FFmpeg: libavcodec/wmadec.c Source File

00001 /*
00002  * WMA compatible decoder
00003  * Copyright (c) 2002 The FFmpeg Project
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
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(avctx->codec->id == CODEC_ID_WMAV2 && avctx->extradata_size >= 8){
00106         if(AV_RL16(extradata+4)==0xd && s->use_variable_block_len){
00107             av_log(avctx, AV_LOG_WARNING, "Disabling use_variable_block_len, if this fails contact the ffmpeg developers and send us the file\n");
00108             s->use_variable_block_len= 0; // this fixes issue1503
00109         }
00110     }
00111 
00112     if(avctx->channels > MAX_CHANNELS){
00113         av_log(avctx, AV_LOG_ERROR, "Invalid number of channels (%d)\n", avctx->channels);
00114         return -1;
00115     }
00116 
00117     if(ff_wma_init(avctx, flags2)<0)
00118         return -1;
00119 
00120     /* init MDCT */
00121     for(i = 0; i < s->nb_block_sizes; i++)
00122         ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1, 1.0);
00123 
00124     if (s->use_noise_coding) {
00125         init_vlc(&s->hgain_vlc, HGAINVLCBITS, sizeof(ff_wma_hgain_huffbits),
00126                  ff_wma_hgain_huffbits, 1, 1,
00127                  ff_wma_hgain_huffcodes, 2, 2, 0);
00128     }
00129 
00130     if (s->use_exp_vlc) {
00131         init_vlc(&s->exp_vlc, EXPVLCBITS, sizeof(ff_aac_scalefactor_bits), //FIXME move out of context
00132                  ff_aac_scalefactor_bits, 1, 1,
00133                  ff_aac_scalefactor_code, 4, 4, 0);
00134     } else {
00135         wma_lsp_to_curve_init(s, s->frame_len);
00136     }
00137 
00138     avctx->sample_fmt = AV_SAMPLE_FMT_S16;
00139 
00140     avcodec_get_frame_defaults(&s->frame);
00141     avctx->coded_frame = &s->frame;
00142 
00143     return 0;
00144 }
00145 
00152 static inline float pow_m1_4(WMACodecContext *s, float x)
00153 {
00154     union {
00155         float f;
00156         unsigned int v;
00157     } u, t;
00158     unsigned int e, m;
00159     float a, b;
00160 
00161     u.f = x;
00162     e = u.v >> 23;
00163     m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
00164     /* build interpolation scale: 1 <= t < 2. */
00165     t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
00166     a = s->lsp_pow_m_table1[m];
00167     b = s->lsp_pow_m_table2[m];
00168     return s->lsp_pow_e_table[e] * (a + b * t.f);
00169 }
00170 
00171 static void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len)
00172 {
00173     float wdel, a, b;
00174     int i, e, m;
00175 
00176     wdel = M_PI / frame_len;
00177     for(i=0;i<frame_len;i++)
00178         s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
00179 
00180     /* tables for x^-0.25 computation */
00181     for(i=0;i<256;i++) {
00182         e = i - 126;
00183         s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
00184     }
00185 
00186     /* NOTE: these two tables are needed to avoid two operations in
00187        pow_m1_4 */
00188     b = 1.0;
00189     for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) {
00190         m = (1 << LSP_POW_BITS) + i;
00191         a = (float)m * (0.5 / (1 << LSP_POW_BITS));
00192         a = pow(a, -0.25);
00193         s->lsp_pow_m_table1[i] = 2 * a - b;
00194         s->lsp_pow_m_table2[i] = b - a;
00195         b = a;
00196     }
00197 }
00198 
00203 static void wma_lsp_to_curve(WMACodecContext *s,
00204                              float *out, float *val_max_ptr,
00205                              int n, float *lsp)
00206 {
00207     int i, j;
00208     float p, q, w, v, val_max;
00209 
00210     val_max = 0;
00211     for(i=0;i<n;i++) {
00212         p = 0.5f;
00213         q = 0.5f;
00214         w = s->lsp_cos_table[i];
00215         for(j=1;j<NB_LSP_COEFS;j+=2){
00216             q *= w - lsp[j - 1];
00217             p *= w - lsp[j];
00218         }
00219         p *= p * (2.0f - w);
00220         q *= q * (2.0f + w);
00221         v = p + q;
00222         v = pow_m1_4(s, v);
00223         if (v > val_max)
00224             val_max = v;
00225         out[i] = v;
00226     }
00227     *val_max_ptr = val_max;
00228 }
00229 
