LCOV - code coverage report
Current view: top level - src/libavcodec - ac3enc_template.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 193 216 89.4 %
Date: 2017-04-23 07:57:23 Functions: 8 8 100.0 %

          Line data    Source code
       1             : /*
       2             :  * AC-3 encoder float/fixed template
       3             :  * Copyright (c) 2000 Fabrice Bellard
       4             :  * Copyright (c) 2006-2011 Justin Ruggles <justin.ruggles@gmail.com>
       5             :  * Copyright (c) 2006-2010 Prakash Punnoor <prakash@punnoor.de>
       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             :  */
      23             : 
      24             : /**
      25             :  * @file
      26             :  * AC-3 encoder float/fixed template
      27             :  */
      28             : 
      29             : #include <stdint.h>
      30             : 
      31             : #include "libavutil/attributes.h"
      32             : #include "libavutil/internal.h"
      33             : 
      34             : #include "audiodsp.h"
      35             : #include "internal.h"
      36             : #include "ac3enc.h"
      37             : #include "eac3enc.h"
      38             : 
      39             : 
      40           5 : int AC3_NAME(allocate_sample_buffers)(AC3EncodeContext *s)
      41             : {
      42             :     int ch;
      43             : 
      44           5 :     FF_ALLOC_OR_GOTO(s->avctx, s->windowed_samples, AC3_WINDOW_SIZE *
      45             :                      sizeof(*s->windowed_samples), alloc_fail);
      46           5 :     FF_ALLOC_ARRAY_OR_GOTO(s->avctx, s->planar_samples, s->channels, sizeof(*s->planar_samples),
      47             :                      alloc_fail);
      48          13 :     for (ch = 0; ch < s->channels; ch++) {
      49           8 :         FF_ALLOCZ_OR_GOTO(s->avctx, s->planar_samples[ch],
      50             :                           (AC3_FRAME_SIZE+AC3_BLOCK_SIZE) * sizeof(**s->planar_samples),
      51             :                           alloc_fail);
      52             :     }
      53             : 
      54           5 :     return 0;
      55             : alloc_fail:
      56           0 :     return AVERROR(ENOMEM);
      57             : }
      58             : 
      59             : 
      60             : /*
      61             :  * Copy input samples.
      62             :  * Channels are reordered from FFmpeg's default order to AC-3 order.
      63             :  */
      64        1093 : static void copy_input_samples(AC3EncodeContext *s, SampleType **samples)
      65             : {
      66             :     int ch;
      67             : 
      68             :     /* copy and remap input samples */
      69        2905 :     for (ch = 0; ch < s->channels; ch++) {
      70             :         /* copy last 256 samples of previous frame to the start of the current frame */
      71        1812 :         memcpy(&s->planar_samples[ch][0], &s->planar_samples[ch][AC3_BLOCK_SIZE * s->num_blocks],
      72             :                AC3_BLOCK_SIZE * sizeof(s->planar_samples[0][0]));
      73             : 
      74             :         /* copy new samples for current frame */
      75        3624 :         memcpy(&s->planar_samples[ch][AC3_BLOCK_SIZE],
      76        1812 :                samples[s->channel_map[ch]],
      77        1812 :                AC3_BLOCK_SIZE * s->num_blocks * sizeof(s->planar_samples[0][0]));
      78             :     }
      79        1093 : }
      80             : 
      81             : 
      82             : /*
      83             :  * Apply the MDCT to input samples to generate frequency coefficients.
      84             :  * This applies the KBD window and normalizes the input to reduce precision
      85             :  * loss due to fixed-point calculations.
      86             :  */
      87        1093 : static void apply_mdct(AC3EncodeContext *s)
      88             : {
      89             :     int blk, ch;
      90             : 
      91        2905 :     for (ch = 0; ch < s->channels; ch++) {
      92       12684 :         for (blk = 0; blk < s->num_blocks; blk++) {
      93       10872 :             AC3Block *block = &s->blocks[blk];
      94       10872 :             const SampleType *input_samples = &s->planar_samples[ch][blk * AC3_BLOCK_SIZE];
      95             : 
      96             : #if CONFIG_AC3ENC_FLOAT
      97       13104 :             s->fdsp->vector_fmul(s->windowed_samples, input_samples,
      98        6552 :                                 s->mdct_window, AC3_WINDOW_SIZE);
      99             : #else
     100        8640 :             s->ac3dsp.apply_window_int16(s->windowed_samples, input_samples,
     101        4320 :                                          s->mdct_window, AC3_WINDOW_SIZE);
     102             : 
     103        4320 :             if (s->fixed_point)
     104        4320 :                 block->coeff_shift[ch+1] = normalize_samples(s);
     105             : #endif
     106             : 
     107       21744 :             s->mdct.mdct_calcw(&s->mdct, block->mdct_coef[ch+1],
     108       10872 :                                s->windowed_samples);
     109             :         }
     110             :     }
     111        1093 : }
     112             : 
     113             : 
     114             : /*
     115             :  * Calculate coupling channel and coupling coordinates.
