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 "libavutil/attributes.h"

38 #include "avcodec.h"

39 #include "internal.h"

40 #include "wma.h"

42 #define EXPVLCBITS 8

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

45 #define HGAINVLCBITS 9

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

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

50 #ifdef TRACE

51 static void dump_floats(WMACodecContext *s, const char *name,

52 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 /* TRACE */

69 static av_cold 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);

90 s->use_exp_vlc = flags2 & 0x0001;

91 s->use_bit_reservoir = flags2 & 0x0002;

92 s->use_variable_block_len = flags2 & 0x0004;

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

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

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

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

98 }

99 }

100

101 for (i=0; i<MAX_CHANNELS; i++)

102 s->max_exponent[i] = 1.0;

103

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

105 return -1;

106

107 /* init MDCT */

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

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

110

111 if (s->use_noise_coding) {

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

113 ff_wma_hgain_huffbits, 1, 1,

114 ff_wma_hgain_huffcodes, 2, 2, 0);

115 }

116

117 if (s->use_exp_vlc)

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

119 ff_aac_scalefactor_bits, 1, 1,

120 ff_aac_scalefactor_code, 4, 4, 0);

121 else

122 wma_lsp_to_curve_init(s, s->frame_len);

123

124 avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;

125

126 return 0;

127 }

128

129 /**

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

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

132 * expense (linear interpolation approximately doubles the number of

133 * bits of precision).

134 */

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

136 {

137 union {

138 float f;

139 unsigned int v;

140 } u, t;

141 unsigned int e, m;

142 float a, b;

143

144 u.f = x;

145 e = u.v >> 23;

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

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

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

149 a = s->lsp_pow_m_table1[m];

150 b = s->lsp_pow_m_table2[m];

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

152 }

153

154 static av_cold void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len)

155 {

156 float wdel, a, b;

157 int i, e, m;

158

159 wdel = M_PI / frame_len;

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

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

162

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

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

165 e = i - 126;

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

167 }

168

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

170 * pow_m1_4 */

171 b = 1.0;

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

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

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

175 a = pow(a, -0.25);

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

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

178 b = a;

179 }

180 }

181

182 /**

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

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

185 */

186 static void wma_lsp_to_curve(WMACodecContext *s, float *out, float *val_max_ptr,

187 int n, float *lsp)

188 {

189 int i, j;

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

191

192 val_max = 0;

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

194 p = 0.5f;

195 q = 0.5f;

196 w = s->lsp_cos_table[i];

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

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

199 p *= w - lsp[j];

200 }

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

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

203 v = p + q;

204 v = pow_m1_4(s, v);

205 if (v > val_max)

206 val_max = v;

207 out[i] = v;

208 }

209 *val_max_ptr = val_max;

210 }

211

212 /**

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

214 */

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

216 {

217 float lsp_coefs[NB_LSP_COEFS];

218 int val, i;

219

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

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

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

223 else

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

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

226 }

227

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

229 s->block_len, lsp_coefs);

