FFmpeg: libavcodec/wmadec.c Source File

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wmadec.c

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1 /*

2 * WMA compatible decoder

4 *

5 * This file is part of FFmpeg.

6 *

7 * FFmpeg is free software; you can redistribute it and/or

8 * modify it under the terms of the GNU Lesser General Public

9 * License as published by the Free Software Foundation; either

10 * version 2.1 of the License, or (at your option) any later version.

11 *

12 * FFmpeg is distributed in the hope that it will be useful,

13 * but WITHOUT ANY WARRANTY; without even the implied warranty of

14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

15 * Lesser General Public License for more details.

16 *

17 * You should have received a copy of the GNU Lesser General Public

18 * License along with FFmpeg; if not, write to the Free Software

19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

20 */

22 /**

23 * @file

24 * WMA compatible decoder.

25 * This decoder handles Microsoft Windows Media Audio data, versions 1 & 2.

26 * WMA v1 is identified by audio format 0x160 in Microsoft media files

27 * (ASF/AVI/WAV). WMA v2 is identified by audio format 0x161.

28 *

29 * To use this decoder, a calling application must supply the extra data

30 * bytes provided with the WMA data. These are the extra, codec-specific

31 * bytes at the end of a WAVEFORMATEX data structure. Transmit these bytes

32 * to the decoder using the extradata[_size] fields in AVCodecContext. There

33 * should be 4 extra bytes for v1 data and 6 extra bytes for v2 data.

34 */

36 #include "avcodec.h"

37 #include "internal.h"

38 #include "wma.h"

40 #undef NDEBUG

41 #include <assert.h>

43 #define EXPVLCBITS 8

44 #define EXPMAX ((19+EXPVLCBITS-1)/EXPVLCBITS)

46 #define HGAINVLCBITS 9

47 #define HGAINMAX ((13+HGAINVLCBITS-1)/HGAINVLCBITS)

49 static void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len);

51 #ifdef TRACE

52 static void dump_floats(WMACodecContext *s, const char *name, int prec, const float *tab, int n)

53 {

54 int i;

56 tprintf(s->avctx, "%s[%d]:\n", name, n);

57 for(i=0;i<n;i++) {

58 if ((i & 7) == 0)

59 tprintf(s->avctx, "%4d: ", i);

60 tprintf(s->avctx, " %8.*f", prec, tab[i]);

61 if ((i & 7) == 7)

62 tprintf(s->avctx, "\n");

63 }

64 if ((i & 7) != 0)

65 tprintf(s->avctx, "\n");

66 }

67 #endif

69 static int wma_decode_init(AVCodecContext * avctx)

70 {

71 WMACodecContext *s = avctx->priv_data;

72 int i, flags2;

73 uint8_t *extradata;

75 if (!avctx->block_align) {

76 av_log(avctx, AV_LOG_ERROR, "block_align is not set\n");

77 return AVERROR(EINVAL);

78 }

80 s->avctx = avctx;

82 /* extract flag infos */

83 flags2 = 0;

84 extradata = avctx->extradata;

85 if (avctx->codec->id == AV_CODEC_ID_WMAV1 && avctx->extradata_size >= 4) {

86 flags2 = AV_RL16(extradata+2);

87 } else if (avctx->codec->id == AV_CODEC_ID_WMAV2 && avctx->extradata_size >= 6) {

88 flags2 = AV_RL16(extradata+4);

89 }

91 s->use_exp_vlc = flags2 & 0x0001;

92 s->use_bit_reservoir = flags2 & 0x0002;

93 s->use_variable_block_len = flags2 & 0x0004;

95 if(avctx->codec->id == AV_CODEC_ID_WMAV2 && avctx->extradata_size >= 8){

96 if(AV_RL16(extradata+4)==0xd && s->use_variable_block_len){

97 av_log(avctx, AV_LOG_WARNING, "Disabling use_variable_block_len, if this fails contact the ffmpeg developers and send us the file\n");

98 s->use_variable_block_len= 0; // this fixes issue1503

99 }

100 }

101

102 if(ff_wma_init(avctx, flags2)<0)

103 return -1;

104

105 /* init MDCT */

106 for(i = 0; i < s->nb_block_sizes; i++)

107 ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1, 1.0 / 32768.0);

108

109 if (s->use_noise_coding) {

110 init_vlc(&s->hgain_vlc, HGAINVLCBITS, sizeof(ff_wma_hgain_huffbits),

111 ff_wma_hgain_huffbits, 1, 1,

112 ff_wma_hgain_huffcodes, 2, 2, 0);

113 }

114

115 if (s->use_exp_vlc) {

116 init_vlc(&s->exp_vlc, EXPVLCBITS, sizeof(ff_aac_scalefactor_bits), //FIXME move out of context

117 ff_aac_scalefactor_bits, 1, 1,

118 ff_aac_scalefactor_code, 4, 4, 0);

119 } else {

120 wma_lsp_to_curve_init(s, s->frame_len);

121 }

122

123 avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;

124

125 avcodec_get_frame_defaults(&s->frame);

126 avctx->coded_frame = &s->frame;

127

128 return 0;

129 }

130

131 /**

132 * compute x^-0.25 with an exponent and mantissa table. We use linear

133 * interpolation to reduce the mantissa table size at a small speed

134 * expense (linear interpolation approximately doubles the number of

135 * bits of precision).

