FFmpeg: libavcodec/imc.c Source File

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imc.c

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1 /*

2 * IMC compatible decoder

6 *

7 * This file is part of FFmpeg.

8 *

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

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

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

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

13 *

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

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

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

17 * Lesser General Public License for more details.

18 *

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

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

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

22 */

24 /**

25 * @file

26 * IMC - Intel Music Coder

27 * A mdct based codec using a 256 points large transform

28 * divided into 32 bands with some mix of scale factors.

29 * Only mono is supported.

30 *

31 */

34 #include <math.h>

35 #include <stddef.h>

36 #include <stdio.h>

38 #include "libavutil/channel_layout.h"

39 #include "libavutil/float_dsp.h"

40 #include "libavutil/internal.h"

41 #include "libavutil/libm.h"

42 #include "avcodec.h"

43 #include "get_bits.h"

44 #include "dsputil.h"

45 #include "fft.h"

46 #include "internal.h"

47 #include "sinewin.h"

49 #include "imcdata.h"

51 #define IMC_BLOCK_SIZE 64

52 #define IMC_FRAME_ID 0x21

53 #define BANDS 32

54 #define COEFFS 256

56 typedef struct IMCChannel {

57 float old_floor[BANDS];

58 float flcoeffs1[BANDS];

59 float flcoeffs2[BANDS];

60 float flcoeffs3[BANDS];

61 float flcoeffs4[BANDS];

62 float flcoeffs5[BANDS];

63 float flcoeffs6[BANDS];

64 float CWdecoded[COEFFS];

66 int bandWidthT[BANDS]; ///< codewords per band

67 int bitsBandT[BANDS]; ///< how many bits per codeword in band

68 int CWlengthT[COEFFS]; ///< how many bits in each codeword

69 int levlCoeffBuf[BANDS];

70 int bandFlagsBuf[BANDS]; ///< flags for each band

71 int sumLenArr[BANDS]; ///< bits for all coeffs in band

72 int skipFlagRaw[BANDS]; ///< skip flags are stored in raw form or not

73 int skipFlagBits[BANDS]; ///< bits used to code skip flags

74 int skipFlagCount[BANDS]; ///< skipped coeffients per band

75 int skipFlags[COEFFS]; ///< skip coefficient decoding or not

76 int codewords[COEFFS]; ///< raw codewords read from bitstream

78 float last_fft_im[COEFFS];

80 int decoder_reset;

81 } IMCChannel;

83 typedef struct {

84 IMCChannel chctx[2];

86 /** MDCT tables */

87 //@{

88 float mdct_sine_window[COEFFS];

89 float post_cos[COEFFS];

90 float post_sin[COEFFS];

91 float pre_coef1[COEFFS];

92 float pre_coef2[COEFFS];

93 //@}

95 float sqrt_tab[30];

96 GetBitContext gb;

98 DSPContext dsp;

99 AVFloatDSPContext fdsp;

100 FFTContext fft;

101 DECLARE_ALIGNED(32, FFTComplex, samples)[COEFFS / 2];

102 float *out_samples;

103

104 int coef0_pos;

105

106 int8_t cyclTab[32], cyclTab2[32];

107 float weights1[31], weights2[31];

108 } IMCContext;

109

110 static VLC huffman_vlc[4][4];

111

112 #define VLC_TABLES_SIZE 9512

113

114 static const int vlc_offsets[17] = {

115 0, 640, 1156, 1732, 2308, 2852, 3396, 3924,

116 4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE

117 };

118

119 static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2];

120

121 static inline double freq2bark(double freq)

122 {

123 return 3.5 * atan((freq / 7500.0) * (freq / 7500.0)) + 13.0 * atan(freq * 0.00076);

124 }

125

126 static av_cold void iac_generate_tabs(IMCContext *q, int sampling_rate)

127 {

128 double freqmin[32], freqmid[32], freqmax[32];

129 double scale = sampling_rate / (256.0 * 2.0 * 2.0);

130 double nyquist_freq = sampling_rate * 0.5;

131 double freq, bark, prev_bark = 0, tf, tb;

132 int i, j;

133

134 for (i = 0; i < 32; i++) {

135 freq = (band_tab[i] + band_tab[i + 1] - 1) * scale;

136 bark = freq2bark(freq);

137

138 if (i > 0) {

139 tb = bark - prev_bark;

140 q->weights1[i - 1] = pow(10.0, -1.0 * tb);

141 q->weights2[i - 1] = pow(10.0, -2.7 * tb);

142 }

143 prev_bark = bark;

144

145 freqmid[i] = freq;

146

147 tf = freq;

148 while (tf < nyquist_freq) {

149 tf += 0.5;

150 tb = freq2bark(tf);

151 if (tb > bark + 0.5)

152 break;

153 }

154 freqmax[i] = tf;

155

156 tf = freq;

157 while (tf > 0.0) {

158 tf -= 0.5;

159 tb = freq2bark(tf);

