Libav 0.7.1
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     return 0;
00128 }
00129 
00136 static inline float pow_m1_4(WMACodecContext *s, float x)
00137 {
00138     union {
00139         float f;
00140         unsigned int v;
00141     } u, t;
00142     unsigned int e, m;
00143     float a, b;
00144 
00145     u.f = x;
00146     e = u.v >> 23;
00147     m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
00148     /* build interpolation scale: 1 <= t < 2. */
00149     t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
00150     a = s->lsp_pow_m_table1[m];
00151     b = s->lsp_pow_m_table2[m];
00152     return s->lsp_pow_e_table[e] * (a + b * t.f);
00153 }
00154 
00155 static void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len)
00156 {
00157     float wdel, a, b;
00158     int i, e, m;
00159 
00160     wdel = M_PI / frame_len;
00161     for(i=0;i<frame_len;i++)
00162         s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
00163 
00164     /* tables for x^-0.25 computation */
00165     for(i=0;i<256;i++) {
00166         e = i - 126;
00167         s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
00168     }
00169 
00170     /* NOTE: these two tables are needed to avoid two operations in
00171        pow_m1_4 */
00172     b = 1.0;
00173     for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) {
00174         m = (1 << LSP_POW_BITS) + i;
00175         a = (float)m * (0.5 / (1 << LSP_POW_BITS));
00176         a = pow(a, -0.25);
00177         s->lsp_pow_m_table1[i] = 2 * a - b;
00178         s->lsp_pow_m_table2[i] = b - a;
00179         b = a;
00180     }
00181 }
00182 
00187 static void wma_lsp_to_curve(WMACodecContext *s,
00188                              float *out, float *val_max_ptr,
00189                              int n, float *lsp)
00190 {
00191     int i, j;
00192     float p, q, w, v, val_max;
00193 
00194     val_max = 0;
00195     for(i=0;i<n;i++) {
00196         p = 0.5f;
00197         q = 0.5f;
00198         w = s->lsp_cos_table[i];
00199         for(j=1;j<NB_LSP_COEFS;j+=2){
00200             q *= w - lsp[j - 1];
00201             p *= w - lsp[j];
00202         }
00203         p *= p * (2.0f - w);
00204         q *= q * (2.0f + w);
00205         v = p + q;
00206         v = pow_m1_4(s, v);
00207         if (v > val_max)
00208             val_max = v;
00209         out[i] = v;
00210     }
00211     *val_max_ptr = val_max;
00212 }
00213 
00217 static void decode_exp_lsp(WMACodecContext *s, int ch)
00218 {
00219     float lsp_coefs[NB_LSP_COEFS];
00220     int val, i;
00221 
00222     for(i = 0; i < NB_LSP_COEFS; i++) {
00223         if (i == 0 || i >= 8)
00224             val = get_bits(&s->gb, 3);
00225         else
00226             val = get_bits(&s->gb, 4);
00227         lsp_coefs[i] = ff_wma_lsp_codebook[i][val];
00228     }
00229 
00230     wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
00231                      s->block_len, lsp_coefs);
00232 }
00233 
00235 static const float pow_tab[] = {
00236     1.7782794100389e-04, 2.0535250264571e-04,
00237     2.3713737056617e-04, 2.7384196342644e-04,
00238     3.1622776601684e-04, 3.6517412725484e-04,
00239     4.2169650342858e-04, 4.8696752516586e-04,
00240     5.6234132519035e-04, 6.4938163157621e-04,
00241     7.4989420933246e-04, 8.6596432336006e-04,
00242     1.0000000000000e-03, 1.1547819846895e-03,
00243     1.3335214321633e-03, 1.5399265260595e-03,
00244     1.7782794100389e-03, 2.0535250264571e-03,
00245     2.3713737056617e-03, 2.7384196342644e-03,
00246     3.1622776601684e-03, 3.6517412725484e-03,
00247     4.2169650342858e-03, 4.8696752516586e-03,
00248     5.6234132519035e-03, 6.4938163157621e-03,
00249     7.4989420933246e-03, 8.6596432336006e-03,
00250     1.0000000000000e-02, 1.1547819846895e-02,
00251     1.3335214321633e-02, 1.5399265260595e-02,
00252     1.7782794100389e-02, 2.0535250264571e-02,
