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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     if (!avctx->block_align) {
00089         av_log(avctx, AV_LOG_ERROR, "block_align is not set\n");
00090         return AVERROR(EINVAL);
00091     }
00092 
00093     s->avctx = avctx;
00094 
00095     /* extract flag infos */
00096     flags2 = 0;
00097     extradata = avctx->extradata;
00098     if (avctx->codec->id == CODEC_ID_WMAV1 && avctx->extradata_size >= 4) {
00099         flags2 = AV_RL16(extradata+2);
00100     } else if (avctx->codec->id == CODEC_ID_WMAV2 && avctx->extradata_size >= 6) {
00101         flags2 = AV_RL16(extradata+4);
00102     }
00103 // for(i=0; i<avctx->extradata_size; i++)
00104 //     av_log(NULL, AV_LOG_ERROR, "%02X ", extradata[i]);
00105 
00106     s->use_exp_vlc = flags2 & 0x0001;
00107     s->use_bit_reservoir = flags2 & 0x0002;
00108     s->use_variable_block_len = flags2 & 0x0004;
00109 
00110     if(ff_wma_init(avctx, flags2)<0)
00111         return -1;
00112 
00113     /* init MDCT */
00114     for(i = 0; i < s->nb_block_sizes; i++)
00115         ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1, 1.0);
00116 
00117     if (s->use_noise_coding) {
00118         init_vlc(&s->hgain_vlc, HGAINVLCBITS, sizeof(ff_wma_hgain_huffbits),
00119                  ff_wma_hgain_huffbits, 1, 1,
00120                  ff_wma_hgain_huffcodes, 2, 2, 0);
00121     }
00122 
00123     if (s->use_exp_vlc) {
00124         init_vlc(&s->exp_vlc, EXPVLCBITS, sizeof(ff_aac_scalefactor_bits), //FIXME move out of context
00125                  ff_aac_scalefactor_bits, 1, 1,
00126                  ff_aac_scalefactor_code, 4, 4, 0);
00127     } else {
00128         wma_lsp_to_curve_init(s, s->frame_len);
00129     }
00130 
00131     avctx->sample_fmt = AV_SAMPLE_FMT_S16;
00132 
00133     avcodec_get_frame_defaults(&s->frame);
00134     avctx->coded_frame = &s->frame;
00135 
00136     return 0;
00137 }
00138 
00145 static inline float pow_m1_4(WMACodecContext *s, float x)
00146 {
00147     union {
00148         float f;
00149         unsigned int v;
00150     } u, t;
00151     unsigned int e, m;
00152     float a, b;
00153 
00154     u.f = x;
00155     e = u.v >> 23;
00156     m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
00157     /* build interpolation scale: 1 <= t < 2. */
00158     t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
00159     a = s->lsp_pow_m_table1[m];
00160     b = s->lsp_pow_m_table2[m];
00161     return s->lsp_pow_e_table[e] * (a + b * t.f);
00162 }
00163 
00164 static void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len)
00165 {
00166     float wdel, a, b;
00167     int i, e, m;
00168 
00169     wdel = M_PI / frame_len;
00170     for(i=0;i<frame_len;i++)
00171         s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
00172 
00173     /* tables for x^-0.25 computation */
00174     for(i=0;i<256;i++) {
00175         e = i - 126;
00176         s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
00177     }
00178 
00179     /* NOTE: these two tables are needed to avoid two operations in
00180        pow_m1_4 */
00181     b = 1.0;
00182     for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) {
00183         m = (1 << LSP_POW_BITS) + i;
00184         a = (float)m * (0.5 / (1 << LSP_POW_BITS));
00185         a = pow(a, -0.25);
00186         s->lsp_pow_m_table1[i] = 2 * a - b;
00187         s->lsp_pow_m_table2[i] = b - a;
00188         b = a;
00189     }
00190 }
00191 
00196 static void wma_lsp_to_curve(WMACodecContext *s,
00197                              float *out, float *val_max_ptr,
00198                              int n, float *lsp)
00199 {
00200     int i, j;
00201     float p, q, w, v, val_max;
00202 
00203     val_max = 0;
00204     for(i=0;i<n;i++) {
00205         p = 0.5f;
00206         q = 0.5f;
00207         w = s->lsp_cos_table[i];
00208         for(j=1;j<NB_LSP_COEFS;j+=2){
00209             q *= w - lsp[j - 1];
00210             p *= w - lsp[j];
00211         }
00212         p *= p * (2.0f - w);
00213         q *= q * (2.0f + w);
00214         v = p + q;
00215         v = pow_m1_4(s, v);
00216         if (v > val_max)
00217             val_max = v;
00218         out[i] = v;