230 }

231

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

233 static const float pow_tab[] = {

234 1.7782794100389e-04, 2.0535250264571e-04,

235 2.3713737056617e-04, 2.7384196342644e-04,

236 3.1622776601684e-04, 3.6517412725484e-04,

237 4.2169650342858e-04, 4.8696752516586e-04,

238 5.6234132519035e-04, 6.4938163157621e-04,

239 7.4989420933246e-04, 8.6596432336006e-04,

240 1.0000000000000e-03, 1.1547819846895e-03,

241 1.3335214321633e-03, 1.5399265260595e-03,

242 1.7782794100389e-03, 2.0535250264571e-03,

243 2.3713737056617e-03, 2.7384196342644e-03,

244 3.1622776601684e-03, 3.6517412725484e-03,

245 4.2169650342858e-03, 4.8696752516586e-03,

246 5.6234132519035e-03, 6.4938163157621e-03,

247 7.4989420933246e-03, 8.6596432336006e-03,

248 1.0000000000000e-02, 1.1547819846895e-02,

249 1.3335214321633e-02, 1.5399265260595e-02,

250 1.7782794100389e-02, 2.0535250264571e-02,

251 2.3713737056617e-02, 2.7384196342644e-02,

252 3.1622776601684e-02, 3.6517412725484e-02,

253 4.2169650342858e-02, 4.8696752516586e-02,

254 5.6234132519035e-02, 6.4938163157621e-02,

255 7.4989420933246e-02, 8.6596432336007e-02,

256 1.0000000000000e-01, 1.1547819846895e-01,

257 1.3335214321633e-01, 1.5399265260595e-01,

258 1.7782794100389e-01, 2.0535250264571e-01,

259 2.3713737056617e-01, 2.7384196342644e-01,

260 3.1622776601684e-01, 3.6517412725484e-01,

261 4.2169650342858e-01, 4.8696752516586e-01,

262 5.6234132519035e-01, 6.4938163157621e-01,

263 7.4989420933246e-01, 8.6596432336007e-01,

264 1.0000000000000e+00, 1.1547819846895e+00,

265 1.3335214321633e+00, 1.5399265260595e+00,

266 1.7782794100389e+00, 2.0535250264571e+00,

267 2.3713737056617e+00, 2.7384196342644e+00,

268 3.1622776601684e+00, 3.6517412725484e+00,

269 4.2169650342858e+00, 4.8696752516586e+00,

270 5.6234132519035e+00, 6.4938163157621e+00,

271 7.4989420933246e+00, 8.6596432336007e+00,

272 1.0000000000000e+01, 1.1547819846895e+01,

273 1.3335214321633e+01, 1.5399265260595e+01,

274 1.7782794100389e+01, 2.0535250264571e+01,

275 2.3713737056617e+01, 2.7384196342644e+01,

276 3.1622776601684e+01, 3.6517412725484e+01,

277 4.2169650342858e+01, 4.8696752516586e+01,

278 5.6234132519035e+01, 6.4938163157621e+01,

279 7.4989420933246e+01, 8.6596432336007e+01,

280 1.0000000000000e+02, 1.1547819846895e+02,

281 1.3335214321633e+02, 1.5399265260595e+02,

282 1.7782794100389e+02, 2.0535250264571e+02,

283 2.3713737056617e+02, 2.7384196342644e+02,

284 3.1622776601684e+02, 3.6517412725484e+02,

285 4.2169650342858e+02, 4.8696752516586e+02,

286 5.6234132519035e+02, 6.4938163157621e+02,

287 7.4989420933246e+02, 8.6596432336007e+02,

288 1.0000000000000e+03, 1.1547819846895e+03,

289 1.3335214321633e+03, 1.5399265260595e+03,

290 1.7782794100389e+03, 2.0535250264571e+03,

291 2.3713737056617e+03, 2.7384196342644e+03,

292 3.1622776601684e+03, 3.6517412725484e+03,

293 4.2169650342858e+03, 4.8696752516586e+03,

294 5.6234132519035e+03, 6.4938163157621e+03,

295 7.4989420933246e+03, 8.6596432336007e+03,

296 1.0000000000000e+04, 1.1547819846895e+04,

297 1.3335214321633e+04, 1.5399265260595e+04,

298 1.7782794100389e+04, 2.0535250264571e+04,

299 2.3713737056617e+04, 2.7384196342644e+04,

300 3.1622776601684e+04, 3.6517412725484e+04,

301 4.2169650342858e+04, 4.8696752516586e+04,

302 5.6234132519035e+04, 6.4938163157621e+04,

303 7.4989420933246e+04, 8.6596432336007e+04,

304 1.0000000000000e+05, 1.1547819846895e+05,

305 1.3335214321633e+05, 1.5399265260595e+05,

306 1.7782794100389e+05, 2.0535250264571e+05,

307 2.3713737056617e+05, 2.7384196342644e+05,

308 3.1622776601684e+05, 3.6517412725484e+05,

309 4.2169650342858e+05, 4.8696752516586e+05,

310 5.6234132519035e+05, 6.4938163157621e+05,

311 7.4989420933246e+05, 8.6596432336007e+05,

312 };

313

314 /**

315 * decode exponents coded with VLC codes

316 */

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

318 {

319 int last_exp, n, code;

320 const uint16_t *ptr;

321 float v, max_scale;

322 uint32_t *q, *q_end, iv;

323 const float *ptab = pow_tab + 60;

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

325

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

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

328 q_end = q + s->block_len;

329 max_scale = 0;

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

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

332 v = ptab[last_exp];

333 iv = iptab[last_exp];

334 max_scale = v;

335 n = *ptr++;

336 switch (n & 3) do {

337 case 0: *q++ = iv;

338 case 3: *q++ = iv;

339 case 2: *q++ = iv;

340 case 1: *q++ = iv;

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

342 } else

343 last_exp = 36;

344

345 while (q < q_end) {

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

347 if (code < 0) {

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

349 return -1;

350 }

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

352 last_exp += code - 60;

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

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

355 last_exp);

356 return -1;

357 }

358 v = ptab[last_exp];

359 iv = iptab[last_exp];

360 if (v > max_scale)

361 max_scale = v;

362 n = *ptr++;

363 switch (n & 3) do {

364 case 0: *q++ = iv;

365 case 3: *q++ = iv;

366 case 2: *q++ = iv;

367 case 1: *q++ = iv;

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

369 }

370 s->max_exponent[ch] = max_scale;

371 return 0;

372 }

373

374 /**

375 * Apply MDCT window and add into output.

