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libavcodec/wmadec.c

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00001 /*
00002  * WMA compatible decoder
00003  * Copyright (c) 2002 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 
00036 #include "avcodec.h"
00037 #include "wma.h"
00038 
00039 #undef NDEBUG
00040 #include <assert.h>
00041 
00042 #define EXPVLCBITS 8
00043 #define EXPMAX ((19+EXPVLCBITS-1)/EXPVLCBITS)
00044 
00045 #define HGAINVLCBITS 9
00046 #define HGAINMAX ((13+HGAINVLCBITS-1)/HGAINVLCBITS)
00047 
00048 static void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len);
00049 
00050 #ifdef TRACE
00051 static void dump_shorts(WMACodecContext *s, const char *name, const short *tab, int n)
00052 {
00053     int i;
00054 
00055     tprintf(s->avctx, "%s[%d]:\n", name, n);
00056     for(i=0;i<n;i++) {
00057         if ((i & 7) == 0)
00058             tprintf(s->avctx, "%4d: ", i);
00059         tprintf(s->avctx, " %5d.0", tab[i]);
00060         if ((i & 7) == 7)
00061             tprintf(s->avctx, "\n");
00062     }
00063 }
00064 
00065 static void dump_floats(WMACodecContext *s, const char *name, int prec, const float *tab, int n)
00066 {
00067     int i;
00068 
00069     tprintf(s->avctx, "%s[%d]:\n", name, n);
00070     for(i=0;i<n;i++) {
00071         if ((i & 7) == 0)
00072             tprintf(s->avctx, "%4d: ", i);
00073         tprintf(s->avctx, " %8.*f", prec, tab[i]);
00074         if ((i & 7) == 7)
00075             tprintf(s->avctx, "\n");
00076     }
00077     if ((i & 7) != 0)
00078         tprintf(s->avctx, "\n");
00079 }
00080 #endif
00081 
00082 static int wma_decode_init(AVCodecContext * avctx)
00083 {
00084     WMACodecContext *s = avctx->priv_data;
00085     int i, flags2;
00086     uint8_t *extradata;
00087 
00088     s->avctx = avctx;
00089 
00090     /* extract flag infos */
00091     flags2 = 0;
00092     extradata = avctx->extradata;
00093     if (avctx->codec->id == CODEC_ID_WMAV1 && avctx->extradata_size >= 4) {
00094         flags2 = AV_RL16(extradata+2);
00095     } else if (avctx->codec->id == CODEC_ID_WMAV2 && avctx->extradata_size >= 6) {
00096         flags2 = AV_RL16(extradata+4);
00097     }
00098 // for(i=0; i<avctx->extradata_size; i++)
00099 //     av_log(NULL, AV_LOG_ERROR, "%02X ", extradata[i]);
00100 
00101     s->use_exp_vlc = flags2 & 0x0001;
00102     s->use_bit_reservoir = flags2 & 0x0002;
00103     s->use_variable_block_len = flags2 & 0x0004;
00104 
00105     if(ff_wma_init(avctx, flags2)<0)
00106         return -1;
00107 
00108     /* init MDCT */
00109     for(i = 0; i < s->nb_block_sizes; i++)
00110         ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1, 1.0);
00111 
00112     if (s->use_noise_coding) {
00113         init_vlc(&s->hgain_vlc, HGAINVLCBITS, sizeof(ff_wma_hgain_huffbits),
00114                  ff_wma_hgain_huffbits, 1, 1,
00115                  ff_wma_hgain_huffcodes, 2, 2, 0);
00116     }
00117 
00118     if (s->use_exp_vlc) {
00119         init_vlc(&s->exp_vlc, EXPVLCBITS, sizeof(ff_aac_scalefactor_bits), //FIXME move out of context
00120                  ff_aac_scalefactor_bits, 1, 1,
00121                  ff_aac_scalefactor_code, 4, 4, 0);
00122     } else {
00123         wma_lsp_to_curve_init(s, s->frame_len);
00124     }
00125 
00126     avctx->sample_fmt = AV_SAMPLE_FMT_S16;
00127 
00128     avcodec_get_frame_defaults(&s->frame);
00129     avctx->coded_frame = &s->frame;
00130 
00131     return 0;
00132 }
00133 
00140 static inline float pow_m1_4(WMACodecContext *s, float x)
00141 {
00142     union {
00143         float f;
00144         unsigned int v;
00145     } u, t;
00146     unsigned int e, m;
00147     float a, b;
00148 
00149     u.f = x;
00150     e = u.v >> 23;
00151     m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
00152     /* build interpolation scale: 1 <= t < 2. */
00153     t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
00154     a = s->lsp_pow_m_table1[m];
00155     b = s->lsp_pow_m_table2[m];
00156     return s->lsp_pow_e_table[e] * (a + b * t.f);
00157 }
00158 
00159 static void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len)
00160 {
00161     float wdel, a, b;
00162     int i, e, m;
00163 
00164     wdel = M_PI / frame_len;
00165     for(i=0;i<frame_len;i++)
00166         s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
00167 
00168     /* tables for x^-0.25 computation */
00169     for(i=0;i<256;i++) {
00170         e = i - 126;