160 if (tb <= bark - 0.5)

161 break;

162 }

163 freqmin[i] = tf;

164 }

165

166 for (i = 0; i < 32; i++) {

167 freq = freqmax[i];

168 for (j = 31; j > 0 && freq <= freqmid[j]; j--);

169 q->cyclTab[i] = j + 1;

170

171 freq = freqmin[i];

172 for (j = 0; j < 32 && freq >= freqmid[j]; j++);

173 q->cyclTab2[i] = j - 1;

174 }

175 }

176

177 static av_cold int imc_decode_init(AVCodecContext *avctx)

178 {

179 int i, j, ret;

180 IMCContext *q = avctx->priv_data;

181 double r1, r2;

182

183 if (avctx->codec_id == AV_CODEC_ID_IMC)

184 avctx->channels = 1;

185

186 if (avctx->channels > 2) {

187 avpriv_request_sample(avctx, "Number of channels > 2");

188 return AVERROR_PATCHWELCOME;

189 }

190

191 for (j = 0; j < avctx->channels; j++) {

192 q->chctx[j].decoder_reset = 1;

193

194 for (i = 0; i < BANDS; i++)

195 q->chctx[j].old_floor[i] = 1.0;

196

197 for (i = 0; i < COEFFS / 2; i++)

198 q->chctx[j].last_fft_im[i] = 0;

199 }

200

201 /* Build mdct window, a simple sine window normalized with sqrt(2) */

202 ff_sine_window_init(q->mdct_sine_window, COEFFS);

203 for (i = 0; i < COEFFS; i++)

204 q->mdct_sine_window[i] *= sqrt(2.0);

205 for (i = 0; i < COEFFS / 2; i++) {

206 q->post_cos[i] = (1.0f / 32768) * cos(i / 256.0 * M_PI);

207 q->post_sin[i] = (1.0f / 32768) * sin(i / 256.0 * M_PI);

208

209 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI);

210 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI);

211

212 if (i & 0x1) {

213 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0);

214 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0);

215 } else {

216 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0);

217 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0);

218 }

219 }

220

221 /* Generate a square root table */

222

223 for (i = 0; i < 30; i++)

224 q->sqrt_tab[i] = sqrt(i);

225

226 /* initialize the VLC tables */

227 for (i = 0; i < 4 ; i++) {

228 for (j = 0; j < 4; j++) {

229 huffman_vlc[i][j].table = &vlc_tables[vlc_offsets[i * 4 + j]];

230 huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j];

231 init_vlc(&huffman_vlc[i][j], 9, imc_huffman_sizes[i],

232 imc_huffman_lens[i][j], 1, 1,

233 imc_huffman_bits[i][j], 2, 2, INIT_VLC_USE_NEW_STATIC);

234 }

235 }

236

237 if (avctx->codec_id == AV_CODEC_ID_IAC) {

238 iac_generate_tabs(q, avctx->sample_rate);

239 } else {

240 memcpy(q->cyclTab, cyclTab, sizeof(cyclTab));

241 memcpy(q->cyclTab2, cyclTab2, sizeof(cyclTab2));

242 memcpy(q->weights1, imc_weights1, sizeof(imc_weights1));

243 memcpy(q->weights2, imc_weights2, sizeof(imc_weights2));

244 }

245

246 if ((ret = ff_fft_init(&q->fft, 7, 1))) {

247 av_log(avctx, AV_LOG_INFO, "FFT init failed\n");

248 return ret;

249 }

250 ff_dsputil_init(&q->dsp, avctx);

251 avpriv_float_dsp_init(&q->fdsp, avctx->flags & CODEC_FLAG_BITEXACT);

252 avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;

253 avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO

254 : AV_CH_LAYOUT_STEREO;

255

256 return 0;

257 }

258

259 static void imc_calculate_coeffs(IMCContext *q, float *flcoeffs1,

260 float *flcoeffs2, int *bandWidthT,

261 float *flcoeffs3, float *flcoeffs5)

262 {

263 float workT1[BANDS];

264 float workT2[BANDS];

265 float workT3[BANDS];

266 float snr_limit = 1.e-30;

267 float accum = 0.0;

268 int i, cnt2;

269

270 for (i = 0; i < BANDS; i++) {

271 flcoeffs5[i] = workT2[i] = 0.0;

272 if (bandWidthT[i]) {

273 workT1[i] = flcoeffs1[i] * flcoeffs1[i];

274 flcoeffs3[i] = 2.0 * flcoeffs2[i];

275 } else {

276 workT1[i] = 0.0;

277 flcoeffs3[i] = -30000.0;

278 }

279 workT3[i] = bandWidthT[i] * workT1[i] * 0.01;

280 if (workT3[i] <= snr_limit)

281 workT3[i] = 0.0;

282 }

283

284 for (i = 0; i < BANDS; i++) {

285 for (cnt2 = i; cnt2 < q->cyclTab[i]; cnt2++)

286 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i];