     116             :  */
     117         719 : static void apply_channel_coupling(AC3EncodeContext *s)
     118             : {
     119         719 :     LOCAL_ALIGNED_16(CoefType, cpl_coords,      [AC3_MAX_BLOCKS], [AC3_MAX_CHANNELS][16]);
     120             : #if CONFIG_AC3ENC_FLOAT
     121         546 :     LOCAL_ALIGNED_16(int32_t, fixed_cpl_coords, [AC3_MAX_BLOCKS], [AC3_MAX_CHANNELS][16]);
     122             : #else
     123         173 :     int32_t (*fixed_cpl_coords)[AC3_MAX_CHANNELS][16] = cpl_coords;
     124             : #endif
     125         719 :     int av_uninit(blk), ch, bnd, i, j;
     126         719 :     CoefSumType energy[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][16] = {{{0}}};
     127             :     int cpl_start, num_cpl_coefs;
     128             : 
     129         719 :     memset(cpl_coords,       0, AC3_MAX_BLOCKS * sizeof(*cpl_coords));
     130             : #if CONFIG_AC3ENC_FLOAT
     131         546 :     memset(fixed_cpl_coords, 0, AC3_MAX_BLOCKS * sizeof(*cpl_coords));
     132             : #endif
     133             : 
     134             :     /* align start to 16-byte boundary. align length to multiple of 32.
     135             :         note: coupling start bin % 4 will always be 1 */
     136         719 :     cpl_start     = s->start_freq[CPL_CH] - 1;
     137         719 :     num_cpl_coefs = FFALIGN(s->num_cpl_subbands * 12 + 1, 32);
     138         719 :     cpl_start     = FFMIN(256, cpl_start + num_cpl_coefs) - num_cpl_coefs;
     139             : 
     140             :     /* calculate coupling channel from fbw channels */
     141        5033 :     for (blk = 0; blk < s->num_blocks; blk++) {
     142        4314 :         AC3Block *block = &s->blocks[blk];
     143        4314 :         CoefType *cpl_coef = &block->mdct_coef[CPL_CH][cpl_start];
     144        4314 :         if (!block->cpl_in_use)
     145           0 :             continue;
     146        4314 :         memset(cpl_coef, 0, num_cpl_coefs * sizeof(*cpl_coef));
     147       12942 :         for (ch = 1; ch <= s->fbw_channels; ch++) {
     148        8628 :             CoefType *ch_coef = &block->mdct_coef[ch][cpl_start];
     149        8628 :             if (!block->channel_in_cpl[ch])
     150           0 :                 continue;
     151      560820 :             for (i = 0; i < num_cpl_coefs; i++)
     152      552192 :                 cpl_coef[i] += ch_coef[i];
     153             :         }
     154             : 
     155             :         /* coefficients must be clipped in order to be encoded */
     156        4314 :         clip_coefficients(&s->adsp, cpl_coef, num_cpl_coefs);
     157             :     }
     158             : 
     159             :     /* calculate energy in each band in coupling channel and each fbw channel */
     160             :     /* TODO: possibly use SIMD to speed up energy calculation */
     161         719 :     bnd = 0;
     162         719 :     i = s->start_freq[CPL_CH];
     163        4314 :     while (i < s->cpl_end_freq) {
     164        2876 :         int band_size = s->cpl_band_sizes[bnd];
     165       11504 :         for (ch = CPL_CH; ch <= s->fbw_channels; ch++) {
     166       60396 :             for (blk = 0; blk < s->num_blocks; blk++) {
     167       51768 :                 AC3Block *block = &s->blocks[blk];
     168       51768 :                 if (!block->cpl_in_use || (ch > CPL_CH && !block->channel_in_cpl[ch]))
     169           0 :                     continue;
     170      828288 :                 for (j = 0; j < band_size; j++) {
     171      776520 :                     CoefType v = block->mdct_coef[ch][i+j];
     172      776520 :                     MAC_COEF(energy[blk][ch][bnd], v, v);
     173             :                 }
     174             :             }
     175             :         }
     176        2876 :         i += band_size;
     177        2876 :         bnd++;
     178             :     }
     179             : 
     180             :     /* calculate coupling coordinates for all blocks for all channels */
     181        5033 :     for (blk = 0; blk < s->num_blocks; blk++) {
     182        4314 :         AC3Block *block  = &s->blocks[blk];
     183        4314 :         if (!block->cpl_in_use)
     184           0 :             continue;