376 *

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

378 * is always 1 (MDCT reconstruction rule).

379 */

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

381 {

382 float *in = s->output;

383 int block_len, bsize, n;

384

385 /* left part */

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

387 block_len = s->block_len;

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

389

390 s->fdsp->vector_fmul_add(out, in, s->windows[bsize],

391 out, block_len);

392 } else {

393 block_len = 1 << s->prev_block_len_bits;

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

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

396

397 s->fdsp->vector_fmul_add(out + n, in + n, s->windows[bsize],

398 out + n, block_len);

399

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

401 }

402

403 out += s->block_len;

404 in += s->block_len;

405

406 /* right part */

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

408 block_len = s->block_len;

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

410

411 s->fdsp->vector_fmul_reverse(out, in, s->windows[bsize], block_len);

412 } else {

413 block_len = 1 << s->next_block_len_bits;

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

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

416

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

418

419 s->fdsp->vector_fmul_reverse(out + n, in + n, s->windows[bsize],

420 block_len);

421

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

423 }

424 }

425

426 /**

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

428 * unrecorrable error.

429 */

430 static int wma_decode_block(WMACodecContext *s)

431 {

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

433 int coef_nb_bits, total_gain;

434 int nb_coefs[MAX_CHANNELS];

435 float mdct_norm;

436 FFTContext *mdct;

437

438 #ifdef TRACE

439 tprintf(s->avctx, "***decode_block: %d:%d\n",

440 s->frame_count - 1, s->block_num);

441 #endif /* TRACE */

442

443 /* compute current block length */

444 if (s->use_variable_block_len) {

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

446

447 if (s->reset_block_lengths) {

448 s->reset_block_lengths = 0;

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

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

451 av_log(s->avctx, AV_LOG_ERROR,

452 "prev_block_len_bits %d out of range\n",

453 s->frame_len_bits - v);

454 return -1;

455 }

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

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

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

459 av_log(s->avctx, AV_LOG_ERROR,

460 "block_len_bits %d out of range\n",

461 s->frame_len_bits - v);

462 return -1;

463 }

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

465 } else {

466 /* update block lengths */

467 s->prev_block_len_bits = s->block_len_bits;

468 s->block_len_bits = s->next_block_len_bits;

469 }

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

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

472 av_log(s->avctx, AV_LOG_ERROR,

473 "next_block_len_bits %d out of range\n",

474 s->frame_len_bits - v);

475 return -1;

476 }

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

478 } else {

479 /* fixed block len */

480 s->next_block_len_bits = s->frame_len_bits;

481 s->prev_block_len_bits = s->frame_len_bits;

482 s->block_len_bits = s->frame_len_bits;

483 }

484

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

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

487 return -1;

488 }

489

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

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

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

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

494 return -1;

495 }

496

497 if (s->avctx->channels == 2)

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

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 if (get_bits_left(&s->gb) < 7) {

518 av_log(s->avctx, AV_LOG_ERROR, "total_gain overread\n");

519 return AVERROR_INVALIDDATA;

520 }

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

522 total_gain += a;

523 if (a != 127)

524 break;

525 }

526

527 coef_nb_bits = ff_wma_total_gain_to_bits(total_gain);

528

529 /* compute number of coefficients */

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

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

532 nb_coefs[ch] = n;

533

534 /* complex coding */

535 if (s->use_noise_coding) {

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

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

538 int i, n, a;

539 n = s->exponent_high_sizes[bsize];

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

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

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

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

544 if (a)

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

546 }

547 }

548 }

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

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

551 int i, n, val, code;

552

553 n = s->exponent_high_sizes[bsize];

554 val = (int) 0x80000000;

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

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

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

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

559 } else {

560 code = get_vlc2(&s->gb, s->hgain_vlc.table,

561 HGAINVLCBITS, HGAINMAX);

562 if (code < 0) {

563 av_log(s->avctx, AV_LOG_ERROR,

564 "hgain vlc invalid\n");