00171         s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
00172     }
00173 
00174     /* NOTE: these two tables are needed to avoid two operations in
00175        pow_m1_4 */
00176     b = 1.0;
00177     for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) {
00178         m = (1 << LSP_POW_BITS) + i;
00179         a = (float)m * (0.5 / (1 << LSP_POW_BITS));
00180         a = pow(a, -0.25);
00181         s->lsp_pow_m_table1[i] = 2 * a - b;
00182         s->lsp_pow_m_table2[i] = b - a;
00183         b = a;
00184     }
00185 }
00186 
00191 static void wma_lsp_to_curve(WMACodecContext *s,
00192                              float *out, float *val_max_ptr,
00193                              int n, float *lsp)
00194 {
00195     int i, j;
00196     float p, q, w, v, val_max;
00197 
00198     val_max = 0;
00199     for(i=0;i<n;i++) {
00200         p = 0.5f;
00201         q = 0.5f;
00202         w = s->lsp_cos_table[i];
00203         for(j=1;j<NB_LSP_COEFS;j+=2){
00204             q *= w - lsp[j - 1];
00205             p *= w - lsp[j];
00206         }
00207         p *= p * (2.0f - w);
00208         q *= q * (2.0f + w);
00209         v = p + q;
00210         v = pow_m1_4(s, v);
00211         if (v > val_max)
00212             val_max = v;
00213         out[i] = v;
00214     }
00215     *val_max_ptr = val_max;
00216 }
00217 
00221 static void decode_exp_lsp(WMACodecContext *s, int ch)
00222 {
00223     float lsp_coefs[NB_LSP_COEFS];
00224     int val, i;
00225 
00226     for(i = 0; i < NB_LSP_COEFS; i++) {
00227         if (i == 0 || i >= 8)
00228             val = get_bits(&s->gb, 3);
00229         else
00230             val = get_bits(&s->gb, 4);
00231         lsp_coefs[i] = ff_wma_lsp_codebook[i][val];
00232     }
00233 
00234     wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
00235                      s->block_len, lsp_coefs);
00236 }
00237 
00239 static const float pow_tab[] = {
00240     1.7782794100389e-04, 2.0535250264571e-04,
00241     2.3713737056617e-04, 2.7384196342644e-04,
00242     3.1622776601684e-04, 3.6517412725484e-04,
00243     4.2169650342858e-04, 4.8696752516586e-04,
00244     5.6234132519035e-04, 6.4938163157621e-04,
00245     7.4989420933246e-04, 8.6596432336006e-04,
00246     1.0000000000000e-03, 1.1547819846895e-03,
00247     1.3335214321633e-03, 1.5399265260595e-03,
00248     1.7782794100389e-03, 2.0535250264571e-03,
00249     2.3713737056617e-03, 2.7384196342644e-03,
00250     3.1622776601684e-03, 3.6517412725484e-03,
00251     4.2169650342858e-03, 4.8696752516586e-03,
00252     5.6234132519035e-03, 6.4938163157621e-03,
00253     7.4989420933246e-03, 8.6596432336006e-03,
00254     1.0000000000000e-02, 1.1547819846895e-02,
00255     1.3335214321633e-02, 1.5399265260595e-02,
00256     1.7782794100389e-02, 2.0535250264571e-02,
00257     2.3713737056617e-02, 2.7384196342644e-02,
00258     3.1622776601684e-02, 3.6517412725484e-02,
00259     4.2169650342858e-02, 4.8696752516586e-02,
00260     5.6234132519035e-02, 6.4938163157621e-02,
00261     7.4989420933246e-02, 8.6596432336007e-02,
00262     1.0000000000000e-01, 1.1547819846895e-01,
00263     1.3335214321633e-01, 1.5399265260595e-01,
00264     1.7782794100389e-01, 2.0535250264571e-01,
00265     2.3713737056617e-01, 2.7384196342644e-01,
00266     3.1622776601684e-01, 3.6517412725484e-01,
00267     4.2169650342858e-01, 4.8696752516586e-01,
00268     5.6234132519035e-01, 6.4938163157621e-01,
00269     7.4989420933246e-01, 8.6596432336007e-01,
00270     1.0000000000000e+00, 1.1547819846895e+00,
00271     1.3335214321633e+00, 1.5399265260595e+00,
00272     1.7782794100389e+00, 2.0535250264571e+00,
00273     2.3713737056617e+00, 2.7384196342644e+00,
00274     3.1622776601684e+00, 3.6517412725484e+00,
00275     4.2169650342858e+00, 4.8696752516586e+00,
00276     5.6234132519035e+00, 6.4938163157621e+00,
00277     7.4989420933246e+00, 8.6596432336007e+00,
00278     1.0000000000000e+01, 1.1547819846895e+01,
00279     1.3335214321633e+01, 1.5399265260595e+01,
00280     1.7782794100389e+01, 2.0535250264571e+01,
00281     2.3713737056617e+01, 2.7384196342644e+01,
00282     3.1622776601684e+01, 3.6517412725484e+01,
00283     4.2169650342858e+01, 4.8696752516586e+01,
00284     5.6234132519035e+01, 6.4938163157621e+01,
00285     7.4989420933246e+01, 8.6596432336007e+01,
00286     1.0000000000000e+02, 1.1547819846895e+02,
00287     1.3335214321633e+02, 1.5399265260595e+02,
00288     1.7782794100389e+02, 2.0535250264571e+02,