136 */

137 static inline float pow_m1_4(WMACodecContext *s, float x)

138 {

139 union {

140 float f;

141 unsigned int v;

142 } u, t;

143 unsigned int e, m;

144 float a, b;

145

146 u.f = x;

147 e = u.v >> 23;

148 m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);

149 /* build interpolation scale: 1 <= t < 2. */

150 t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);

151 a = s->lsp_pow_m_table1[m];

152 b = s->lsp_pow_m_table2[m];

153 return s->lsp_pow_e_table[e] * (a + b * t.f);

154 }

155

156 static void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len)

157 {

158 float wdel, a, b;

159 int i, e, m;

160

161 wdel = M_PI / frame_len;

162 for(i=0;i<frame_len;i++)

163 s->lsp_cos_table[i] = 2.0f * cos(wdel * i);

164

165 /* tables for x^-0.25 computation */

166 for(i=0;i<256;i++) {

167 e = i - 126;

168 s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);

169 }

170

171 /* NOTE: these two tables are needed to avoid two operations in

172 pow_m1_4 */

173 b = 1.0;

174 for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) {

175 m = (1 << LSP_POW_BITS) + i;

176 a = (float)m * (0.5 / (1 << LSP_POW_BITS));

177 a = pow(a, -0.25);

178 s->lsp_pow_m_table1[i] = 2 * a - b;

179 s->lsp_pow_m_table2[i] = b - a;

180 b = a;

181 }

182 }

183

184 /**

185 * NOTE: We use the same code as Vorbis here

186 * @todo optimize it further with SSE/3Dnow

187 */

188 static void wma_lsp_to_curve(WMACodecContext *s,

189 float *out, float *val_max_ptr,

190 int n, float *lsp)

191 {

192 int i, j;

193 float p, q, w, v, val_max;

194

195 val_max = 0;

196 for(i=0;i<n;i++) {

197 p = 0.5f;

198 q = 0.5f;

199 w = s->lsp_cos_table[i];

200 for(j=1;j<NB_LSP_COEFS;j+=2){

201 q *= w - lsp[j - 1];

202 p *= w - lsp[j];

203 }

204 p *= p * (2.0f - w);

205 q *= q * (2.0f + w);

206 v = p + q;

207 v = pow_m1_4(s, v);

208 if (v > val_max)

209 val_max = v;

210 out[i] = v;

211 }

212 *val_max_ptr = val_max;

213 }

214

215 /**

216 * decode exponents coded with LSP coefficients (same idea as Vorbis)

217 */

218 static void decode_exp_lsp(WMACodecContext *s, int ch)

219 {

220 float lsp_coefs[NB_LSP_COEFS];

221 int val, i;

222

223 for(i = 0; i < NB_LSP_COEFS; i++) {

224 if (i == 0 || i >= 8)

225 val = get_bits(&s->gb, 3);

226 else

227 val = get_bits(&s->gb, 4);

228 lsp_coefs[i] = ff_wma_lsp_codebook[i][val];

229 }

230

231 wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],

232 s->block_len, lsp_coefs);