00233 static void decode_exp_lsp(WMACodecContext *s, int ch)
00234 {
00235     float lsp_coefs[NB_LSP_COEFS];
00236     int val, i;
00237 
00238     for(i = 0; i < NB_LSP_COEFS; i++) {
00239         if (i == 0 || i >= 8)
00240             val = get_bits(&s->gb, 3);
00241         else
00242             val = get_bits(&s->gb, 4);
00243         lsp_coefs[i] = ff_wma_lsp_codebook[i][val];
00244     }
00245 
00246     wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
00247                      s->block_len, lsp_coefs);
00248 }
00249 
00251 static const float pow_tab[] = {
00252     1.7782794100389e-04, 2.0535250264571e-04,
00253     2.3713737056617e-04, 2.7384196342644e-04,
00254     3.1622776601684e-04, 3.6517412725484e-04,
00255     4.2169650342858e-04, 4.8696752516586e-04,
00256     5.6234132519035e-04, 6.4938163157621e-04,
00257     7.4989420933246e-04, 8.6596432336006e-04,
00258     1.0000000000000e-03, 1.1547819846895e-03,
00259     1.3335214321633e-03, 1.5399265260595e-03,
00260     1.7782794100389e-03, 2.0535250264571e-03,
00261     2.3713737056617e-03, 2.7384196342644e-03,
00262     3.1622776601684e-03, 3.6517412725484e-03,
00263     4.2169650342858e-03, 4.8696752516586e-03,
00264     5.6234132519035e-03, 6.4938163157621e-03,
00265     7.4989420933246e-03, 8.6596432336006e-03,
00266     1.0000000000000e-02, 1.1547819846895e-02,
00267     1.3335214321633e-02, 1.5399265260595e-02,
00268     1.7782794100389e-02, 2.0535250264571e-02,
00269     2.3713737056617e-02, 2.7384196342644e-02,
00270     3.1622776601684e-02, 3.6517412725484e-02,
00271     4.2169650342858e-02, 4.8696752516586e-02,
00272     5.6234132519035e-02, 6.4938163157621e-02,
00273     7.4989420933246e-02, 8.6596432336007e-02,
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+00, 1.1547819846895e+00,
00283     1.3335214321633e+00, 1.5399265260595e+00,
00284     1.7782794100389e+00, 2.0535250264571e+00,
00285     2.3713737056617e+00, 2.7384196342644e+00,
00286     3.1622776601684e+00, 3.6517412725484e+00,
00287     4.2169650342858e+00, 4.8696752516586e+00,
00288     5.6234132519035e+00, 6.4938163157621e+00,
00289     7.4989420933246e+00, 8.6596432336007e+00,
00290     1.0000000000000e+01, 1.1547819846895e+01,
00291     1.3335214321633e+01, 1.5399265260595e+01,
00292     1.7782794100389e+01, 2.0535250264571e+01,
00293     2.3713737056617e+01, 2.7384196342644e+01,
00294     3.1622776601684e+01, 3.6517412725484e+01,
00295     4.2169650342858e+01, 4.8696752516586e+01,
00296     5.6234132519035e+01, 6.4938163157621e+01,
00297     7.4989420933246e+01, 8.6596432336007e+01,
00298     1.0000000000000e+02, 1.1547819846895e+02,
00299     1.3335214321633e+02, 1.5399265260595e+02,
00300     1.7782794100389e+02, 2.0535250264571e+02,
00301     2.3713737056617e+02, 2.7384196342644e+02,
00302     3.1622776601684e+02, 3.6517412725484e+02,
00303     4.2169650342858e+02, 4.8696752516586e+02,
00304     5.6234132519035e+02, 6.4938163157621e+02,
00305     7.4989420933246e+02, 8.6596432336007e+02,
00306     1.0000000000000e+03, 1.1547819846895e+03,
00307     1.3335214321633e+03, 1.5399265260595e+03,
00308     1.7782794100389e+03, 2.0535250264571e+03,
00309     2.3713737056617e+03, 2.7384196342644e+03,
00310     3.1622776601684e+03, 3.6517412725484e+03,
00311     4.2169650342858e+03, 4.8696752516586e+03,
00312     5.6234132519035e+03, 6.4938163157621e+03,
00313     7.4989420933246e+03, 8.6596432336007e+03,
00314     1.0000000000000e+04, 1.1547819846895e+04,
00315     1.3335214321633e+04, 1.5399265260595e+04,
00316     1.7782794100389e+04, 2.0535250264571e+04,
00317     2.3713737056617e+04, 2.7384196342644e+04,
00318     3.1622776601684e+04, 3.6517412725484e+04,
00319     4.2169650342858e+04, 4.8696752516586e+04,
00320     5.6234132519035e+04, 6.4938163157621e+04,
00321     7.4989420933246e+04, 8.6596432336007e+04,
00322     1.0000000000000e+05, 1.1547819846895e+05,
00323     1.3335214321633e+05, 1.5399265260595e+05,
00324     1.7782794100389e+05, 2.0535250264571e+05,
00325     2.3713737056617e+05, 2.7384196342644e+05,
00326     3.1622776601684e+05, 3.6517412725484e+05,
00327     4.2169650342858e+05, 4.8696752516586e+05,
00328     5.6234132519035e+05, 6.4938163157621e+05,
