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 "internal.h"
00038 #include "wma.h"
00039 
00040 #undef NDEBUG
00041 #include <assert.h>
00042 
00043 #define EXPVLCBITS 8
00044 #define EXPMAX ((19+EXPVLCBITS-1)/EXPVLCBITS)
00045 
00046 #define HGAINVLCBITS 9
00047 #define HGAINMAX ((13+HGAINVLCBITS-1)/HGAINVLCBITS)
00048 
00049 static void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len);
00050 
00051 #ifdef TRACE
00052 static void dump_shorts(WMACodecContext *s, const char *name, const short *tab, int n)
00053 {
00054     int i;
00055 
00056     tprintf(s->avctx, "%s[%d]:\n", name, n);
00057     for(i=0;i<n;i++) {
00058         if ((i & 7) == 0)
00059             tprintf(s->avctx, "%4d: ", i);
00060         tprintf(s->avctx, " %5d.0", tab[i]);
00061         if ((i & 7) == 7)
00062             tprintf(s->avctx, "\n");
00063     }
00064 }
00065 
00066 static void dump_floats(WMACodecContext *s, const char *name, int prec, const float *tab, int n)
00067 {
00068     int i;
00069 
00070     tprintf(s->avctx, "%s[%d]:\n", name, n);
00071     for(i=0;i<n;i++) {
00072         if ((i & 7) == 0)
00073             tprintf(s->avctx, "%4d: ", i);
00074         tprintf(s->avctx, " %8.*f", prec, tab[i]);
00075         if ((i & 7) == 7)
00076             tprintf(s->avctx, "\n");
00077     }
00078     if ((i & 7) != 0)
00079         tprintf(s->avctx, "\n");
00080 }
00081 #endif
00082 
00083 static int wma_decode_init(AVCodecContext * avctx)
00084 {
00085     WMACodecContext *s = avctx->priv_data;
00086     int i, flags2;
00087     uint8_t *extradata;
00088 
00089     if (!avctx->block_align) {
00090         av_log(avctx, AV_LOG_ERROR, "block_align is not set\n");
00091         return AVERROR(EINVAL);
00092     }
00093 
00094     s->avctx = avctx;
00095 
00096     /* extract flag infos */
00097     flags2 = 0;
00098     extradata = avctx->extradata;
00099     if (avctx->codec->id == CODEC_ID_WMAV1 && avctx->extradata_size >= 4) {
00100         flags2 = AV_RL16(extradata+2);
00101     } else if (avctx->codec->id == CODEC_ID_WMAV2 && avctx->extradata_size >= 6) {
00102         flags2 = AV_RL16(extradata+4);
00103     }
00104 // for(i=0; i<avctx->extradata_size; i++)
00105 //     av_log(NULL, AV_LOG_ERROR, "%02X ", extradata[i]);
00106 
00107     s->use_exp_vlc = flags2 & 0x0001;
00108     s->use_bit_reservoir = flags2 & 0x0002;
00109     s->use_variable_block_len = flags2 & 0x0004;
00110 
00111     if(ff_wma_init(avctx, flags2)<0)
00112         return -1;
00113 
00114     /* init MDCT */
00115     for(i = 0; i < s->nb_block_sizes; i++)
00116         ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1, 1.0);
00117 
00118     if (s->use_noise_coding) {
00119         init_vlc(&s->hgain_vlc, HGAINVLCBITS, sizeof(ff_wma_hgain_huffbits),
00120                  ff_wma_hgain_huffbits, 1, 1,
00121                  ff_wma_hgain_huffcodes, 2, 2, 0);
00122     }
00123 
00124     if (s->use_exp_vlc) {
00125         init_vlc(&s->exp_vlc, EXPVLCBITS, sizeof(ff_aac_scalefactor_bits), //FIXME move out of context
00126                  ff_aac_scalefactor_bits, 1, 1,
00127                  ff_aac_scalefactor_code, 4, 4, 0);
00128     } else {
00129         wma_lsp_to_curve_init(s, s->frame_len);
00130     }
00131 
00132     avctx->sample_fmt = AV_SAMPLE_FMT_S16;
00133 
00134     avcodec_get_frame_defaults(&s->frame);
00135     avctx->coded_frame = &s->frame;
00136 
00137     return 0;
00138 }
00139 
00146 static inline float pow_m1_4(WMACodecContext *s, float x)
00147 {
00148     union {
00149         float f;
00150         unsigned int v;
00151     } u, t;
00152     unsigned int e, m;
00153     float a, b;
00154 
00155     u.f = x;
00156     e = u.v >> 23;
00157     m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
00158     /* build interpolation scale: 1 <= t < 2. */
00159     t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
00160     a = s->lsp_pow_m_table1[m];
00161     b = s->lsp_pow_m_table2[m];
00162     return s->lsp_pow_e_table[e] * (a + b * t.f);
00163 }
00164 
00165 static void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len)
00166 {
00167     float wdel, a, b;
00168     int i, e, m;
00169 
00170     wdel = M_PI / frame_len;
00171     for(i=0;i<frame_len;i++)
00172         s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
00173 
00174     /* tables for x^-0.25 computation */
00175     for(i=0;i<256;i++) {
00176         e = i - 126;