233 }

234

235 /** pow(10, i / 16.0) for i in -60..95 */

236 static const float pow_tab[] = {

237 1.7782794100389e-04, 2.0535250264571e-04,

238 2.3713737056617e-04, 2.7384196342644e-04,

239 3.1622776601684e-04, 3.6517412725484e-04,

240 4.2169650342858e-04, 4.8696752516586e-04,

241 5.6234132519035e-04, 6.4938163157621e-04,

242 7.4989420933246e-04, 8.6596432336006e-04,

243 1.0000000000000e-03, 1.1547819846895e-03,

244 1.3335214321633e-03, 1.5399265260595e-03,

245 1.7782794100389e-03, 2.0535250264571e-03,

246 2.3713737056617e-03, 2.7384196342644e-03,

247 3.1622776601684e-03, 3.6517412725484e-03,

248 4.2169650342858e-03, 4.8696752516586e-03,

249 5.6234132519035e-03, 6.4938163157621e-03,

250 7.4989420933246e-03, 8.6596432336006e-03,

251 1.0000000000000e-02, 1.1547819846895e-02,

252 1.3335214321633e-02, 1.5399265260595e-02,

253 1.7782794100389e-02, 2.0535250264571e-02,

254 2.3713737056617e-02, 2.7384196342644e-02,

255 3.1622776601684e-02, 3.6517412725484e-02,

256 4.2169650342858e-02, 4.8696752516586e-02,

257 5.6234132519035e-02, 6.4938163157621e-02,

258 7.4989420933246e-02, 8.6596432336007e-02,

259 1.0000000000000e-01, 1.1547819846895e-01,

260 1.3335214321633e-01, 1.5399265260595e-01,

261 1.7782794100389e-01, 2.0535250264571e-01,

262 2.3713737056617e-01, 2.7384196342644e-01,

263 3.1622776601684e-01, 3.6517412725484e-01,

264 4.2169650342858e-01, 4.8696752516586e-01,

265 5.6234132519035e-01, 6.4938163157621e-01,

266 7.4989420933246e-01, 8.6596432336007e-01,

267 1.0000000000000e+00, 1.1547819846895e+00,

268 1.3335214321633e+00, 1.5399265260595e+00,

269 1.7782794100389e+00, 2.0535250264571e+00,

270 2.3713737056617e+00, 2.7384196342644e+00,

271 3.1622776601684e+00, 3.6517412725484e+00,

272 4.2169650342858e+00, 4.8696752516586e+00,

273 5.6234132519035e+00, 6.4938163157621e+00,

274 7.4989420933246e+00, 8.6596432336007e+00,

275 1.0000000000000e+01, 1.1547819846895e+01,

276 1.3335214321633e+01, 1.5399265260595e+01,

277 1.7782794100389e+01, 2.0535250264571e+01,

278 2.3713737056617e+01, 2.7384196342644e+01,

279 3.1622776601684e+01, 3.6517412725484e+01,

280 4.2169650342858e+01, 4.8696752516586e+01,

281 5.6234132519035e+01, 6.4938163157621e+01,

282 7.4989420933246e+01, 8.6596432336007e+01,

283 1.0000000000000e+02, 1.1547819846895e+02,

284 1.3335214321633e+02, 1.5399265260595e+02,

285 1.7782794100389e+02, 2.0535250264571e+02,

286 2.3713737056617e+02, 2.7384196342644e+02,

287 3.1622776601684e+02, 3.6517412725484e+02,

288 4.2169650342858e+02, 4.8696752516586e+02,

289 5.6234132519035e+02, 6.4938163157621e+02,

290 7.4989420933246e+02, 8.6596432336007e+02,

291 1.0000000000000e+03, 1.1547819846895e+03,

292 1.3335214321633e+03, 1.5399265260595e+03,

293 1.7782794100389e+03, 2.0535250264571e+03,

294 2.3713737056617e+03, 2.7384196342644e+03,

295 3.1622776601684e+03, 3.6517412725484e+03,

296 4.2169650342858e+03, 4.8696752516586e+03,

297 5.6234132519035e+03, 6.4938163157621e+03,

298 7.4989420933246e+03, 8.6596432336007e+03,

299 1.0000000000000e+04, 1.1547819846895e+04,

300 1.3335214321633e+04, 1.5399265260595e+04,

301 1.7782794100389e+04, 2.0535250264571e+04,

302 2.3713737056617e+04, 2.7384196342644e+04,

303 3.1622776601684e+04, 3.6517412725484e+04,

304 4.2169650342858e+04, 4.8696752516586e+04,

305 5.6234132519035e+04, 6.4938163157621e+04,

306 7.4989420933246e+04, 8.6596432336007e+04,

307 1.0000000000000e+05, 1.1547819846895e+05,

308 1.3335214321633e+05, 1.5399265260595e+05,

309 1.7782794100389e+05, 2.0535250264571e+05,

310 2.3713737056617e+05, 2.7384196342644e+05,

311 3.1622776601684e+05, 3.6517412725484e+05,

312 4.2169650342858e+05, 4.8696752516586e+05,

313 5.6234132519035e+05, 6.4938163157621e+05,

314 7.4989420933246e+05, 8.6596432336007e+05,

315 };

316

317 /**

318 * decode exponents coded with VLC codes

319 */

320 static int decode_exp_vlc(WMACodecContext *s, int ch)

321 {

322 int last_exp, n, code;

323 const uint16_t *ptr;

324 float v, max_scale;

325 uint32_t *q, *q_end, iv;

326 const float *ptab = pow_tab + 60;

327 const uint32_t *iptab = (const uint32_t*)ptab;

328

329 ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];

330 q = (uint32_t *)s->exponents[ch];