00253     2.3713737056617e-02, 2.7384196342644e-02,
00254     3.1622776601684e-02, 3.6517412725484e-02,
00255     4.2169650342858e-02, 4.8696752516586e-02,
00256     5.6234132519035e-02, 6.4938163157621e-02,
00257     7.4989420933246e-02, 8.6596432336007e-02,
00258     1.0000000000000e-01, 1.1547819846895e-01,
00259     1.3335214321633e-01, 1.5399265260595e-01,
00260     1.7782794100389e-01, 2.0535250264571e-01,
00261     2.3713737056617e-01, 2.7384196342644e-01,
00262     3.1622776601684e-01, 3.6517412725484e-01,
00263     4.2169650342858e-01, 4.8696752516586e-01,
00264     5.6234132519035e-01, 6.4938163157621e-01,
00265     7.4989420933246e-01, 8.6596432336007e-01,
00266     1.0000000000000e+00, 1.1547819846895e+00,
00267     1.3335214321633e+00, 1.5399265260595e+00,
00268     1.7782794100389e+00, 2.0535250264571e+00,
00269     2.3713737056617e+00, 2.7384196342644e+00,
00270     3.1622776601684e+00, 3.6517412725484e+00,
00271     4.2169650342858e+00, 4.8696752516586e+00,
00272     5.6234132519035e+00, 6.4938163157621e+00,
00273     7.4989420933246e+00, 8.6596432336007e+00,
00274     1.0000000000000e+01, 1.1547819846895e+01,
00275     1.3335214321633e+01, 1.5399265260595e+01,
00276     1.7782794100389e+01, 2.0535250264571e+01,
00277     2.3713737056617e+01, 2.7384196342644e+01,
00278     3.1622776601684e+01, 3.6517412725484e+01,
00279     4.2169650342858e+01, 4.8696752516586e+01,
00280     5.6234132519035e+01, 6.4938163157621e+01,
00281     7.4989420933246e+01, 8.6596432336007e+01,
00282     1.0000000000000e+02, 1.1547819846895e+02,
00283     1.3335214321633e+02, 1.5399265260595e+02,
00284     1.7782794100389e+02, 2.0535250264571e+02,
00285     2.3713737056617e+02, 2.7384196342644e+02,
00286     3.1622776601684e+02, 3.6517412725484e+02,
00287     4.2169650342858e+02, 4.8696752516586e+02,
00288     5.6234132519035e+02, 6.4938163157621e+02,
00289     7.4989420933246e+02, 8.6596432336007e+02,
00290     1.0000000000000e+03, 1.1547819846895e+03,
00291     1.3335214321633e+03, 1.5399265260595e+03,
00292     1.7782794100389e+03, 2.0535250264571e+03,
00293     2.3713737056617e+03, 2.7384196342644e+03,
00294     3.1622776601684e+03, 3.6517412725484e+03,
00295     4.2169650342858e+03, 4.8696752516586e+03,
00296     5.6234132519035e+03, 6.4938163157621e+03,
00297     7.4989420933246e+03, 8.6596432336007e+03,
00298     1.0000000000000e+04, 1.1547819846895e+04,
00299     1.3335214321633e+04, 1.5399265260595e+04,
00300     1.7782794100389e+04, 2.0535250264571e+04,
00301     2.3713737056617e+04, 2.7384196342644e+04,
00302     3.1622776601684e+04, 3.6517412725484e+04,
00303     4.2169650342858e+04, 4.8696752516586e+04,
00304     5.6234132519035e+04, 6.4938163157621e+04,
00305     7.4989420933246e+04, 8.6596432336007e+04,
00306     1.0000000000000e+05, 1.1547819846895e+05,
00307     1.3335214321633e+05, 1.5399265260595e+05,
00308     1.7782794100389e+05, 2.0535250264571e+05,
00309     2.3713737056617e+05, 2.7384196342644e+05,
00310     3.1622776601684e+05, 3.6517412725484e+05,
00311     4.2169650342858e+05, 4.8696752516586e+05,
00312     5.6234132519035e+05, 6.4938163157621e+05,
00313     7.4989420933246e+05, 8.6596432336007e+05,
00314 };
00315 
00319 static int decode_exp_vlc(WMACodecContext *s, int ch)
00320 {
00321     int last_exp, n, code;
00322     const uint16_t *ptr;
00323     float v, max_scale;
00324     uint32_t *q, *q_end, iv;
00325     const float *ptab = pow_tab + 60;
00326     const uint32_t *iptab = (const uint32_t*)ptab;
00327 
00328     ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
00329     q = (uint32_t *)s->exponents[ch];
00330     q_end = q + s->block_len;
00331     max_scale = 0;
00332     if (s->version == 1) {
00333         last_exp = get_bits(&s->gb, 5) + 10;
00334         v = ptab[last_exp];
00335         iv = iptab[last_exp];
00336         max_scale = v;
00337         n = *ptr++;
00338         switch (n & 3) do {