00289     2.3713737056617e+02, 2.7384196342644e+02,
00290     3.1622776601684e+02, 3.6517412725484e+02,
00291     4.2169650342858e+02, 4.8696752516586e+02,
00292     5.6234132519035e+02, 6.4938163157621e+02,
00293     7.4989420933246e+02, 8.6596432336007e+02,
00294     1.0000000000000e+03, 1.1547819846895e+03,
00295     1.3335214321633e+03, 1.5399265260595e+03,
00296     1.7782794100389e+03, 2.0535250264571e+03,
00297     2.3713737056617e+03, 2.7384196342644e+03,
00298     3.1622776601684e+03, 3.6517412725484e+03,
00299     4.2169650342858e+03, 4.8696752516586e+03,
00300     5.6234132519035e+03, 6.4938163157621e+03,
00301     7.4989420933246e+03, 8.6596432336007e+03,
00302     1.0000000000000e+04, 1.1547819846895e+04,
00303     1.3335214321633e+04, 1.5399265260595e+04,
00304     1.7782794100389e+04, 2.0535250264571e+04,
00305     2.3713737056617e+04, 2.7384196342644e+04,
00306     3.1622776601684e+04, 3.6517412725484e+04,
00307     4.2169650342858e+04, 4.8696752516586e+04,
00308     5.6234132519035e+04, 6.4938163157621e+04,
00309     7.4989420933246e+04, 8.6596432336007e+04,
00310     1.0000000000000e+05, 1.1547819846895e+05,
00311     1.3335214321633e+05, 1.5399265260595e+05,
00312     1.7782794100389e+05, 2.0535250264571e+05,
00313     2.3713737056617e+05, 2.7384196342644e+05,
00314     3.1622776601684e+05, 3.6517412725484e+05,
00315     4.2169650342858e+05, 4.8696752516586e+05,
00316     5.6234132519035e+05, 6.4938163157621e+05,
00317     7.4989420933246e+05, 8.6596432336007e+05,
00318 };
00319 
00323 static int decode_exp_vlc(WMACodecContext *s, int ch)
00324 {
00325     int last_exp, n, code;
00326     const uint16_t *ptr;
00327     float v, max_scale;
00328     uint32_t *q, *q_end, iv;
00329     const float *ptab = pow_tab + 60;
00330     const uint32_t *iptab = (const uint32_t*)ptab;
00331 
00332     ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
00333     q = (uint32_t *)s->exponents[ch];
00334     q_end = q + s->block_len;
00335     max_scale = 0;
00336     if (s->version == 1) {
00337         last_exp = get_bits(&s->gb, 5) + 10;
00338         v = ptab[last_exp];
00339         iv = iptab[last_exp];
00340         max_scale = v;
00341         n = *ptr++;
00342         switch (n & 3) do {
00343         case 0: *q++ = iv;
00344         case 3: *q++ = iv;
00345         case 2: *q++ = iv;
00346         case 1: *q++ = iv;
00347         } while ((n -= 4) > 0);
00348     }else
00349         last_exp = 36;
00350 
00351     while (q < q_end) {
00352         code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);
00353         if (code < 0){
00354             av_log(s->avctx, AV_LOG_ERROR, "Exponent vlc invalid\n");
00355             return -1;
00356         }
00357         /* NOTE: this offset is the same as MPEG4 AAC ! */
00358         last_exp += code - 60;
00359         if ((unsigned)last_exp + 60 > FF_ARRAY_ELEMS(pow_tab)) {
00360             av_log(s->avctx, AV_LOG_ERROR, "Exponent out of range: %d\n",
00361                    last_exp);
00362             return -1;
00363         }
00364         v = ptab[last_exp];
00365         iv = iptab[last_exp];
00366         if (v > max_scale)
00367             max_scale = v;
00368         n = *ptr++;
00369         switch (n & 3) do {
00370         case 0: *q++ = iv;
00371         case 3: *q++ = iv;
00372         case 2: *q++ = iv;
00373         case 1: *q++ = iv;
00374         } while ((n -= 4) > 0);
00375     }
00376     s->max_exponent[ch] = max_scale;
00377     return 0;
00378 }
00379 
00380 
00387 static void wma_window(WMACodecContext *s, float *out)
00388 {
00389     float *in = s->output;
00390     int block_len, bsize, n;
00391 
00392     /* left part */
00393     if (s->block_len_bits <= s->prev_block_len_bits) {
00394         block_len = s->block_len;
00395         bsize = s->frame_len_bits - s->block_len_bits;
00396 
00397         s->dsp.vector_fmul_add(out, in, s->windows[bsize],
00398                                out, block_len);
00399 
00400     } else {
00401         block_len = 1 << s->prev_block_len_bits;
00402         n = (s->block_len - block_len) / 2;
00403         bsize = s->frame_len_bits - s->prev_block_len_bits;
00404 
00405         s->dsp.vector_fmul_add(out+n, in+n, s->windows[bsize],
00406                                out+n, block_len);
00407 
00408         memcpy(out+n+block_len, in+n+block_len, n*sizeof(float));
00409     }
00410 
00411     out += s->block_len;
00412     in += s->block_len;
00413 
00414     /* right part */