287 workT2[cnt2 - 1] = workT2[cnt2 - 1] + workT3[i];

288 }

289

290 for (i = 1; i < BANDS; i++) {

291 accum = (workT2[i - 1] + accum) * q->weights1[i - 1];

292 flcoeffs5[i] += accum;

293 }

294

295 for (i = 0; i < BANDS; i++)

296 workT2[i] = 0.0;

297

298 for (i = 0; i < BANDS; i++) {

299 for (cnt2 = i - 1; cnt2 > q->cyclTab2[i]; cnt2--)

300 flcoeffs5[cnt2] += workT3[i];

301 workT2[cnt2+1] += workT3[i];

302 }

303

304 accum = 0.0;

305

306 for (i = BANDS-2; i >= 0; i--) {

307 accum = (workT2[i+1] + accum) * q->weights2[i];

308 flcoeffs5[i] += accum;

309 // there is missing code here, but it seems to never be triggered

310 }

311 }

312

313

314 static void imc_read_level_coeffs(IMCContext *q, int stream_format_code,

315 int *levlCoeffs)

316 {

317 int i;

318 VLC *hufftab[4];

319 int start = 0;

320 const uint8_t *cb_sel;

321 int s;

322

323 s = stream_format_code >> 1;

324 hufftab[0] = &huffman_vlc[s][0];

325 hufftab[1] = &huffman_vlc[s][1];

326 hufftab[2] = &huffman_vlc[s][2];

327 hufftab[3] = &huffman_vlc[s][3];

328 cb_sel = imc_cb_select[s];

329

330 if (stream_format_code & 4)

331 start = 1;

332 if (start)

333 levlCoeffs[0] = get_bits(&q->gb, 7);

334 for (i = start; i < BANDS; i++) {

335 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table,

336 hufftab[cb_sel[i]]->bits, 2);

337 if (levlCoeffs[i] == 17)

338 levlCoeffs[i] += get_bits(&q->gb, 4);

339 }

340 }

341

342 static void imc_read_level_coeffs_raw(IMCContext *q, int stream_format_code,

343 int *levlCoeffs)

344 {

345 int i;

346

347 q->coef0_pos = get_bits(&q->gb, 5);

348 levlCoeffs[0] = get_bits(&q->gb, 7);

349 for (i = 1; i < BANDS; i++)

350 levlCoeffs[i] = get_bits(&q->gb, 4);

351 }

352

353 static void imc_decode_level_coefficients(IMCContext *q, int *levlCoeffBuf,

354 float *flcoeffs1, float *flcoeffs2)

355 {

356 int i, level;

357 float tmp, tmp2;

358 // maybe some frequency division thingy

359

360 flcoeffs1[0] = 20000.0 / exp2 (levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125

361 flcoeffs2[0] = log2f(flcoeffs1[0]);

362 tmp = flcoeffs1[0];

363 tmp2 = flcoeffs2[0];

364

365 for (i = 1; i < BANDS; i++) {

366 level = levlCoeffBuf[i];

367 if (level == 16) {

368 flcoeffs1[i] = 1.0;

369 flcoeffs2[i] = 0.0;

370 } else {

371 if (level < 17)

372 level -= 7;

373 else if (level <= 24)

374 level -= 32;

375 else

376 level -= 16;

377

378 tmp *= imc_exp_tab[15 + level];

379 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25

380 flcoeffs1[i] = tmp;

381 flcoeffs2[i] = tmp2;

382 }

383 }

384 }

385

386

387 static void imc_decode_level_coefficients2(IMCContext *q, int *levlCoeffBuf,

388 float *old_floor, float *flcoeffs1,

389 float *flcoeffs2)

390 {

391 int i;

392 /* FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors

393 * and flcoeffs2 old scale factors

394 * might be incomplete due to a missing table that is in the binary code

395 */

396 for (i = 0; i < BANDS; i++) {

397 flcoeffs1[i] = 0;

398 if (levlCoeffBuf[i] < 16) {

399 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];

400 flcoeffs2[i] = (levlCoeffBuf[i] - 7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25

401 } else {

402 flcoeffs1[i] = old_floor[i];

403 }

404 }

405 }

406

407 static void imc_decode_level_coefficients_raw(IMCContext *q, int *levlCoeffBuf,

408 float *flcoeffs1, float *flcoeffs2)

409 {

410 int i, level, pos;

411 float tmp, tmp2;

412

413 pos = q->coef0_pos;

414 flcoeffs1[pos] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125

415 flcoeffs2[pos] = log2f(flcoeffs1[0]);

416 tmp = flcoeffs1[pos];

417 tmp2 = flcoeffs2[pos];

418

419 levlCoeffBuf++;

420 for (i = 0; i < BANDS; i++) {

421 if (i == pos)

422 continue;

423 level = *levlCoeffBuf++;