00219     }
00220     *val_max_ptr = val_max;
00221 }
00222 
00226 static void decode_exp_lsp(WMACodecContext *s, int ch)
00227 {
00228     float lsp_coefs[NB_LSP_COEFS];
00229     int val, i;
00230 
00231     for(i = 0; i < NB_LSP_COEFS; i++) {
00232         if (i == 0 || i >= 8)
00233             val = get_bits(&s->gb, 3);
00234         else
00235             val = get_bits(&s->gb, 4);
00236         lsp_coefs[i] = ff_wma_lsp_codebook[i][val];
00237     }
00238 
00239     wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
00240                      s->block_len, lsp_coefs);
00241 }
00242 
00244 static const float pow_tab[] = {
00245     1.7782794100389e-04, 2.0535250264571e-04,
00246     2.3713737056617e-04, 2.7384196342644e-04,
00247     3.1622776601684e-04, 3.6517412725484e-04,
00248     4.2169650342858e-04, 4.8696752516586e-04,
00249     5.6234132519035e-04, 6.4938163157621e-04,
00250     7.4989420933246e-04, 8.6596432336006e-04,
00251     1.0000000000000e-03, 1.1547819846895e-03,
00252     1.3335214321633e-03, 1.5399265260595e-03,
00253     1.7782794100389e-03, 2.0535250264571e-03,
00254     2.3713737056617e-03, 2.7384196342644e-03,
00255     3.1622776601684e-03, 3.6517412725484e-03,
00256     4.2169650342858e-03, 4.8696752516586e-03,
00257     5.6234132519035e-03, 6.4938163157621e-03,
00258     7.4989420933246e-03, 8.6596432336006e-03,
00259     1.0000000000000e-02, 1.1547819846895e-02,
00260     1.3335214321633e-02, 1.5399265260595e-02,
00261     1.7782794100389e-02, 2.0535250264571e-02,
00262     2.3713737056617e-02, 2.7384196342644e-02,
00263     3.1622776601684e-02, 3.6517412725484e-02,
00264     4.2169650342858e-02, 4.8696752516586e-02,
00265     5.6234132519035e-02, 6.4938163157621e-02,
00266     7.4989420933246e-02, 8.6596432336007e-02,
00267     1.0000000000000e-01, 1.1547819846895e-01,
00268     1.3335214321633e-01, 1.5399265260595e-01,
00269     1.7782794100389e-01, 2.0535250264571e-01,
00270     2.3713737056617e-01, 2.7384196342644e-01,
00271     3.1622776601684e-01, 3.6517412725484e-01,
00272     4.2169650342858e-01, 4.8696752516586e-01,
00273     5.6234132519035e-01, 6.4938163157621e-01,
00274     7.4989420933246e-01, 8.6596432336007e-01,
00275     1.0000000000000e+00, 1.1547819846895e+00,
00276     1.3335214321633e+00, 1.5399265260595e+00,
00277     1.7782794100389e+00, 2.0535250264571e+00,
00278     2.3713737056617e+00, 2.7384196342644e+00,
00279     3.1622776601684e+00, 3.6517412725484e+00,
00280     4.2169650342858e+00, 4.8696752516586e+00,
00281     5.6234132519035e+00, 6.4938163157621e+00,
00282     7.4989420933246e+00, 8.6596432336007e+00,
00283     1.0000000000000e+01, 1.1547819846895e+01,
00284     1.3335214321633e+01, 1.5399265260595e+01,
00285     1.7782794100389e+01, 2.0535250264571e+01,
00286     2.3713737056617e+01, 2.7384196342644e+01,
00287     3.1622776601684e+01, 3.6517412725484e+01,
00288     4.2169650342858e+01, 4.8696752516586e+01,
00289     5.6234132519035e+01, 6.4938163157621e+01,
00290     7.4989420933246e+01, 8.6596432336007e+01,
00291     1.0000000000000e+02, 1.1547819846895e+02,
00292     1.3335214321633e+02, 1.5399265260595e+02,
00293     1.7782794100389e+02, 2.0535250264571e+02,
00294     2.3713737056617e+02, 2.7384196342644e+02,
00295     3.1622776601684e+02, 3.6517412725484e+02,
00296     4.2169650342858e+02, 4.8696752516586e+02,
00297     5.6234132519035e+02, 6.4938163157621e+02,
00298     7.4989420933246e+02, 8.6596432336007e+02,
00299     1.0000000000000e+03, 1.1547819846895e+03,
00300     1.3335214321633e+03, 1.5399265260595e+03,
00301     1.7782794100389e+03, 2.0535250264571e+03,
00302     2.3713737056617e+03, 2.7384196342644e+03,
00303     3.1622776601684e+03, 3.6517412725484e+03,
00304     4.2169650342858e+03, 4.8696752516586e+03,
00305     5.6234132519035e+03, 6.4938163157621e+03,
00306     7.4989420933246e+03, 8.6596432336007e+03,
00307     1.0000000000000e+04, 1.1547819846895e+04,
00308     1.3335214321633e+04, 1.5399265260595e+04,
00309     1.7782794100389e+04, 2.0535250264571e+04,
00310     2.3713737056617e+04, 2.7384196342644e+04,
00311     3.1622776601684e+04, 3.6517412725484e+04,
00312     4.2169650342858e+04, 4.8696752516586e+04,
00313     5.6234132519035e+04, 6.4938163157621e+04,