331 q_end = q + s->block_len;

332 max_scale = 0;

333 if (s->version == 1) {

334 last_exp = get_bits(&s->gb, 5) + 10;

335 v = ptab[last_exp];

336 iv = iptab[last_exp];

337 max_scale = v;

338 n = *ptr++;

339 switch (n & 3) do {

340 case 0: *q++ = iv;

341 case 3: *q++ = iv;

342 case 2: *q++ = iv;

343 case 1: *q++ = iv;

344 } while ((n -= 4) > 0);

345 }else

346 last_exp = 36;

347

348 while (q < q_end) {

349 code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);

350 if (code < 0){

351 av_log(s->avctx, AV_LOG_ERROR, "Exponent vlc invalid\n");

352 return -1;

353 }

354 /* NOTE: this offset is the same as MPEG4 AAC ! */

355 last_exp += code - 60;

356 if ((unsigned)last_exp + 60 >= FF_ARRAY_ELEMS(pow_tab)) {

357 av_log(s->avctx, AV_LOG_ERROR, "Exponent out of range: %d\n",

358 last_exp);

359 return -1;

360 }

361 v = ptab[last_exp];

362 iv = iptab[last_exp];

363 if (v > max_scale)

364 max_scale = v;

365 n = *ptr++;

366 switch (n & 3) do {

367 case 0: *q++ = iv;

368 case 3: *q++ = iv;

369 case 2: *q++ = iv;

370 case 1: *q++ = iv;

371 } while ((n -= 4) > 0);

372 }

373 s->max_exponent[ch] = max_scale;

374 return 0;

375 }

376

377

378 /**

379 * Apply MDCT window and add into output.

380 *

381 * We ensure that when the windows overlap their squared sum

382 * is always 1 (MDCT reconstruction rule).

383 */

384 static void wma_window(WMACodecContext *s, float *out)

385 {

386 float *in = s->output;

387 int block_len, bsize, n;

388

389 /* left part */

390 if (s->block_len_bits <= s->prev_block_len_bits) {

391 block_len = s->block_len;

392 bsize = s->frame_len_bits - s->block_len_bits;

393

394 s->dsp.vector_fmul_add(out, in, s->windows[bsize],

395 out, block_len);

396

397 } else {

398 block_len = 1 << s->prev_block_len_bits;

399 n = (s->block_len - block_len) / 2;

400 bsize = s->frame_len_bits - s->prev_block_len_bits;

401

402 s->dsp.vector_fmul_add(out+n, in+n, s->windows[bsize],

403 out+n, block_len);

404

405 memcpy(out+n+block_len, in+n+block_len, n*sizeof(float));

406 }

407

408 out += s->block_len;

409 in += s->block_len;

410

411 /* right part */

412 if (s->block_len_bits <= s->next_block_len_bits) {

413 block_len = s->block_len;

414 bsize = s->frame_len_bits - s->block_len_bits;

415

416 s->dsp.vector_fmul_reverse(out, in, s->windows[bsize], block_len);

417

418 } else {

419 block_len = 1 << s->next_block_len_bits;

420 n = (s->block_len - block_len) / 2;

421 bsize = s->frame_len_bits - s->next_block_len_bits;

422

423 memcpy(out, in, n*sizeof(float));

424

425 s->dsp.vector_fmul_reverse(out+n, in+n, s->windows[bsize], block_len);

426

427 memset(out+n+block_len, 0, n*sizeof(float));

428 }

429 }

430

431

432 /**

433 * @return 0 if OK. 1 if last block of frame. return -1 if

434 * unrecorrable error.

435 */

436 static int wma_decode_block(WMACodecContext *s)

437 {

438 int n, v, a, ch, bsize;

439 int coef_nb_bits, total_gain;

440 int nb_coefs[MAX_CHANNELS];

441 float mdct_norm;

442 FFTContext *mdct;

443

444 #ifdef TRACE

445 tprintf(s->avctx, "***decode_block: %d:%d\n", s->frame_count - 1, s->block_num);

446 #endif

447

448 /* compute current block length */

449 if (s->use_variable_block_len) {

450 n = av_log2(s->nb_block_sizes - 1) + 1;

451

452 if (s->reset_block_lengths) {

453 s->reset_block_lengths = 0;

454 v = get_bits(&s->gb, n);

455 if (v >= s->nb_block_sizes){

456 av_log(s->avctx, AV_LOG_ERROR, "prev_block_len_bits %d out of range\n", s->frame_len_bits - v);

457 return -1;

458 }

459 s->prev_block_len_bits = s->frame_len_bits - v;

460 v = get_bits(&s->gb, n);

461 if (v >= s->nb_block_sizes){

462 av_log(s->avctx, AV_LOG_ERROR, "block_len_bits %d out of range\n", s->frame_len_bits - v);

