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00032 #include "libavutil/audioconvert.h"
00033 #include "libavutil/avassert.h"
00034 #include "libavutil/crc.h"
00035 #include "avcodec.h"
00036 #include "put_bits.h"
00037 #include "dsputil.h"
00038 #include "ac3dsp.h"
00039 #include "ac3.h"
00040 #include "audioconvert.h"
00041
00042
00043 #ifndef CONFIG_AC3ENC_FLOAT
00044 #define CONFIG_AC3ENC_FLOAT 0
00045 #endif
00046
00047
00049 #define AC3_MAX_EXP_GROUPS 85
00050
00051
00052 #define AC3_REMATRIXING_IS_STATIC 0x1
00053 #define AC3_REMATRIXING_SUMS 0
00054 #define AC3_REMATRIXING_NONE 1
00055 #define AC3_REMATRIXING_ALWAYS 3
00056
00058 #define SCALE_FLOAT(a, bits) lrintf((a) * (float)(1 << (bits)))
00059
00060
00061 #if CONFIG_AC3ENC_FLOAT
00062 #include "ac3enc_float.h"
00063 #else
00064 #include "ac3enc_fixed.h"
00065 #endif
00066
00067
00071 typedef struct AC3Block {
00072 uint8_t **bap;
00073 CoefType **mdct_coef;
00074 int32_t **fixed_coef;
00075 uint8_t **exp;
00076 uint8_t **grouped_exp;
00077 int16_t **psd;
00078 int16_t **band_psd;
00079 int16_t **mask;
00080 uint16_t **qmant;
00081 int8_t exp_shift[AC3_MAX_CHANNELS];
00082 uint8_t new_rematrixing_strategy;
00083 uint8_t rematrixing_flags[4];
00084 } AC3Block;
00085
00089 typedef struct AC3EncodeContext {
00090 PutBitContext pb;
00091 DSPContext dsp;
00092 AC3DSPContext ac3dsp;
00093 AC3MDCTContext mdct;
00094
00095 AC3Block blocks[AC3_MAX_BLOCKS];
00096
00097 int bitstream_id;
00098 int bitstream_mode;
00099
00100 int bit_rate;
00101 int sample_rate;
00102
00103 int frame_size_min;
00104 int frame_size;
00105 int frame_size_code;
00106 uint16_t crc_inv[2];
00107 int bits_written;
00108 int samples_written;
00109
00110 int fbw_channels;
00111 int channels;
00112 int lfe_on;
00113 int lfe_channel;
00114 int channel_mode;
00115 const uint8_t *channel_map;
00116
00117 int cutoff;
00118 int bandwidth_code[AC3_MAX_CHANNELS];
00119 int nb_coefs[AC3_MAX_CHANNELS];
00120
00121 int rematrixing;
00122 int num_rematrixing_bands;
00123
00124
00125 int slow_gain_code;
00126 int slow_decay_code;
00127 int fast_decay_code;
00128 int db_per_bit_code;
00129 int floor_code;
00130 AC3BitAllocParameters bit_alloc;
00131 int coarse_snr_offset;
00132 int fast_gain_code[AC3_MAX_CHANNELS];
00133 int fine_snr_offset[AC3_MAX_CHANNELS];
00134 int frame_bits_fixed;
00135 int frame_bits;
00136 int exponent_bits;
00137
00138
00139 int mant1_cnt, mant2_cnt, mant4_cnt;
00140 uint16_t *qmant1_ptr, *qmant2_ptr, *qmant4_ptr;
00141
00142 SampleType **planar_samples;
00143 uint8_t *bap_buffer;
00144 uint8_t *bap1_buffer;
00145 CoefType *mdct_coef_buffer;
00146 int32_t *fixed_coef_buffer;
00147 uint8_t *exp_buffer;
00148 uint8_t *grouped_exp_buffer;
00149 int16_t *psd_buffer;
00150 int16_t *band_psd_buffer;
00151 int16_t *mask_buffer;
00152 uint16_t *qmant_buffer;
00153
00154 uint8_t exp_strategy[AC3_MAX_CHANNELS][AC3_MAX_BLOCKS];
00155
00156 DECLARE_ALIGNED(16, SampleType, windowed_samples)[AC3_WINDOW_SIZE];
00157 } AC3EncodeContext;
00158
00159
00160
00161
00162 static av_cold void mdct_end(AC3MDCTContext *mdct);
00163
00164 static av_cold int mdct_init(AVCodecContext *avctx, AC3MDCTContext *mdct,
00165 int nbits);
00166
00167 static void mdct512(AC3MDCTContext *mdct, CoefType *out, SampleType *in);
00168
00169 static void apply_window(DSPContext *dsp, SampleType *output, const SampleType *input,
00170 const SampleType *window, int n);
00171
00172 static int normalize_samples(AC3EncodeContext *s);
00173
00174 static void scale_coefficients(AC3EncodeContext *s);
00175
00176
00181 static uint8_t exponent_group_tab[3][256];
00182
00183
00187 static const int64_t ac3_channel_layouts[] = {
00188 AV_CH_LAYOUT_MONO,
00189 AV_CH_LAYOUT_STEREO,
00190 AV_CH_LAYOUT_2_1,
00191 AV_CH_LAYOUT_SURROUND,
00192 AV_CH_LAYOUT_2_2,
00193 AV_CH_LAYOUT_QUAD,
00194 AV_CH_LAYOUT_4POINT0,
00195 AV_CH_LAYOUT_5POINT0,
00196 AV_CH_LAYOUT_5POINT0_BACK,
00197 (AV_CH_LAYOUT_MONO | AV_CH_LOW_FREQUENCY),
00198 (AV_CH_LAYOUT_STEREO | AV_CH_LOW_FREQUENCY),
00199 (AV_CH_LAYOUT_2_1 | AV_CH_LOW_FREQUENCY),
00200 (AV_CH_LAYOUT_SURROUND | AV_CH_LOW_FREQUENCY),
00201 (AV_CH_LAYOUT_2_2 | AV_CH_LOW_FREQUENCY),
00202 (AV_CH_LAYOUT_QUAD | AV_CH_LOW_FREQUENCY),
00203 (AV_CH_LAYOUT_4POINT0 | AV_CH_LOW_FREQUENCY),
00204 AV_CH_LAYOUT_5POINT1,
00205 AV_CH_LAYOUT_5POINT1_BACK,
00206 0
00207 };
00208
00209
00214 static void adjust_frame_size(AC3EncodeContext *s)
00215 {
00216 while (s->bits_written >= s->bit_rate && s->samples_written >= s->sample_rate) {
00217 s->bits_written -= s->bit_rate;
00218 s->samples_written -= s->sample_rate;
00219 }
00220 s->frame_size = s->frame_size_min +
00221 2 * (s->bits_written * s->sample_rate < s->samples_written * s->bit_rate);
00222 s->bits_written += s->frame_size * 8;
00223 s->samples_written += AC3_FRAME_SIZE;
00224 }
00225
00226
00231 static void deinterleave_input_samples(AC3EncodeContext *s,
00232 const SampleType *samples)
00233 {
00234 int ch, i;
00235
00236
00237 for (ch = 0; ch < s->channels; ch++) {
00238 const SampleType *sptr;
00239 int sinc;
00240
00241
00242 memcpy(&s->planar_samples[ch][0], &s->planar_samples[ch][AC3_FRAME_SIZE],
00243 AC3_BLOCK_SIZE * sizeof(s->planar_samples[0][0]));
00244
00245
00246 sinc = s->channels;
00247 sptr = samples + s->channel_map[ch];
00248 for (i = AC3_BLOCK_SIZE; i < AC3_FRAME_SIZE+AC3_BLOCK_SIZE; i++) {
00249 s->planar_samples[ch][i] = *sptr;
00250 sptr += sinc;
00251 }
00252 }
00253 }
00254
00255
00261 static void apply_mdct(AC3EncodeContext *s)
00262 {
00263 int blk, ch;
00264