00339         case 0: *q++ = iv;
00340         case 3: *q++ = iv;
00341         case 2: *q++ = iv;
00342         case 1: *q++ = iv;
00343         } while ((n -= 4) > 0);
00344     }else
00345         last_exp = 36;
00346 
00347     while (q < q_end) {
00348         code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);
00349         if (code < 0){
00350             av_log(s->avctx, AV_LOG_ERROR, "Exponent vlc invalid\n");
00351             return -1;
00352         }
00353         /* NOTE: this offset is the same as MPEG4 AAC ! */
00354         last_exp += code - 60;
00355         if ((unsigned)last_exp + 60 > FF_ARRAY_ELEMS(pow_tab)) {
00356             av_log(s->avctx, AV_LOG_ERROR, "Exponent out of range: %d\n",
00357                    last_exp);
00358             return -1;
00359         }
00360         v = ptab[last_exp];
00361         iv = iptab[last_exp];
00362         if (v > max_scale)
00363             max_scale = v;
00364         n = *ptr++;
00365         switch (n & 3) do {
00366         case 0: *q++ = iv;
00367         case 3: *q++ = iv;
00368         case 2: *q++ = iv;
00369         case 1: *q++ = iv;
00370         } while ((n -= 4) > 0);
00371     }
00372     s->max_exponent[ch] = max_scale;
00373     return 0;
00374 }
00375 
00376 
00383 static void wma_window(WMACodecContext *s, float *out)
00384 {
00385     float *in = s->output;
00386     int block_len, bsize, n;
00387 
00388     /* left part */
00389     if (s->block_len_bits <= s->prev_block_len_bits) {
00390         block_len = s->block_len;
00391         bsize = s->frame_len_bits - s->block_len_bits;
00392 
00393         s->dsp.vector_fmul_add(out, in, s->windows[bsize],
00394                                out, block_len);
00395 
00396     } else {
00397         block_len = 1 << s->prev_block_len_bits;
00398         n = (s->block_len - block_len) / 2;
00399         bsize = s->frame_len_bits - s->prev_block_len_bits;
00400 
00401         s->dsp.vector_fmul_add(out+n, in+n, s->windows[bsize],
00402                                out+n, block_len);
00403 
00404         memcpy(out+n+block_len, in+n+block_len, n*sizeof(float));
00405     }
00406 
00407     out += s->block_len;
00408     in += s->block_len;
00409 
00410     /* right part */
00411     if (s->block_len_bits <= s->next_block_len_bits) {
00412         block_len = s->block_len;
00413         bsize = s->frame_len_bits - s->block_len_bits;
00414 
00415         s->dsp.vector_fmul_reverse(out, in, s->windows[bsize], block_len);
00416 
00417     } else {
00418         block_len = 1 << s->next_block_len_bits;
00419         n = (s->block_len - block_len) / 2;
00420         bsize = s->frame_len_bits - s->next_block_len_bits;
00421 
00422         memcpy(out, in, n*sizeof(float));
00423 
00424         s->dsp.vector_fmul_reverse(out+n, in+n, s->windows[bsize], block_len);
00425 
00426         memset(out+n+block_len, 0, n*sizeof(float));
00427     }
00428 }
00429 
00430 
00435 static int wma_decode_block(WMACodecContext *s)
00436 {
00437     int n, v, a, ch, bsize;
00438     int coef_nb_bits, total_gain;
00439     int nb_coefs[MAX_CHANNELS];
00440     float mdct_norm;
00441     FFTContext *mdct;
00442 
00443 #ifdef TRACE
00444     tprintf(s->avctx, "***decode_block: %d:%d\n", s->frame_count - 1, s->block_num);
00445 #endif
00446 
00447     /* compute current block length */
00448     if (s->use_variable_block_len) {
00449         n = av_log2(s->nb_block_sizes - 1) + 1;
00450 
00451         if (s->reset_block_lengths) {
00452             s->reset_block_lengths = 0;
00453             v = get_bits(&s->gb, n);
00454             if (v >= s->nb_block_sizes){
00455                 av_log(s->avctx, AV_LOG_ERROR, "prev_block_len_bits %d out of range\n", s->frame_len_bits - v);
00456                 return -1;
00457             }
00458             s->prev_block_len_bits = s->frame_len_bits - v;
00459             v = get_bits(&s->gb, n);