463 return -1;

464 }

465 s->block_len_bits = s->frame_len_bits - v;

466 } else {

467 /* update block lengths */

468 s->prev_block_len_bits = s->block_len_bits;

469 s->block_len_bits = s->next_block_len_bits;

470 }

471 v = get_bits(&s->gb, n);

472 if (v >= s->nb_block_sizes){

473 av_log(s->avctx, AV_LOG_ERROR, "next_block_len_bits %d out of range\n", s->frame_len_bits - v);

474 return -1;

475 }

476 s->next_block_len_bits = s->frame_len_bits - v;

477 } else {

478 /* fixed block len */

479 s->next_block_len_bits = s->frame_len_bits;

480 s->prev_block_len_bits = s->frame_len_bits;

481 s->block_len_bits = s->frame_len_bits;

482 }

483

484 if (s->frame_len_bits - s->block_len_bits >= s->nb_block_sizes){

485 av_log(s->avctx, AV_LOG_ERROR, "block_len_bits not initialized to a valid value\n");

486 return -1;

487 }

488

489 /* now check if the block length is coherent with the frame length */

490 s->block_len = 1 << s->block_len_bits;

491 if ((s->block_pos + s->block_len) > s->frame_len){

492 av_log(s->avctx, AV_LOG_ERROR, "frame_len overflow\n");

493 return -1;

494 }

495

496 if (s->avctx->channels == 2) {

497 s->ms_stereo = get_bits1(&s->gb);

498 }

499 v = 0;

500 for(ch = 0; ch < s->avctx->channels; ch++) {

501 a = get_bits1(&s->gb);

502 s->channel_coded[ch] = a;

503 v |= a;

504 }

505

506 bsize = s->frame_len_bits - s->block_len_bits;

507

508 /* if no channel coded, no need to go further */

509 /* XXX: fix potential framing problems */

510 if (!v)

511 goto next;

512

513 /* read total gain and extract corresponding number of bits for

514 coef escape coding */

515 total_gain = 1;

516 for(;;) {

517 a = get_bits(&s->gb, 7);

518 total_gain += a;

519 if (a != 127)

520 break;

521 }

522

523 coef_nb_bits= ff_wma_total_gain_to_bits(total_gain);

524

525 /* compute number of coefficients */

526 n = s->coefs_end[bsize] - s->coefs_start;

527 for(ch = 0; ch < s->avctx->channels; ch++)

528 nb_coefs[ch] = n;

529

530 /* complex coding */

531 if (s->use_noise_coding) {

532

533 for(ch = 0; ch < s->avctx->channels; ch++) {

534 if (s->channel_coded[ch]) {

535 int i, n, a;

536 n = s->exponent_high_sizes[bsize];

537 for(i=0;i<n;i++) {

538 a = get_bits1(&s->gb);

539 s->high_band_coded[ch][i] = a;

540 /* if noise coding, the coefficients are not transmitted */

541 if (a)

542 nb_coefs[ch] -= s->exponent_high_bands[bsize][i];

543 }

544 }

545 }

546 for(ch = 0; ch < s->avctx->channels; ch++) {

547 if (s->channel_coded[ch]) {

548 int i, n, val, code;

549

550 n = s->exponent_high_sizes[bsize];

551 val = (int)0x80000000;

552 for(i=0;i<n;i++) {

553 if (s->high_band_coded[ch][i]) {

554 if (val == (int)0x80000000) {

555 val = get_bits(&s->gb, 7) - 19;

556 } else {

557 code = get_vlc2(&s->gb, s->hgain_vlc.table, HGAINVLCBITS, HGAINMAX);

558 if (code < 0){

559 av_log(s->avctx, AV_LOG_ERROR, "hgain vlc invalid\n");

560 return -1;

561 }

562 val += code - 18;

563 }

564 s->high_band_values[ch][i] = val;

565 }

566 }

567 }

568 }

569 }

570

571 /* exponents can be reused in short blocks. */

572 if ((s->block_len_bits == s->frame_len_bits) ||

573 get_bits1(&s->gb)) {

574 for(ch = 0; ch < s->avctx->channels; ch++) {

575 if (s->channel_coded[ch]) {

576 if (s->use_exp_vlc) {

577 if (decode_exp_vlc(s, ch) < 0)

578 return -1;

579 } else {

580 decode_exp_lsp(s, ch);

581 }

582 s->exponents_bsize[ch] = bsize;

583 }

584 }

585 }

586

587 /* parse spectral coefficients : just RLE encoding */

588 for (ch = 0; ch < s->avctx->channels; ch++) {

589 if (s->channel_coded[ch]) {

590 int tindex;