00265 for (ch = 0; ch < s->channels; ch++) {
00266 for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
00267 AC3Block *block = &s->blocks[blk];
00268 const SampleType *input_samples = &s->planar_samples[ch][blk * AC3_BLOCK_SIZE];
00269
00270 apply_window(&s->dsp, s->windowed_samples, input_samples, s->mdct.window, AC3_WINDOW_SIZE);
00271
00272 block->exp_shift[ch] = normalize_samples(s);
00273
00274 mdct512(&s->mdct, block->mdct_coef[ch], s->windowed_samples);
00275 }
00276 }
00277 }
00278
00279
00284 static void rematrixing_init(AC3EncodeContext *s)
00285 {
00286 if (s->channel_mode == AC3_CHMODE_STEREO)
00287 s->rematrixing = AC3_REMATRIXING_SUMS;
00288 else
00289 s->rematrixing = AC3_REMATRIXING_NONE;
00290
00291
00292
00293 if (s->rematrixing & AC3_REMATRIXING_IS_STATIC) {
00294 int flag = (s->rematrixing == AC3_REMATRIXING_ALWAYS);
00295 s->blocks[0].new_rematrixing_strategy = 1;
00296 memset(s->blocks[0].rematrixing_flags, flag,
00297 sizeof(s->blocks[0].rematrixing_flags));
00298 }
00299 }
00300
00301
00305 static void compute_rematrixing_strategy(AC3EncodeContext *s)
00306 {
00307 int nb_coefs;
00308 int blk, bnd, i;
00309 AC3Block *block, *block0;
00310
00311 s->num_rematrixing_bands = 4;
00312
00313 if (s->rematrixing & AC3_REMATRIXING_IS_STATIC)
00314 return;
00315
00316 nb_coefs = FFMIN(s->nb_coefs[0], s->nb_coefs[1]);
00317
00318 for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
00319 block = &s->blocks[blk];
00320 block->new_rematrixing_strategy = !blk;
00321 for (bnd = 0; bnd < s->num_rematrixing_bands; bnd++) {
00322
00323 int start = ff_ac3_rematrix_band_tab[bnd];
00324 int end = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]);
00325 CoefSumType sum[4] = {0,};
00326 for (i = start; i < end; i++) {
00327 CoefType lt = block->mdct_coef[0][i];
00328 CoefType rt = block->mdct_coef[1][i];
00329 CoefType md = lt + rt;
00330 CoefType sd = lt - rt;
00331 sum[0] += lt * lt;
00332 sum[1] += rt * rt;
00333 sum[2] += md * md;
00334 sum[3] += sd * sd;
00335 }
00336
00337
00338 if (FFMIN(sum[2], sum[3]) < FFMIN(sum[0], sum[1]))
00339 block->rematrixing_flags[bnd] = 1;
00340 else
00341 block->rematrixing_flags[bnd] = 0;
00342
00343
00344 if (blk &&
00345 block->rematrixing_flags[bnd] != block0->rematrixing_flags[bnd]) {
00346 block->new_rematrixing_strategy = 1;
00347 }
00348 }
00349 block0 = block;
00350 }
00351 }
00352
00353
00357 static void apply_rematrixing(AC3EncodeContext *s)
00358 {
00359 int nb_coefs;
00360 int blk, bnd, i;
00361 int start, end;
00362 uint8_t *flags;
00363
00364 if (s->rematrixing == AC3_REMATRIXING_NONE)
00365 return;
00366
00367 nb_coefs = FFMIN(s->nb_coefs[0], s->nb_coefs[1]);
00368
00369 for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
00370 AC3Block *block = &s->blocks[blk];
00371 if (block->new_rematrixing_strategy)
00372 flags = block->rematrixing_flags;
00373 for (bnd = 0; bnd < s->num_rematrixing_bands; bnd++) {
00374 if (flags[bnd]) {
00375 start = ff_ac3_rematrix_band_tab[bnd];
00376 end = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]);
00377 for (i = start; i < end; i++) {
00378 int32_t lt = block->fixed_coef[0][i];
00379 int32_t rt = block->fixed_coef[1][i];
00380 block->fixed_coef[0][i] = (lt + rt) >> 1;
00381 block->fixed_coef[1][i] = (lt - rt) >> 1;
00382 }
00383 }
00384 }
00385 }
00386 }
00387
00388
00392 static av_cold void exponent_init(AC3EncodeContext *s)
00393 {
00394 int i;
00395 for (i = 73; i < 256; i++) {
00396 exponent_group_tab[0][i] = (i - 1) / 3;
00397 exponent_group_tab[1][i] = (i + 2) / 6;
00398 exponent_group_tab[2][i] = (i + 8) / 12;
00399 }
00400
00401 exponent_group_tab[0][7] = 2;
00402 }
00403
00404
00410 static void extract_exponents(AC3EncodeContext *s)
00411 {
00412 int blk, ch, i;
00413
00414 for (ch = 0; ch < s->channels; ch++) {
00415 for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
00416 AC3Block *block = &s->blocks[blk];
00417 uint8_t *exp = block->exp[ch];
00418 int32_t *coef = block->fixed_coef[ch];
00419 int exp_shift = block->exp_shift[ch];
00420 for (i = 0; i < AC3_MAX_COEFS; i++) {
00421 int e;
00422 int v = abs(coef[i]);
00423 if (v == 0)
00424 e = 24;
00425 else {
00426 e = 23 - av_log2(v) + exp_shift;
00427 if (e >= 24) {
00428 e = 24;
00429 coef[i] = 0;
00430 }
00431 av_assert2(e >= 0);
00432 }
00433 exp[i] = e;
00434 }
00435 }
00436 }
00437 }
00438
00439
00444 #define EXP_DIFF_THRESHOLD 500
00445
00446
00450 static void compute_exp_strategy_ch(AC3EncodeContext *s, uint8_t *exp_strategy,
00451 uint8_t *exp)
00452 {
00453 int blk, blk1;
00454 int exp_diff;
00455
00456
00457
00458 exp_strategy[0] = EXP_NEW;
00459 exp += AC3_MAX_COEFS;
00460 for (blk = 1; blk < AC3_MAX_BLOCKS; blk++) {
00461 exp_diff = s->dsp.sad[0](NULL, exp, exp - AC3_MAX_COEFS, 16, 16);
00462 if (exp_diff > EXP_DIFF_THRESHOLD)
00463 exp_strategy[blk] = EXP_NEW;
00464 else
00465 exp_strategy[blk] = EXP_REUSE;
00466 exp += AC3_MAX_COEFS;
00467 }
00468
00469
00470
00471 blk = 0;
00472 while (blk < AC3_MAX_BLOCKS) {
00473 blk1 = blk + 1;
00474 while (blk1 < AC3_MAX_BLOCKS && exp_strategy[blk1] == EXP_REUSE)
00475 blk1++;
00476 switch (blk1 - blk) {
00477 case 1: exp_strategy[blk] = EXP_D45; break;
00478 case 2:
00479 case 3: exp_strategy[blk] = EXP_D25; break;
00480 default: exp_strategy[blk] = EXP_D15; break;
00481 }
00482 blk = blk1;
00483 }
00484 }
00485
00486
00491 static void compute_exp_strategy(AC3EncodeContext *s)
00492 {
00493 int ch, blk;
00494
00495 for (ch = 0; ch < s->fbw_channels; ch++) {
00496 compute_exp_strategy_ch(s, s->exp_strategy[ch], s->blocks[0].exp[ch]);
00497 }