00329     7.4989420933246e+05, 8.6596432336007e+05,
00330 };
00331 
00335 static int decode_exp_vlc(WMACodecContext *s, int ch)
00336 {
00337     int last_exp, n, code;
00338     const uint16_t *ptr;
00339     float v, max_scale;
00340     uint32_t *q, *q_end, iv;
00341     const float *ptab = pow_tab + 60;
00342     const uint32_t *iptab = (const uint32_t*)ptab;
00343 
00344     ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
00345     q = (uint32_t *)s->exponents[ch];
00346     q_end = q + s->block_len;
00347     max_scale = 0;
00348     if (s->version == 1) {
00349         last_exp = get_bits(&s->gb, 5) + 10;
00350         v = ptab[last_exp];
00351         iv = iptab[last_exp];
00352         max_scale = v;
00353         n = *ptr++;
00354         switch (n & 3) do {
00355         case 0: *q++ = iv;
00356         case 3: *q++ = iv;
00357         case 2: *q++ = iv;
00358         case 1: *q++ = iv;
00359         } while ((n -= 4) > 0);
00360     }else
00361         last_exp = 36;
00362 
00363     while (q < q_end) {
00364         code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);
00365         if (code < 0){
00366             av_log(s->avctx, AV_LOG_ERROR, "Exponent vlc invalid\n");
00367             return -1;
00368         }
00369         /* NOTE: this offset is the same as MPEG4 AAC ! */
00370         last_exp += code - 60;
00371         if ((unsigned)last_exp + 60 >= FF_ARRAY_ELEMS(pow_tab)) {
00372             av_log(s->avctx, AV_LOG_ERROR, "Exponent out of range: %d\n",
00373                    last_exp);
00374             return -1;
00375         }
00376         v = ptab[last_exp];
00377         iv = iptab[last_exp];
00378         if (v > max_scale)
00379             max_scale = v;
00380         n = *ptr++;
00381         switch (n & 3) do {
00382         case 0: *q++ = iv;
00383         case 3: *q++ = iv;
00384         case 2: *q++ = iv;
00385         case 1: *q++ = iv;
00386         } while ((n -= 4) > 0);
00387     }
00388     s->max_exponent[ch] = max_scale;
00389     return 0;
00390 }
00391 
00392 
00399 static void wma_window(WMACodecContext *s, float *out)
00400 {
00401     float *in = s->output;
00402     int block_len, bsize, n;
00403 
00404     /* left part */
00405     if (s->block_len_bits <= s->prev_block_len_bits) {
00406         block_len = s->block_len;
00407         bsize = s->frame_len_bits - s->block_len_bits;
00408 
00409         s->dsp.vector_fmul_add(out, in, s->windows[bsize],
00410                                out, block_len);
00411 
00412     } else {
00413         block_len = 1 << s->prev_block_len_bits;
00414         n = (s->block_len - block_len) / 2;
00415         bsize = s->frame_len_bits - s->prev_block_len_bits;
00416 
00417         s->dsp.vector_fmul_add(out+n, in+n, s->windows[bsize],
00418                                out+n, block_len);
00419 
00420         memcpy(out+n+block_len, in+n+block_len, n*sizeof(float));
00421     }
00422 
00423     out += s->block_len;
00424     in += s->block_len;
00425 
00426     /* right part */
00427     if (s->block_len_bits <= s->next_block_len_bits) {
00428         block_len = s->block_len;
00429         bsize = s->frame_len_bits - s->block_len_bits;
00430 
00431         s->dsp.vector_fmul_reverse(out, in, s->windows[bsize], block_len);
00432 
00433     } else {
00434         block_len = 1 << s->next_block_len_bits;
00435         n = (s->block_len - block_len) / 2;
00436         bsize = s->frame_len_bits - s->next_block_len_bits;
00437 
00438         memcpy(out, in, n*sizeof(float));
00439 
00440         s->dsp.vector_fmul_reverse(out+n, in+n, s->windows[bsize], block_len);
00441 
00442         memset(out+n+block_len, 0, n*sizeof(float));
00443     }
00444 }
00445 
00446 
00451 static int wma_decode_block(WMACodecContext *s)
00452 {
00453     int n, v, a, ch, bsize;
00454     int coef_nb_bits, total_gain;
00455     int nb_coefs[MAX_CHANNELS];
00456     float mdct_norm;
00457     FFTContext *mdct;
00458 
00459 #ifdef TRACE
00460     tprintf(s->avctx, "***decode_block: %d:%d\n", s->frame_count - 1, s->block_num);
00461 #endif
00462 
00463     /* compute current block length */
00464     if (s->use_variable_block_len) {
00465         n = av_log2(s->nb_block_sizes - 1) + 1;