591 WMACoef* ptr = &s->coefs1[ch][0];

592

593 /* special VLC tables are used for ms stereo because

594 there is potentially less energy there */

595 tindex = (ch == 1 && s->ms_stereo);

596 memset(ptr, 0, s->block_len * sizeof(WMACoef));

597 ff_wma_run_level_decode(s->avctx, &s->gb, &s->coef_vlc[tindex],

598 s->level_table[tindex], s->run_table[tindex],

599 0, ptr, 0, nb_coefs[ch],

600 s->block_len, s->frame_len_bits, coef_nb_bits);

601 }

602 if (s->version == 1 && s->avctx->channels >= 2) {

603 align_get_bits(&s->gb);

604 }

605 }

606

607 /* normalize */

608 {

609 int n4 = s->block_len / 2;

610 mdct_norm = 1.0 / (float)n4;

611 if (s->version == 1) {

612 mdct_norm *= sqrt(n4);

613 }

614 }

615

616 /* finally compute the MDCT coefficients */

617 for (ch = 0; ch < s->avctx->channels; ch++) {

618 if (s->channel_coded[ch]) {

619 WMACoef *coefs1;

620 float *coefs, *exponents, mult, mult1, noise;

621 int i, j, n, n1, last_high_band, esize;

622 float exp_power[HIGH_BAND_MAX_SIZE];

623

624 coefs1 = s->coefs1[ch];

625 exponents = s->exponents[ch];

626 esize = s->exponents_bsize[ch];

627 mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];

628 mult *= mdct_norm;

629 coefs = s->coefs[ch];

630 if (s->use_noise_coding) {

631 mult1 = mult;

632 /* very low freqs : noise */

633 for(i = 0;i < s->coefs_start; i++) {

634 *coefs++ = s->noise_table[s->noise_index] *

635 exponents[i<<bsize>>esize] * mult1;

636 s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);

637 }

638

639 n1 = s->exponent_high_sizes[bsize];

640

641 /* compute power of high bands */

642 exponents = s->exponents[ch] +

643 (s->high_band_start[bsize]<<bsize>>esize);

644 last_high_band = 0; /* avoid warning */

645 for(j=0;j<n1;j++) {

646 n = s->exponent_high_bands[s->frame_len_bits -

647 s->block_len_bits][j];

648 if (s->high_band_coded[ch][j]) {

649 float e2, v;

650 e2 = 0;

651 for(i = 0;i < n; i++) {

652 v = exponents[i<<bsize>>esize];

653 e2 += v * v;

654 }

655 exp_power[j] = e2 / n;

656 last_high_band = j;

657 tprintf(s->avctx, "%d: power=%f (%d)\n", j, exp_power[j], n);

658 }

659 exponents += n<<bsize>>esize;

660 }

661

662 /* main freqs and high freqs */

663 exponents = s->exponents[ch] + (s->coefs_start<<bsize>>esize);

664 for(j=-1;j<n1;j++) {

665 if (j < 0) {

666 n = s->high_band_start[bsize] -

667 s->coefs_start;

668 } else {

669 n = s->exponent_high_bands[s->frame_len_bits -

670 s->block_len_bits][j];

671 }

672 if (j >= 0 && s->high_band_coded[ch][j]) {

673 /* use noise with specified power */

674 mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);

675 /* XXX: use a table */

676 mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);

677 mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);

678 mult1 *= mdct_norm;

679 for(i = 0;i < n; i++) {

680 noise = s->noise_table[s->noise_index];

681 s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);

682 *coefs++ = noise *

683 exponents[i<<bsize>>esize] * mult1;

684 }

685 exponents += n<<bsize>>esize;

686 } else {

687 /* coded values + small noise */

688 for(i = 0;i < n; i++) {

689 noise = s->noise_table[s->noise_index];

690 s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);

691 *coefs++ = ((*coefs1++) + noise) *

692 exponents[i<<bsize>>esize] * mult;

693 }

694 exponents += n<<bsize>>esize;

695 }

696 }

697

698 /* very high freqs : noise */

699 n = s->block_len - s->coefs_end[bsize];

700 mult1 = mult * exponents[((-1<<bsize))>>esize];

701 for(i = 0; i < n; i++) {

702 *coefs++ = s->noise_table[s->noise_index] * mult1;

703 s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);

704 }

705 } else {

706 /* XXX: optimize more */

707 for(i = 0;i < s->coefs_start; i++)

708 *coefs++ = 0.0;

709 n = nb_coefs[ch];

710 for(i = 0;i < n; i++) {

711 *coefs++ = coefs1[i] * exponents[i<<bsize>>esize] * mult;

712 }

713 n = s->block_len - s->coefs_end[bsize];