00460             if (v >= s->nb_block_sizes){
00461                 av_log(s->avctx, AV_LOG_ERROR, "block_len_bits %d out of range\n", s->frame_len_bits - v);
00462                 return -1;
00463             }
00464             s->block_len_bits = s->frame_len_bits - v;
00465         } else {
00466             /* update block lengths */
00467             s->prev_block_len_bits = s->block_len_bits;
00468             s->block_len_bits = s->next_block_len_bits;
00469         }
00470         v = get_bits(&s->gb, n);
00471         if (v >= s->nb_block_sizes){
00472             av_log(s->avctx, AV_LOG_ERROR, "next_block_len_bits %d out of range\n", s->frame_len_bits - v);
00473             return -1;
00474         }
00475         s->next_block_len_bits = s->frame_len_bits - v;
00476     } else {
00477         /* fixed block len */
00478         s->next_block_len_bits = s->frame_len_bits;
00479         s->prev_block_len_bits = s->frame_len_bits;
00480         s->block_len_bits = s->frame_len_bits;
00481     }
00482 
00483     /* now check if the block length is coherent with the frame length */
00484     s->block_len = 1 << s->block_len_bits;
00485     if ((s->block_pos + s->block_len) > s->frame_len){
00486         av_log(s->avctx, AV_LOG_ERROR, "frame_len overflow\n");
00487         return -1;
00488     }
00489 
00490     if (s->nb_channels == 2) {
00491         s->ms_stereo = get_bits1(&s->gb);
00492     }
00493     v = 0;
00494     for(ch = 0; ch < s->nb_channels; ch++) {
00495         a = get_bits1(&s->gb);
00496         s->channel_coded[ch] = a;
00497         v |= a;
00498     }
00499 
00500     bsize = s->frame_len_bits - s->block_len_bits;
00501 
00502     /* if no channel coded, no need to go further */
00503     /* XXX: fix potential framing problems */
00504     if (!v)
00505         goto next;
00506 
00507     /* read total gain and extract corresponding number of bits for
00508        coef escape coding */
00509     total_gain = 1;
00510     for(;;) {
00511         a = get_bits(&s->gb, 7);
00512         total_gain += a;
00513         if (a != 127)
00514             break;
00515     }
00516 
00517     coef_nb_bits= ff_wma_total_gain_to_bits(total_gain);
00518 
00519     /* compute number of coefficients */
00520     n = s->coefs_end[bsize] - s->coefs_start;
00521     for(ch = 0; ch < s->nb_channels; ch++)
00522         nb_coefs[ch] = n;
00523 
00524     /* complex coding */
00525     if (s->use_noise_coding) {
00526 
00527         for(ch = 0; ch < s->nb_channels; ch++) {
00528             if (s->channel_coded[ch]) {
00529                 int i, n, a;
00530                 n = s->exponent_high_sizes[bsize];
00531                 for(i=0;i<n;i++) {
00532                     a = get_bits1(&s->gb);
00533                     s->high_band_coded[ch][i] = a;
00534                     /* if noise coding, the coefficients are not transmitted */
00535                     if (a)
00536                         nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
00537                 }
00538             }
00539         }
00540         for(ch = 0; ch < s->nb_channels; ch++) {
00541             if (s->channel_coded[ch]) {
00542                 int i, n, val, code;
00543 
00544                 n = s->exponent_high_sizes[bsize];
00545                 val = (int)0x80000000;
00546                 for(i=0;i<n;i++) {
00547                     if (s->high_band_coded[ch][i]) {
00548                         if (val == (int)0x80000000) {
00549                             val = get_bits(&s->gb, 7) - 19;
00550                         } else {
00551                             code = get_vlc2(&s->gb, s->hgain_vlc.table, HGAINVLCBITS, HGAINMAX);
00552                             if (code < 0){
00553                                 av_log(s->avctx, AV_LOG_ERROR, "hgain vlc invalid\n");
00554                                 return -1;
00555                             }