00314     7.4989420933246e+04, 8.6596432336007e+04,
00315     1.0000000000000e+05, 1.1547819846895e+05,
00316     1.3335214321633e+05, 1.5399265260595e+05,
00317     1.7782794100389e+05, 2.0535250264571e+05,
00318     2.3713737056617e+05, 2.7384196342644e+05,
00319     3.1622776601684e+05, 3.6517412725484e+05,
00320     4.2169650342858e+05, 4.8696752516586e+05,
00321     5.6234132519035e+05, 6.4938163157621e+05,
00322     7.4989420933246e+05, 8.6596432336007e+05,
00323 };
00324 
00328 static int decode_exp_vlc(WMACodecContext *s, int ch)
00329 {
00330     int last_exp, n, code;
00331     const uint16_t *ptr;
00332     float v, max_scale;
00333     uint32_t *q, *q_end, iv;
00334     const float *ptab = pow_tab + 60;
00335     const uint32_t *iptab = (const uint32_t*)ptab;
00336 
00337     ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
00338     q = (uint32_t *)s->exponents[ch];
00339     q_end = q + s->block_len;
00340     max_scale = 0;
00341     if (s->version == 1) {
00342         last_exp = get_bits(&s->gb, 5) + 10;
00343         v = ptab[last_exp];
00344         iv = iptab[last_exp];
00345         max_scale = v;
00346         n = *ptr++;
00347         switch (n & 3) do {
00348         case 0: *q++ = iv;
00349         case 3: *q++ = iv;
00350         case 2: *q++ = iv;
00351         case 1: *q++ = iv;
00352         } while ((n -= 4) > 0);
00353     }else
00354         last_exp = 36;
00355 
00356     while (q < q_end) {
00357         code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);
00358         if (code < 0){
00359             av_log(s->avctx, AV_LOG_ERROR, "Exponent vlc invalid\n");
00360             return -1;
00361         }
00362         /* NOTE: this offset is the same as MPEG4 AAC ! */
00363         last_exp += code - 60;
00364         if ((unsigned)last_exp + 60 >= FF_ARRAY_ELEMS(pow_tab)) {
00365             av_log(s->avctx, AV_LOG_ERROR, "Exponent out of range: %d\n",
00366                    last_exp);
00367             return -1;
00368         }
00369         v = ptab[last_exp];
00370         iv = iptab[last_exp];
00371         if (v > max_scale)
00372             max_scale = v;
00373         n = *ptr++;
00374         switch (n & 3) do {
00375         case 0: *q++ = iv;
00376         case 3: *q++ = iv;
00377         case 2: *q++ = iv;
00378         case 1: *q++ = iv;
00379         } while ((n -= 4) > 0);
00380     }
00381     s->max_exponent[ch] = max_scale;
00382     return 0;
00383 }
00384 
00385 
00392 static void wma_window(WMACodecContext *s, float *out)
00393 {
00394     float *in = s->output;
00395     int block_len, bsize, n;
00396 
00397     /* left part */
00398     if (s->block_len_bits <= s->prev_block_len_bits) {
00399         block_len = s->block_len;
00400         bsize = s->frame_len_bits - s->block_len_bits;
00401 
00402         s->dsp.vector_fmul_add(out, in, s->windows[bsize],
00403                                out, block_len);
00404 
00405     } else {
00406         block_len = 1 << s->prev_block_len_bits;
00407         n = (s->block_len - block_len) / 2;
00408         bsize = s->frame_len_bits - s->prev_block_len_bits;
00409 
00410         s->dsp.vector_fmul_add(out+n, in+n, s->windows[bsize],
00411                                out+n, block_len);
00412 
00413         memcpy(out+n+block_len, in+n+block_len, n*sizeof(float));
00414     }
00415 
00416     out += s->block_len;
00417     in += s->block_len;
00418 
00419     /* right part */
00420     if (s->block_len_bits <= s->next_block_len_bits) {
00421         block_len = s->block_len;
00422         bsize = s->frame_len_bits - s->block_len_bits;
00423 
00424         s->dsp.vector_fmul_reverse(out, in, s->windows[bsize], block_len);
00425 
00426     } else {
00427         block_len = 1 << s->next_block_len_bits;
00428         n = (s->block_len - block_len) / 2;
00429         bsize = s->frame_len_bits - s->next_block_len_bits;
00430 
00431         memcpy(out, in, n*sizeof(float));
00432 
00433         s->dsp.vector_fmul_reverse(out+n, in+n, s->windows[bsize], block_len);
00434 
00435         memset(out+n+block_len, 0, n*sizeof(float));
00436     }
00437 }
00438 
00439 
00444 static int wma_decode_block(WMACodecContext *s)
00445 {
00446     int n, v, a, ch, bsize;
00447     int coef_nb_bits, total_gain;