424 flcoeffs1[i] = tmp * powf(10.0, -level * 0.4375); //todo tab

425 flcoeffs2[i] = tmp2 - 1.4533435415 * level; // 1.4533435415 = log2(10) * 0.4375

426 }

427 }

428

429 /**

430 * Perform bit allocation depending on bits available

431 */

432 static int bit_allocation(IMCContext *q, IMCChannel *chctx,

433 int stream_format_code, int freebits, int flag)

434 {

435 int i, j;

436 const float limit = -1.e20;

437 float highest = 0.0;

438 int indx;

439 int t1 = 0;

440 int t2 = 1;

441 float summa = 0.0;

442 int iacc = 0;

443 int summer = 0;

444 int rres, cwlen;

445 float lowest = 1.e10;

446 int low_indx = 0;

447 float workT[32];

448 int flg;

449 int found_indx = 0;

450

451 for (i = 0; i < BANDS; i++)

452 highest = FFMAX(highest, chctx->flcoeffs1[i]);

453

454 for (i = 0; i < BANDS - 1; i++) {

455 if (chctx->flcoeffs5[i] <= 0) {

456 av_log(NULL, AV_LOG_ERROR, "flcoeffs5 %f invalid\n", chctx->flcoeffs5[i]);

457 return AVERROR_INVALIDDATA;

458 }

459 chctx->flcoeffs4[i] = chctx->flcoeffs3[i] - log2f(chctx->flcoeffs5[i]);

460 }

461 chctx->flcoeffs4[BANDS - 1] = limit;

462

463 highest = highest * 0.25;

464

465 for (i = 0; i < BANDS; i++) {

466 indx = -1;

467 if ((band_tab[i + 1] - band_tab[i]) == chctx->bandWidthT[i])

468 indx = 0;

469

470 if ((band_tab[i + 1] - band_tab[i]) > chctx->bandWidthT[i])

471 indx = 1;

472

473 if (((band_tab[i + 1] - band_tab[i]) / 2) >= chctx->bandWidthT[i])

474 indx = 2;

475

476 if (indx == -1)

477 return AVERROR_INVALIDDATA;

478

479 chctx->flcoeffs4[i] += xTab[(indx * 2 + (chctx->flcoeffs1[i] < highest)) * 2 + flag];

480 }

481

482 if (stream_format_code & 0x2) {

483 chctx->flcoeffs4[0] = limit;

484 chctx->flcoeffs4[1] = limit;

485 chctx->flcoeffs4[2] = limit;

486 chctx->flcoeffs4[3] = limit;

487 }

488

489 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS - 1; i++) {

490 iacc += chctx->bandWidthT[i];

491 summa += chctx->bandWidthT[i] * chctx->flcoeffs4[i];

492 }

493

494 if (!iacc)

495 return AVERROR_INVALIDDATA;

496

497 chctx->bandWidthT[BANDS - 1] = 0;

498 summa = (summa * 0.5 - freebits) / iacc;

499

500

501 for (i = 0; i < BANDS / 2; i++) {

502 rres = summer - freebits;

503 if ((rres >= -8) && (rres <= 8))

504 break;

505

506 summer = 0;

507 iacc = 0;

508

509 for (j = (stream_format_code & 0x2) ? 4 : 0; j < BANDS; j++) {

510 cwlen = av_clipf(((chctx->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);

511

512 chctx->bitsBandT[j] = cwlen;

513 summer += chctx->bandWidthT[j] * cwlen;

514

515 if (cwlen > 0)

516 iacc += chctx->bandWidthT[j];

517 }

518

519 flg = t2;

520 t2 = 1;

521 if (freebits < summer)

522 t2 = -1;

523 if (i == 0)

524 flg = t2;

525 if (flg != t2)

526 t1++;

527

528 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;

529 }

530

531 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS; i++) {

532 for (j = band_tab[i]; j < band_tab[i + 1]; j++)

533 chctx->CWlengthT[j] = chctx->bitsBandT[i];

534 }

535

536 if (freebits > summer) {

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

538 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20

539 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);

540 }

541

542 highest = 0.0;

543

544 do {

545 if (highest <= -1.e20)

546 break;

547

548 found_indx = 0;

549 highest = -1.e20;

550

551 for (i = 0; i < BANDS; i++) {

552 if (workT[i] > highest) {

553 highest = workT[i];

554 found_indx = i;

555 }

556 }

557

558 if (highest > -1.e20) {

559 workT[found_indx] -= 2.0;

560 if (++chctx->bitsBandT[found_indx] == 6)

561 workT[found_indx] = -1.e20;

562

563 for (j = band_tab[found_indx]; j < band_tab[found_indx + 1] && (freebits > summer); j++) {

564 chctx->CWlengthT[j]++;

565 summer++;

566 }

567 }

568 } while (freebits > summer);

569 }

570 if (freebits < summer) {

571 for (i = 0; i < BANDS; i++) {

572 workT[i] = chctx->bitsBandT[i] ? (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] + 1.585)

573 : 1.e20;