00177         s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
00178     }
00179 
00180     /* NOTE: these two tables are needed to avoid two operations in
00181        pow_m1_4 */
00182     b = 1.0;
00183     for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) {
00184         m = (1 << LSP_POW_BITS) + i;
00185         a = (float)m * (0.5 / (1 << LSP_POW_BITS));
00186         a = pow(a, -0.25);
00187         s->lsp_pow_m_table1[i] = 2 * a - b;
00188         s->lsp_pow_m_table2[i] = b - a;
00189         b = a;
00190     }
00191 }
00192 
00197 static void wma_lsp_to_curve(WMACodecContext *s,
00198                              float *out, float *val_max_ptr,
00199                              int n, float *lsp)
00200 {
00201     int i, j;
00202     float p, q, w, v, val_max;
00203 
00204     val_max = 0;
00205     for(i=0;i<n;i++) {
00206         p = 0.5f;
00207         q = 0.5f;
00208         w = s->lsp_cos_table[i];
00209         for(j=1;j<NB_LSP_COEFS;j+=2){
00210             q *= w - lsp[j - 1];
00211             p *= w - lsp[j];
00212         }
00213         p *= p * (2.0f - w);
00214         q *= q * (2.0f + w);
00215         v = p + q;
00216         v = pow_m1_4(s, v);
00217         if (v > val_max)
00218             val_max = v;
00219         out[i] = v;
00220     }
00221     *val_max_ptr = val_max;
00222 }
00223 
00227 static void decode_exp_lsp(WMACodecContext *s, int ch)
00228 {
00229     float lsp_coefs[NB_LSP_COEFS];
00230     int val, i;
00231 
00232     for(i = 0; i < NB_LSP_COEFS; i++) {
00233         if (i == 0 || i >= 8)
00234             val = get_bits(&s->gb, 3);
00235         else
00236             val = get_bits(&s->gb, 4);
00237         lsp_coefs[i] = ff_wma_lsp_codebook[i][val];
00238     }
00239 
00240     wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
00241                      s->block_len, lsp_coefs);
00242 }
00243 
00245 static const float pow_tab[] = {
00246     1.7782794100389e-04, 2.0535250264571e-04,
00247     2.3713737056617e-04, 2.7384196342644e-04,
00248     3.1622776601684e-04, 3.6517412725484e-04,
00249     4.2169650342858e-04, 4.8696752516586e-04,
00250     5.6234132519035e-04, 6.4938163157621e-04,
00251     7.4989420933246e-04, 8.6596432336006e-04,
00252     1.0000000000000e-03, 1.1547819846895e-03,
00253     1.3335214321633e-03, 1.5399265260595e-03,
00254     1.7782794100389e-03, 2.0535250264571e-03,
00255     2.3713737056617e-03, 2.7384196342644e-03,
00256     3.1622776601684e-03, 3.6517412725484e-03,
00257     4.2169650342858e-03, 4.8696752516586e-03,
00258     5.6234132519035e-03, 6.4938163157621e-03,
00259     7.4989420933246e-03, 8.6596432336006e-03,
00260     1.0000000000000e-02, 1.1547819846895e-02,
00261     1.3335214321633e-02, 1.5399265260595e-02,
00262     1.7782794100389e-02, 2.0535250264571e-02,
00263     2.3713737056617e-02, 2.7384196342644e-02,
00264     3.1622776601684e-02, 3.6517412725484e-02,
00265     4.2169650342858e-02, 4.8696752516586e-02,
00266     5.6234132519035e-02, 6.4938163157621e-02,
00267     7.4989420933246e-02, 8.6596432336007e-02,
00268     1.0000000000000e-01, 1.1547819846895e-01,
00269     1.3335214321633e-01, 1.5399265260595e-01,
00270     1.7782794100389e-01, 2.0535250264571e-01,
00271     2.3713737056617e-01, 2.7384196342644e-01,
00272     3.1622776601684e-01, 3.6517412725484e-01,
00273     4.2169650342858e-01, 4.8696752516586e-01,
00274     5.6234132519035e-01, 6.4938163157621e-01,
00275     7.4989420933246e-01, 8.6596432336007e-01,
00276     1.0000000000000e+00, 1.1547819846895e+00,
00277     1.3335214321633e+00, 1.5399265260595e+00,
00278     1.7782794100389e+00, 2.0535250264571e+00,
00279     2.3713737056617e+00, 2.7384196342644e+00,
00280     3.1622776601684e+00, 3.6517412725484e+00,
00281     4.2169650342858e+00, 4.8696752516586e+00,
00282     5.6234132519035e+00, 6.4938163157621e+00,
00283     7.4989420933246e+00, 8.6596432336007e+00,
00284     1.0000000000000e+01, 1.1547819846895e+01,
00285     1.3335214321633e+01, 1.5399265260595e+01,
00286     1.7782794100389e+01, 2.0535250264571e+01,
00287     2.3713737056617e+01, 2.7384196342644e+01,
00288     3.1622776601684e+01, 3.6517412725484e+01,
00289     4.2169650342858e+01, 4.8696752516586e+01,
00290     5.6234132519035e+01, 6.4938163157621e+01,
00291     7.4989420933246e+01, 8.6596432336007e+01,
00292     1.0000000000000e+02, 1.1547819846895e+02,
00293     1.3335214321633e+02, 1.5399265260595e+02,
00294     1.7782794100389e+02, 2.0535250264571e+02,