00448     int nb_coefs[MAX_CHANNELS];
00449     float mdct_norm;
00450     FFTContext *mdct;
00451 
00452 #ifdef TRACE
00453     tprintf(s->avctx, "***decode_block: %d:%d\n", s->frame_count - 1, s->block_num);
00454 #endif
00455 
00456     /* compute current block length */
00457     if (s->use_variable_block_len) {
00458         n = av_log2(s->nb_block_sizes - 1) + 1;
00459 
00460         if (s->reset_block_lengths) {
00461             s->reset_block_lengths = 0;
00462             v = get_bits(&s->gb, n);
00463             if (v >= s->nb_block_sizes){
00464                 av_log(s->avctx, AV_LOG_ERROR, "prev_block_len_bits %d out of range\n", s->frame_len_bits - v);
00465                 return -1;
00466             }
00467             s->prev_block_len_bits = s->frame_len_bits - v;
00468             v = get_bits(&s->gb, n);
00469             if (v >= s->nb_block_sizes){
00470                 av_log(s->avctx, AV_LOG_ERROR, "block_len_bits %d out of range\n", s->frame_len_bits - v);
00471                 return -1;
00472             }
00473             s->block_len_bits = s->frame_len_bits - v;
00474         } else {
00475             /* update block lengths */
00476             s->prev_block_len_bits = s->block_len_bits;
00477             s->block_len_bits = s->next_block_len_bits;
00478         }
00479         v = get_bits(&s->gb, n);
00480         if (v >= s->nb_block_sizes){
00481             av_log(s->avctx, AV_LOG_ERROR, "next_block_len_bits %d out of range\n", s->frame_len_bits - v);
00482             return -1;
00483         }
00484         s->next_block_len_bits = s->frame_len_bits - v;
00485     } else {
00486         /* fixed block len */
00487         s->next_block_len_bits = s->frame_len_bits;
00488         s->prev_block_len_bits = s->frame_len_bits;
00489         s->block_len_bits = s->frame_len_bits;
00490     }
00491 
00492     /* now check if the block length is coherent with the frame length */
00493     s->block_len = 1 << s->block_len_bits;
00494     if ((s->block_pos + s->block_len) > s->frame_len){
00495         av_log(s->avctx, AV_LOG_ERROR, "frame_len overflow\n");
00496         return -1;
00497     }
00498 
00499     if (s->nb_channels == 2) {
00500         s->ms_stereo = get_bits1(&s->gb);
00501     }
00502     v = 0;
00503     for(ch = 0; ch < s->nb_channels; ch++) {
00504         a = get_bits1(&s->gb);
00505         s->channel_coded[ch] = a;
00506         v |= a;
00507     }
00508 
00509     bsize = s->frame_len_bits - s->block_len_bits;
00510 
00511     /* if no channel coded, no need to go further */
00512     /* XXX: fix potential framing problems */
00513     if (!v)
00514         goto next;
00515 
00516     /* read total gain and extract corresponding number of bits for
00517        coef escape coding */
00518     total_gain = 1;
00519     for(;;) {
00520         a = get_bits(&s->gb, 7);
00521         total_gain += a;
00522         if (a != 127)
00523             break;
00524     }
00525 
00526     coef_nb_bits= ff_wma_total_gain_to_bits(total_gain);
00527 
00528     /* compute number of coefficients */
00529     n = s->coefs_end[bsize] - s->coefs_start;
00530     for(ch = 0; ch < s->nb_channels; ch++)
00531         nb_coefs[ch] = n;
00532 
00533     /* complex coding */
00534     if (s->use_noise_coding) {
00535 
00536         for(ch = 0; ch < s->nb_channels; ch++) {
00537             if (s->channel_coded[ch]) {
00538                 int i, n, a;
00539                 n = s->exponent_high_sizes[bsize];
00540                 for(i=0;i<n;i++) {
00541                     a = get_bits1(&s->gb);
00542                     s->high_band_coded[ch][i] = a;
00543                     /* if noise coding, the coefficients are not transmitted */
00544                     if (a)
00545                         nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
00546                 }
00547             }
00548         }
00549         for(ch = 0; ch < s->nb_channels; ch++) {
00550             if (s->channel_coded[ch]) {
00551                 int i, n, val, code;
00552 
00553                 n = s->exponent_high_sizes[bsize];
00554                 val = (int)0x80000000;
00555                 for(i=0;i<n;i++) {