00556                             val += code - 18;
00557                         }
00558                         s->high_band_values[ch][i] = val;
00559                     }
00560                 }
00561             }
00562         }
00563     }
00564 
00565     /* exponents can be reused in short blocks. */
00566     if ((s->block_len_bits == s->frame_len_bits) ||
00567         get_bits1(&s->gb)) {
00568         for(ch = 0; ch < s->nb_channels; ch++) {
00569             if (s->channel_coded[ch]) {
00570                 if (s->use_exp_vlc) {
00571                     if (decode_exp_vlc(s, ch) < 0)
00572                         return -1;
00573                 } else {
00574                     decode_exp_lsp(s, ch);
00575                 }
00576                 s->exponents_bsize[ch] = bsize;
00577             }
00578         }
00579     }
00580 
00581     /* parse spectral coefficients : just RLE encoding */
00582     for(ch = 0; ch < s->nb_channels; ch++) {
00583         if (s->channel_coded[ch]) {
00584             int tindex;
00585             WMACoef* ptr = &s->coefs1[ch][0];
00586 
00587             /* special VLC tables are used for ms stereo because
00588                there is potentially less energy there */
00589             tindex = (ch == 1 && s->ms_stereo);
00590             memset(ptr, 0, s->block_len * sizeof(WMACoef));
00591             ff_wma_run_level_decode(s->avctx, &s->gb, &s->coef_vlc[tindex],
00592                   s->level_table[tindex], s->run_table[tindex],
00593                   0, ptr, 0, nb_coefs[ch],
00594                   s->block_len, s->frame_len_bits, coef_nb_bits);
00595         }
00596         if (s->version == 1 && s->nb_channels >= 2) {
00597             align_get_bits(&s->gb);
00598         }
00599     }
00600 
00601     /* normalize */
00602     {
00603         int n4 = s->block_len / 2;
00604         mdct_norm = 1.0 / (float)n4;
00605         if (s->version == 1) {
00606             mdct_norm *= sqrt(n4);
00607         }
00608     }
00609 
00610     /* finally compute the MDCT coefficients */
00611     for(ch = 0; ch < s->nb_channels; ch++) {
00612         if (s->channel_coded[ch]) {
00613             WMACoef *coefs1;
00614             float *coefs, *exponents, mult, mult1, noise;
00615             int i, j, n, n1, last_high_band, esize;
00616             float exp_power[HIGH_BAND_MAX_SIZE];
00617 
00618             coefs1 = s->coefs1[ch];
00619             exponents = s->exponents[ch];
00620             esize = s->exponents_bsize[ch];
00621             mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
00622             mult *= mdct_norm;
00623             coefs = s->coefs[ch];
00624             if (s->use_noise_coding) {
00625                 mult1 = mult;
00626                 /* very low freqs : noise */
00627                 for(i = 0;i < s->coefs_start; i++) {
00628                     *coefs++ = s->noise_table[s->noise_index] *
00629                       exponents[i<<bsize>>esize] * mult1;
00630                     s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
00631                 }
00632 
00633                 n1 = s->exponent_high_sizes[bsize];
00634 
00635                 /* compute power of high bands */
00636                 exponents = s->exponents[ch] +
00637                     (s->high_band_start[bsize]<<bsize>>esize);
00638                 last_high_band = 0; /* avoid warning */
00639                 for(j=0;j<n1;j++) {
00640                     n = s->exponent_high_bands[s->frame_len_bits -
00641                                               s->block_len_bits][j];
00642                     if (s->high_band_coded[ch][j]) {
00643                         float e2, v;
00644                         e2 = 0;
00645                         for(i = 0;i < n; i++) {
00646                             v = exponents[i<<bsize>>esize];
00647                             e2 += v * v;