00295     2.3713737056617e+02, 2.7384196342644e+02,
00296     3.1622776601684e+02, 3.6517412725484e+02,
00297     4.2169650342858e+02, 4.8696752516586e+02,
00298     5.6234132519035e+02, 6.4938163157621e+02,
00299     7.4989420933246e+02, 8.6596432336007e+02,
00300     1.0000000000000e+03, 1.1547819846895e+03,
00301     1.3335214321633e+03, 1.5399265260595e+03,
00302     1.7782794100389e+03, 2.0535250264571e+03,
00303     2.3713737056617e+03, 2.7384196342644e+03,
00304     3.1622776601684e+03, 3.6517412725484e+03,
00305     4.2169650342858e+03, 4.8696752516586e+03,
00306     5.6234132519035e+03, 6.4938163157621e+03,
00307     7.4989420933246e+03, 8.6596432336007e+03,
00308     1.0000000000000e+04, 1.1547819846895e+04,
00309     1.3335214321633e+04, 1.5399265260595e+04,
00310     1.7782794100389e+04, 2.0535250264571e+04,
00311     2.3713737056617e+04, 2.7384196342644e+04,
00312     3.1622776601684e+04, 3.6517412725484e+04,
00313     4.2169650342858e+04, 4.8696752516586e+04,
00314     5.6234132519035e+04, 6.4938163157621e+04,
00315     7.4989420933246e+04, 8.6596432336007e+04,
00316     1.0000000000000e+05, 1.1547819846895e+05,
00317     1.3335214321633e+05, 1.5399265260595e+05,
00318     1.7782794100389e+05, 2.0535250264571e+05,
00319     2.3713737056617e+05, 2.7384196342644e+05,
00320     3.1622776601684e+05, 3.6517412725484e+05,
00321     4.2169650342858e+05, 4.8696752516586e+05,
00322     5.6234132519035e+05, 6.4938163157621e+05,
00323     7.4989420933246e+05, 8.6596432336007e+05,
00324 };
00325 
00329 static int decode_exp_vlc(WMACodecContext *s, int ch)
00330 {
00331     int last_exp, n, code;
00332     const uint16_t *ptr;
00333     float v, max_scale;
00334     uint32_t *q, *q_end, iv;
00335     const float *ptab = pow_tab + 60;
00336     const uint32_t *iptab = (const uint32_t*)ptab;
00337 
00338     ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
00339     q = (uint32_t *)s->exponents[ch];
00340     q_end = q + s->block_len;
00341     max_scale = 0;
00342     if (s->version == 1) {
00343         last_exp = get_bits(&s->gb, 5) + 10;
00344         v = ptab[last_exp];
00345         iv = iptab[last_exp];
00346         max_scale = v;
00347         n = *ptr++;
00348         switch (n & 3) do {
00349         case 0: *q++ = iv;
00350         case 3: *q++ = iv;
00351         case 2: *q++ = iv;
00352         case 1: *q++ = iv;
00353         } while ((n -= 4) > 0);
00354     }else
00355         last_exp = 36;
00356 
00357     while (q < q_end) {
00358         code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);
00359         if (code < 0){
00360             av_log(s->avctx, AV_LOG_ERROR, "Exponent vlc invalid\n");
00361             return -1;
00362         }
00363         /* NOTE: this offset is the same as MPEG4 AAC ! */
00364         last_exp += code - 60;
00365         if ((unsigned)last_exp + 60 >= FF_ARRAY_ELEMS(pow_tab)) {
00366             av_log(s->avctx, AV_LOG_ERROR, "Exponent out of range: %d\n",
00367                    last_exp);
00368             return -1;
00369         }
00370         v = ptab[last_exp];
00371         iv = iptab[last_exp];
00372         if (v > max_scale)
00373             max_scale = v;
00374         n = *ptr++;
00375         switch (n & 3) do {
00376         case 0: *q++ = iv;
00377         case 3: *q++ = iv;
00378         case 2: *q++ = iv;
00379         case 1: *q++ = iv;
00380         } while ((n -= 4) > 0);
00381     }
00382     s->max_exponent[ch] = max_scale;
00383     return 0;
00384 }
00385 
00386 
00393 static void wma_window(WMACodecContext *s, float *out)
00394 {
00395     float *in = s->output;
00396     int block_len, bsize, n;
00397 
00398     /* left part */
00399     if (s->block_len_bits <= s->prev_block_len_bits) {
00400         block_len = s->block_len;
00401         bsize = s->frame_len_bits - s->block_len_bits;
00402 
00403         s->dsp.vector_fmul_add(out, in, s->windows[bsize],
00404                                out, block_len);
00405 
00406     } else {
00407         block_len = 1 << s->prev_block_len_bits;
00408         n = (s->block_len - block_len) / 2;
00409         bsize = s->frame_len_bits - s->prev_block_len_bits;
00410 
00411         s->dsp.vector_fmul_add(out+n, in+n, s->windows[bsize],
00412                                out+n, block_len);
00413 
00414         memcpy(out+n+block_len, in+n+block_len, n*sizeof(float));
00415     }
00416 
00417     out += s->block_len;
