponent_band_44100[a];
00274                     } else if (s->sample_rate >= 32000) {
00275                         table = exponent_band_32000[a];
00276                     } else if (s->sample_rate >= 22050) {
00277                         table = exponent_band_22050[a];
00278                     }
00279                 }
00280                 if (table) {
00281                     n = *table++;
00282                     for (i = 0; i < n; i++)
00283                         s->exponent_bands[k][i] = table[i];
00284                     s->exponent_sizes[k] = n;
00285                 } else {
00286                     j = 0;
00287                     lpos = 0;
00288                     for (i = 0; i < 25; i++) {
00289                         a = ff_wma_critical_freqs[i];
00290                         b = s->sample_rate;
00291                         pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
00292                         pos <<= 2;
00293                         if (pos > block_len)
00294                             pos = block_len;
00295                         if (pos > lpos)
00296                             s->exponent_bands[k][j++] = pos - lpos;
00297                         if (pos >= block_len)
00298                             break;
00299                         lpos = pos;
00300                     }
00301                     s->exponent_sizes[k] = j;
00302                 }
00303             }
00304 
00305             /* max number of coefs */
00306             s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
00307             /* high freq computation */
00308             s->high_band_start[k] = (int)((block_len * 2 * high_freq) /
00309                                           s->sample_rate + 0.5);
00310             n = s->exponent_sizes[k];
00311             j = 0;
00312             pos = 0;
00313             for (i = 0; i < n; i++) {
00314                 int start, end;
00315                 start = pos;
00316                 pos += s->exponent_bands[k][i];
00317                 end = pos;
00318                 if (start < s->high_band_start[k])
00319                     start = s->high_band_start[k];
00320                 if (end > s->coefs_end[k])
00321                     end = s->coefs_end[k];
00322                 if (end > start)
00323                     s->exponent_high_bands[k][j++] = end - start;
00324             }
00325             s->exponent_high_sizes[k] = j;
00326 #if 0
00327             tprintf(s->avctx, "%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ",
00328                     s->frame_len >> k,
00329                     s->coefs_end[k],
00330                     s->high_band_start[k],
00331                     s->exponent_high_sizes[k]);
00332             for (j = 0; j < s->exponent_high_sizes[k]; j++)
00333                 tprintf(s->avctx, " %d", s->exponent_high_bands[k][j]);
00334             tprintf(s->avctx, "\n");
00335 #endif
00336         }
00337     }
00338 
00339 #ifdef TRACE
00340     {
00341         int i, j;
00342         for (i = 0; i < s->nb_block_sizes; i++) {
00343             tprintf(s->avctx, "%5d: n=%2d:",
00344                     s->frame_len >> i,
00345                     s->exponent_sizes[i]);
00346             for (j = 0; j < s->exponent_sizes[i]; j++)
00347                 tprintf(s->avctx, " %d", s->exponent_bands[i][j]);
00348             tprintf(s->avctx, "\n");
00349         }
00350     }
00351 #endif
00352 
00353     /* init MDCT windows : simple sinus window */
00354     for (i = 0; i < s->nb_block_sizes; i++) {
00355         ff_init_ff_sine_windows(s->frame_len_bits - i);
00356         s->windows[i] = ff_sine_windows[s->frame_len_bits - i];
00357     }
00358 
00359     s->reset_block_lengths = 1;
00360 
00361     if (s->use_noise_coding) {
00362 
00363         /* init the noise generator */
00364         if (s->use_exp_vlc) {
00365             s->noise_mult = 0.02;
00366         } else {
00367             s->noise_mult = 0.04;
00368         }
00369 
00370 #ifdef TRACE
00371         for (i = 0; i < NOISE_TAB_SIZE; i++)
00372             s->noise_table[i] = 1.0 * s->noise_mult;
00373 #else
00374         {
00375             unsigned int seed;
00376             float norm;
00377             seed = 1;
00378             norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult;
00379             for (i = 0; i < NOISE_TAB_SIZE; i++) {
00380                 seed = seed * 314159 + 1;