574 }

575 if (stream_format_code & 0x2) {

576 workT[0] = 1.e20;

577 workT[1] = 1.e20;

578 workT[2] = 1.e20;

579 workT[3] = 1.e20;

580 }

581 while (freebits < summer) {

582 lowest = 1.e10;

583 low_indx = 0;

584 for (i = 0; i < BANDS; i++) {

585 if (workT[i] < lowest) {

586 lowest = workT[i];

587 low_indx = i;

588 }

589 }

590 // if (lowest >= 1.e10)

591 // break;

592 workT[low_indx] = lowest + 2.0;

593

594 if (!--chctx->bitsBandT[low_indx])

595 workT[low_indx] = 1.e20;

596

597 for (j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++) {

598 if (chctx->CWlengthT[j] > 0) {

599 chctx->CWlengthT[j]--;

600 summer--;

601 }

602 }

603 }

604 }

605 return 0;

606 }

607

608 static void imc_get_skip_coeff(IMCContext *q, IMCChannel *chctx)

609 {

610 int i, j;

611

612 memset(chctx->skipFlagBits, 0, sizeof(chctx->skipFlagBits));

613 memset(chctx->skipFlagCount, 0, sizeof(chctx->skipFlagCount));

614 for (i = 0; i < BANDS; i++) {

615 if (!chctx->bandFlagsBuf[i] || !chctx->bandWidthT[i])

616 continue;

617

618 if (!chctx->skipFlagRaw[i]) {

619 chctx->skipFlagBits[i] = band_tab[i + 1] - band_tab[i];

620

621 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {

622 chctx->skipFlags[j] = get_bits1(&q->gb);

623 if (chctx->skipFlags[j])

624 chctx->skipFlagCount[i]++;

625 }

626 } else {

627 for (j = band_tab[i]; j < band_tab[i + 1] - 1; j += 2) {

628 if (!get_bits1(&q->gb)) { // 0

629 chctx->skipFlagBits[i]++;

630 chctx->skipFlags[j] = 1;

631 chctx->skipFlags[j + 1] = 1;

632 chctx->skipFlagCount[i] += 2;

633 } else {

634 if (get_bits1(&q->gb)) { // 11

635 chctx->skipFlagBits[i] += 2;

636 chctx->skipFlags[j] = 0;

637 chctx->skipFlags[j + 1] = 1;

638 chctx->skipFlagCount[i]++;

639 } else {

640 chctx->skipFlagBits[i] += 3;

641 chctx->skipFlags[j + 1] = 0;

642 if (!get_bits1(&q->gb)) { // 100

643 chctx->skipFlags[j] = 1;

644 chctx->skipFlagCount[i]++;

645 } else { // 101

646 chctx->skipFlags[j] = 0;

647 }

648 }

649 }

650 }

651

652 if (j < band_tab[i + 1]) {

653 chctx->skipFlagBits[i]++;

654 if ((chctx->skipFlags[j] = get_bits1(&q->gb)))

655 chctx->skipFlagCount[i]++;

656 }

657 }

658 }

659 }

660

661 /**

662 * Increase highest' band coefficient sizes as some bits won't be used

663 */

664 static void imc_adjust_bit_allocation(IMCContext *q, IMCChannel *chctx,

665 int summer)

666 {

667 float workT[32];

668 int corrected = 0;

669 int i, j;

670 float highest = 0;

671 int found_indx = 0;

672

673 for (i = 0; i < BANDS; i++) {

674 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20

675 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);

676 }

677

678 while (corrected < summer) {

679 if (highest <= -1.e20)

680 break;

681

682 highest = -1.e20;

683

684 for (i = 0; i < BANDS; i++) {

685 if (workT[i] > highest) {

686 highest = workT[i];

687 found_indx = i;

688 }

689 }

690

691 if (highest > -1.e20) {

692 workT[found_indx] -= 2.0;

693 if (++(chctx->bitsBandT[found_indx]) == 6)

694 workT[found_indx] = -1.e20;

695

696 for (j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {

697 if (!chctx->skipFlags[j] && (chctx->CWlengthT[j] < 6)) {

698 chctx->CWlengthT[j]++;

699 corrected++;

700 }

701 }

702 }

703 }

704 }

705

706 static void imc_imdct256(IMCContext *q, IMCChannel *chctx, int channels)

707 {

708 int i;

709 float re, im;

710 float *dst1 = q->out_samples;

711 float *dst2 = q->out_samples + (COEFFS - 1);

712

713 /* prerotation */

714 for (i = 0; i < COEFFS / 2; i++) {

715 q->samples[i].re = -(q->pre_coef1[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -

716 (q->pre_coef2[i] * chctx->CWdecoded[i * 2]);

717 q->samples[i].im = (q->pre_coef2[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -

718 (q->pre_coef1[i] * chctx->CWdecoded[i * 2]);

719 }

720

721 /* FFT */

722 q->fft.fft_permute(&q->fft, q->samples);