00418     in += s->block_len;
00419 
00420     /* right part */
00421     if (s->block_len_bits <= s->next_block_len_bits) {
00422         block_len = s->block_len;
00423         bsize = s->frame_len_bits - s->block_len_bits;
00424 
00425         s->dsp.vector_fmul_reverse(out, in, s->windows[bsize], block_len);
00426 
00427     } else {
00428         block_len = 1 << s->next_block_len_bits;
00429         n = (s->block_len - block_len) / 2;
00430         bsize = s->frame_len_bits - s->next_block_len_bits;
00431 
00432         memcpy(out, in, n*sizeof(float));
00433 
00434         s->dsp.vector_fmul_reverse(out+n, in+n, s->windows[bsize], block_len);
00435 
00436         memset(out+n+block_len, 0, n*sizeof(float));
00437     }
00438 }
00439 
00440 
00445 static int wma_decode_block(WMACodecContext *s)
00446 {
00447     int n, v, a, ch, bsize;
00448     int coef_nb_bits, total_gain;
00449     int nb_coefs[MAX_CHANNELS];
00450     float mdct_norm;
00451     FFTContext *mdct;
00452 
00453 #ifdef TRACE
00454     tprintf(s->avctx, "***decode_block: %d:%d\n", s->frame_count - 1, s->block_num);
00455 #endif
00456 
00457     /* compute current block length */
00458     if (s->use_variable_block_len) {
00459         n = av_log2(s->nb_block_sizes - 1) + 1;
00460 
00461         if (s->reset_block_lengths) {
00462             s->reset_block_lengths = 0;
00463             v = get_bits(&s->gb, n);
00464             if (v >= s->nb_block_sizes){
00465                 av_log(s->avctx, AV_LOG_ERROR, "prev_block_len_bits %d out of range\n", s->frame_len_bits - v);
00466                 return -1;
00467             }
00468             s->prev_block_len_bits = s->frame_len_bits - v;
00469             v = get_bits(&s->gb, n);
00470             if (v >= s->nb_block_sizes){
00471                 av_log(s->avctx, AV_LOG_ERROR, "block_len_bits %d out of range\n", s->frame_len_bits - v);
00472                 return -1;
00473             }
00474             s->block_len_bits = s->frame_len_bits - v;
00475         } else {
00476             /* update block lengths */
00477             s->prev_block_len_bits = s->block_len_bits;
00478             s->block_len_bits = s->next_block_len_bits;
00479         }
00480         v = get_bits(&s->gb, n);
00481         if (v >= s->nb_block_sizes){
00482             av_log(s->avctx, AV_LOG_ERROR, "next_block_len_bits %d out of range\n", s->frame_len_bits - v);
00483             return -1;
00484         }
00485         s->next_block_len_bits = s->frame_len_bits - v;
00486     } else {
00487         /* fixed block len */
00488         s->next_block_len_bits = s->frame_len_bits;
00489         s->prev_block_len_bits = s->frame_len_bits;
00490         s->block_len_bits = s->frame_len_bits;
00491     }
00492 
00493     /* now check if the block length is coherent with the frame length */
00494     s->block_len = 1 << s->block_len_bits;
00495     if ((s->block_pos + s->block_len) > s->frame_len){
00496         av_log(s->avctx, AV_LOG_ERROR, "frame_len overflow\n");
00497         return -1;
00498     }
00499 
00500     if (s->nb_channels == 2) {
00501         s->ms_stereo = get_bits1(&s->gb);
00502     }
00503     v = 0;
00504     for(ch = 0; ch < s->nb_channels; ch++) {
00505         a = get_bits1(&s->gb);
00506         s->channel_coded[ch] = a;
00507         v |= a;
00508     }
00509 
00510     bsize = s->frame_len_bits - s->block_len_bits;
00511 
00512     /* if no channel coded, no need to go further */
00513     /* XXX: fix potential framing problems */
00514     if (!v)
00515         goto next;
00516 
00517     /* read total gain and extract corresponding number of bits for
00518        coef escape coding */
00519     total_gain = 1;
00520     for(;;) {
00521         a = get_bits(&s->gb, 7);
00522         total_gain += a;
00523         if (a != 127)
00524             break;
00525     }
00526 
00527     coef_nb_bits= ff_wma_total_gain_to_bits(total_gain);
00528 
00529     /* compute number of coefficients */
00530     n = s->coefs_end[bsize] - s->coefs_start;
00531     for(ch = 0; ch < s->nb_channels; ch++)
00532         nb_coefs[ch] = n;
00533 
00534     /* complex coding */
00535     if (s->use_noise_coding) {
00536 
00537         for(ch = 0; ch < s->nb_channels; ch++) {
00538             if (s->channel_coded[ch]) {
00539                 int i, n, a;
00540                 n = s->exponent_high_sizes[bsize];
00541                 for(i=0;i<n;i++) {