00415     if (s->block_len_bits <= s->next_block_len_bits) {
00416         block_len = s->block_len;
00417         bsize = s->frame_len_bits - s->block_len_bits;
00418 
00419         s->dsp.vector_fmul_reverse(out, in, s->windows[bsize], block_len);
00420 
00421     } else {
00422         block_len = 1 << s->next_block_len_bits;
00423         n = (s->block_len - block_len) / 2;
00424         bsize = s->frame_len_bits - s->next_block_len_bits;
00425 
00426         memcpy(out, in, n*sizeof(float));
00427 
00428         s->dsp.vector_fmul_reverse(out+n, in+n, s->windows[bsize], block_len);
00429 
00430         memset(out+n+block_len, 0, n*sizeof(float));
00431     }
00432 }
00433 
00434 
00439 static int wma_decode_block(WMACodecContext *s)
00440 {
00441     int n, v, a, ch, bsize;
00442     int coef_nb_bits, total_gain;
00443     int nb_coefs[MAX_CHANNELS];
00444     float mdct_norm;
00445     FFTContext *mdct;
00446 
00447 #ifdef TRACE
00448     tprintf(s->avctx, "***decode_block: %d:%d\n", s->frame_count - 1, s->block_num);
00449 #endif
00450 
00451     /* compute current block length */
00452     if (s->use_variable_block_len) {
00453         n = av_log2(s->nb_block_sizes - 1) + 1;
00454 
00455         if (s->reset_block_lengths) {
00456             s->reset_block_lengths = 0;
00457             v = get_bits(&s->gb, n);
00458             if (v >= s->nb_block_sizes){
00459                 av_log(s->avctx, AV_LOG_ERROR, "prev_block_len_bits %d out of range\n", s->frame_len_bits - v);
00460                 return -1;
00461             }
00462             s->prev_block_len_bits = s->frame_len_bits - v;
00463             v = get_bits(&s->gb, n);
00464             if (v >= s->nb_block_sizes){
00465                 av_log(s->avctx, AV_LOG_ERROR, "block_len_bits %d out of range\n", s->frame_len_bits - v);
00466                 return -1;
00467             }
00468             s->block_len_bits = s->frame_len_bits - v;
00469         } else {
00470             /* update block lengths */
00471             s->prev_block_len_bits = s->block_len_bits;
00472             s->block_len_bits = s->next_block_len_bits;
00473         }
00474         v = get_bits(&s->gb, n);
00475         if (v >= s->nb_block_sizes){
00476             av_log(s->avctx, AV_LOG_ERROR, "next_block_len_bits %d out of range\n", s->frame_len_bits - v);
00477             return -1;
00478         }
00479         s->next_block_len_bits = s->frame_len_bits - v;
00480     } else {
00481         /* fixed block len */
00482         s->next_block_len_bits = s->frame_len_bits;
00483         s->prev_block_len_bits = s->frame_len_bits;
00484         s->block_len_bits = s->frame_len_bits;
00485     }
00486 
00487     /* now check if the block length is coherent with the frame length */
00488     s->block_len = 1 << s->block_len_bits;
00489     if ((s->block_pos + s->block_len) > s->frame_len){
00490         av_log(s->avctx, AV_LOG_ERROR, "frame_len overflow\n");
00491         return -1;
00492     }
00493 
00494     if (s->nb_channels == 2) {
00495         s->ms_stereo = get_bits1(&s->gb);
00496     }
00497     v = 0;
00498     for(ch = 0; ch < s->nb_channels; ch++) {
00499         a = get_bits1(&s->gb);
00500         s->channel_coded[ch] = a;
00501         v |= a;
00502     }
00503 
00504     bsize = s->frame_len_bits - s->block_len_bits;
00505 
00506     /* if no channel coded, no need to go further */
00507     /* XXX: fix potential framing problems */
00508     if (!v)
00509         goto next;
00510 
00511     /* read total gain and extract corresponding number of bits for
00512        coef escape coding */
00513     total_gain = 1;
00514     for(;;) {
00515         a = get_bits(&s->gb, 7);
00516         total_gain += a;
00517         if (a != 127)
00518             break;
00519     }
00520 
00521     coef_nb_bits= ff_wma_total_gain_to_bits(total_gain);
00522 
00523     /* compute number of coefficients */
00524     n = s->coefs_end[bsize] - s->coefs_start;
00525     for(ch = 0; ch < s->nb_channels; ch++)
00526         nb_coefs[ch] = n;
00527 
00528     /* complex coding */
00529     if (s->use_noise_coding) {
00530 
00531         for(ch = 0; ch < s->nb_channels; ch++) {
00532             if (s->channel_coded[ch]) {
00533                 int i, n, a;
00534                 n = s->exponent_high_sizes[bsize];
00535                 for(i=0;i<n;i++) {
00536                     a = get_bits1(&s->gb);
00537                     s->high_band_coded[ch][i] = a;