00648                         }
00649                         exp_power[j] = e2 / n;
00650                         last_high_band = j;
00651                         tprintf(s->avctx, "%d: power=%f (%d)\n", j, exp_power[j], n);
00652                     }
00653                     exponents += n<<bsize>>esize;
00654                 }
00655 
00656                 /* main freqs and high freqs */
00657                 exponents = s->exponents[ch] + (s->coefs_start<<bsize>>esize);
00658                 for(j=-1;j<n1;j++) {
00659                     if (j < 0) {
00660                         n = s->high_band_start[bsize] -
00661                             s->coefs_start;
00662                     } else {
00663                         n = s->exponent_high_bands[s->frame_len_bits -
00664                                                   s->block_len_bits][j];
00665                     }
00666                     if (j >= 0 && s->high_band_coded[ch][j]) {
00667                         /* use noise with specified power */
00668                         mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);
00669                         /* XXX: use a table */
00670                         mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);
00671                         mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);
00672                         mult1 *= mdct_norm;
00673                         for(i = 0;i < n; i++) {
00674                             noise = s->noise_table[s->noise_index];
00675                             s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
00676                             *coefs++ =  noise *
00677                                 exponents[i<<bsize>>esize] * mult1;
00678                         }
00679                         exponents += n<<bsize>>esize;
00680                     } else {
00681                         /* coded values + small noise */
00682                         for(i = 0;i < n; i++) {
00683                             noise = s->noise_table[s->noise_index];
00684                             s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
00685                             *coefs++ = ((*coefs1++) + noise) *
00686                                 exponents[i<<bsize>>esize] * mult;
00687                         }
00688                         exponents += n<<bsize>>esize;
00689                     }
00690                 }
00691 
00692                 /* very high freqs : noise */
00693                 n = s->block_len - s->coefs_end[bsize];
00694                 mult1 = mult * exponents[((-1<<bsize))>>esize];
00695                 for(i = 0; i < n; i++) {
00696                     *coefs++ = s->noise_table[s->noise_index] * mult1;
00697                     s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
00698                 }
00699             } else {
00700                 /* XXX: optimize more */
00701                 for(i = 0;i < s->coefs_start; i++)
00702                     *coefs++ = 0.0;
00703                 n = nb_coefs[ch];
00704                 for(i = 0;i < n; i++) {
00705                     *coefs++ = coefs1[i] * exponents[i<<bsize>>esize] * mult;
00706                 }
00707                 n = s->block_len - s->coefs_end[bsize];
00708                 for(i = 0;i < n; i++)
00709                     *coefs++ = 0.0;
00710             }
00711         }
00712     }
00713 
00714 #ifdef TRACE
00715     for(ch = 0; ch < s->nb_channels; ch++) {
00716         if (s->channel_coded[ch]) {
00717             dump_floats(s, "exponents", 3, s->exponents[ch], s->block_len);
00718             dump_floats(s, "coefs", 1, s->coefs[ch], s->block_len);
00719         }
00720     }
00721 #endif
00722 
00723     if (s->ms_stereo && s->channel_coded[1]) {
00724         /* nominal case for ms stereo: we do it before mdct */