00542                     a = get_bits1(&s->gb);
00543                     s->high_band_coded[ch][i] = a;
00544                     /* if noise coding, the coefficients are not transmitted */
00545                     if (a)
00546                         nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
00547                 }
00548             }
00549         }
00550         for(ch = 0; ch < s->nb_channels; ch++) {
00551             if (s->channel_coded[ch]) {
00552                 int i, n, val, code;
00553 
00554                 n = s->exponent_high_sizes[bsize];
00555                 val = (int)0x80000000;
00556                 for(i=0;i<n;i++) {
00557                     if (s->high_band_coded[ch][i]) {
00558                         if (val == (int)0x80000000) {
00559                             val = get_bits(&s->gb, 7) - 19;
00560                         } else {
00561                             code = get_vlc2(&s->gb, s->hgain_vlc.table, HGAINVLCBITS, HGAINMAX);
00562                             if (code < 0){
00563                                 av_log(s->avctx, AV_LOG_ERROR, "hgain vlc invalid\n");
00564                                 return -1;
00565                             }
00566                             val += code - 18;
00567                         }
00568                         s->high_band_values[ch][i] = val;
00569                     }
00570                 }
00571             }
00572         }
00573     }
00574 
00575     /* exponents can be reused in short blocks. */
00576     if ((s->block_len_bits == s->frame_len_bits) ||
00577         get_bits1(&s->gb)) {
00578         for(ch = 0; ch < s->nb_channels; ch++) {
00579             if (s->channel_coded[ch]) {
00580                 if (s->use_exp_vlc) {
00581                     if (decode_exp_vlc(s, ch) < 0)
00582                         return -1;
00583                 } else {
00584                     decode_exp_lsp(s, ch);
00585                 }
00586                 s->exponents_bsize[ch] = bsize;
00587             }
00588         }
00589     }
00590 
00591     /* parse spectral coefficients : just RLE encoding */
00592     for(ch = 0; ch < s->nb_channels; ch++) {
00593         if (s->channel_coded[ch]) {
00594             int tindex;
00595             WMACoef* ptr = &s->coefs1[ch][0];
00596 
00597             /* special VLC tables are used for ms stereo because
00598                there is potentially less energy there */
00599             tindex = (ch == 1 && s->ms_stereo);
00600             memset(ptr, 0, s->block_len * sizeof(WMACoef));
00601             ff_wma_run_level_decode(s->avctx, &s->gb, &s->coef_vlc[tindex],
00602                   s->level_table[tindex], s->run_table[tindex],
00603                   0, ptr, 0, nb_coefs[ch],
00604                   s->block_len, s->frame_len_bits, coef_nb_bits);
00605         }
00606         if (s->version == 1 && s->nb_channels >= 2) {
00607             align_get_bits(&s->gb);
00608         }
00609     }
00610 
00611     /* normalize */
00612     {
00613         int n4 = s->block_len / 2;
00614         mdct_norm = 1.0 / (float)n4;
00615         if (s->version == 1) {
00616             mdct_norm *= sqrt(n4);
00617         }
00618     }
00619 
00620     /* finally compute the MDCT coefficients */
00621     for(ch = 0; ch < s->nb_channels; ch++) {
00622         if (s->channel_coded[ch]) {
00623             WMACoef *coefs1;
00624             float *coefs, *exponents, mult, mult1, noise;
00625             int i, j, n, n1, last_high_band, esize;
00626             float exp_power[HIGH_BAND_MAX_SIZE];
00627 
00628             coefs1 = s->coefs1[ch];
00629             exponents = s->exponents[ch];
00630             esize = s->exponents_bsize[ch];
00631             mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
00632             mult *= mdct_norm;
00633             coefs = s->coefs[ch];
00634             if (s->use_noise_coding) {
00635                 mult1 = mult;
00636                 /* very low freqs : noise */
00637                 for(i = 0;i < s->coefs_start; i++) {
00638                     *coefs++ = s->noise_table[s->noise_index] *
00639                       exponents[i<<bsize>>esize] * mult1;
00640                     s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
00641                 }
00642 
00643                 n1 = s->exponent_high_sizes[bsize];
00644 
00645                 /* compute power of high bands */