00498 if (s->lfe_on) {
00499 ch = s->lfe_channel;
00500 s->exp_strategy[ch][0] = EXP_D15;
00501 for (blk = 1; blk < AC3_MAX_BLOCKS; blk++)
00502 s->exp_strategy[ch][blk] = EXP_REUSE;
00503 }
00504 }
00505
00506
00510 static void encode_exponents_blk_ch(uint8_t *exp, int nb_exps, int exp_strategy)
00511 {
00512 int nb_groups, i, k;
00513
00514 nb_groups = exponent_group_tab[exp_strategy-1][nb_exps] * 3;
00515
00516
00517 switch(exp_strategy) {
00518 case EXP_D25:
00519 for (i = 1, k = 1; i <= nb_groups; i++) {
00520 uint8_t exp_min = exp[k];
00521 if (exp[k+1] < exp_min)
00522 exp_min = exp[k+1];
00523 exp[i] = exp_min;
00524 k += 2;
00525 }
00526 break;
00527 case EXP_D45:
00528 for (i = 1, k = 1; i <= nb_groups; i++) {
00529 uint8_t exp_min = exp[k];
00530 if (exp[k+1] < exp_min)
00531 exp_min = exp[k+1];
00532 if (exp[k+2] < exp_min)
00533 exp_min = exp[k+2];
00534 if (exp[k+3] < exp_min)
00535 exp_min = exp[k+3];
00536 exp[i] = exp_min;
00537 k += 4;
00538 }
00539 break;
00540 }
00541
00542
00543 if (exp[0] > 15)
00544 exp[0] = 15;
00545
00546
00547
00548 for (i = 1; i <= nb_groups; i++)
00549 exp[i] = FFMIN(exp[i], exp[i-1] + 2);
00550 i--;
00551 while (--i >= 0)
00552 exp[i] = FFMIN(exp[i], exp[i+1] + 2);
00553
00554
00555 switch (exp_strategy) {
00556 case EXP_D25:
00557 for (i = nb_groups, k = nb_groups * 2; i > 0; i--) {
00558 uint8_t exp1 = exp[i];
00559 exp[k--] = exp1;
00560 exp[k--] = exp1;
00561 }
00562 break;
00563 case EXP_D45:
00564 for (i = nb_groups, k = nb_groups * 4; i > 0; i--) {
00565 exp[k] = exp[k-1] = exp[k-2] = exp[k-3] = exp[i];
00566 k -= 4;
00567 }
00568 break;
00569 }
00570 }
00571
00572
00579 static void encode_exponents(AC3EncodeContext *s)
00580 {
00581 int blk, blk1, ch;
00582 uint8_t *exp, *exp1, *exp_strategy;
00583 int nb_coefs, num_reuse_blocks;
00584
00585 for (ch = 0; ch < s->channels; ch++) {
00586 exp = s->blocks[0].exp[ch];
00587 exp_strategy = s->exp_strategy[ch];
00588 nb_coefs = s->nb_coefs[ch];
00589
00590 blk = 0;
00591 while (blk < AC3_MAX_BLOCKS) {
00592 blk1 = blk + 1;
00593
00594
00595 while (blk1 < AC3_MAX_BLOCKS && exp_strategy[blk1] == EXP_REUSE)
00596 blk1++;
00597 num_reuse_blocks = blk1 - blk - 1;
00598
00599
00600 s->ac3dsp.ac3_exponent_min(exp, num_reuse_blocks, nb_coefs);
00601
00602 encode_exponents_blk_ch(exp, nb_coefs, exp_strategy[blk]);
00603
00604
00605 exp1 = exp + AC3_MAX_COEFS;
00606 while (blk < blk1-1) {
00607 memcpy(exp1, exp, nb_coefs * sizeof(*exp));
00608 exp1 += AC3_MAX_COEFS;
00609 blk++;
00610 }
00611 blk = blk1;
00612 exp = exp1;
00613 }
00614 }
00615 }
00616
00617
00623 static void group_exponents(AC3EncodeContext *s)
00624 {
00625 int blk, ch, i;
00626 int group_size, nb_groups, bit_count;
00627 uint8_t *p;
00628 int delta0, delta1, delta2;
00629 int exp0, exp1;
00630
00631 bit_count = 0;
00632 for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
00633 AC3Block *block = &s->blocks[blk];
00634 for (ch = 0; ch < s->channels; ch++) {
00635 int exp_strategy = s->exp_strategy[ch][blk];
00636 if (exp_strategy == EXP_REUSE)
00637 continue;
00638 group_size = exp_strategy + (exp_strategy == EXP_D45);
00639 nb_groups = exponent_group_tab[exp_strategy-1][s->nb_coefs[ch]];
00640 bit_count += 4 + (nb_groups * 7);
00641 p = block->exp[ch];
00642
00643
00644 exp1 = *p++;
00645 block->grouped_exp[ch][0] = exp1;
00646
00647
00648 for (i = 1; i <= nb_groups; i++) {
00649
00650 exp0 = exp1;
00651 exp1 = p[0];
00652 p += group_size;
00653 delta0 = exp1 - exp0 + 2;
00654 av_assert2(delta0 >= 0 && delta0 <= 4);
00655
00656 exp0 = exp1;
00657 exp1 = p[0];
00658 p += group_size;
00659 delta1 = exp1 - exp0 + 2;
00660 av_assert2(delta1 >= 0 && delta1 <= 4);
00661
00662 exp0 = exp1;
00663 exp1 = p[0];
00664 p += group_size;
00665 delta2 = exp1 - exp0 + 2;
00666 av_assert2(delta2 >= 0 && delta2 <= 4);
00667
00668 block->grouped_exp[ch][i] = ((delta0 * 5 + delta1) * 5) + delta2;
00669 }
00670 }
00671 }
00672
00673 s->exponent_bits = bit_count;
00674 }
00675
00676
00682 static void process_exponents(AC3EncodeContext *s)
00683 {
00684 extract_exponents(s);
00685
00686 compute_exp_strategy(s);
00687
00688 encode_exponents(s);
00689
00690 group_exponents(s);
00691
00692 emms_c();
00693 }
00694
00695
00700 static void count_frame_bits_fixed(AC3EncodeContext *s)
00701 {
00702 static const int frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 };
00703 int blk;
00704 int frame_bits;
00705
00706
00707
00708
00709
00710
00711
00712
00713
00714
00715
00716
00717 frame_bits = 65;
00718 frame_bits += frame_bits_inc[s->channel_mode];
00719
00720
00721 for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
00722 frame_bits += s->fbw_channels * 2 + 2;
00723 if (s->channel_mode == AC3_CHMODE_STEREO) {
00724 frame_bits++;
00725 }
00726 frame_bits += 2 * s->fbw_channels;
00727 if (s->lfe_on)
00728 frame_bits++;
00729 frame_bits++;
00730 frame_bits++;
00731 frame_bits += 2;
00732 }
00733 frame_bits++;
00734
00735
00736
00737
00738 frame_bits += 2*4 + 3 + 6 + s->channels * (4 + 3);
00739
00740
00741 frame_bits += 2;
00742
00743
00744 frame_bits += 16;
00745
00746 s->frame_bits_fixed = frame_bits;
00747 }
00748
00749
00754 static void bit_alloc_init(AC3EncodeContext *s)
00755 {
00756 int ch;
00757
00758
00759 s->slow_decay_code = 2;
00760 s->fast_decay_code = 1;
00761 s->slow_gain_code = 1;
00762 s->db_per_bit_code = 3;
00763 s->floor_code = 7;
00764 for (ch = 0; ch < s->channels; ch++)
00765 s->fast_gain_code[ch] = 4;
00766
00767
00768 s->coarse_snr_offset = 40;
00769
00770
00771
00772