00556                     if (s->high_band_coded[ch][i]) {
00557                         if (val == (int)0x80000000) {
00558                             val = get_bits(&s->gb, 7) - 19;
00559                         } else {
00560                             code = get_vlc2(&s->gb, s->hgain_vlc.table, HGAINVLCBITS, HGAINMAX);
00561                             if (code < 0){
00562                                 av_log(s->avctx, AV_LOG_ERROR, "hgain vlc invalid\n");
00563                                 return -1;
00564                             }
00565                             val += code - 18;
00566                         }
00567                         s->high_band_values[ch][i] = val;
00568                     }
00569                 }
00570             }
00571         }
00572     }
00573 
00574     /* exponents can be reused in short blocks. */
00575     if ((s->block_len_bits == s->frame_len_bits) ||
00576         get_bits1(&s->gb)) {
00577         for(ch = 0; ch < s->nb_channels; ch++) {
00578             if (s->channel_coded[ch]) {
00579                 if (s->use_exp_vlc) {
00580                     if (decode_exp_vlc(s, ch) < 0)
00581                         return -1;
00582                 } else {
00583                     decode_exp_lsp(s, ch);
00584                 }
00585                 s->exponents_bsize[ch] = bsize;
00586             }
00587         }
00588     }
00589 
00590     /* parse spectral coefficients : just RLE encoding */
00591     for(ch = 0; ch < s->nb_channels; ch++) {
00592         if (s->channel_coded[ch]) {
00593             int tindex;
00594             WMACoef* ptr = &s->coefs1[ch][0];
00595 
00596             /* special VLC tables are used for ms stereo because
00597                there is potentially less energy there */
00598             tindex = (ch == 1 && s->ms_stereo);
00599             memset(ptr, 0, s->block_len * sizeof(WMACoef));
00600             ff_wma_run_level_decode(s->avctx, &s->gb, &s->coef_vlc[tindex],
00601                   s->level_table[tindex], s->run_table[tindex],
00602                   0, ptr, 0, nb_coefs[ch],
00603                   s->block_len, s->frame_len_bits, coef_nb_bits);
00604         }
00605         if (s->version == 1 && s->nb_channels >= 2) {
00606             align_get_bits(&s->gb);
00607         }
00608     }
00609 
00610     /* normalize */
00611     {
00612         int n4 = s->block_len / 2;
00613         mdct_norm = 1.0 / (float)n4;
00614         if (s->version == 1) {
00615             mdct_norm *= sqrt(n4);
00616         }
00617     }
00618 
00619     /* finally compute the MDCT coefficients */
00620     for(ch = 0; ch < s->nb_channels; ch++) {
00621         if (s->channel_coded[ch]) {
00622             WMACoef *coefs1;
00623             float *coefs, *exponents, mult, mult1, noise;
00624             int i, j, n, n1, last_high_band, esize;
00625             float exp_power[HIGH_BAND_MAX_SIZE];
00626 
00627             coefs1 = s->coefs1[ch];
00628             exponents = s->exponents[ch];
00629             esize = s->exponents_bsize[ch];
00630             mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
00631             mult *= mdct_norm;
00632             coefs = s->coefs[ch];
00633             if (s->use_noise_coding) {
00634                 mult1 = mult;
00635                 /* very low freqs : noise */
00636                 for(i = 0;i < s->coefs_start; i++) {
00637                     *coefs++ = s->noise_table[s->noise_index] *
00638                       exponents[i<<bsize>>esize] * mult1;
00639                     s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
00640                 }
00641 
00642                 n1 = s->exponent_high_sizes[bsize];
00643 
00644                 /* compute power of high bands */
00645                 exponents = s->exponents[ch] +
00646                     (s->high_band_start[bsize]<<bsize>>esize);
00647                 last_high_band = 0; /* avoid warning */
00648                 for(j=0;j<n1;j++) {
00649                     n = s->exponent_high_bands[s->frame_len_bits -
00650                                               s->block_len_bits][j];
00651                     if (s->high_band_coded[ch][j]) {
00652                         float e2, v;