00646                 exponents = s->exponents[ch] +
00647                     (s->high_band_start[bsize]<<bsize>>esize);
00648                 last_high_band = 0; /* avoid warning */
00649                 for(j=0;j<n1;j++) {
00650                     n = s->exponent_high_bands[s->frame_len_bits -
00651                                               s->block_len_bits][j];
00652                     if (s->high_band_coded[ch][j]) {
00653                         float e2, v;
00654                         e2 = 0;
00655                         for(i = 0;i < n; i++) {
00656                             v = exponents[i<<bsize>>esize];
00657                             e2 += v * v;
00658                         }
00659                         exp_power[j] = e2 / n;
00660                         last_high_band = j;
00661                         tprintf(s->avctx, "%d: power=%f (%d)\n", j, exp_power[j], n);
00662                     }
00663                     exponents += n<<bsize>>esize;
00664                 }
00665 
00666                 /* main freqs and high freqs */
00667                 exponents = s->exponents[ch] + (s->coefs_start<<bsize>>esize);
00668                 for(j=-1;j<n1;j++) {
00669                     if (j < 0) {
00670                         n = s->high_band_start[bsize] -
00671                             s->coefs_start;
00672                     } else {
00673                         n = s->exponent_high_bands[s->frame_len_bits -
00674                                                   s->block_len_bits][j];
00675                     }
00676                     if (j >= 0 && s->high_band_coded[ch][j]) {
00677                         /* use noise with specified power */
00678                         mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);
00679                         /* XXX: use a table */
00680                         mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);
00681                         mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);
00682                         mult1 *= mdct_norm;
00683                         for(i = 0;i < n; i++) {
00684                             noise = s->noise_table[s->noise_index];
00685                             s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
00686                             *coefs++ =  noise *
00687                                 exponents[i<<bsize>>esize] * mult1;
00688                         }
00689                         exponents += n<<bsize>>esize;
00690                     } else {
00691                         /* coded values + small noise */
00692                         for(i = 0;i < n; i++) {
00693                             noise = s->noise_table[s->noise_index];
00694                             s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
00695                             *coefs++ = ((*coefs1++) + noise) *
00696                                 exponents[i<<bsize>>esize] * mult;
00697                         }
00698                         exponents += n<<bsize>>esize;
00699                     }
00700                 }
00701 
00702                 /* very high freqs : noise */
00703                 n = s->block_len - s->coefs_end[bsize];
00704                 mult1 = mult * exponents[((-1<<bsize))>>esize];
00705                 for(i = 0; i < n; i++) {
00706                     *coefs++ = s->noise_table[s->noise_index] * mult1;
00707                     s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
00708                 }
00709             } else {
00710                 /* XXX: optimize more */
00711                 for(i = 0;i < s->coefs_start; i++)
00712                     *coefs++ = 0.0;
00713                 n = nb_coefs[ch];
00714                 for(i = 0;i < n; i++) {
00715                     *coefs++ = coefs1[i] * exponents[i<<bsize>>esize] * mult;
00716                 }
00717                 n = s->block_len - s->coefs_end[bsize];
00718                 for(i = 0;i < n; i++)
00719                     *coefs++ = 0.0;
00720             }
00721         }
00722     }
00723 
00724 #ifdef TRACE
00725     for(ch = 0; ch < s->nb_channels; ch++) {
00726         if (s->channel_coded[ch]) {
00727             dump_floats(s, "exponents", 3, s->exponents[ch], s->block_len);
00728             dump_floats(s, "coefs", 1, s->coefs[ch], s->block_len);
00729         }
00730     }
00731 #endif
00732 
00733     if (s->ms_stereo && s->channel_coded[1]) {