565 return -1;

566 }

567 val += code - 18;

568 }

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

570 }

571 }

572 }

573 }

574 }

575

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

577 if ((s->block_len_bits == s->frame_len_bits) || get_bits1(&s->gb)) {

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

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

580 if (s->use_exp_vlc) {

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

582 return -1;

583 } else {

584 decode_exp_lsp(s, ch);

585 }

586 s->exponents_bsize[ch] = bsize;

587 }

588 }

589 }

590

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

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

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

594 int tindex;

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

596

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

598 * there is potentially less energy there */

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

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

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

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

603 0, ptr, 0, nb_coefs[ch],

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

605 }

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

607 align_get_bits(&s->gb);

608 }

609

610 /* normalize */

611 {

612 int n4 = s->block_len / 2;

613 mdct_norm = 1.0 / (float) n4;

614 if (s->version == 1)

615 mdct_norm *= sqrt(n4);

616 }

617

618 /* finally compute the MDCT coefficients */

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

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

621 WMACoef *coefs1;

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

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

624 float exp_power[HIGH_BAND_MAX_SIZE];

625

626 coefs1 = s->coefs1[ch];

627 exponents = s->exponents[ch];

628 esize = s->exponents_bsize[ch];

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

630 mult *= mdct_norm;

631 coefs = s->coefs[ch];

632 if (s->use_noise_coding) {

633 mult1 = mult;

634 /* very low freqs : noise */

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

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

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

638 s->noise_index = (s->noise_index + 1) &

639 (NOISE_TAB_SIZE - 1);

640 }

641

642 n1 = s->exponent_high_sizes[bsize];

643

644 /* compute power of high bands */

645 exponents = s->exponents[ch] +

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

647 last_high_band = 0; /* avoid warning */

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

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

650 s->block_len_bits][j];

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

652 float e2, v;

653 e2 = 0;

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

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

656 e2 += v * v;

657 }

658 exp_power[j] = e2 / n;

659 last_high_band = j;

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

661 }

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

663 }

664

665 /* main freqs and high freqs */

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

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

668 if (j < 0)

669 n = s->high_band_start[bsize] - s->coefs_start;

670 else

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

672 s->block_len_bits][j];

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

674 /* use noise with specified power */

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

676 /* XXX: use a table */

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

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

679 mult1 *= mdct_norm;

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

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

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

683 *coefs++ = noise * 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 n = s->block_len - s->coefs_end[bsize];

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

714 *coefs++ = 0.0;

715 }

716 }

717 }

718

719 #ifdef TRACE

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

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

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

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

724 }

725 }

726 #endif /* TRACE */

727

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

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

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

731 * never happen */

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

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

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

735 s->channel_coded[0] = 1;

736 }

737

738 s->fdsp->butterflies_float(s->coefs[0], s->coefs[1], s->block_len);

739 }

740

741 next:

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

743

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

745 int n4, index;

746

747 n4 = s->block_len / 2;

748 if (s->channel_coded[ch])

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

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

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

752

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

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

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

756 }

757

758 /* update block number */

759 s->block_num++;

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

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

762 return 1;

763 else

764 return 0;

765 }

766

767 /* decode a frame of frame_len samples */

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

769 int samples_offset)

770 {

771 int ret, ch;

772

773 #ifdef TRACE

774 tprintf(s->avctx, "***decode_frame: %d size=%d\n",

775 s->frame_count++, s->frame_len);

776 #endif /* TRACE */

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,

799 s->frame_len);

800 #endif /* TRACE */

801 }

802

803 return 0;

804 }

805

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

807 int *got_frame_ptr, AVPacket *avpkt)

808 {

809 AVFrame *frame = data;

810 const uint8_t *buf = avpkt->data;

811 int buf_size = avpkt->size;

812 WMACodecContext *s = avctx->priv_data;

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

814 uint8_t *q;

815 float **samples;

816 int samples_offset;

817

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

819

820 if (buf_size == 0) {

821 s->last_superframe_len = 0;

822 return 0;

823 }

824 if (buf_size < avctx->block_align) {

825 av_log(avctx, AV_LOG_ERROR,

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

827 buf_size, avctx->block_align);

828 return AVERROR_INVALIDDATA;

829 }

830 if (avctx->block_align)

831 buf_size = avctx->block_align;

832

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

834

835 if (s->use_bit_reservoir) {

836 /* read super frame header */

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

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

839 if (nb_frames <= 0) {

840 int is_error = nb_frames < 0 || get_bits_left(&s->gb) <= 8;