00653                         e2 = 0;
00654                         for(i = 0;i < n; i++) {
00655                             v = exponents[i<<bsize>>esize];
00656                             e2 += v * v;
00657                         }
00658                         exp_power[j] = e2 / n;
00659                         last_high_band = j;
00660                         tprintf(s->avctx, "%d: power=%f (%d)\n", j, exp_power[j], n);
00661                     }
00662                     exponents += n<<bsize>>esize;
00663                 }
00664 
00665                 /* main freqs and high freqs */
00666                 exponents = s->exponents[ch] + (s->coefs_start<<bsize>>esize);
00667                 for(j=-1;j<n1;j++) {
00668                     if (j < 0) {
00669                         n = s->high_band_start[bsize] -
00670                             s->coefs_start;
00671                     } else {
00672                         n = s->exponent_high_bands[s->frame_len_bits -
00673                                                   s->block_len_bits][j];
00674                     }
00675                     if (j >= 0 && s->high_band_coded[ch][j]) {
00676                         /* use noise with specified power */
00677                         mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);
00678                         /* XXX: use a table */
00679                         mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);
00680                         mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);
00681                         mult1 *= mdct_norm;
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++ =  noise *
00686                                 exponents[i<<bsize>>esize] * mult1;
00687                         }
00688                         exponents += n<<bsize>>esize;
00689                     } else {
00690                         /* coded values + small noise */
00691                         for(i = 0;i < n; i++) {
00692                             noise = s->noise_table[s->noise_index];
00693                             s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
00694                             *coefs++ = ((*coefs1++) + noise) *
00695                                 exponents[i<<bsize>>esize] * mult;
00696                         }
00697                         exponents += n<<bsize>>esize;
00698                     }
00699                 }
00700 
00701                 /* very high freqs : noise */
00702                 n = s->block_len - s->coefs_end[bsize];
00703                 mult1 = mult * exponents[((-1<<bsize))>>esize];
00704                 for(i = 0; i < n; i++) {
00705                     *coefs++ = s->noise_table[s->noise_index] * mult1;
00706                     s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
00707                 }
00708             } else {
00709                 /* XXX: optimize more */
00710                 for(i = 0;i < s->coefs_start; i++)
00711                     *coefs++ = 0.0;
00712                 n = nb_coefs[ch];
00713                 for(i = 0;i < n; i++) {
00714                     *coefs++ = coefs1[i] * exponents[i<<bsize>>esize] * mult;
00715                 }
00716                 n = s->block_len - s->coefs_end[bsize];
00717                 for(i = 0;i < n; i++)
00718                     *coefs++ = 0.0;
00719             }
00720         }
00721     }
00722 
00723 #ifdef TRACE
00724     for(ch = 0; ch < s->nb_channels; ch++) {
00725         if (s->channel_coded[ch]) {
00726             dump_floats(s, "exponents", 3, s->exponents[ch], s->block_len);
00727             dump_floats(s, "coefs", 1, s->coefs[ch], s->block_len);
00728         }
00729     }
00730 #endif
00731 
00732     if (s->ms_stereo && s->channel_coded[1]) {
00733         /* nominal case for ms stereo: we do it before mdct */
00734         /* no need to optimize this case because it should almost
00735            never happen */
00736         if (!s->channel_coded[0]) {
00737             tprintf(s->avctx, "rare ms-stereo case happened\n");
00738             memset(s->coefs[0], 0, sizeof(float) * s->block_len);
00739             s->channel_coded[0] = 1;
00740         }
00741 