00538                     /* if noise coding, the coefficients are not transmitted */
00539                     if (a)
00540                         nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
00541                 }
00542             }
00543         }
00544         for(ch = 0; ch < s->nb_channels; ch++) {
00545             if (s->channel_coded[ch]) {
00546                 int i, n, val, code;
00547 
00548                 n = s->exponent_high_sizes[bsize];
00549                 val = (int)0x80000000;
00550                 for(i=0;i<n;i++) {
00551                     if (s->high_band_coded[ch][i]) {
00552                         if (val == (int)0x80000000) {
00553                             val = get_bits(&s->gb, 7) - 19;
00554                         } else {
00555                             code = get_vlc2(&s->gb, s->hgain_vlc.table, HGAINVLCBITS, HGAINMAX);
00556                             if (code < 0){
00557                                 av_log(s->avctx, AV_LOG_ERROR, "hgain vlc invalid\n");
00558                                 return -1;
00559                             }
00560                             val += code - 18;
00561                         }
00562                         s->high_band_values[ch][i] = val;
00563                     }
00564                 }
00565             }
00566         }
00567     }
00568 
00569     /* exponents can be reused in short blocks. */
00570     if ((s->block_len_bits == s->frame_len_bits) ||
00571         get_bits1(&s->gb)) {
00572         for(ch = 0; ch < s->nb_channels; ch++) {
00573             if (s->channel_coded[ch]) {
00574                 if (s->use_exp_vlc) {
00575                     if (decode_exp_vlc(s, ch) < 0)
00576                         return -1;
00577                 } else {
00578                     decode_exp_lsp(s, ch);
00579                 }
00580                 s->exponents_bsize[ch] = bsize;
00581             }
00582         }
00583     }
00584 
00585     /* parse spectral coefficients : just RLE encoding */
00586     for(ch = 0; ch < s->nb_channels; ch++) {
00587         if (s->channel_coded[ch]) {
00588             int tindex;
00589             WMACoef* ptr = &s->coefs1[ch][0];
00590 
00591             /* special VLC tables are used for ms stereo because
00592                there is potentially less energy there */
00593             tindex = (ch == 1 && s->ms_stereo);
00594             memset(ptr, 0, s->block_len * sizeof(WMACoef));
00595             ff_wma_run_level_decode(s->avctx, &s->gb, &s->coef_vlc[tindex],
00596                   s->level_table[tindex], s->run_table[tindex],
00597                   0, ptr, 0, nb_coefs[ch],
00598                   s->block_len, s->frame_len_bits, coef_nb_bits);
00599         }
00600         if (s->version == 1 && s->nb_channels >= 2) {
00601             align_get_bits(&s->gb);
00602         }
00603     }
00604 
00605     /* normalize */
00606     {
00607         int n4 = s->block_len / 2;
00608         mdct_norm = 1.0 / (float)n4;
00609         if (s->version == 1) {
00610             mdct_norm *= sqrt(n4);
00611         }
00612     }
00613 
00614     /* finally compute the MDCT coefficients */
00615     for(ch = 0; ch < s->nb_channels; ch++) {
00616         if (s->channel_coded[ch]) {
00617             WMACoef *coefs1;
00618             float *coefs, *exponents, mult, mult1, noise;
00619             int i, j, n, n1, last_high_band, esize;
00620             float exp_power[HIGH_BAND_MAX_SIZE];
00621 
00622             coefs1 = s->coefs1[ch];
00623             exponents = s->exponents[ch];
00624             esize = s->exponents_bsize[ch];
00625             mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
00626             mult *= mdct_norm;
00627             coefs = s->coefs[ch];
00628             if (s->use_noise_coding) {
00629                 mult1 = mult;
00630                 /* very low freqs : noise */
00631                 for(i = 0;i < s->coefs_start; i++) {
00632                     *coefs++ = s->noise_table[s->noise_index] *
00633                       exponents[i<<bsize>>esize] * mult1;
00634                     s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
00635                 }
00636 
00637                 n1 = s->exponent_high_sizes[bsize];
00638 
00639                 /* compute power of high bands */
00640                 exponents = s->exponents[ch] +
00641                     (s->high_band_start[bsize]<<bsize>>esize);