00466 
00467         if (s->reset_block_lengths) {
00468             s->reset_block_lengths = 0;
00469             v = get_bits(&s->gb, n);
00470             if (v >= s->nb_block_sizes){
00471                 av_log(s->avctx, AV_LOG_ERROR, "prev_block_len_bits %d out of range\n", s->frame_len_bits - v);
00472                 return -1;
00473             }
00474             s->prev_block_len_bits = s->frame_len_bits - v;
00475             v = get_bits(&s->gb, n);
00476             if (v >= s->nb_block_sizes){
00477                 av_log(s->avctx, AV_LOG_ERROR, "block_len_bits %d out of range\n", s->frame_len_bits - v);
00478                 return -1;
00479             }
00480             s->block_len_bits = s->frame_len_bits - v;
00481         } else {
00482             /* update block lengths */
00483             s->prev_block_len_bits = s->block_len_bits;
00484             s->block_len_bits = s->next_block_len_bits;
00485         }
00486         v = get_bits(&s->gb, n);
00487         if (v >= s->nb_block_sizes){
00488             av_log(s->avctx, AV_LOG_ERROR, "next_block_len_bits %d out of range\n", s->frame_len_bits - v);
00489             return -1;
00490         }
00491         s->next_block_len_bits = s->frame_len_bits - v;
00492     } else {
00493         /* fixed block len */
00494         s->next_block_len_bits = s->frame_len_bits;
00495         s->prev_block_len_bits = s->frame_len_bits;
00496         s->block_len_bits = s->frame_len_bits;
00497     }
00498 
00499     if (s->frame_len_bits - s->block_len_bits >= s->nb_block_sizes){
00500         av_log(s->avctx, AV_LOG_ERROR, "block_len_bits not initialized to a valid value\n");
00501         return -1;
00502     }
00503 
00504     /* now check if the block length is coherent with the frame length */
00505     s->block_len = 1 << s->block_len_bits;
00506     if ((s->block_pos + s->block_len) > s->frame_len){
00507         av_log(s->avctx, AV_LOG_ERROR, "frame_len overflow\n");
00508         return -1;
00509     }
00510 
00511     if (s->nb_channels == 2) {
00512         s->ms_stereo = get_bits1(&s->gb);
00513     }
00514     v = 0;
00515     for(ch = 0; ch < s->nb_channels; ch++) {
00516         a = get_bits1(&s->gb);
00517         s->channel_coded[ch] = a;
00518         v |= a;
00519     }
00520 
00521     bsize = s->frame_len_bits - s->block_len_bits;
00522 
00523     /* if no channel coded, no need to go further */
00524     /* XXX: fix potential framing problems */
00525     if (!v)
00526         goto next;
00527 
00528     /* read total gain and extract corresponding number of bits for
00529        coef escape coding */
00530     total_gain = 1;
00531     for(;;) {
00532         a = get_bits(&s->gb, 7);
00533         total_gain += a;
00534         if (a != 127)
00535             break;
00536     }
00537 
00538     coef_nb_bits= ff_wma_total_gain_to_bits(total_gain);
00539 
00540     /* compute number of coefficients */
00541     n = s->coefs_end[bsize] - s->coefs_start;
00542     for(ch = 0; ch < s->nb_channels; ch++)
00543         nb_coefs[ch] = n;
00544 
00545     /* complex coding */
00546     if (s->use_noise_coding) {
00547 
00548         for(ch = 0; ch < s->nb_channels; ch++) {
00549             if (s->channel_coded[ch]) {
00550                 int i, n, a;
00551                 n = s->exponent_high_sizes[bsize];
00552                 for(i=0;i<n;i++) {
00553                     a = get_bits1(&s->gb);
00554                     s->high_band_coded[ch][i] = a;
00555                     /* if noise coding, the coefficients are not transmitted */
00556                     if (a)
00557                         nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
00558                 }
00559             }
00560         }
00561         for(ch = 0; ch < s->nb_channels; ch++) {
00562             if (s->channel_coded[ch]) {
00563                 int i, n, val, code;
00564 
00565                 n = s->exponent_high_sizes[bsize];
00566                 val = (int)0x80000000;
00567                 for(i=0;i<n;i++) {
00568                     if (s->high_band_coded[ch][i]) {
00569                         if (val == (int)0x80000000) {