841 av_log(avctx, is_error ? AV_LOG_ERROR : AV_LOG_WARNING,

842 "nb_frames is %d bits left %d\n",

843 nb_frames, get_bits_left(&s->gb));

844 if (is_error)

845 return AVERROR_INVALIDDATA;

846

847 if ((s->last_superframe_len + buf_size - 1) >

848 MAX_CODED_SUPERFRAME_SIZE)

849 goto fail;

850

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

852 len = buf_size - 1;

853 while (len > 0) {

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

855 len --;

856 }

857 memset(q, 0, FF_INPUT_BUFFER_PADDING_SIZE);

858

859 s->last_superframe_len += 8*buf_size - 8;

860 // s->reset_block_lengths = 1; //XXX is this needed ?

861 *got_frame_ptr = 0;

862 return buf_size;

863 }

864 } else

865 nb_frames = 1;

866

867 /* get output buffer */

868 frame->nb_samples = nb_frames * s->frame_len;

869 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)

870 return ret;

871 samples = (float **) frame->extended_data;

872 samples_offset = 0;

873

874 if (s->use_bit_reservoir) {

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

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

877 av_log(avctx, AV_LOG_ERROR,

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

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

880 goto fail;

881 }

882

883 if (s->last_superframe_len > 0) {

884 /* add bit_offset bits to last frame */

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

886 MAX_CODED_SUPERFRAME_SIZE)

887 goto fail;

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

889 len = bit_offset;

890 while (len > 7) {

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

892 len -= 8;

893 }

894 if (len > 0)

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

896 memset(q, 0, FF_INPUT_BUFFER_PADDING_SIZE);

897

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

899 init_get_bits(&s->gb, s->last_superframe,

900 s->last_superframe_len * 8 + bit_offset);

901 /* skip unused bits */

902 if (s->last_bitoffset > 0)

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

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

905 * current one */

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

907 goto fail;

908 samples_offset += s->frame_len;

909 nb_frames--;

910 }

911

912 /* read each frame starting from bit_offset */

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

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

915 return AVERROR_INVALIDDATA;

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

917 len = pos & 7;

918 if (len > 0)

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

920

921 s->reset_block_lengths = 1;

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

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

924 goto fail;

925 samples_offset += s->frame_len;

926 }

927

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

929 pos = get_bits_count(&s->gb) +

930 ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);

931 s->last_bitoffset = pos & 7;

932 pos >>= 3;

933 len = buf_size - pos;

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

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

936 goto fail;

937 }

938 s->last_superframe_len = len;

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

940 } else {

941 /* single frame decode */

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

943 goto fail;

944 samples_offset += s->frame_len;

945 }

946

947 av_dlog(s->avctx, "%d %d %d %d outbytes:%"PTRDIFF_SPECIFIER " eaten:%d\n",

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

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

950

951 *got_frame_ptr = 1;

952

953 return buf_size;

954

955 fail:

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

957 s->last_superframe_len = 0;

958 return -1;

959 }

960

961 static av_cold void flush(AVCodecContext *avctx)

962 {

963 WMACodecContext *s = avctx->priv_data;

964

965 s->last_bitoffset =

966 s->last_superframe_len = 0;

967 }

968

969 #if CONFIG_WMAV1_DECODER

970 AVCodec ff_wmav1_decoder = {

971 .name = "wmav1",

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

973 .type = AVMEDIA_TYPE_AUDIO,

974 .id = AV_CODEC_ID_WMAV1,

975 .priv_data_size = sizeof(WMACodecContext),

976 .init = wma_decode_init,

977 .close = ff_wma_end,

978 .decode = wma_decode_superframe,

979 .flush = flush,

980 .capabilities = CODEC_CAP_DR1,

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

982 AV_SAMPLE_FMT_NONE },

983 };

984 #endif

985 #if CONFIG_WMAV2_DECODER

986 AVCodec ff_wmav2_decoder = {

987 .name = "wmav2",

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

989 .type = AVMEDIA_TYPE_AUDIO,

990 .id = AV_CODEC_ID_WMAV2,

991 .priv_data_size = sizeof(WMACodecContext),

992 .init = wma_decode_init,

993 .close = ff_wma_end,

994 .decode = wma_decode_superframe,

995 .flush = flush,

996 .capabilities = CODEC_CAP_DR1,

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

998 AV_SAMPLE_FMT_NONE },

999 };

1000 #endif

Generated on Sun Mar 8 2015 02:35:03 for FFmpeg by doxygen 1.8.2