00642                 last_high_band = 0; /* avoid warning */
00643                 for(j=0;j<n1;j++) {
00644                     n = s->exponent_high_bands[s->frame_len_bits -
00645                                               s->block_len_bits][j];
00646                     if (s->high_band_coded[ch][j]) {
00647                         float e2, v;
00648                         e2 = 0;
00649                         for(i = 0;i < n; i++) {
00650                             v = exponents[i<<bsize>>esize];
00651                             e2 += v * v;
00652                         }
00653                         exp_power[j] = e2 / n;
00654                         last_high_band = j;
00655                         tprintf(s->avctx, "%d: power=%f (%d)\n", j, exp_power[j], n);
00656                     }
00657                     exponents += n<<bsize>>esize;
00658                 }
00659 
00660                 /* main freqs and high freqs */
00661                 exponents = s->exponents[ch] + (s->coefs_start<<bsize>>esize);
00662                 for(j=-1;j<n1;j++) {
00663                     if (j < 0) {
00664                         n = s->high_band_start[bsize] -
00665                             s->coefs_start;
00666                     } else {
00667                         n = s->exponent_high_bands[s->frame_len_bits -
00668                                                   s->block_len_bits][j];
00669                     }
00670                     if (j >= 0 && s->high_band_coded[ch][j]) {
00671                         /* use noise with specified power */
00672                         mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);
00673                         /* XXX: use a table */
00674                         mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);
00675                         mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);
00676                         mult1 *= mdct_norm;
00677                         for(i = 0;i < n; i++) {
00678                             noise = s->noise_table[s->noise_index];
00679                             s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
00680                             *coefs++ =  noise *
00681                                 exponents[i<<bsize>>esize] * mult1;
00682                         }
00683                         exponents += n<<bsize>>esize;
00684                     } else {
00685                         /* coded values + small noise */
00686                         for(i = 0;i < n; i++) {
00687                             noise = s->noise_table[s->noise_index];
00688                             s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
00689                             *coefs++ = ((*coefs1++) + noise) *
00690                                 exponents[i<<bsize>>esize] * mult;
00691                         }
00692                         exponents += n<<bsize>>esize;
00693                     }
00694                 }
00695 
00696                 /* very high freqs : noise */
00697                 n = s->block_len - s->coefs_end[bsize];
00698                 mult1 = mult * exponents[((-1<<bsize))>>esize];
00699                 for(i = 0; i < n; i++) {
00700                     *coefs++ = s->noise_table[s->noise_index] * mult1;
00701                     s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
00702                 }
00703             } else {
00704                 /* XXX: optimize more */
00705                 for(i = 0;i < s->coefs_start; i++)
00706                     *coefs++ = 0.0;
00707                 n = nb_coefs[ch];
00708                 for(i = 0;i < n; i++) {
00709                     *coefs++ = coefs1[i] * exponents[i<<bsize>>esize] * mult;
00710                 }
00711                 n = s->block_len - s->coefs_end[bsize];
00712                 for(i = 0;i < n; i++)
00713                     *coefs++ = 0.0;
00714             }
00715         }
00716     }
00717 
00718 #ifdef TRACE
00719     for(ch = 0; ch < s->nb_channels; ch++) {
00720         if (s->channel_coded[ch]) {
00721             dump_floats(s, "exponents", 3, s->exponents[ch], s->block_len);
00722             dump_floats(s, "coefs", 1, s->coefs[ch], s->block_len);
00723         }
00724     }
00725 #endif
00726 
00727     if (s->ms_stereo && s->channel_coded[1]) {
00728         /* nominal case for ms stereo: we do it before mdct */
00729         /* no need to optimize this case because it should almost