723 q->fft.fft_calc(&q->fft, q->samples);

724

725 /* postrotation, window and reorder */

726 for (i = 0; i < COEFFS / 2; i++) {

727 re = ( q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);

728 im = (-q->samples[i].im * q->post_cos[i]) - ( q->samples[i].re * q->post_sin[i]);

729 *dst1 = (q->mdct_sine_window[COEFFS - 1 - i * 2] * chctx->last_fft_im[i])

730 + (q->mdct_sine_window[i * 2] * re);

731 *dst2 = (q->mdct_sine_window[i * 2] * chctx->last_fft_im[i])

732 - (q->mdct_sine_window[COEFFS - 1 - i * 2] * re);

733 dst1 += 2;

734 dst2 -= 2;

735 chctx->last_fft_im[i] = im;

736 }

737 }

738

739 static int inverse_quant_coeff(IMCContext *q, IMCChannel *chctx,

740 int stream_format_code)

741 {

742 int i, j;

743 int middle_value, cw_len, max_size;

744 const float *quantizer;

745

746 for (i = 0; i < BANDS; i++) {

747 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {

748 chctx->CWdecoded[j] = 0;

749 cw_len = chctx->CWlengthT[j];

750

751 if (cw_len <= 0 || chctx->skipFlags[j])

752 continue;

753

754 max_size = 1 << cw_len;

755 middle_value = max_size >> 1;

756

757 if (chctx->codewords[j] >= max_size || chctx->codewords[j] < 0)

758 return AVERROR_INVALIDDATA;

759

760 if (cw_len >= 4) {

761 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];

762 if (chctx->codewords[j] >= middle_value)

763 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 8] * chctx->flcoeffs6[i];

764 else

765 chctx->CWdecoded[j] = -quantizer[max_size - chctx->codewords[j] - 8 - 1] * chctx->flcoeffs6[i];

766 }else{

767 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (chctx->bandFlagsBuf[i] << 1)];

768 if (chctx->codewords[j] >= middle_value)

769 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 1] * chctx->flcoeffs6[i];

770 else

771 chctx->CWdecoded[j] = -quantizer[max_size - 2 - chctx->codewords[j]] * chctx->flcoeffs6[i];

772 }

773 }

774 }

775 return 0;

776 }

777

778

779 static int imc_get_coeffs(IMCContext *q, IMCChannel *chctx)

780 {

781 int i, j, cw_len, cw;

782

783 for (i = 0; i < BANDS; i++) {

784 if (!chctx->sumLenArr[i])

785 continue;

786 if (chctx->bandFlagsBuf[i] || chctx->bandWidthT[i]) {

787 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {

788 cw_len = chctx->CWlengthT[j];

789 cw = 0;

790

791 if (get_bits_count(&q->gb) + cw_len > 512) {

792 av_dlog(NULL, "Band %i coeff %i cw_len %i\n", i, j, cw_len);

793 return AVERROR_INVALIDDATA;

794 }

795

796 if (cw_len && (!chctx->bandFlagsBuf[i] || !chctx->skipFlags[j]))

797 cw = get_bits(&q->gb, cw_len);

798

799 chctx->codewords[j] = cw;

800 }

801 }

802 }

803 return 0;

804 }

805

806 static void imc_refine_bit_allocation(IMCContext *q, IMCChannel *chctx)

807 {

808 int i, j;

809 int bits, summer;

810

811 for (i = 0; i < BANDS; i++) {

812 chctx->sumLenArr[i] = 0;

813 chctx->skipFlagRaw[i] = 0;

814 for (j = band_tab[i]; j < band_tab[i + 1]; j++)

815 chctx->sumLenArr[i] += chctx->CWlengthT[j];

816 if (chctx->bandFlagsBuf[i])

817 if ((((band_tab[i + 1] - band_tab[i]) * 1.5) > chctx->sumLenArr[i]) && (chctx->sumLenArr[i] > 0))

818 chctx->skipFlagRaw[i] = 1;

819 }

820

821 imc_get_skip_coeff(q, chctx);

822

823 for (i = 0; i < BANDS; i++) {

824 chctx->flcoeffs6[i] = chctx->flcoeffs1[i];

825 /* band has flag set and at least one coded coefficient */

826 if (chctx->bandFlagsBuf[i] && (band_tab[i + 1] - band_tab[i]) != chctx->skipFlagCount[i]) {

827 chctx->flcoeffs6[i] *= q->sqrt_tab[ band_tab[i + 1] - band_tab[i]] /

828 q->sqrt_tab[(band_tab[i + 1] - band_tab[i] - chctx->skipFlagCount[i])];

829 }

830 }

831

832 /* calculate bits left, bits needed and adjust bit allocation */

833 bits = summer = 0;

834

835 for (i = 0; i < BANDS; i++) {

836 if (chctx->bandFlagsBuf[i]) {

837 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {

838 if (chctx->skipFlags[j]) {

839 summer += chctx->CWlengthT[j];