00773 s->bit_alloc.slow_decay = ff_ac3_slow_decay_tab[s->slow_decay_code] >> s->bit_alloc.sr_shift;
00774 s->bit_alloc.fast_decay = ff_ac3_fast_decay_tab[s->fast_decay_code] >> s->bit_alloc.sr_shift;
00775 s->bit_alloc.slow_gain = ff_ac3_slow_gain_tab[s->slow_gain_code];
00776 s->bit_alloc.db_per_bit = ff_ac3_db_per_bit_tab[s->db_per_bit_code];
00777 s->bit_alloc.floor = ff_ac3_floor_tab[s->floor_code];
00778
00779 count_frame_bits_fixed(s);
00780 }
00781
00782
00788 static void count_frame_bits(AC3EncodeContext *s)
00789 {
00790 int blk, ch;
00791 int frame_bits = 0;
00792
00793 for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
00794
00795 if (s->channel_mode == AC3_CHMODE_STEREO &&
00796 s->blocks[blk].new_rematrixing_strategy) {
00797 frame_bits += s->num_rematrixing_bands;
00798 }
00799
00800 for (ch = 0; ch < s->fbw_channels; ch++) {
00801 if (s->exp_strategy[ch][blk] != EXP_REUSE)
00802 frame_bits += 6 + 2;
00803 }
00804 }
00805 s->frame_bits = s->frame_bits_fixed + frame_bits;
00806 }
00807
00808
00812 static int compute_mantissa_size(int mant_cnt[5], uint8_t *bap, int nb_coefs)
00813 {
00814 int bits, b, i;
00815
00816 bits = 0;
00817 for (i = 0; i < nb_coefs; i++) {
00818 b = bap[i];
00819 if (b <= 4) {
00820
00821 mant_cnt[b]++;
00822 } else if (b <= 13) {
00823
00824 bits += b - 1;
00825 } else {
00826
00827 bits += (b == 14) ? 14 : 16;
00828 }
00829 }
00830 return bits;
00831 }
00832
00833
00837 static int compute_mantissa_size_final(int mant_cnt[5])
00838 {
00839
00840 int bits = (mant_cnt[1] / 3) * 5;
00841
00842
00843 bits += ((mant_cnt[2] / 3) + (mant_cnt[4] >> 1)) * 7;
00844
00845 bits += mant_cnt[3] * 3;
00846 return bits;
00847 }
00848
00849
00854 static void bit_alloc_masking(AC3EncodeContext *s)
00855 {
00856 int blk, ch;
00857
00858 for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
00859 AC3Block *block = &s->blocks[blk];
00860 for (ch = 0; ch < s->channels; ch++) {
00861
00862
00863
00864 if (s->exp_strategy[ch][blk] != EXP_REUSE) {
00865 ff_ac3_bit_alloc_calc_psd(block->exp[ch], 0,
00866 s->nb_coefs[ch],
00867 block->psd[ch], block->band_psd[ch]);
00868 ff_ac3_bit_alloc_calc_mask(&s->bit_alloc, block->band_psd[ch],
00869 0, s->nb_coefs[ch],
00870 ff_ac3_fast_gain_tab[s->fast_gain_code[ch]],
00871 ch == s->lfe_channel,
00872 DBA_NONE, 0, NULL, NULL, NULL,
00873 block->mask[ch]);
00874 }
00875 }
00876 }
00877 }
00878
00879
00884 static void reset_block_bap(AC3EncodeContext *s)
00885 {
00886 int blk, ch;
00887 if (s->blocks[0].bap[0] == s->bap_buffer)
00888 return;
00889 for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
00890 for (ch = 0; ch < s->channels; ch++) {
00891 s->blocks[blk].bap[ch] = &s->bap_buffer[AC3_MAX_COEFS * (blk * s->channels + ch)];
00892 }
00893 }
00894 }
00895
00896
00904 static int bit_alloc(AC3EncodeContext *s, int snr_offset)
00905 {
00906 int blk, ch;
00907 int mantissa_bits;
00908 int mant_cnt[5];
00909
00910 snr_offset = (snr_offset - 240) << 2;
00911
00912 reset_block_bap(s);
00913 mantissa_bits = 0;
00914 for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
00915 AC3Block *block = &s->blocks[blk];
00916
00917
00918
00919 mant_cnt[0] = mant_cnt[3] = 0;
00920 mant_cnt[1] = mant_cnt[2] = 2;
00921 mant_cnt[4] = 1;
00922 for (ch = 0; ch < s->channels; ch++) {
00923
00924
00925
00926
00927 if (s->exp_strategy[ch][blk] == EXP_REUSE) {
00928 memcpy(block->bap[ch], s->blocks[blk-1].bap[ch], AC3_MAX_COEFS);
00929 } else {
00930 ff_ac3_bit_alloc_calc_bap(block->mask[ch], block->psd[ch], 0,
00931 s->nb_coefs[ch], snr_offset,
00932 s->bit_alloc.floor, ff_ac3_bap_tab,
00933 block->bap[ch]);
00934 }
00935 mantissa_bits += compute_mantissa_size(mant_cnt, block->bap[ch], s->nb_coefs[ch]);
00936 }
00937 mantissa_bits += compute_mantissa_size_final(mant_cnt);
00938 }
00939 return mantissa_bits;
00940 }
00941
00942
00947 static int cbr_bit_allocation(AC3EncodeContext *s)
00948 {
00949 int ch;
00950 int bits_left;
00951 int snr_offset, snr_incr;
00952
00953 bits_left = 8 * s->frame_size - (s->frame_bits + s->exponent_bits);
00954 av_assert2(bits_left >= 0);
00955
00956 snr_offset = s->coarse_snr_offset << 4;
00957
00958
00959
00960 if ((snr_offset | s->fine_snr_offset[0]) == 1023) {
00961 if (bit_alloc(s, 1023) <= bits_left)
00962 return 0;
00963 }
00964
00965 while (snr_offset >= 0 &&
00966 bit_alloc(s, snr_offset) > bits_left) {
00967 snr_offset -= 64;
00968 }
00969 if (snr_offset < 0)
00970 return AVERROR(EINVAL);
00971
00972 FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
00973 for (snr_incr = 64; snr_incr > 0; snr_incr >>= 2) {
00974 while (snr_offset + snr_incr <= 1023 &&
00975 bit_alloc(s, snr_offset + snr_incr) <= bits_left) {
00976 snr_offset += snr_incr;
00977 FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
00978 }
00979 }
00980 FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
00981 reset_block_bap(s);
00982
00983 s->coarse_snr_offset = snr_offset >> 4;
00984 for (ch = 0; ch < s->channels; ch++)
00985 s->fine_snr_offset[ch] = snr_offset & 0xF;
00986
00987 return 0;
00988 }
00989
00990
00998 static int downgrade_exponents(AC3EncodeContext *s)
00999 {
01000 int ch, blk;
01001
01002 for (ch = 0; ch < s->fbw_channels; ch++) {
01003 for (blk = AC3_MAX_BLOCKS-1; blk >= 0; blk--) {
01004 if (s->exp_strategy[ch][blk] == EXP_D15) {
01005 s->exp_strategy[ch][blk] = EXP_D25;
01006 return 0;
01007 }
01008 }
01009 }
01010 for (ch = 0; ch < s->fbw_channels; ch++) {
01011 for (blk = AC3_MAX_BLOCKS-1; blk >= 0; blk--) {
01012 if (s->exp_strategy[ch][blk] == EXP_D25) {
01013 s->exp_strategy[ch][blk] = EXP_D45;
01014 return 0;
01015 }