00570                             val = get_bits(&s->gb, 7) - 19;
00571                         } else {
00572                             code = get_vlc2(&s->gb, s->hgain_vlc.table, HGAINVLCBITS, HGAINMAX);
00573                             if (code < 0){
00574                                 av_log(s->avctx, AV_LOG_ERROR, "hgain vlc invalid\n");
00575                                 return -1;
00576                             }
00577                             val += code - 18;
00578                         }
00579                         s->high_band_values[ch][i] = val;
00580                     }
00581                 }
00582             }
00583         }
00584     }
00585 
00586     /* exponents can be reused in short blocks. */
00587     if ((s->block_len_bits == s->frame_len_bits) ||
00588         get_bits1(&s->gb)) {
00589         for(ch = 0; ch < s->nb_channels; ch++) {
00590             if (s->channel_coded[ch]) {
00591                 if (s->use_exp_vlc) {
00592                     if (decode_exp_vlc(s, ch) < 0)
00593                         return -1;
00594                 } else {
00595                     decode_exp_lsp(s, ch);
00596                 }
00597                 s->exponents_bsize[ch] = bsize;
00598             }
00599         }
00600     }
00601 
00602     /* parse spectral coefficients : just RLE encoding */
00603     for(ch = 0; ch < s->nb_channels; ch++) {
00604         if (s->channel_coded[ch]) {
00605             int tindex;
00606             WMACoef* ptr = &s->coefs1[ch][0];
00607 
00608             /* special VLC tables are used for ms stereo because
00609                there is potentially less energy there */
00610             tindex = (ch == 1 && s->ms_stereo);
00611             memset(ptr, 0, s->block_len * sizeof(WMACoef));
00612             ff_wma_run_level_decode(s->avctx, &s->gb, &s->coef_vlc[tindex],
00613                   s->level_table[tindex], s->run_table[tindex],
00614                   0, ptr, 0, nb_coefs[ch],
00615                   s->block_len, s->frame_len_bits, coef_nb_bits);
00616         }
00617         if (s->version == 1 && s->nb_channels >= 2) {
00618             align_get_bits(&s->gb);
00619         }
00620     }
00621 
00622     /* normalize */
00623     {
00624         int n4 = s->block_len / 2;
00625         mdct_norm = 1.0 / (float)n4;
00626         if (s->version == 1) {
00627             mdct_norm *= sqrt(n4);
00628         }
00629     }
00630 
00631     /* finally compute the MDCT coefficients */
00632     for(ch = 0; ch < s->nb_channels; ch++) {
00633         if (s->channel_coded[ch]) {
00634             WMACoef *coefs1;
00635             float *coefs, *exponents, mult, mult1, noise;
00636             int i, j, n, n1, last_high_band, esize;
00637             float exp_power[HIGH_BAND_MAX_SIZE];
00638 
00639             coefs1 = s->coefs1[ch];
00640             exponents = s->exponents[ch];
00641             esize = s->exponents_bsize[ch];
00642             mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
00643             mult *= mdct_norm;
00644             coefs = s->coefs[ch];
00645             if (s->use_noise_coding) {
00646                 mult1 = mult;
00647                 /* very low freqs : noise */
00648                 for(i = 0;i < s->coefs_start; i++) {
00649                     *coefs++ = s->noise_table[s->noise_index] *
00650                       exponents[i<<bsize>>esize] * mult1;
00651                     s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
00652                 }
00653 
00654                 n1 = s->exponent_high_sizes[bsize];
00655 
00656                 /* compute power of high bands */
00657                 exponents = s->exponents[ch] +
00658                     (s->high_band_start[bsize]<<bsize>>esize);
00659                 last_high_band = 0; /* avoid warning */
00660                 for(j=0;j<n1;j++) {
00661                     n = s->exponent_high_bands[s->frame_len_bits -
00662                                               s->block_len_bits][j];
00663                     if (s->high_band_coded[ch][j]) {
00664                         float e2, v;
00665                         e2 = 0;