00734         /* nominal case for ms stereo: we do it before mdct */
00735         /* no need to optimize this case because it should almost
00736            never happen */
00737         if (!s->channel_coded[0]) {
00738             tprintf(s->avctx, "rare ms-stereo case happened\n");
00739             memset(s->coefs[0], 0, sizeof(float) * s->block_len);
00740             s->channel_coded[0] = 1;
00741         }
00742 
00743         s->dsp.butterflies_float(s->coefs[0], s->coefs[1], s->block_len);
00744     }
00745 
00746 next:
00747     mdct = &s->mdct_ctx[bsize];
00748 
00749     for(ch = 0; ch < s->nb_channels; ch++) {
00750         int n4, index;
00751 
00752         n4 = s->block_len / 2;
00753         if(s->channel_coded[ch]){
00754             mdct->imdct_calc(mdct, s->output, s->coefs[ch]);
00755         }else if(!(s->ms_stereo && ch==1))
00756             memset(s->output, 0, sizeof(s->output));
00757 
00758         /* multiply by the window and add in the frame */
00759         index = (s->frame_len / 2) + s->block_pos - n4;
00760         wma_window(s, &s->frame_out[ch][index]);
00761     }
00762 
00763     /* update block number */
00764     s->block_num++;
00765     s->block_pos += s->block_len;
00766     if (s->block_pos >= s->frame_len)
00767         return 1;
00768     else
00769         return 0;
00770 }
00771 
00772 /* decode a frame of frame_len samples */
00773 static int wma_decode_frame(WMACodecContext *s, int16_t *samples)
00774 {
00775     int ret, n, ch, incr;
00776     const float *output[MAX_CHANNELS];
00777 
00778 #ifdef TRACE
00779     tprintf(s->avctx, "***decode_frame: %d size=%d\n", s->frame_count++, s->frame_len);
00780 #endif
00781 
00782     /* read each block */
00783     s->block_num = 0;
00784     s->block_pos = 0;
00785     for(;;) {
00786         ret = wma_decode_block(s);
00787         if (ret < 0)
00788             return -1;
00789         if (ret)
00790             break;
00791     }
00792 
00793     /* convert frame to integer */
00794     n = s->frame_len;
00795     incr = s->nb_channels;
00796     for (ch = 0; ch < MAX_CHANNELS; ch++)
00797         output[ch] = s->frame_out[ch];
00798     s->fmt_conv.float_to_int16_interleave(samples, output, n, incr);
00799     for (ch = 0; ch < incr; ch++) {
00800         /* prepare for next block */
00801         memmove(&s->frame_out[ch][0], &s->frame_out[ch][n], n * sizeof(float));
00802     }
00803 
00804 #ifdef TRACE
00805     dump_shorts(s, "samples", samples, n * s->nb_channels);
00806 #endif
00807     return 0;
00808 }
00809 
00810 static int wma_decode_superframe(AVCodecContext *avctx, void *data,
00811                                  int *got_frame_ptr, AVPacket *avpkt)
00812 {
00813     const uint8_t *buf = avpkt->data;
00814     int buf_size = avpkt->size;
00815     WMACodecContext *s = avctx->priv_data;
00816     int nb_frames, bit_offset, i, pos, len, ret;
00817     uint8_t *q;
00818     int16_t *samples;
00819 
00820     tprintf(avctx, "***decode_superframe:\n");
00821 
00822     if(buf_size==0){
00823         s->last_superframe_len = 0;
00824         return 0;
00825     }
00826     if (buf_size < s->block_align) {
00827         av_log(avctx, AV_LOG_ERROR,
00828                "Input packet size too small (%d < %d)\n",
00829                buf_size, s->block_align);
00830         return AVERROR_INVALIDDATA;
00831     }
00832     buf_size = s->block_align;
00833 
00834     init_get_bits(&s->gb, buf, buf_size*8);
00835 
00836     if (s->use_bit_reservoir) {
00837         /* read super frame header */
00838         skip_bits(&s->gb, 4); /* super frame index */
00839         nb_frames = get_bits(&s->gb, 4) - (s->last_superframe_len <= 0);
00840     } else {
00841         nb_frames = 1;
00842     }
00843 
00844     /* get output buffer */
00845     s->frame.nb_samples = nb_frames * s->frame_len;
00846     if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) {
00847         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00848         return ret;
00849     }
00850     samples = (int16_t *)s->frame.data[0];
00851 
00852     if (s->use_bit_reservoir) {
00853         bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
00854         if (bit_offset > get_bits_left(&s->gb)) {
00855             av_log(avctx, AV_LOG_ERROR,
00856                    "Invalid last frame bit offset %d > buf size %d (%d)\n",
00857                    bit_offset, get_bits_left(&s->gb), buf_size);