00381                 s->noise_table[i] = (float)((int)seed) * norm;
00382             }
00383         }
00384 #endif
00385     }
00386 
00387     /* choose the VLC tables for the coefficients */
00388     coef_vlc_table = 2;
00389     if (s->sample_rate >= 32000) {
00390         if (bps1 < 0.72) {
00391             coef_vlc_table = 0;
00392         } else if (bps1 < 1.16) {
00393             coef_vlc_table = 1;
00394         }
00395     }
00396     s->coef_vlcs[0]= &coef_vlcs[coef_vlc_table * 2    ];
00397     s->coef_vlcs[1]= &coef_vlcs[coef_vlc_table * 2 + 1];
00398     init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0], &s->int_table[0],
00399                   s->coef_vlcs[0]);
00400     init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1], &s->int_table[1],
00401                   s->coef_vlcs[1]);
00402 
00403     return 0;
00404 }
00405 
00406 int ff_wma_total_gain_to_bits(int total_gain)
00407 {
00408          if (total_gain < 15) return 13;
00409     else if (total_gain < 32) return 12;
00410     else if (total_gain < 40) return 11;
00411     else if (total_gain < 45) return 10;
00412     else                      return  9;
00413 }
00414 
00415 int ff_wma_end(AVCodecContext *avctx)
00416 {
00417     WMACodecContext *s = avctx->priv_data;
00418     int i;
00419 
00420     for (i = 0; i < s->nb_block_sizes; i++)
00421         ff_mdct_end(&s->mdct_ctx[i]);
00422 
00423     if (s->use_exp_vlc) {
00424         free_vlc(&s->exp_vlc);
00425     }
00426     if (s->use_noise_coding) {
00427         free_vlc(&s->hgain_vlc);
00428     }
00429     for (i = 0; i < 2; i++) {
00430         free_vlc(&s->coef_vlc[i]);
00431         av_free(s->run_table[i]);
00432         av_free(s->level_table[i]);
00433         av_free(s->int_table[i]);
00434     }
00435 
00436     return 0;
00437 }
00438 
00444 unsigned int ff_wma_get_large_val(GetBitContext* gb)
00445 {
00447     int n_bits = 8;
00449     if (get_bits1(gb)) {
00450         n_bits += 8;
00451         if (get_bits1(gb)) {
00452             n_bits += 8;
00453             if (get_bits1(gb)) {
00454                 n_bits += 7;
00455             }
00456         }
00457     }
00458     return get_bits_long(gb, n_bits);
00459 }
00460 
00477 int ff_wma_run_level_decode(AVCodecContext* avctx, GetBitContext* gb,
00478                             VLC *vlc,
00479                             const float *level_table, const uint16_t *run_table,
00480                             int version, WMACoef *ptr, int offset,
00481                             int num_coefs, int block_len, int frame_len_bits,
00482                             int coef_nb_bits)
00483 {
00484     int code, level, sign;
00485     const uint32_t *ilvl = (const uint32_t*)level_table;
00486     uint32_t *iptr = (uint32_t*)ptr;
00487     const unsigned int coef_mask = block_len - 1;
00488     for (; offset < num_coefs; offset++) {
00489         code = get_vlc2(gb, vlc->table, VLCBITS, VLCMAX);
00490         if (code > 1) {
00492             offset += run_table[code];
00493             sign = get_bits1(gb) - 1;
00494             iptr[offset & coef_mask] = ilvl[code] ^ sign<<31;
00495         } else if (code == 1) {
00497             break;
00498         } else {
00500             if (!version) {
00501                 level = get_bits(gb, coef_nb_bits);
00504                 offset += get_bits(gb, frame_len_bits);
00505             } else {
00506                 level = ff_wma_get_large_val(gb);
00508                 if (get_bits1(gb)) {
00509                     if (get_bits1(gb)) {
00510                         if (get_bits1(gb)) {
00511                             av_log(avctx,AV_LOG_ERROR,
00512                                 "broken escape sequence\n");
00513                             return -1;
00514                         } else
00515                             offset += get_bits(gb, frame_len_bits) + 4;
00516                     } else
00517                         offset += get_bits(gb, 2) + 1;
00518                 }
00519             }
00520             sign = get_bits1(gb) - 1;
00521             ptr[offset & coef_mask] = (level^sign) - sign;
00522         }
00523     }
00525     if (offset > num_coefs) {
00526         av_log(avctx, AV_LOG_ERROR, "overflow in spectral RLE, ignoring\n");
00527         return -1;
00528     }
00529 
00530     return 0;
00531 }
00532 

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