840 chctx->CWlengthT[j] = 0;

841 }

842 }

843 bits += chctx->skipFlagBits[i];

844 summer -= chctx->skipFlagBits[i];

845 }

846 }

847 imc_adjust_bit_allocation(q, chctx, summer);

848 }

849

850 static int imc_decode_block(AVCodecContext *avctx, IMCContext *q, int ch)

851 {

852 int stream_format_code;

853 int imc_hdr, i, j, ret;

854 int flag;

855 int bits;

856 int counter, bitscount;

857 IMCChannel *chctx = q->chctx + ch;

858

859

860 /* Check the frame header */

861 imc_hdr = get_bits(&q->gb, 9);

862 if (imc_hdr & 0x18) {

863 av_log(avctx, AV_LOG_ERROR, "frame header check failed!\n");

864 av_log(avctx, AV_LOG_ERROR, "got %X.\n", imc_hdr);

865 return AVERROR_INVALIDDATA;

866 }

867 stream_format_code = get_bits(&q->gb, 3);

868

869 if (stream_format_code & 0x04)

870 chctx->decoder_reset = 1;

871

872 if (chctx->decoder_reset) {

873 for (i = 0; i < BANDS; i++)

874 chctx->old_floor[i] = 1.0;

875 for (i = 0; i < COEFFS; i++)

876 chctx->CWdecoded[i] = 0;

877 chctx->decoder_reset = 0;

878 }

879

880 flag = get_bits1(&q->gb);

881 if (stream_format_code & 0x1)

882 imc_decode_level_coefficients_raw(q, chctx->levlCoeffBuf,

883 chctx->flcoeffs1, chctx->flcoeffs2);

884 else if (stream_format_code & 0x1)

885 imc_read_level_coeffs_raw(q, stream_format_code, chctx->levlCoeffBuf);

886 else

887 imc_read_level_coeffs(q, stream_format_code, chctx->levlCoeffBuf);

888

889 if (stream_format_code & 0x4)

890 imc_decode_level_coefficients(q, chctx->levlCoeffBuf,

891 chctx->flcoeffs1, chctx->flcoeffs2);

892 else

893 imc_decode_level_coefficients2(q, chctx->levlCoeffBuf, chctx->old_floor,

894 chctx->flcoeffs1, chctx->flcoeffs2);

895

896 for(i=0; i<BANDS; i++) {

897 if(chctx->flcoeffs1[i] > INT_MAX) {

898 av_log(avctx, AV_LOG_ERROR, "scalefactor out of range\n");

899 return AVERROR_INVALIDDATA;

900 }

901 }

902

903 memcpy(chctx->old_floor, chctx->flcoeffs1, 32 * sizeof(float));

904

905 counter = 0;

906 if (stream_format_code & 0x1) {

907 for (i = 0; i < BANDS; i++) {

908 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];

909 chctx->bandFlagsBuf[i] = 0;

910 chctx->flcoeffs3[i] = chctx->flcoeffs2[i] * 2;

911 chctx->flcoeffs5[i] = 1.0;

912 }

913 } else {

914 for (i = 0; i < BANDS; i++) {

915 if (chctx->levlCoeffBuf[i] == 16) {

916 chctx->bandWidthT[i] = 0;

917 counter++;

918 } else

919 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];

920 }

921

922 memset(chctx->bandFlagsBuf, 0, BANDS * sizeof(int));

923 for (i = 0; i < BANDS - 1; i++)

924 if (chctx->bandWidthT[i])

925 chctx->bandFlagsBuf[i] = get_bits1(&q->gb);

926

927 imc_calculate_coeffs(q, chctx->flcoeffs1, chctx->flcoeffs2,

928 chctx->bandWidthT, chctx->flcoeffs3,

929 chctx->flcoeffs5);

930 }

931

932 bitscount = 0;

933 /* first 4 bands will be assigned 5 bits per coefficient */

934 if (stream_format_code & 0x2) {

935 bitscount += 15;

936

937 chctx->bitsBandT[0] = 5;

938 chctx->CWlengthT[0] = 5;

939 chctx->CWlengthT[1] = 5;

940 chctx->CWlengthT[2] = 5;

941 for (i = 1; i < 4; i++) {

942 if (stream_format_code & 0x1)

943 bits = 5;

944 else

945 bits = (chctx->levlCoeffBuf[i] == 16) ? 0 : 5;

946 chctx->bitsBandT[i] = bits;

947 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {

948 chctx->CWlengthT[j] = bits;

949 bitscount += bits;

950 }

951 }

952 }

953 if (avctx->codec_id == AV_CODEC_ID_IAC) {

954 bitscount += !!chctx->bandWidthT[BANDS - 1];

955 if (!(stream_format_code & 0x2))

956 bitscount += 16;

957 }

958

959 if ((ret = bit_allocation(q, chctx, stream_format_code,

960 512 - bitscount - get_bits_count(&q->gb),

961 flag)) < 0) {

962 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");