00666                         for(i = 0;i < n; i++) {
00667                             v = exponents[i<<bsize>>esize];
00668                             e2 += v * v;
00669                         }
00670                         exp_power[j] = e2 / n;
00671                         last_high_band = j;
00672                         tprintf(s->avctx, "%d: power=%f (%d)\n", j, exp_power[j], n);
00673                     }
00674                     exponents += n<<bsize>>esize;
00675                 }
00676 
00677                 /* main freqs and high freqs */
00678                 exponents = s->exponents[ch] + (s->coefs_start<<bsize>>esize);
00679                 for(j=-1;j<n1;j++) {
00680                     if (j < 0) {
00681                         n = s->high_band_start[bsize] -
00682                             s->coefs_start;
00683                     } else {
00684                         n = s->exponent_high_bands[s->frame_len_bits -
00685                                                   s->block_len_bits][j];
00686                     }
00687                     if (j >= 0 && s->high_band_coded[ch][j]) {
00688                         /* use noise with specified power */
00689                         mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);
00690                         /* XXX: use a table */
00691                         mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);
00692                         mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);
00693                         mult1 *= mdct_norm;
00694                         for(i = 0;i < n; i++) {
00695                             noise = s->noise_table[s->noise_index];
00696                             s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
00697                             *coefs++ =  noise *
00698                                 exponents[i<<bsize>>esize] * mult1;
00699                         }
00700                         exponents += n<<bsize>>esize;
00701                     } else {
00702                         /* coded values + small noise */
00703                         for(i = 0;i < n; i++) {
00704                             noise = s->noise_table[s->noise_index];
00705                             s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
00706                             *coefs++ = ((*coefs1++) + noise) *
00707                                 exponents[i<<bsize>>esize] * mult;
00708                         }
00709                         exponents += n<<bsize>>esize;
00710                     }
00711                 }
00712 
00713                 /* very high freqs : noise */
00714                 n = s->block_len - s->coefs_end[bsize];
00715                 mult1 = mult * exponents[((-1<<bsize))>>esize];
00716                 for(i = 0; i < n; i++) {
00717                     *coefs++ = s->noise_table[s->noise_index] * mult1;
00718                     s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
00719                 }
00720             } else {
00721                 /* XXX: optimize more */
00722                 for(i = 0;i < s->coefs_start; i++)
00723                     *coefs++ = 0.0;
00724                 n = nb_coefs[ch];
00725                 for(i = 0;i < n; i++) {
00726                     *coefs++ = coefs1[i] * exponents[i<<bsize>>esize] * mult;
00727                 }
00728                 n = s->block_len - s->coefs_end[bsize];
00729                 for(i = 0;i < n; i++)
00730                     *coefs++ = 0.0;
00731             }
00732         }
00733     }
00734 
00735 #ifdef TRACE
00736     for(ch = 0; ch < s->nb_channels; ch++) {
00737         if (s->channel_coded[ch]) {
00738             dump_floats(s, "exponents", 3, s->exponents[ch], s->block_len);
00739             dump_floats(s, "coefs", 1, s->coefs[ch], s->block_len);
00740         }
00741     }
00742 #endif
00743 
00744     if (s->ms_stereo && s->channel_coded[1]) {
00745         /* nominal case for ms stereo: we do it before mdct */
00746         /* no need to optimize this case because it should almost
00747            never happen */
00748         if (!s->channel_coded[0]) {