00725         /* no need to optimize this case because it should almost
00726            never happen */
00727         if (!s->channel_coded[0]) {
00728             tprintf(s->avctx, "rare ms-stereo case happened\n");
00729             memset(s->coefs[0], 0, sizeof(float) * s->block_len);
00730             s->channel_coded[0] = 1;
00731         }
00732 
00733         s->dsp.butterflies_float(s->coefs[0], s->coefs[1], s->block_len);
00734     }
00735 
00736 next:
00737     mdct = &s->mdct_ctx[bsize];
00738 
00739     for(ch = 0; ch < s->nb_channels; ch++) {
00740         int n4, index;
00741 
00742         n4 = s->block_len / 2;
00743         if(s->channel_coded[ch]){
00744             mdct->imdct_calc(mdct, s->output, s->coefs[ch]);
00745         }else if(!(s->ms_stereo && ch==1))
00746             memset(s->output, 0, sizeof(s->output));
00747 
00748         /* multiply by the window and add in the frame */
00749         index = (s->frame_len / 2) + s->block_pos - n4;
00750         wma_window(s, &s->frame_out[ch][index]);
00751     }
00752 
00753     /* update block number */
00754     s->block_num++;
00755     s->block_pos += s->block_len;
00756     if (s->block_pos >= s->frame_len)
00757         return 1;
00758     else
00759         return 0;
00760 }
00761 
00762 /* decode a frame of frame_len samples */
00763 static int wma_decode_frame(WMACodecContext *s, int16_t *samples)
00764 {
00765     int ret, n, ch, incr;
00766     const float *output[MAX_CHANNELS];
00767 
00768 #ifdef TRACE
00769     tprintf(s->avctx, "***decode_frame: %d size=%d\n", s->frame_count++, s->frame_len);
00770 #endif
00771 
00772     /* read each block */
00773     s->block_num = 0;
00774     s->block_pos = 0;
00775     for(;;) {
00776         ret = wma_decode_block(s);
00777         if (ret < 0)
00778             return -1;
00779         if (ret)
00780             break;
00781     }
00782 
00783     /* convert frame to integer */
00784     n = s->frame_len;
00785     incr = s->nb_channels;
00786     for (ch = 0; ch < MAX_CHANNELS; ch++)
00787         output[ch] = s->frame_out[ch];
00788     s->fmt_conv.float_to_int16_interleave(samples, output, n, incr);
00789     for (ch = 0; ch < incr; ch++) {
00790         /* prepare for next block */
00791         memmove(&s->frame_out[ch][0], &s->frame_out[ch][n], n * sizeof(float));
00792     }
00793 
00794 #ifdef TRACE
00795     dump_shorts(s, "samples", samples, n * s->nb_channels);
00796 #endif
00797     return 0;
00798 }
00799 
00800 static int wma_decode_superframe(AVCodecContext *avctx,
00801                                  void *data, int *data_size,
00802                                  AVPacket *avpkt)
00803 {
00804     const uint8_t *buf = avpkt->data;
00805     int buf_size = avpkt->size;
00806     WMACodecContext *s = avctx->priv_data;
00807     int nb_frames, bit_offset, i, pos, len;
00808     uint8_t *q;
00809     int16_t *samples;
00810 
00811     tprintf(avctx, "***decode_superframe:\n");
00812 
00813     if(buf_size==0){
00814         s->last_superframe_len = 0;
00815         return 0;
00816     }
00817     if (buf_size < s->block_align)
00818         return 0;
00819     buf_size = s->block_align;
00820 
00821     samples = data;
00822 
00823     init_get_bits(&s->gb, buf, buf_size*8);
00824 
00825     if (s->use_bit_reservoir) {
00826         /* read super frame header */
00827         skip_bits(&s->gb, 4); /* super frame index */
00828         nb_frames = get_bits(&s->gb, 4) - 1;
00829 
00830         if((nb_frames+1) * s->nb_channels * s->frame_len * sizeof(int16_t) > *data_size){
00831             av_log(s->avctx, AV_LOG_ERROR, "Insufficient output space\n");
00832             goto fail;
00833         }
00834 
00835         bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
00836 
00837         if (s->last_superframe_len > 0) {
00838             //        printf("skip=%d\n", s->last_bitoffset);
00839             /* add bit_offset bits to last frame */