00730            never happen */
00731         if (!s->channel_coded[0]) {
00732             tprintf(s->avctx, "rare ms-stereo case happened\n");
00733             memset(s->coefs[0], 0, sizeof(float) * s->block_len);
00734             s->channel_coded[0] = 1;
00735         }
00736 
00737         s->dsp.butterflies_float(s->coefs[0], s->coefs[1], s->block_len);
00738     }
00739 
00740 next:
00741     mdct = &s->mdct_ctx[bsize];
00742 
00743     for(ch = 0; ch < s->nb_channels; ch++) {
00744         int n4, index;
00745 
00746         n4 = s->block_len / 2;
00747         if(s->channel_coded[ch]){
00748             mdct->imdct_calc(mdct, s->output, s->coefs[ch]);
00749         }else if(!(s->ms_stereo && ch==1))
00750             memset(s->output, 0, sizeof(s->output));
00751 
00752         /* multiply by the window and add in the frame */
00753         index = (s->frame_len / 2) + s->block_pos - n4;
00754         wma_window(s, &s->frame_out[ch][index]);
00755     }
00756 
00757     /* update block number */
00758     s->block_num++;
00759     s->block_pos += s->block_len;
00760     if (s->block_pos >= s->frame_len)
00761         return 1;
00762     else
00763         return 0;
00764 }
00765 
00766 /* decode a frame of frame_len samples */
00767 static int wma_decode_frame(WMACodecContext *s, int16_t *samples)
00768 {
00769     int ret, n, ch, incr;
00770     const float *output[MAX_CHANNELS];
00771 
00772 #ifdef TRACE
00773     tprintf(s->avctx, "***decode_frame: %d size=%d\n", s->frame_count++, s->frame_len);
00774 #endif
00775 
00776     /* read each block */
00777     s->block_num = 0;
00778     s->block_pos = 0;
00779     for(;;) {
00780         ret = wma_decode_block(s);
00781         if (ret < 0)
00782             return -1;
00783         if (ret)
00784             break;
00785     }
00786 
00787     /* convert frame to integer */
00788     n = s->frame_len;
00789     incr = s->nb_channels;
00790     for (ch = 0; ch < MAX_CHANNELS; ch++)
00791         output[ch] = s->frame_out[ch];
00792     s->fmt_conv.float_to_int16_interleave(samples, output, n, incr);
00793     for (ch = 0; ch < incr; ch++) {
00794         /* prepare for next block */
00795         memmove(&s->frame_out[ch][0], &s->frame_out[ch][n], n * sizeof(float));
00796     }
00797 
00798 #ifdef TRACE
00799     dump_shorts(s, "samples", samples, n * s->nb_channels);
00800 #endif
00801     return 0;
00802 }
00803 
00804 static int wma_decode_superframe(AVCodecContext *avctx, void *data,
00805                                  int *got_frame_ptr, AVPacket *avpkt)
00806 {
00807     const uint8_t *buf = avpkt->data;
00808     int buf_size = avpkt->size;
00809     WMACodecContext *s = avctx->priv_data;
00810     int nb_frames, bit_offset, i, pos, len, ret;
00811     uint8_t *q;
00812     int16_t *samples;
00813 
00814     tprintf(avctx, "***decode_superframe:\n");
00815 
00816     if(buf_size==0){
00817         s->last_superframe_len = 0;
00818         return 0;
00819     }
00820     if (buf_size < s->block_align) {
00821         av_log(avctx, AV_LOG_ERROR,
00822                "Input packet size too small (%d < %d)\n",
00823                buf_size, s->block_align);
00824         return AVERROR_INVALIDDATA;
00825     }
00826     buf_size = s->block_align;
00827 
00828     init_get_bits(&s->gb, buf, buf_size*8);
00829 
00830     if (s->use_bit_reservoir) {
00831         /* read super frame header */
00832         skip_bits(&s->gb, 4); /* super frame index */
00833         nb_frames = get_bits(&s->gb, 4) - (s->last_superframe_len <= 0);
00834     } else {
00835         nb_frames = 1;
00836     }
00837 
00838     /* get output buffer */
00839     s->frame.nb_samples = nb_frames * s->frame_len;
00840     if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
00841         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00842         return ret;
00843     }
00844     samples = (int16_t *)s->frame.data[0];
00845 
00846     if (s->use_bit_reservoir) {
00847         bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
00848         if (bit_offset > get_bits_left(&s->gb)) {
00849             av_log(avctx, AV_LOG_ERROR,
00850                    "Invalid last frame bit offset %d > buf size %d (%d)\n",
00851                    bit_offset, get_bits_left(&s->gb), buf_size);
00852             goto fail;
00853         }
00854 
00855         if (s->last_superframe_len > 0) {
00856             //        printf("skip=%d\n", s->last_bitoffset);