     185       12942 :         for (ch = 1; ch <= s->fbw_channels; ch++) {
     186        8628 :             if (!block->channel_in_cpl[ch])
     187           0 :                 continue;
     188       43140 :             for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
     189       34512 :                 cpl_coords[blk][ch][bnd] = calc_cpl_coord(energy[blk][ch][bnd],
     190             :                                                           energy[blk][CPL_CH][bnd]);
     191             :             }
     192             :         }
     193             :     }
     194             : 
     195             :     /* determine which blocks to send new coupling coordinates for */
     196        5033 :     for (blk = 0; blk < s->num_blocks; blk++) {
     197        4314 :         AC3Block *block  = &s->blocks[blk];
     198        4314 :         AC3Block *block0 = blk ? &s->blocks[blk-1] : NULL;
     199             : 
     200        4314 :         memset(block->new_cpl_coords, 0, sizeof(block->new_cpl_coords));
     201             : 
     202        4314 :         if (block->cpl_in_use) {
     203             :             /* send new coordinates if this is the first block, if previous
     204             :              * block did not use coupling but this block does, the channels
     205             :              * using coupling has changed from the previous block, or the
     206             :              * coordinate difference from the last block for any channel is
     207             :              * greater than a threshold value. */
     208        5033 :             if (blk == 0 || !block0->cpl_in_use) {
     209        2157 :                 for (ch = 1; ch <= s->fbw_channels; ch++)
     210        1438 :                     block->new_cpl_coords[ch] = 1;
     211             :             } else {
     212       10785 :                 for (ch = 1; ch <= s->fbw_channels; ch++) {
     213        7190 :                     if (!block->channel_in_cpl[ch])
     214           0 :                         continue;
     215        7190 :                     if (!block0->channel_in_cpl[ch]) {
     216           0 :                         block->new_cpl_coords[ch] = 1;
     217             :                     } else {
     218        7190 :                         CoefSumType coord_diff = 0;
     219       35950 :                         for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
     220       28760 :                             coord_diff += FFABS(cpl_coords[blk-1][ch][bnd] -
     221             :                                                 cpl_coords[blk  ][ch][bnd]);
     222             :                         }
     223        7190 :                         coord_diff /= s->num_cpl_bands;
     224        7190 :                         if (coord_diff > NEW_CPL_COORD_THRESHOLD)
     225          32 :                             block->new_cpl_coords[ch] = 1;
     226             :                     }
     227             :                 }
     228             :             }
     229             :         }
     230             :     }
     231             : 
     232             :     /* calculate final coupling coordinates, taking into account reusing of
     233             :        coordinates in successive blocks */
     234        3595 :     for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
     235        2876 :         blk = 0;
     236        8716 :         while (blk < s->num_blocks) {
     237        2964 :             int av_uninit(blk1);
     238        2964 :             AC3Block *block  = &s->blocks[blk];
     239             : 
     240        2964 :             if (!block->cpl_in_use) {
     241           0 :                 blk++;
     242           0 :                 continue;
     243             :             }
     244             : 
     245        8892 :             for (ch = 1; ch <= s->fbw_channels; ch++) {
     246             :                 CoefSumType energy_ch, energy_cpl;
     247        5928 :                 if (!block->channel_in_cpl[ch])
     248           0 :                     continue;
     249        5928 :                 energy_cpl = energy[blk][CPL_CH][bnd];
     250        5928 :                 energy_ch = energy[blk][ch][bnd];