01016 }
01017 }
01018 for (ch = 0; ch < s->fbw_channels; ch++) {
01019
01020
01021 for (blk = AC3_MAX_BLOCKS-1; blk > 0; blk--) {
01022 if (s->exp_strategy[ch][blk] > EXP_REUSE) {
01023 s->exp_strategy[ch][blk] = EXP_REUSE;
01024 return 0;
01025 }
01026 }
01027 }
01028 return -1;
01029 }
01030
01031
01038 static int reduce_bandwidth(AC3EncodeContext *s, int min_bw_code)
01039 {
01040 int ch;
01041
01042 if (s->bandwidth_code[0] > min_bw_code) {
01043 for (ch = 0; ch < s->fbw_channels; ch++) {
01044 s->bandwidth_code[ch]--;
01045 s->nb_coefs[ch] = s->bandwidth_code[ch] * 3 + 73;
01046 }
01047 return 0;
01048 }
01049 return -1;
01050 }
01051
01052
01059 static int compute_bit_allocation(AC3EncodeContext *s)
01060 {
01061 int ret;
01062
01063 count_frame_bits(s);
01064
01065 bit_alloc_masking(s);
01066
01067 ret = cbr_bit_allocation(s);
01068 while (ret) {
01069
01070 if (!downgrade_exponents(s)) {
01071 extract_exponents(s);
01072 encode_exponents(s);
01073 group_exponents(s);
01074 ret = compute_bit_allocation(s);
01075 continue;
01076 }
01077
01078
01079
01080
01081 if (!s->cutoff && !reduce_bandwidth(s, 0)) {
01082 process_exponents(s);
01083 ret = compute_bit_allocation(s);
01084 continue;
01085 }
01086
01087
01088 break;
01089 }
01090
01091 return ret;
01092 }
01093
01094
01098 static inline int sym_quant(int c, int e, int levels)
01099 {
01100 int v;
01101
01102 if (c >= 0) {
01103 v = (levels * (c << e)) >> 24;
01104 v = (v + 1) >> 1;
01105 v = (levels >> 1) + v;
01106 } else {
01107 v = (levels * ((-c) << e)) >> 24;
01108 v = (v + 1) >> 1;
01109 v = (levels >> 1) - v;
01110 }
01111 av_assert2(v >= 0 && v < levels);
01112 return v;
01113 }
01114
01115
01119 static inline int asym_quant(int c, int e, int qbits)
01120 {
01121 int lshift, m, v;
01122
01123 lshift = e + qbits - 24;
01124 if (lshift >= 0)
01125 v = c << lshift;
01126 else
01127 v = c >> (-lshift);
01128
01129 v = (v + 1) >> 1;
01130 m = (1 << (qbits-1));
01131 if (v >= m)
01132 v = m - 1;
01133 av_assert2(v >= -m);
01134 return v & ((1 << qbits)-1);
01135 }
01136
01137
01141 static void quantize_mantissas_blk_ch(AC3EncodeContext *s, int32_t *fixed_coef,
01142 int8_t exp_shift, uint8_t *exp,
01143 uint8_t *bap, uint16_t *qmant, int n)
01144 {
01145 int i;
01146
01147 for (i = 0; i < n; i++) {
01148 int v;
01149 int c = fixed_coef[i];
01150 int e = exp[i] - exp_shift;
01151 int b = bap[i];
01152 switch (b) {
01153 case 0:
01154 v = 0;
01155 break;
01156 case 1:
01157 v = sym_quant(c, e, 3);
01158 switch (s->mant1_cnt) {
01159 case 0:
01160 s->qmant1_ptr = &qmant[i];
01161 v = 9 * v;
01162 s->mant1_cnt = 1;
01163 break;
01164 case 1:
01165 *s->qmant1_ptr += 3 * v;
01166 s->mant1_cnt = 2;
01167 v = 128;
01168 break;
01169 default:
01170 *s->qmant1_ptr += v;
01171 s->mant1_cnt = 0;
01172 v = 128;
01173 break;
01174 }
01175 break;
01176 case 2:
01177 v = sym_quant(c, e, 5);
01178 switch (s->mant2_cnt) {
01179 case 0:
01180 s->qmant2_ptr = &qmant[i];
01181 v = 25 * v;
01182 s->mant2_cnt = 1;
01183 break;
01184 case 1:
01185 *s->qmant2_ptr += 5 * v;
01186 s->mant2_cnt = 2;
01187 v = 128;
01188 break;
01189 default:
01190 *s->qmant2_ptr += v;
01191 s->mant2_cnt = 0;
01192 v = 128;
01193 break;
01194 }
01195 break;
01196 case 3:
01197 v = sym_quant(c, e, 7);
01198 break;
01199 case 4:
01200 v = sym_quant(c, e, 11);
01201 switch (s->mant4_cnt) {
01202 case 0:
01203 s->qmant4_ptr = &qmant[i];
01204 v = 11 * v;
01205 s->mant4_cnt = 1;
01206 break;
01207 default:
01208 *s->qmant4_ptr += v;
01209 s->mant4_cnt = 0;
01210 v = 128;
01211 break;
01212 }
01213 break;
01214 case 5:
01215 v = sym_quant(c, e, 15);
01216 break;
01217 case 14:
01218 v = asym_quant(c, e, 14);
01219 break;
01220 case 15:
01221 v = asym_quant(c, e, 16);
01222 break;
01223 default:
01224 v = asym_quant(c, e, b - 1);
01225 break;
01226 }
01227 qmant[i] = v;
01228 }
01229 }
01230
01231
01235 static void quantize_mantissas(AC3EncodeContext *s)
01236 {
01237 int blk, ch;
01238
01239
01240 for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
01241 AC3Block *block = &s->blocks[blk];
01242 s->mant1_cnt = s->mant2_cnt = s->mant4_cnt = 0;
01243 s->qmant1_ptr = s->qmant2_ptr = s->qmant4_ptr = NULL;
01244
01245 for (ch = 0; ch < s->channels; ch++) {
01246 quantize_mantissas_blk_ch(s, block->fixed_coef[ch], block->exp_shift[ch],
01247 block->exp[ch], block->bap[ch],
01248 block->qmant[ch], s->nb_coefs[ch]);
01249 }
01250 }
01251 }
01252
01253
01257 static void output_frame_header(AC3EncodeContext *s)
01258 {
01259 put_bits(&s->pb, 16, 0x0b77);
01260 put_bits(&s->pb, 16, 0);
01261 put_bits(&s->pb, 2, s->bit_alloc.sr_code);
01262 put_bits(&s->pb, 6, s->frame_size_code + (s->frame_size - s->frame_size_min) / 2);
01263 put_bits(&s->pb, 5, s->bitstream_id);
01264 put_bits(&s->pb, 3, s->bitstream_mode);
01265 put_bits(&s->pb, 3, s->channel_mode);
01266 if ((s->channel_mode & 0x01) && s->channel_mode != AC3_CHMODE_MONO)
01267 put_bits(&s->pb, 2, 1);
01268 if (s->channel_mode & 0x04)
01269 put_bits(&s->pb, 2, 1);
01270 if (s->channel_mode == AC3_CHMODE_STEREO)
01271 put_bits(&s->pb, 2, 0);
01272 put_bits(&s->pb, 1, s->lfe_on);
01273 put_bits(&s->pb, 5, 31);
01274 put_bits(&s->pb, 1, 0);
01275 put_bits(&s->pb, 1, 0);
01276 put_bits(&s->pb, 1, 0);
01277 put_bits(&s->pb, 1, 0);
01278 put_bits(&s->pb, 1, 1);
01279 put_bits(&s->pb, 1, 0);
01280 put_bits(&s->pb, 1, 0);
01281 put_bits(&s->pb, 1, 0);
01282 }
01283
01284
01288 static void output_audio_block(AC3EncodeContext *s, int blk)
01289 {
01290 int ch, i, baie, rbnd;
01291 AC3Block *block = &s->blocks[blk];
01292