00742         s->dsp.butterflies_float(s->coefs[0], s->coefs[1], s->block_len);
00743     }
00744 
00745 next:
00746     mdct = &s->mdct_ctx[bsize];
00747 
00748     for(ch = 0; ch < s->nb_channels; ch++) {
00749         int n4, index;
00750 
00751         n4 = s->block_len / 2;
00752         if(s->channel_coded[ch]){
00753             mdct->imdct_calc(mdct, s->output, s->coefs[ch]);
00754         }else if(!(s->ms_stereo && ch==1))
00755             memset(s->output, 0, sizeof(s->output));
00756 
00757         /* multiply by the window and add in the frame */
00758         index = (s->frame_len / 2) + s->block_pos - n4;
00759         wma_window(s, &s->frame_out[ch][index]);
00760     }
00761 
00762     /* update block number */
00763     s->block_num++;
00764     s->block_pos += s->block_len;
00765     if (s->block_pos >= s->frame_len)
00766         return 1;
00767     else
00768         return 0;
00769 }
00770 
00771 /* decode a frame of frame_len samples */
00772 static int wma_decode_frame(WMACodecContext *s, int16_t *samples)
00773 {
00774     int ret, n, ch, incr;
00775     const float *output[MAX_CHANNELS];
00776 
00777 #ifdef TRACE
00778     tprintf(s->avctx, "***decode_frame: %d size=%d\n", s->frame_count++, s->frame_len);
00779 #endif
00780 
00781     /* read each block */
00782     s->block_num = 0;
00783     s->block_pos = 0;
00784     for(;;) {
00785         ret = wma_decode_block(s);
00786         if (ret < 0)
00787             return -1;
00788         if (ret)
00789             break;
00790     }
00791 
00792     /* convert frame to integer */
00793     n = s->frame_len;
00794     incr = s->nb_channels;
00795     for (ch = 0; ch < MAX_CHANNELS; ch++)
00796         output[ch] = s->frame_out[ch];
00797     s->fmt_conv.float_to_int16_interleave(samples, output, n, incr);
00798     for (ch = 0; ch < incr; ch++) {
00799         /* prepare for next block */
00800         memmove(&s->frame_out[ch][0], &s->frame_out[ch][n], n * sizeof(float));
00801     }
00802 
00803 #ifdef TRACE
00804     dump_shorts(s, "samples", samples, n * s->nb_channels);
00805 #endif
00806     return 0;
00807 }
00808 
00809 static int wma_decode_superframe(AVCodecContext *avctx, void *data,
00810                                  int *got_frame_ptr, AVPacket *avpkt)
00811 {
00812     const uint8_t *buf = avpkt->data;
00813     int buf_size = avpkt->size;
00814     WMACodecContext *s = avctx->priv_data;
00815     int nb_frames, bit_offset, i, pos, len, ret;
00816     uint8_t *q;
00817     int16_t *samples;
00818 
00819     tprintf(avctx, "***decode_superframe:\n");
00820 
00821     if(buf_size==0){
00822         s->last_superframe_len = 0;
00823         return 0;
00824     }
00825     if (buf_size < s->block_align) {
00826         av_log(avctx, AV_LOG_ERROR,
00827                "Input packet size too small (%d < %d)\n",
00828                buf_size, s->block_align);
00829         return AVERROR_INVALIDDATA;
00830     }
00831     buf_size = s->block_align;
00832 
00833     init_get_bits(&s->gb, buf, buf_size*8);
00834 
00835     if (s->use_bit_reservoir) {
00836         /* read super frame header */
00837         skip_bits(&s->gb, 4); /* super frame index */
00838         nb_frames = get_bits(&s->gb, 4) - (s->last_superframe_len <= 0);
00839     } else {
00840         nb_frames = 1;
00841     }
00842 
00843     /* get output buffer */
00844     s->frame.nb_samples = nb_frames * s->frame_len;
00845     if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
00846         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00847         return ret;
00848     }
00849     samples = (int16_t *)s->frame.data[0];
00850 
00851     if (s->use_bit_reservoir) {
00852         bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
00853         if (bit_offset > get_bits_left(&s->gb)) {
00854             av_log(avctx, AV_LOG_ERROR,
00855                    "Invalid last frame bit offset %d > buf size %d (%d)\n",
00856                    bit_offset, get_bits_left(&s->gb), buf_size);
00857             goto fail;
00858         }
00859 
00860         if (s->last_superframe_len > 0) {
00861             //        printf("skip=%d\n", s->last_bitoffset);
00862             /* add bit_offset bits to last frame */