714 for(i = 0;i < n; i++)

715 *coefs++ = 0.0;

716 }

717 }

718 }

719

720 #ifdef TRACE

721 for (ch = 0; ch < s->avctx->channels; ch++) {

722 if (s->channel_coded[ch]) {

723 dump_floats(s, "exponents", 3, s->exponents[ch], s->block_len);

724 dump_floats(s, "coefs", 1, s->coefs[ch], s->block_len);

725 }

726 }

727 #endif

728

729 if (s->ms_stereo && s->channel_coded[1]) {

730 /* nominal case for ms stereo: we do it before mdct */

731 /* no need to optimize this case because it should almost

732 never happen */

733 if (!s->channel_coded[0]) {

734 tprintf(s->avctx, "rare ms-stereo case happened\n");

735 memset(s->coefs[0], 0, sizeof(float) * s->block_len);

736 s->channel_coded[0] = 1;

737 }

738

739 s->dsp.butterflies_float(s->coefs[0], s->coefs[1], s->block_len);

740 }

741

742 next:

743 mdct = &s->mdct_ctx[bsize];

744

745 for (ch = 0; ch < s->avctx->channels; ch++) {

746 int n4, index;

747

748 n4 = s->block_len / 2;

749 if(s->channel_coded[ch]){

750 mdct->imdct_calc(mdct, s->output, s->coefs[ch]);

751 }else if(!(s->ms_stereo && ch==1))

752 memset(s->output, 0, sizeof(s->output));

753

754 /* multiply by the window and add in the frame */

755 index = (s->frame_len / 2) + s->block_pos - n4;

756 wma_window(s, &s->frame_out[ch][index]);

757 }

758

759 /* update block number */

760 s->block_num++;

761 s->block_pos += s->block_len;

762 if (s->block_pos >= s->frame_len)

763 return 1;

764 else

765 return 0;

766 }

767

768 /* decode a frame of frame_len samples */

769 static int wma_decode_frame(WMACodecContext *s, float **samples,

770 int samples_offset)

771 {

772 int ret, ch;

773

774 #ifdef TRACE

775 tprintf(s->avctx, "***decode_frame: %d size=%d\n", s->frame_count++, s->frame_len);

776 #endif

777

778 /* read each block */

779 s->block_num = 0;

780 s->block_pos = 0;

781 for(;;) {

782 ret = wma_decode_block(s);

783 if (ret < 0)

784 return -1;

785 if (ret)

786 break;

787 }

788

789 for (ch = 0; ch < s->avctx->channels; ch++) {

790 /* copy current block to output */

791 memcpy(samples[ch] + samples_offset, s->frame_out[ch],

792 s->frame_len * sizeof(*s->frame_out[ch]));

793 /* prepare for next block */

794 memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len],

795 s->frame_len * sizeof(*s->frame_out[ch]));

796

797 #ifdef TRACE

798 dump_floats(s, "samples", 6, samples[ch] + samples_offset, s->frame_len);

799 #endif

800 }

801

802 return 0;

803 }

804

805 static int wma_decode_superframe(AVCodecContext *avctx, void *data,

806 int *got_frame_ptr, AVPacket *avpkt)

807 {

808 const uint8_t *buf = avpkt->data;

809 int buf_size = avpkt->size;

810 WMACodecContext *s = avctx->priv_data;

811 int nb_frames, bit_offset, i, pos, len, ret;

812 uint8_t *q;

813 float **samples;

814 int samples_offset;

815

816 tprintf(avctx, "***decode_superframe:\n");

817

818 if(buf_size==0){

819 s->last_superframe_len = 0;

820 return 0;

821 }

822 if (buf_size < avctx->block_align) {

823 av_log(avctx, AV_LOG_ERROR,

824 "Input packet size too small (%d < %d)\n",

825 buf_size, avctx->block_align);

826 return AVERROR_INVALIDDATA;

827 }

828 if(avctx->block_align)

829 buf_size = avctx->block_align;

830

831 init_get_bits(&s->gb, buf, buf_size*8);

832

833 if (s->use_bit_reservoir) {

834 /* read super frame header */

835 skip_bits(&s->gb, 4); /* super frame index */

836 nb_frames = get_bits(&s->gb, 4) - (s->last_superframe_len <= 0);

837 } else {

838 nb_frames = 1;

839 }

840

841 /* get output buffer */

842 s->frame.nb_samples = nb_frames * s->frame_len;

843 if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) {

844 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");

845 return ret;

846 }

847 samples = (float **)s->frame.extended_data;

848 samples_offset = 0;

849

850 if (s->use_bit_reservoir) {

851 bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);