00840             if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
00841                 MAX_CODED_SUPERFRAME_SIZE)
00842                 goto fail;
00843             q = s->last_superframe + s->last_superframe_len;
00844             len = bit_offset;
00845             while (len > 7) {
00846                 *q++ = (get_bits)(&s->gb, 8);
00847                 len -= 8;
00848             }
00849             if (len > 0) {
00850                 *q++ = (get_bits)(&s->gb, len) << (8 - len);
00851             }
00852 
00853             /* XXX: bit_offset bits into last frame */
00854             init_get_bits(&s->gb, s->last_superframe, MAX_CODED_SUPERFRAME_SIZE*8);
00855             /* skip unused bits */
00856             if (s->last_bitoffset > 0)
00857                 skip_bits(&s->gb, s->last_bitoffset);
00858             /* this frame is stored in the last superframe and in the
00859                current one */
00860             if (wma_decode_frame(s, samples) < 0)
00861                 goto fail;
00862             samples += s->nb_channels * s->frame_len;
00863         }
00864 
00865         /* read each frame starting from bit_offset */
00866         pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
00867         init_get_bits(&s->gb, buf + (pos >> 3), (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3))*8);
00868         len = pos & 7;
00869         if (len > 0)
00870             skip_bits(&s->gb, len);
00871 
00872         s->reset_block_lengths = 1;
00873         for(i=0;i<nb_frames;i++) {
00874             if (wma_decode_frame(s, samples) < 0)
00875                 goto fail;
00876             samples += s->nb_channels * s->frame_len;
00877         }
00878 
00879         /* we copy the end of the frame in the last frame buffer */
00880         pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
00881         s->last_bitoffset = pos & 7;
00882         pos >>= 3;
00883         len = buf_size - pos;
00884         if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
00885             av_log(s->avctx, AV_LOG_ERROR, "len %d invalid\n", len);
00886             goto fail;
00887         }
00888         s->last_superframe_len = len;
00889         memcpy(s->last_superframe, buf + pos, len);
00890     } else {
00891         if(s->nb_channels * s->frame_len * sizeof(int16_t) > *data_size){
00892             av_log(s->avctx, AV_LOG_ERROR, "Insufficient output space\n");
00893             goto fail;
00894         }
00895         /* single frame decode */
00896         if (wma_decode_frame(s, samples) < 0)
00897             goto fail;
00898         samples += s->nb_channels * s->frame_len;
00899     }
00900 
00901 //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);
00902 
00903     *data_size = (int8_t *)samples - (int8_t *)data;
00904     return s->block_align;
00905  fail:
00906     /* when error, we reset the bit reservoir */
00907     s->last_superframe_len = 0;
00908     return -1;
00909 }
00910 
00911 static av_cold void flush(AVCodecContext *avctx)
00912 {
00913     WMACodecContext *s = avctx->priv_data;
00914 
00915     s->last_bitoffset=
00916     s->last_superframe_len= 0;
00917 }
00918 
00919 AVCodec ff_wmav1_decoder =
00920 {
00921     "wmav1",
00922     AVMEDIA_TYPE_AUDIO,
00923     CODEC_ID_WMAV1,
00924     sizeof(WMACodecContext),
00925     wma_decode_init,
00926     NULL,
00927     ff_wma_end,
00928     wma_decode_superframe,
00929     .flush=flush,
00930     .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 1"),
00931 };
00932 
00933 AVCodec ff_wmav2_decoder =
00934 {
00935     "wmav2",
00936     AVMEDIA_TYPE_AUDIO,
00937     CODEC_ID_WMAV2,
00938     sizeof(WMACodecContext),
00939     wma_decode_init,
00940     NULL,
00941     ff_wma_end,
00942     wma_decode_superframe,
00943     .flush=flush,
00944     .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 2"),
00945 };