963 chctx->decoder_reset = 1;

964 return ret;

965 }

966

967 if (stream_format_code & 0x1) {

968 for (i = 0; i < BANDS; i++)

969 chctx->skipFlags[i] = 0;

970 } else {

971 imc_refine_bit_allocation(q, chctx);

972 }

973

974 for (i = 0; i < BANDS; i++) {

975 chctx->sumLenArr[i] = 0;

976

977 for (j = band_tab[i]; j < band_tab[i + 1]; j++)

978 if (!chctx->skipFlags[j])

979 chctx->sumLenArr[i] += chctx->CWlengthT[j];

980 }

981

982 memset(chctx->codewords, 0, sizeof(chctx->codewords));

983

984 if (imc_get_coeffs(q, chctx) < 0) {

985 av_log(avctx, AV_LOG_ERROR, "Read coefficients failed\n");

986 chctx->decoder_reset = 1;

987 return AVERROR_INVALIDDATA;

988 }

989

990 if (inverse_quant_coeff(q, chctx, stream_format_code) < 0) {

991 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");

992 chctx->decoder_reset = 1;

993 return AVERROR_INVALIDDATA;

994 }

995

996 memset(chctx->skipFlags, 0, sizeof(chctx->skipFlags));

997

998 imc_imdct256(q, chctx, avctx->channels);

999

1000 return 0;

1001 }

1002

1003 static int imc_decode_frame(AVCodecContext *avctx, void *data,

1004 int *got_frame_ptr, AVPacket *avpkt)

1005 {

1006 AVFrame *frame = data;

1007 const uint8_t *buf = avpkt->data;

1008 int buf_size = avpkt->size;

1009 int ret, i;

1010

1011 IMCContext *q = avctx->priv_data;

1012

1013 LOCAL_ALIGNED_16(uint16_t, buf16, [IMC_BLOCK_SIZE / 2]);

1014

1015 if (buf_size < IMC_BLOCK_SIZE * avctx->channels) {

1016 av_log(avctx, AV_LOG_ERROR, "frame too small!\n");

1017 return AVERROR_INVALIDDATA;

1018 }

1019

1020 /* get output buffer */

1021 frame->nb_samples = COEFFS;

1022 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)

1023 return ret;

1024

1025 for (i = 0; i < avctx->channels; i++) {

1026 q->out_samples = (float *)frame->extended_data[i];

1027

1028 q->dsp.bswap16_buf(buf16, (const uint16_t*)buf, IMC_BLOCK_SIZE / 2);

1029

1030 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);

1031

1032 buf += IMC_BLOCK_SIZE;

1033

1034 if ((ret = imc_decode_block(avctx, q, i)) < 0)

1035 return ret;

1036 }

1037

1038 if (avctx->channels == 2) {

1039 q->fdsp.butterflies_float((float *)frame->extended_data[0],

1040 (float *)frame->extended_data[1], COEFFS);

1041 }

1042

1043 *got_frame_ptr = 1;

1044

1045 return IMC_BLOCK_SIZE * avctx->channels;

1046 }

1047

1048

1049 static av_cold int imc_decode_close(AVCodecContext * avctx)

1050 {

1051 IMCContext *q = avctx->priv_data;

1052

1053 ff_fft_end(&q->fft);

1054

1055 return 0;

1056 }

1057

1058 static av_cold void flush(AVCodecContext *avctx)

1059 {

1060 IMCContext *q = avctx->priv_data;

1061

1062 q->chctx[0].decoder_reset =

1063 q->chctx[1].decoder_reset = 1;

1064 }

1065

1066 #if CONFIG_IMC_DECODER

1067 AVCodec ff_imc_decoder = {

1068 .name = "imc",

1069 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),

1070 .type = AVMEDIA_TYPE_AUDIO,

1071 .id = AV_CODEC_ID_IMC,

1072 .priv_data_size = sizeof(IMCContext),

1073 .init = imc_decode_init,

1074 .close = imc_decode_close,

1075 .decode = imc_decode_frame,

1076 .flush = flush,

1077 .capabilities = CODEC_CAP_DR1,

1078 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,

1079 AV_SAMPLE_FMT_NONE },

1080 };

1081 #endif

1082 #if CONFIG_IAC_DECODER

1083 AVCodec ff_iac_decoder = {

1084 .name = "iac",

1085 .long_name = NULL_IF_CONFIG_SMALL("IAC (Indeo Audio Coder)"),

1086 .type = AVMEDIA_TYPE_AUDIO,

1087 .id = AV_CODEC_ID_IAC,

1088 .priv_data_size = sizeof(IMCContext),

1089 .init = imc_decode_init,

1090 .close = imc_decode_close,

1091 .decode = imc_decode_frame,

1092 .flush = flush,

1093 .capabilities = CODEC_CAP_DR1,

1094 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,

1095 AV_SAMPLE_FMT_NONE },

1096 };

1097 #endif

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