00749             tprintf(s->avctx, "rare ms-stereo case happened\n");
00750             memset(s->coefs[0], 0, sizeof(float) * s->block_len);
00751             s->channel_coded[0] = 1;
00752         }
00753 
00754         s->dsp.butterflies_float(s->coefs[0], s->coefs[1], s->block_len);
00755     }
00756 
00757 next:
00758     mdct = &s->mdct_ctx[bsize];
00759 
00760     for(ch = 0; ch < s->nb_channels; ch++) {
00761         int n4, index;
00762 
00763         n4 = s->block_len / 2;
00764         if(s->channel_coded[ch]){
00765             mdct->imdct_calc(mdct, s->output, s->coefs[ch]);
00766         }else if(!(s->ms_stereo && ch==1))
00767             memset(s->output, 0, sizeof(s->output));
00768 
00769         /* multiply by the window and add in the frame */
00770         index = (s->frame_len / 2) + s->block_pos - n4;
00771         wma_window(s, &s->frame_out[ch][index]);
00772     }
00773 
00774     /* update block number */
00775     s->block_num++;
00776     s->block_pos += s->block_len;
00777     if (s->block_pos >= s->frame_len)
00778         return 1;
00779     else
00780         return 0;
00781 }
00782 
00783 /* decode a frame of frame_len samples */
00784 static int wma_decode_frame(WMACodecContext *s, int16_t *samples)
00785 {
00786     int ret, n, ch, incr;
00787     const float *output[MAX_CHANNELS];
00788 
00789 #ifdef TRACE
00790     tprintf(s->avctx, "***decode_frame: %d size=%d\n", s->frame_count++, s->frame_len);
00791 #endif
00792 
00793     /* read each block */
00794     s->block_num = 0;
00795     s->block_pos = 0;
00796     for(;;) {
00797         ret = wma_decode_block(s);
00798         if (ret < 0)
00799             return -1;
00800         if (ret)
00801             break;
00802     }
00803 
00804     /* convert frame to integer */
00805     n = s->frame_len;
00806     incr = s->nb_channels;
00807     for (ch = 0; ch < MAX_CHANNELS; ch++)
00808         output[ch] = s->frame_out[ch];
00809     s->fmt_conv.float_to_int16_interleave(samples, output, n, incr);
00810     for (ch = 0; ch < incr; ch++) {
00811         /* prepare for next block */
00812         memmove(&s->frame_out[ch][0], &s->frame_out[ch][n], n * sizeof(float));
00813     }
00814 
00815 #ifdef TRACE
00816     dump_shorts(s, "samples", samples, n * s->nb_channels);
00817 #endif
00818     return 0;
00819 }
00820 
00821 static int wma_decode_superframe(AVCodecContext *avctx, void *data,
00822                                  int *got_frame_ptr, AVPacket *avpkt)
00823 {
00824     const uint8_t *buf = avpkt->data;
00825     int buf_size = avpkt->size;
00826     WMACodecContext *s = avctx->priv_data;
00827     int nb_frames, bit_offset, i, pos, len, ret;
00828     uint8_t *q;
00829     int16_t *samples;
00830 
00831     tprintf(avctx, "***decode_superframe:\n");
00832 
00833     if(buf_size==0){
00834         s->last_superframe_len = 0;
00835         return 0;
00836     }
00837     if (buf_size < s->block_align) {
00838         av_log(avctx, AV_LOG_ERROR,
00839                "Input packet size too small (%d < %d)\n",
00840                buf_size, s->block_align);
00841         return AVERROR_INVALIDDATA;
00842     }
00843     if(s->block_align)
00844         buf_size = s->block_align;
00845 
00846     init_get_bits(&s->gb, buf, buf_size*8);
00847 
00848     if (s->use_bit_reservoir) {
00849         /* read super frame header */
00850         skip_bits(&s->gb, 4); /* super frame index */
00851         nb_frames = get_bits(&s->gb, 4) - (s->last_superframe_len <= 0);
00852     } else {
00853         nb_frames = 1;
00854     }
00855 
00856     /* get output buffer */
00857     s->frame.nb_samples = nb_frames * s->frame_len;
00858     if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
00859         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00860         return ret;
00861     }
00862     samples = (int16_t *)s->frame.data[0];
00863 
00864     if (s->use_bit_reservoir) {
00865         bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
00866         if (bit_offset > get_bits_left(&s->gb)) {
00867             av_log(avctx, AV_LOG_ERROR,
00868                    "Invalid last frame bit offset %d > buf size %d (%d)\n",