00857             /* add bit_offset bits to last frame */
00858             if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
00859                 MAX_CODED_SUPERFRAME_SIZE)
00860                 goto fail;
00861             q = s->last_superframe + s->last_superframe_len;
00862             len = bit_offset;
00863             while (len > 7) {
00864                 *q++ = (get_bits)(&s->gb, 8);
00865                 len -= 8;
00866             }
00867             if (len > 0) {
00868                 *q++ = (get_bits)(&s->gb, len) << (8 - len);
00869             }
00870             memset(q, 0, FF_INPUT_BUFFER_PADDING_SIZE);
00871 
00872             /* XXX: bit_offset bits into last frame */
00873             init_get_bits(&s->gb, s->last_superframe, s->last_superframe_len * 8 + bit_offset);
00874             /* skip unused bits */
00875             if (s->last_bitoffset > 0)
00876                 skip_bits(&s->gb, s->last_bitoffset);
00877             /* this frame is stored in the last superframe and in the
00878                current one */
00879             if (wma_decode_frame(s, samples) < 0)
00880                 goto fail;
00881             samples += s->nb_channels * s->frame_len;
00882             nb_frames--;
00883         }
00884 
00885         /* read each frame starting from bit_offset */
00886         pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
00887         if (pos >= MAX_CODED_SUPERFRAME_SIZE * 8 || pos > buf_size * 8)
00888             return AVERROR_INVALIDDATA;
00889         init_get_bits(&s->gb, buf + (pos >> 3), (buf_size - (pos >> 3))*8);
00890         len = pos & 7;
00891         if (len > 0)
00892             skip_bits(&s->gb, len);
00893 
00894         s->reset_block_lengths = 1;
00895         for(i=0;i<nb_frames;i++) {
00896             if (wma_decode_frame(s, samples) < 0)
00897                 goto fail;
00898             samples += s->nb_channels * s->frame_len;
00899         }
00900 
00901         /* we copy the end of the frame in the last frame buffer */
00902         pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
00903         s->last_bitoffset = pos & 7;
00904         pos >>= 3;
00905         len = buf_size - pos;
00906         if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
00907             av_log(s->avctx, AV_LOG_ERROR, "len %d invalid\n", len);
00908             goto fail;
00909         }
00910         s->last_superframe_len = len;
00911         memcpy(s->last_superframe, buf + pos, len);
00912     } else {
00913         /* single frame decode */
00914         if (wma_decode_frame(s, samples) < 0)
00915             goto fail;
00916         samples += s->nb_channels * s->frame_len;
00917     }
00918 
00919 //av_log(NULL, AV_LOG_ERROR, "%d %d %d %d outbytes:%d eaten:%d\n", s->frame_len_bits, s->block_len_bits, s->frame_len, s->block_len,        (int8_t *)samples - (int8_t *)data, s->block_align);
00920 
00921     *got_frame_ptr   = 1;
00922     *(AVFrame *)data = s->frame;
00923 
00924     return s->block_align;
00925  fail:
00926     /* when error, we reset the bit reservoir */
00927     s->last_superframe_len = 0;
00928     return -1;
00929 }
00930 
00931 static av_cold void flush(AVCodecContext *avctx)
00932 {
00933     WMACodecContext *s = avctx->priv_data;
00934 
00935     s->last_bitoffset=
00936     s->last_superframe_len= 0;
00937 }
00938 
00939 AVCodec ff_wmav1_decoder = {
00940     .name           = "wmav1",
00941     .type           = AVMEDIA_TYPE_AUDIO,
00942     .id             = CODEC_ID_WMAV1,
00943     .priv_data_size = sizeof(WMACodecContext),
00944     .init           = wma_decode_init,
00945     .close          = ff_wma_end,
00946     .decode         = wma_decode_superframe,
00947     .flush          = flush,
00948     .capabilities   = CODEC_CAP_DR1,
00949     .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Audio 1"),
00950 };
00951 
00952 AVCodec ff_wmav2_decoder = {
00953     .name           = "wmav2",
00954     .type           = AVMEDIA_TYPE_AUDIO,
00955     .id             = CODEC_ID_WMAV2,
00956     .priv_data_size = sizeof(WMACodecContext),
00957     .init           = wma_decode_init,
00958     .close          = ff_wma_end,
00959     .decode         = wma_decode_superframe,
00960     .flush          = flush,
00961     .capabilities   = CODEC_CAP_DR1,
00962     .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Audio 2"),
00963 };
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