00863             if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
00864                 MAX_CODED_SUPERFRAME_SIZE)
00865                 goto fail;
00866             q = s->last_superframe + s->last_superframe_len;
00867             len = bit_offset;
00868             while (len > 7) {
00869                 *q++ = (get_bits)(&s->gb, 8);
00870                 len -= 8;
00871             }
00872             if (len > 0) {
00873                 *q++ = (get_bits)(&s->gb, len) << (8 - len);
00874             }
00875             memset(q, 0, FF_INPUT_BUFFER_PADDING_SIZE);
00876 
00877             /* XXX: bit_offset bits into last frame */
00878             init_get_bits(&s->gb, s->last_superframe, s->last_superframe_len * 8 + bit_offset);
00879             /* skip unused bits */
00880             if (s->last_bitoffset > 0)
00881                 skip_bits(&s->gb, s->last_bitoffset);
00882             /* this frame is stored in the last superframe and in the
00883                current one */
00884             if (wma_decode_frame(s, samples) < 0)
00885                 goto fail;
00886             samples += s->nb_channels * s->frame_len;
00887             nb_frames--;
00888         }
00889 
00890         /* read each frame starting from bit_offset */
00891         pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
00892         if (pos >= MAX_CODED_SUPERFRAME_SIZE * 8 || pos > buf_size * 8)
00893             return AVERROR_INVALIDDATA;
00894         init_get_bits(&s->gb, buf + (pos >> 3), (buf_size - (pos >> 3))*8);
00895         len = pos & 7;
00896         if (len > 0)
00897             skip_bits(&s->gb, len);
00898 
00899         s->reset_block_lengths = 1;
00900         for(i=0;i<nb_frames;i++) {
00901             if (wma_decode_frame(s, samples) < 0)
00902                 goto fail;
00903             samples += s->nb_channels * s->frame_len;
00904         }
00905 
00906         /* we copy the end of the frame in the last frame buffer */
00907         pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
00908         s->last_bitoffset = pos & 7;
00909         pos >>= 3;
00910         len = buf_size - pos;
00911         if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
00912             av_log(s->avctx, AV_LOG_ERROR, "len %d invalid\n", len);
00913             goto fail;
00914         }
00915         s->last_superframe_len = len;
00916         memcpy(s->last_superframe, buf + pos, len);
00917     } else {
00918         /* single frame decode */
00919         if (wma_decode_frame(s, samples) < 0)
00920             goto fail;
00921         samples += s->nb_channels * s->frame_len;
00922     }
00923 
00924 //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);
00925 
00926     *got_frame_ptr   = 1;
00927     *(AVFrame *)data = s->frame;
00928 
00929     return s->block_align;
00930  fail:
00931     /* when error, we reset the bit reservoir */
00932     s->last_superframe_len = 0;
00933     return -1;
00934 }
00935 
00936 static av_cold void flush(AVCodecContext *avctx)
00937 {
00938     WMACodecContext *s = avctx->priv_data;
00939 
00940     s->last_bitoffset=
00941     s->last_superframe_len= 0;
00942 }
00943 
00944 AVCodec ff_wmav1_decoder = {
00945     .name           = "wmav1",
00946     .type           = AVMEDIA_TYPE_AUDIO,
00947     .id             = CODEC_ID_WMAV1,
00948     .priv_data_size = sizeof(WMACodecContext),
00949     .init           = wma_decode_init,
00950     .close          = ff_wma_end,
00951     .decode         = wma_decode_superframe,
00952     .flush          = flush,
00953     .capabilities   = CODEC_CAP_DR1,
00954     .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Audio 1"),
00955 };
00956 
00957 AVCodec ff_wmav2_decoder = {
00958     .name           = "wmav2",
00959     .type           = AVMEDIA_TYPE_AUDIO,
00960     .id             = CODEC_ID_WMAV2,
00961     .priv_data_size = sizeof(WMACodecContext),
00962     .init           = wma_decode_init,
00963     .close          = ff_wma_end,
00964     .decode         = wma_decode_superframe,
00965     .flush          = flush,
00966     .capabilities   = CODEC_CAP_DR1,
00967     .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Audio 2"),
00968 };
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