01293
01294 for (ch = 0; ch < s->fbw_channels; ch++)
01295 put_bits(&s->pb, 1, 0);
01296
01297
01298 for (ch = 0; ch < s->fbw_channels; ch++)
01299 put_bits(&s->pb, 1, 1);
01300
01301
01302 put_bits(&s->pb, 1, 0);
01303
01304
01305 if (!blk) {
01306 put_bits(&s->pb, 1, 1);
01307 put_bits(&s->pb, 1, 0);
01308 } else {
01309 put_bits(&s->pb, 1, 0);
01310 }
01311
01312
01313 if (s->channel_mode == AC3_CHMODE_STEREO) {
01314 put_bits(&s->pb, 1, block->new_rematrixing_strategy);
01315 if (block->new_rematrixing_strategy) {
01316
01317 for (rbnd = 0; rbnd < s->num_rematrixing_bands; rbnd++)
01318 put_bits(&s->pb, 1, block->rematrixing_flags[rbnd]);
01319 }
01320 }
01321
01322
01323 for (ch = 0; ch < s->fbw_channels; ch++)
01324 put_bits(&s->pb, 2, s->exp_strategy[ch][blk]);
01325 if (s->lfe_on)
01326 put_bits(&s->pb, 1, s->exp_strategy[s->lfe_channel][blk]);
01327
01328
01329 for (ch = 0; ch < s->fbw_channels; ch++) {
01330 if (s->exp_strategy[ch][blk] != EXP_REUSE)
01331 put_bits(&s->pb, 6, s->bandwidth_code[ch]);
01332 }
01333
01334
01335 for (ch = 0; ch < s->channels; ch++) {
01336 int nb_groups;
01337
01338 if (s->exp_strategy[ch][blk] == EXP_REUSE)
01339 continue;
01340
01341
01342 put_bits(&s->pb, 4, block->grouped_exp[ch][0]);
01343
01344
01345 nb_groups = exponent_group_tab[s->exp_strategy[ch][blk]-1][s->nb_coefs[ch]];
01346 for (i = 1; i <= nb_groups; i++)
01347 put_bits(&s->pb, 7, block->grouped_exp[ch][i]);
01348
01349
01350 if (ch != s->lfe_channel)
01351 put_bits(&s->pb, 2, 0);
01352 }
01353
01354
01355 baie = (blk == 0);
01356 put_bits(&s->pb, 1, baie);
01357 if (baie) {
01358 put_bits(&s->pb, 2, s->slow_decay_code);
01359 put_bits(&s->pb, 2, s->fast_decay_code);
01360 put_bits(&s->pb, 2, s->slow_gain_code);
01361 put_bits(&s->pb, 2, s->db_per_bit_code);
01362 put_bits(&s->pb, 3, s->floor_code);
01363 }
01364
01365
01366 put_bits(&s->pb, 1, baie);
01367 if (baie) {
01368 put_bits(&s->pb, 6, s->coarse_snr_offset);
01369 for (ch = 0; ch < s->channels; ch++) {
01370 put_bits(&s->pb, 4, s->fine_snr_offset[ch]);
01371 put_bits(&s->pb, 3, s->fast_gain_code[ch]);
01372 }
01373 }
01374
01375 put_bits(&s->pb, 1, 0);
01376 put_bits(&s->pb, 1, 0);
01377
01378
01379 for (ch = 0; ch < s->channels; ch++) {
01380 int b, q;
01381 for (i = 0; i < s->nb_coefs[ch]; i++) {
01382 q = block->qmant[ch][i];
01383 b = block->bap[ch][i];
01384 switch (b) {
01385 case 0: break;
01386 case 1: if (q != 128) put_bits(&s->pb, 5, q); break;
01387 case 2: if (q != 128) put_bits(&s->pb, 7, q); break;
01388 case 3: put_bits(&s->pb, 3, q); break;
01389 case 4: if (q != 128) put_bits(&s->pb, 7, q); break;
01390 case 14: put_bits(&s->pb, 14, q); break;
01391 case 15: put_bits(&s->pb, 16, q); break;
01392 default: put_bits(&s->pb, b-1, q); break;
01393 }
01394 }
01395 }
01396 }
01397
01398
01400 #define CRC16_POLY ((1 << 0) | (1 << 2) | (1 << 15) | (1 << 16))
01401
01402
01403 static unsigned int mul_poly(unsigned int a, unsigned int b, unsigned int poly)
01404 {
01405 unsigned int c;
01406
01407 c = 0;
01408 while (a) {
01409 if (a & 1)
01410 c ^= b;
01411 a = a >> 1;
01412 b = b << 1;
01413 if (b & (1 << 16))
01414 b ^= poly;
01415 }
01416 return c;
01417 }
01418
01419
01420 static unsigned int pow_poly(unsigned int a, unsigned int n, unsigned int poly)
01421 {
01422 unsigned int r;
01423 r = 1;
01424 while (n) {
01425 if (n & 1)
01426 r = mul_poly(r, a, poly);
01427 a = mul_poly(a, a, poly);
01428 n >>= 1;
01429 }
01430 return r;
01431 }
01432
01433
01437 static void output_frame_end(AC3EncodeContext *s)
01438 {
01439 const AVCRC *crc_ctx = av_crc_get_table(AV_CRC_16_ANSI);
01440 int frame_size_58, pad_bytes, crc1, crc2_partial, crc2, crc_inv;
01441 uint8_t *frame;
01442
01443 frame_size_58 = ((s->frame_size >> 2) + (s->frame_size >> 4)) << 1;
01444
01445
01446 av_assert2(s->frame_size * 8 - put_bits_count(&s->pb) >= 18);
01447 flush_put_bits(&s->pb);
01448 frame = s->pb.buf;
01449 pad_bytes = s->frame_size - (put_bits_ptr(&s->pb) - frame) - 2;
01450 av_assert2(pad_bytes >= 0);
01451 if (pad_bytes > 0)
01452 memset(put_bits_ptr(&s->pb), 0, pad_bytes);
01453
01454
01455
01456 crc1 = av_bswap16(av_crc(crc_ctx, 0, frame + 4, frame_size_58 - 4));
01457 crc_inv = s->crc_inv[s->frame_size > s->frame_size_min];
01458 crc1 = mul_poly(crc_inv, crc1, CRC16_POLY);
01459 AV_WB16(frame + 2, crc1);
01460
01461
01462 crc2_partial = av_crc(crc_ctx, 0, frame + frame_size_58,
01463 s->frame_size - frame_size_58 - 3);
01464 crc2 = av_crc(crc_ctx, crc2_partial, frame + s->frame_size - 3, 1);
01465
01466 if (crc2 == 0x770B) {
01467 frame[s->frame_size - 3] ^= 0x1;
01468 crc2 = av_crc(crc_ctx, crc2_partial, frame + s->frame_size - 3, 1);
01469 }
01470 crc2 = av_bswap16(crc2);
01471 AV_WB16(frame + s->frame_size - 2, crc2);
01472 }
01473
01474
01478 static void output_frame(AC3EncodeContext *s, unsigned char *frame)
01479 {
01480 int blk;
01481
01482 init_put_bits(&s->pb, frame, AC3_MAX_CODED_FRAME_SIZE);
01483
01484 output_frame_header(s);
01485
01486 for (blk = 0; blk < AC3_MAX_BLOCKS; blk++)
01487 output_audio_block(s, blk);
01488
01489 output_frame_end(s);
01490 }
01491
01492
01496 static int ac3_encode_frame(AVCodecContext *avctx, unsigned char *frame,
01497 int buf_size, void *data)
01498 {
01499 AC3EncodeContext *s = avctx->priv_data;
01500 const SampleType *samples = data;
01501 int ret;
01502
01503 if (s->bit_alloc.sr_code == 1)
01504 adjust_frame_size(s);
01505
01506 deinterleave_input_samples(s, samples);
01507
01508 apply_mdct(s);
01509
01510 compute_rematrixing_strategy(s);
01511
01512 scale_coefficients(s);