     251        5928 :                 blk1 = blk+1;
     252       40624 :                 while (blk1 < s->num_blocks && !s->blocks[blk1].new_cpl_coords[ch]) {
     253       28768 :                     if (s->blocks[blk1].cpl_in_use) {
     254       28768 :                         energy_cpl += energy[blk1][CPL_CH][bnd];
     255       28768 :                         energy_ch += energy[blk1][ch][bnd];
     256             :                     }
     257       28768 :                     blk1++;
     258             :                 }
     259        5928 :                 cpl_coords[blk][ch][bnd] = calc_cpl_coord(energy_ch, energy_cpl);
     260             :             }
     261        2964 :             blk = blk1;
     262             :         }
     263             :     }
     264             : 
     265             :     /* calculate exponents/mantissas for coupling coordinates */
     266        5033 :     for (blk = 0; blk < s->num_blocks; blk++) {
     267        4314 :         AC3Block *block = &s->blocks[blk];
     268        4314 :         if (!block->cpl_in_use)
     269           0 :             continue;
     270             : 
     271             : #if CONFIG_AC3ENC_FLOAT
     272        9828 :         s->ac3dsp.float_to_fixed24(fixed_cpl_coords[blk][1],
     273        3276 :                                    cpl_coords[blk][1],
     274        3276 :                                    s->fbw_channels * 16);
     275             : #endif
     276       12942 :         s->ac3dsp.extract_exponents(block->cpl_coord_exp[1],
     277        4314 :                                     fixed_cpl_coords[blk][1],
     278        4314 :                                     s->fbw_channels * 16);
     279             : 
     280       12942 :         for (ch = 1; ch <= s->fbw_channels; ch++) {
     281             :             int bnd, min_exp, max_exp, master_exp;
     282             : 
     283        8628 :             if (!block->new_cpl_coords[ch])
     284        7158 :                 continue;
     285             : 
     286             :             /* determine master exponent */
     287        1470 :             min_exp = max_exp = block->cpl_coord_exp[ch][0];
     288        5880 :             for (bnd = 1; bnd < s->num_cpl_bands; bnd++) {
     289        4410 :                 int exp = block->cpl_coord_exp[ch][bnd];
     290        4410 :                 min_exp = FFMIN(exp, min_exp);
     291        4410 :                 max_exp = FFMAX(exp, max_exp);
     292             :             }
     293        1470 :             master_exp = ((max_exp - 15) + 2) / 3;
     294        1470 :             master_exp = FFMAX(master_exp, 0);
     295        2940 :             while (min_exp < master_exp * 3)
     296           0 :                 master_exp--;
     297        7350 :             for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
     298       11760 :                 block->cpl_coord_exp[ch][bnd] = av_clip(block->cpl_coord_exp[ch][bnd] -
     299        5880 :                                                         master_exp * 3, 0, 15);
     300             :             }
     301        1470 :             block->cpl_master_exp[ch] = master_exp;
     302             : 
     303             :             /* quantize mantissas */
     304        7350 :             for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
     305        5880 :                 int cpl_exp  = block->cpl_coord_exp[ch][bnd];
     306        5880 :                 int cpl_mant = (fixed_cpl_coords[blk][ch][bnd] << (5 + cpl_exp + master_exp * 3)) >> 24;
     307        5880 :                 if (cpl_exp == 15)
     308           0 :                     cpl_mant >>= 1;
     309             :                 else
     310        5880 :                     cpl_mant -= 16;
     311             : 
     312        5880 :                 block->cpl_coord_mant[ch][bnd] = cpl_mant;
     313             :             }
     314             :         }
     315             :     }
     316             : 
     317         719 :     if (CONFIG_EAC3_ENCODER && s->eac3)
     318         273 :         ff_eac3_set_cpl_states(s);
     319         719 : }
     320             : 
     321             : 
     322             : /*
     323             :  * Determine rematrixing flags for each block and band.