00858             goto fail;
00859         }
00860 
00861         if (s->last_superframe_len > 0) {
00862             //        printf("skip=%d\n", s->last_bitoffset);
00863             /* add bit_offset bits to last frame */
00864             if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
00865                 MAX_CODED_SUPERFRAME_SIZE)
00866                 goto fail;
00867             q = s->last_superframe + s->last_superframe_len;
00868             len = bit_offset;
00869             while (len > 7) {
00870                 *q++ = (get_bits)(&s->gb, 8);
00871                 len -= 8;
00872             }
00873             if (len > 0) {
00874                 *q++ = (get_bits)(&s->gb, len) << (8 - len);
00875             }
00876             memset(q, 0, FF_INPUT_BUFFER_PADDING_SIZE);
00877 
00878             /* XXX: bit_offset bits into last frame */
00879             init_get_bits(&s->gb, s->last_superframe, s->last_superframe_len * 8 + bit_offset);
00880             /* skip unused bits */
00881             if (s->last_bitoffset > 0)
00882                 skip_bits(&s->gb, s->last_bitoffset);
00883             /* this frame is stored in the last superframe and in the
00884                current one */
00885             if (wma_decode_frame(s, samples) < 0)
00886                 goto fail;
00887             samples += s->nb_channels * s->frame_len;
00888             nb_frames--;
00889         }
00890 
00891         /* read each frame starting from bit_offset */
00892         pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
00893         if (pos >= MAX_CODED_SUPERFRAME_SIZE * 8 || pos > buf_size * 8)
00894             return AVERROR_INVALIDDATA;
00895         init_get_bits(&s->gb, buf + (pos >> 3), (buf_size - (pos >> 3))*8);
00896         len = pos & 7;
00897         if (len > 0)
00898             skip_bits(&s->gb, len);
00899 
00900         s->reset_block_lengths = 1;
00901         for(i=0;i<nb_frames;i++) {
00902             if (wma_decode_frame(s, samples) < 0)
00903                 goto fail;
00904             samples += s->nb_channels * s->frame_len;
00905         }
00906 
00907         /* we copy the end of the frame in the last frame buffer */
00908         pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
00909         s->last_bitoffset = pos & 7;
00910         pos >>= 3;
00911         len = buf_size - pos;
00912         if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
00913             av_log(s->avctx, AV_LOG_ERROR, "len %d invalid\n", len);
00914             goto fail;
00915         }
00916         s->last_superframe_len = len;
00917         memcpy(s->last_superframe, buf + pos, len);
00918     } else {
00919         /* single frame decode */
00920         if (wma_decode_frame(s, samples) < 0)
00921             goto fail;
00922         samples += s->nb_channels * s->frame_len;
00923     }
00924 
00925 //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);
00926 
00927     *got_frame_ptr   = 1;
00928     *(AVFrame *)data = s->frame;
00929 
00930     return s->block_align;
00931  fail:
00932     /* when error, we reset the bit reservoir */
00933     s->last_superframe_len = 0;
00934     return -1;
00935 }
00936 
00937 static av_cold void flush(AVCodecContext *avctx)
00938 {
00939     WMACodecContext *s = avctx->priv_data;
00940 
00941     s->last_bitoffset=
00942     s->last_superframe_len= 0;
00943 }
00944 
00945 AVCodec ff_wmav1_decoder = {
00946     .name           = "wmav1",
00947     .type           = AVMEDIA_TYPE_AUDIO,
00948     .id             = CODEC_ID_WMAV1,
00949     .priv_data_size = sizeof(WMACodecContext),
00950     .init           = wma_decode_init,
00951     .close          = ff_wma_end,
00952     .decode         = wma_decode_superframe,
00953     .flush          = flush,
00954     .capabilities   = CODEC_CAP_DR1,
00955     .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Audio 1"),
00956 };
00957 
00958 AVCodec ff_wmav2_decoder = {
00959     .name           = "wmav2",
00960     .type           = AVMEDIA_TYPE_AUDIO,
00961     .id             = CODEC_ID_WMAV2,
00962     .priv_data_size = sizeof(WMACodecContext),
00963     .init           = wma_decode_init,
00964     .close          = ff_wma_end,
00965     .decode         = wma_decode_superframe,
00966     .flush          = flush,
00967     .capabilities   = CODEC_CAP_DR1,
00968     .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Audio 2"),
00969 };