01513
01514 apply_rematrixing(s);
01515
01516 process_exponents(s);
01517
01518 ret = compute_bit_allocation(s);
01519 if (ret) {
01520 av_log(avctx, AV_LOG_ERROR, "Bit allocation failed. Try increasing the bitrate.\n");
01521 return ret;
01522 }
01523
01524 quantize_mantissas(s);
01525
01526 output_frame(s, frame);
01527
01528 return s->frame_size;
01529 }
01530
01531
01535 static av_cold int ac3_encode_close(AVCodecContext *avctx)
01536 {
01537 int blk, ch;
01538 AC3EncodeContext *s = avctx->priv_data;
01539
01540 for (ch = 0; ch < s->channels; ch++)
01541 av_freep(&s->planar_samples[ch]);
01542 av_freep(&s->planar_samples);
01543 av_freep(&s->bap_buffer);
01544 av_freep(&s->bap1_buffer);
01545 av_freep(&s->mdct_coef_buffer);
01546 av_freep(&s->fixed_coef_buffer);
01547 av_freep(&s->exp_buffer);
01548 av_freep(&s->grouped_exp_buffer);
01549 av_freep(&s->psd_buffer);
01550 av_freep(&s->band_psd_buffer);
01551 av_freep(&s->mask_buffer);
01552 av_freep(&s->qmant_buffer);
01553 for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
01554 AC3Block *block = &s->blocks[blk];
01555 av_freep(&block->bap);
01556 av_freep(&block->mdct_coef);
01557 av_freep(&block->fixed_coef);
01558 av_freep(&block->exp);
01559 av_freep(&block->grouped_exp);
01560 av_freep(&block->psd);
01561 av_freep(&block->band_psd);
01562 av_freep(&block->mask);
01563 av_freep(&block->qmant);
01564 }
01565
01566 mdct_end(&s->mdct);
01567
01568 av_freep(&avctx->coded_frame);
01569 return 0;
01570 }
01571
01572
01576 static av_cold int set_channel_info(AC3EncodeContext *s, int channels,
01577 int64_t *channel_layout)
01578 {
01579 int ch_layout;
01580
01581 if (channels < 1 || channels > AC3_MAX_CHANNELS)
01582 return AVERROR(EINVAL);
01583 if ((uint64_t)*channel_layout > 0x7FF)
01584 return AVERROR(EINVAL);
01585 ch_layout = *channel_layout;
01586 if (!ch_layout)
01587 ch_layout = avcodec_guess_channel_layout(channels, CODEC_ID_AC3, NULL);
01588 if (av_get_channel_layout_nb_channels(ch_layout) != channels)
01589 return AVERROR(EINVAL);
01590
01591 s->lfe_on = !!(ch_layout & AV_CH_LOW_FREQUENCY);
01592 s->channels = channels;
01593 s->fbw_channels = channels - s->lfe_on;
01594 s->lfe_channel = s->lfe_on ? s->fbw_channels : -1;
01595 if (s->lfe_on)
01596 ch_layout -= AV_CH_LOW_FREQUENCY;
01597
01598 switch (ch_layout) {
01599 case AV_CH_LAYOUT_MONO: s->channel_mode = AC3_CHMODE_MONO; break;
01600 case AV_CH_LAYOUT_STEREO: s->channel_mode = AC3_CHMODE_STEREO; break;
01601 case AV_CH_LAYOUT_SURROUND: s->channel_mode = AC3_CHMODE_3F; break;
01602 case AV_CH_LAYOUT_2_1: s->channel_mode = AC3_CHMODE_2F1R; break;
01603 case AV_CH_LAYOUT_4POINT0: s->channel_mode = AC3_CHMODE_3F1R; break;
01604 case AV_CH_LAYOUT_QUAD:
01605 case AV_CH_LAYOUT_2_2: s->channel_mode = AC3_CHMODE_2F2R; break;
01606 case AV_CH_LAYOUT_5POINT0:
01607 case AV_CH_LAYOUT_5POINT0_BACK: s->channel_mode = AC3_CHMODE_3F2R; break;
01608 default:
01609 return AVERROR(EINVAL);
01610 }
01611
01612 s->channel_map = ff_ac3_enc_channel_map[s->channel_mode][s->lfe_on];
01613 *channel_layout = ch_layout;
01614 if (s->lfe_on)
01615 *channel_layout |= AV_CH_LOW_FREQUENCY;
01616
01617 return 0;
01618 }
01619
01620
01621 static av_cold int validate_options(AVCodecContext *avctx, AC3EncodeContext *s)
01622 {
01623 int i, ret;
01624
01625
01626 if (!avctx->channel_layout) {
01627 av_log(avctx, AV_LOG_WARNING, "No channel layout specified. The "
01628 "encoder will guess the layout, but it "
01629 "might be incorrect.\n");
01630 }
01631 ret = set_channel_info(s, avctx->channels, &avctx->channel_layout);
01632 if (ret) {
01633 av_log(avctx, AV_LOG_ERROR, "invalid channel layout\n");
01634 return ret;
01635 }
01636
01637
01638 for (i = 0; i < 9; i++) {
01639 if ((ff_ac3_sample_rate_tab[i / 3] >> (i % 3)) == avctx->sample_rate)
01640 break;
01641 }
01642 if (i == 9) {
01643 av_log(avctx, AV_LOG_ERROR, "invalid sample rate\n");
01644 return AVERROR(EINVAL);
01645 }
01646 s->sample_rate = avctx->sample_rate;
01647 s->bit_alloc.sr_shift = i % 3;
01648 s->bit_alloc.sr_code = i / 3;
01649
01650
01651 for (i = 0; i < 19; i++) {
01652 if ((ff_ac3_bitrate_tab[i] >> s->bit_alloc.sr_shift)*1000 == avctx->bit_rate)
01653 break;
01654 }
01655 if (i == 19) {
01656 av_log(avctx, AV_LOG_ERROR, "invalid bit rate\n");
01657 return AVERROR(EINVAL);
01658 }
01659 s->bit_rate = avctx->bit_rate;
01660 s->frame_size_code = i << 1;
01661
01662
01663 if (avctx->cutoff < 0) {
01664 av_log(avctx, AV_LOG_ERROR, "invalid cutoff frequency\n");
01665 return AVERROR(EINVAL);
01666 }
01667 s->cutoff = avctx->cutoff;
01668 if (s->cutoff > (s->sample_rate >> 1))
01669 s->cutoff = s->sample_rate >> 1;
01670
01671 return 0;
01672 }
01673
01674
01680 static av_cold void set_bandwidth(AC3EncodeContext *s)
01681 {
01682 int ch, bw_code;
01683
01684 if (s->cutoff) {
01685
01686 int fbw_coeffs;
01687 fbw_coeffs = s->cutoff * 2 * AC3_MAX_COEFS / s->sample_rate;
01688 bw_code = av_clip((fbw_coeffs - 73) / 3, 0, 60);
01689 } else {
01690
01691
01692
01693 bw_code = 50;
01694 }
01695
01696
01697 for (ch = 0; ch < s->fbw_channels; ch++) {
01698 s->bandwidth_code[ch] = bw_code;
01699 s->nb_coefs[ch] = bw_code * 3 + 73;
01700 }
01701 if (s->lfe_on)
01702 s->nb_coefs[s->lfe_channel] = 7;
01703 }
01704
01705
01706 static av_cold int allocate_buffers(AVCodecContext *avctx)
01707 {
01708 int blk, ch;
01709 AC3EncodeContext *s = avctx->priv_data;
01710
01711 FF_ALLOC_OR_GOTO(avctx, s->planar_samples, s->channels * sizeof(*s->planar_samples),
01712 alloc_fail);
01713 for (ch = 0; ch < s->channels; ch++) {