852 if (bit_offset > get_bits_left(&s->gb)) {

853 av_log(avctx, AV_LOG_ERROR,

854 "Invalid last frame bit offset %d > buf size %d (%d)\n",

855 bit_offset, get_bits_left(&s->gb), buf_size);

856 goto fail;

857 }

858

859 if (s->last_superframe_len > 0) {

860 /* add bit_offset bits to last frame */

861 if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >

862 MAX_CODED_SUPERFRAME_SIZE)

863 goto fail;

864 q = s->last_superframe + s->last_superframe_len;

865 len = bit_offset;

866 while (len > 7) {

867 *q++ = (get_bits)(&s->gb, 8);

868 len -= 8;

869 }

870 if (len > 0) {

871 *q++ = (get_bits)(&s->gb, len) << (8 - len);

872 }

873 memset(q, 0, FF_INPUT_BUFFER_PADDING_SIZE);

874

875 /* XXX: bit_offset bits into last frame */

876 init_get_bits(&s->gb, s->last_superframe, s->last_superframe_len * 8 + bit_offset);

877 /* skip unused bits */

878 if (s->last_bitoffset > 0)

879 skip_bits(&s->gb, s->last_bitoffset);

880 /* this frame is stored in the last superframe and in the

881 current one */

882 if (wma_decode_frame(s, samples, samples_offset) < 0)

883 goto fail;

884 samples_offset += s->frame_len;

885 nb_frames--;

886 }

887

888 /* read each frame starting from bit_offset */

889 pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;

890 if (pos >= MAX_CODED_SUPERFRAME_SIZE * 8 || pos > buf_size * 8)

891 return AVERROR_INVALIDDATA;

892 init_get_bits(&s->gb, buf + (pos >> 3), (buf_size - (pos >> 3))*8);

893 len = pos & 7;

894 if (len > 0)

895 skip_bits(&s->gb, len);

896

897 s->reset_block_lengths = 1;

898 for(i=0;i<nb_frames;i++) {

899 if (wma_decode_frame(s, samples, samples_offset) < 0)

900 goto fail;

901 samples_offset += s->frame_len;

902 }

903

904 /* we copy the end of the frame in the last frame buffer */

905 pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);

906 s->last_bitoffset = pos & 7;

907 pos >>= 3;

908 len = buf_size - pos;

909 if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {

910 av_log(s->avctx, AV_LOG_ERROR, "len %d invalid\n", len);

911 goto fail;

912 }

913 s->last_superframe_len = len;

914 memcpy(s->last_superframe, buf + pos, len);

915 } else {

916 /* single frame decode */

917 if (wma_decode_frame(s, samples, samples_offset) < 0)

918 goto fail;

919 samples_offset += s->frame_len;

920 }

921

922 av_dlog(s->avctx, "%d %d %d %d outbytes:%td eaten:%d\n",

923 s->frame_len_bits, s->block_len_bits, s->frame_len, s->block_len,

924 (int8_t *)samples - (int8_t *)data, avctx->block_align);

925

926 *got_frame_ptr = 1;

927 *(AVFrame *)data = s->frame;

928

929 return buf_size;

930 fail:

931 /* when error, we reset the bit reservoir */

932 s->last_superframe_len = 0;

933 return -1;

934 }

935

936 static av_cold void flush(AVCodecContext *avctx)

937 {

938 WMACodecContext *s = avctx->priv_data;

939

940 s->last_bitoffset=

941 s->last_superframe_len= 0;

942 }

943

944 #if CONFIG_WMAV1_DECODER

945 AVCodec ff_wmav1_decoder = {

946 .name = "wmav1",

947 .type = AVMEDIA_TYPE_AUDIO,

948 .id = AV_CODEC_ID_WMAV1,

949 .priv_data_size = sizeof(WMACodecContext),

950 .init = wma_decode_init,

951 .close = ff_wma_end,

952 .decode = wma_decode_superframe,

953 .flush = flush,

954 .capabilities = CODEC_CAP_DR1,

955 .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 1"),

956 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,

957 AV_SAMPLE_FMT_NONE },

958 };

959 #endif

960 #if CONFIG_WMAV2_DECODER

961 AVCodec ff_wmav2_decoder = {

962 .name = "wmav2",

963 .type = AVMEDIA_TYPE_AUDIO,

964 .id = AV_CODEC_ID_WMAV2,

965 .priv_data_size = sizeof(WMACodecContext),

966 .init = wma_decode_init,

967 .close = ff_wma_end,

968 .decode = wma_decode_superframe,

969 .flush = flush,

970 .capabilities = CODEC_CAP_DR1,

971 .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 2"),

972 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,

973 AV_SAMPLE_FMT_NONE },

974 };

975 #endif

Generated on Sat May 25 2013 03:58:43 for FFmpeg by doxygen 1.8.2