00869                    bit_offset, get_bits_left(&s->gb), buf_size);
00870             goto fail;
00871         }
00872 
00873         if (s->last_superframe_len > 0) {
00874             //        printf("skip=%d\n", s->last_bitoffset);
00875             /* add bit_offset bits to last frame */
00876             if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
00877                 MAX_CODED_SUPERFRAME_SIZE)
00878                 goto fail;
00879             q = s->last_superframe + s->last_superframe_len;
00880             len = bit_offset;
00881             while (len > 7) {
00882                 *q++ = (get_bits)(&s->gb, 8);
00883                 len -= 8;
00884             }
00885             if (len > 0) {
00886                 *q++ = (get_bits)(&s->gb, len) << (8 - len);
00887             }
00888             memset(q, 0, FF_INPUT_BUFFER_PADDING_SIZE);
00889 
00890             /* XXX: bit_offset bits into last frame */
00891             init_get_bits(&s->gb, s->last_superframe, s->last_superframe_len * 8 + bit_offset);
00892             /* skip unused bits */
00893             if (s->last_bitoffset > 0)
00894                 skip_bits(&s->gb, s->last_bitoffset);
00895             /* this frame is stored in the last superframe and in the
00896                current one */
00897             if (wma_decode_frame(s, samples) < 0)
00898                 goto fail;
00899             samples += s->nb_channels * s->frame_len;
00900             nb_frames--;
00901         }
00902 
00903         /* read each frame starting from bit_offset */
00904         pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
00905         if (pos >= MAX_CODED_SUPERFRAME_SIZE * 8 || pos > buf_size * 8)
00906             return AVERROR_INVALIDDATA;
00907         init_get_bits(&s->gb, buf + (pos >> 3), (buf_size - (pos >> 3))*8);
00908         len = pos & 7;
00909         if (len > 0)
00910             skip_bits(&s->gb, len);
00911 
00912         s->reset_block_lengths = 1;
00913         for(i=0;i<nb_frames;i++) {
00914             if (wma_decode_frame(s, samples) < 0)
00915                 goto fail;
00916             samples += s->nb_channels * s->frame_len;
00917         }
00918 
00919         /* we copy the end of the frame in the last frame buffer */
00920         pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
00921         s->last_bitoffset = pos & 7;
00922         pos >>= 3;
00923         len = buf_size - pos;
00924         if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
00925             av_log(s->avctx, AV_LOG_ERROR, "len %d invalid\n", len);
00926             goto fail;
00927         }
00928         s->last_superframe_len = len;
00929         memcpy(s->last_superframe, buf + pos, len);
00930     } else {
00931         /* single frame decode */
00932         if (wma_decode_frame(s, samples) < 0)
00933             goto fail;
00934         samples += s->nb_channels * s->frame_len;
00935     }
00936 
00937 //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);
00938 
00939     *got_frame_ptr   = 1;
00940     *(AVFrame *)data = s->frame;
00941 
00942     return buf_size;
00943  fail:
00944     /* when error, we reset the bit reservoir */
00945     s->last_superframe_len = 0;
00946     return -1;
00947 }
00948 
00949 static av_cold void flush(AVCodecContext *avctx)
00950 {
00951     WMACodecContext *s = avctx->priv_data;
00952 
00953     s->last_bitoffset=
00954     s->last_superframe_len= 0;
00955 }
00956 
00957 AVCodec ff_wmav1_decoder = {
00958     .name           = "wmav1",
00959     .type           = AVMEDIA_TYPE_AUDIO,
00960     .id             = CODEC_ID_WMAV1,
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 1"),
00968 };
00969 
00970 AVCodec ff_wmav2_decoder = {
00971     .name           = "wmav2",
00972     .type           = AVMEDIA_TYPE_AUDIO,
00973     .id             = CODEC_ID_WMAV2,
00974     .priv_data_size = sizeof(WMACodecContext),
00975     .init           = wma_decode_init,
00976     .close          = ff_wma_end,
00977     .decode         = wma_decode_superframe,
00978     .flush          = flush,
00979     .capabilities   = CODEC_CAP_DR1,
00980     .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Audio 2"),
00981 };