01714 FF_ALLOCZ_OR_GOTO(avctx, s->planar_samples[ch],
01715 (AC3_FRAME_SIZE+AC3_BLOCK_SIZE) * sizeof(**s->planar_samples),
01716 alloc_fail);
01717 }
01718 FF_ALLOC_OR_GOTO(avctx, s->bap_buffer, AC3_MAX_BLOCKS * s->channels *
01719 AC3_MAX_COEFS * sizeof(*s->bap_buffer), alloc_fail);
01720 FF_ALLOC_OR_GOTO(avctx, s->bap1_buffer, AC3_MAX_BLOCKS * s->channels *
01721 AC3_MAX_COEFS * sizeof(*s->bap1_buffer), alloc_fail);
01722 FF_ALLOC_OR_GOTO(avctx, s->mdct_coef_buffer, AC3_MAX_BLOCKS * s->channels *
01723 AC3_MAX_COEFS * sizeof(*s->mdct_coef_buffer), alloc_fail);
01724 FF_ALLOC_OR_GOTO(avctx, s->exp_buffer, AC3_MAX_BLOCKS * s->channels *
01725 AC3_MAX_COEFS * sizeof(*s->exp_buffer), alloc_fail);
01726 FF_ALLOC_OR_GOTO(avctx, s->grouped_exp_buffer, AC3_MAX_BLOCKS * s->channels *
01727 128 * sizeof(*s->grouped_exp_buffer), alloc_fail);
01728 FF_ALLOC_OR_GOTO(avctx, s->psd_buffer, AC3_MAX_BLOCKS * s->channels *
01729 AC3_MAX_COEFS * sizeof(*s->psd_buffer), alloc_fail);
01730 FF_ALLOC_OR_GOTO(avctx, s->band_psd_buffer, AC3_MAX_BLOCKS * s->channels *
01731 64 * sizeof(*s->band_psd_buffer), alloc_fail);
01732 FF_ALLOC_OR_GOTO(avctx, s->mask_buffer, AC3_MAX_BLOCKS * s->channels *
01733 64 * sizeof(*s->mask_buffer), alloc_fail);
01734 FF_ALLOC_OR_GOTO(avctx, s->qmant_buffer, AC3_MAX_BLOCKS * s->channels *
01735 AC3_MAX_COEFS * sizeof(*s->qmant_buffer), alloc_fail);
01736 for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
01737 AC3Block *block = &s->blocks[blk];
01738 FF_ALLOC_OR_GOTO(avctx, block->bap, s->channels * sizeof(*block->bap),
01739 alloc_fail);
01740 FF_ALLOCZ_OR_GOTO(avctx, block->mdct_coef, s->channels * sizeof(*block->mdct_coef),
01741 alloc_fail);
01742 FF_ALLOCZ_OR_GOTO(avctx, block->exp, s->channels * sizeof(*block->exp),
01743 alloc_fail);
01744 FF_ALLOCZ_OR_GOTO(avctx, block->grouped_exp, s->channels * sizeof(*block->grouped_exp),
01745 alloc_fail);
01746 FF_ALLOCZ_OR_GOTO(avctx, block->psd, s->channels * sizeof(*block->psd),
01747 alloc_fail);
01748 FF_ALLOCZ_OR_GOTO(avctx, block->band_psd, s->channels * sizeof(*block->band_psd),
01749 alloc_fail);
01750 FF_ALLOCZ_OR_GOTO(avctx, block->mask, s->channels * sizeof(*block->mask),
01751 alloc_fail);
01752 FF_ALLOCZ_OR_GOTO(avctx, block->qmant, s->channels * sizeof(*block->qmant),
01753 alloc_fail);
01754
01755 for (ch = 0; ch < s->channels; ch++) {
01756
01757 block->bap[ch] = &s->bap_buffer [AC3_MAX_COEFS * (blk * s->channels + ch)];
01758 block->mdct_coef[ch] = &s->mdct_coef_buffer [AC3_MAX_COEFS * (blk * s->channels + ch)];
01759 block->grouped_exp[ch] = &s->grouped_exp_buffer[128 * (blk * s->channels + ch)];
01760 block->psd[ch] = &s->psd_buffer [AC3_MAX_COEFS * (blk * s->channels + ch)];
01761 block->band_psd[ch] = &s->band_psd_buffer [64 * (blk * s->channels + ch)];
01762 block->mask[ch] = &s->mask_buffer [64 * (blk * s->channels + ch)];
01763 block->qmant[ch] = &s->qmant_buffer [AC3_MAX_COEFS * (blk * s->channels + ch)];
01764
01765
01766 block->exp[ch] = &s->exp_buffer [AC3_MAX_COEFS * (AC3_MAX_BLOCKS * ch + blk)];
01767 }
01768 }
01769
01770 if (CONFIG_AC3ENC_FLOAT) {
01771 FF_ALLOC_OR_GOTO(avctx, s->fixed_coef_buffer, AC3_MAX_BLOCKS * s->channels *
01772 AC3_MAX_COEFS * sizeof(*s->fixed_coef_buffer), alloc_fail);
01773 for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
01774 AC3Block *block = &s->blocks[blk];
01775 FF_ALLOCZ_OR_GOTO(avctx, block->fixed_coef, s->channels *
01776 sizeof(*block->fixed_coef), alloc_fail);
01777 for (ch = 0; ch < s->channels; ch++)
01778 block->fixed_coef[ch] = &s->fixed_coef_buffer[AC3_MAX_COEFS * (blk * s->channels + ch)];
01779 }
01780 } else {
01781 for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
01782 AC3Block *block = &s->blocks[blk];
01783 FF_ALLOCZ_OR_GOTO(avctx, block->fixed_coef, s->channels *
01784 sizeof(*block->fixed_coef), alloc_fail);
01785 for (ch = 0; ch < s->channels; ch++)
01786 block->fixed_coef[ch] = (int32_t *)block->mdct_coef[ch];
01787 }
01788 }
01789
01790 return 0;
01791 alloc_fail:
01792 return AVERROR(ENOMEM);
01793 }
01794
01795
01799 static av_cold int ac3_encode_init(AVCodecContext *avctx)
01800 {
01801 AC3EncodeContext *s = avctx->priv_data;
01802 int ret, frame_size_58;
01803
01804 avctx->frame_size = AC3_FRAME_SIZE;
01805
01806 ff_ac3_common_init();
01807
01808 ret = validate_options(avctx, s);
01809 if (ret)
01810 return ret;
01811
01812 s->bitstream_id = 8 + s->bit_alloc.sr_shift;
01813 s->bitstream_mode = 0;
01814
01815 s->frame_size_min = 2 * ff_ac3_frame_size_tab[s->frame_size_code][s->bit_alloc.sr_code];
01816 s->bits_written = 0;
01817 s->samples_written = 0;
01818 s->frame_size = s->frame_size_min;
01819
01820
01821 frame_size_58 = (( s->frame_size >> 2) + ( s->frame_size >> 4)) << 1;
01822 s->crc_inv[0] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58) - 16, CRC16_POLY);
01823 if (s->bit_alloc.sr_code == 1) {
01824 frame_size_58 = (((s->frame_size+2) >> 2) + ((s->frame_size+2) >> 4)) << 1;
01825 s->crc_inv[1] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58) - 16, CRC16_POLY);
01826 }
01827
01828 set_bandwidth(s);
01829
01830 rematrixing_init(s);
01831
01832 exponent_init(s);
01833
01834 bit_alloc_init(s);
01835
01836 ret = mdct_init(avctx, &s->mdct, 9);
01837 if (ret)
01838 goto init_fail;
01839
01840 ret = allocate_buffers(avctx);
01841 if (ret)
01842 goto init_fail;
01843
01844 avctx->coded_frame= avcodec_alloc_frame();
01845
01846 dsputil_init(&s->dsp, avctx);
01847 ff_ac3dsp_init(&s->ac3dsp);
01848
01849 return 0;
01850 init_fail:
01851 ac3_encode_close(avctx);
01852 return ret;
01853 }