     324             :  */
     325        1093 : static void compute_rematrixing_strategy(AC3EncodeContext *s)
     326             : {
     327             :     int nb_coefs;
     328             :     int blk, bnd;
     329        1093 :     AC3Block *block, *block0 = NULL;
     330             : 
     331        1093 :     if (s->channel_mode != AC3_CHMODE_STEREO)
     332         374 :         return;
     333             : 
     334        5033 :     for (blk = 0; blk < s->num_blocks; blk++) {
     335        4314 :         block = &s->blocks[blk];
     336        4314 :         block->new_rematrixing_strategy = !blk;
     337             : 
     338        4314 :         block->num_rematrixing_bands = 4;
     339        4314 :         if (block->cpl_in_use) {
     340        4314 :             block->num_rematrixing_bands -= (s->start_freq[CPL_CH] <= 61);
     341        4314 :             block->num_rematrixing_bands -= (s->start_freq[CPL_CH] == 37);
     342        4314 :             if (blk && block->num_rematrixing_bands != block0->num_rematrixing_bands)
     343           0 :                 block->new_rematrixing_strategy = 1;
     344             :         }
     345        4314 :         nb_coefs = FFMIN(block->end_freq[1], block->end_freq[2]);
     346             : 
     347        4314 :         if (!s->rematrixing_enabled) {
     348           0 :             block0 = block;
     349           0 :             continue;
     350             :         }
     351             : 
     352       21570 :         for (bnd = 0; bnd < block->num_rematrixing_bands; bnd++) {
     353             :             /* calculate sum of squared coeffs for one band in one block */
     354       17256 :             int start = ff_ac3_rematrix_band_tab[bnd];
     355       17256 :             int end   = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]);
     356             :             CoefSumType sum[4];
     357       34512 :             sum_square_butterfly(s, sum, block->mdct_coef[1] + start,
     358       17256 :                                  block->mdct_coef[2] + start, end - start);
     359             : 
     360             :             /* compare sums to determine if rematrixing will be used for this band */
     361       17256 :             if (FFMIN(sum[2], sum[3]) < FFMIN(sum[0], sum[1]))
     362        9589 :                 block->rematrixing_flags[bnd] = 1;
     363             :             else
     364        7667 :                 block->rematrixing_flags[bnd] = 0;
     365             : 
     366             :             /* determine if new rematrixing flags will be sent */
     367       31636 :             if (blk &&
     368       14380 :                 block->rematrixing_flags[bnd] != block0->rematrixing_flags[bnd]) {
     369        1932 :                 block->new_rematrixing_strategy = 1;
     370             :             }
     371             :         }
     372        4314 :         block0 = block;
     373             :     }
     374             : }
     375             : 
     376             : 
     377        1093 : int AC3_NAME(encode_frame)(AVCodecContext *avctx, AVPacket *avpkt,
     378             :                            const AVFrame *frame, int *got_packet_ptr)
     379             : {
     380        1093 :     AC3EncodeContext *s = avctx->priv_data;
     381             :     int ret;
     382             : 
     383        1093 :     if (s->options.allow_per_frame_metadata) {
     384           0 :         ret = ff_ac3_validate_metadata(s);
     385           0 :         if (ret)
     386           0 :             return ret;
     387             :     }
     388             : 
     389        1093 :     if (s->bit_alloc.sr_code == 1 || s->eac3)
     390        1093 :         ff_ac3_adjust_frame_size(s);
     391             : 
     392        1093 :     copy_input_samples(s, (SampleType **)frame->extended_data);
     393             : 
     394        1093 :     apply_mdct(s);
     395             : 
     396        1093 :     if (s->fixed_point)
     397         547 :         scale_coefficients(s);
     398             : 
     399        1093 :     clip_coefficients(&s->adsp, s->blocks[0].mdct_coef[1],
     400        1093 :                       AC3_MAX_COEFS * s->num_blocks * s->channels);
     401             : 
     402        1093 :     s->cpl_on = s->cpl_enabled;
     403        1093 :     ff_ac3_compute_coupling_strategy(s);
     404             : 
     405        1093 :     if (s->cpl_on)
     406         719 :         apply_channel_coupling(s);
     407             : 
     408        1093 :     compute_rematrixing_strategy(s);
     409             : 
     410        1093 :     if (!s->fixed_point)
     411         546 :         scale_coefficients(s);
     412             : 
     413        1093 :     ff_ac3_apply_rematrixing(s);
     414             : 
     415        1093 :     ff_ac3_process_exponents(s);
     416             : 
     417        1093 :     ret = ff_ac3_compute_bit_allocation(s);
     418        1093 :     if (ret) {
     419           0 :         av_log(avctx, AV_LOG_ERROR, "Bit allocation failed. Try increasing the bitrate.\n");
     420           0 :         return ret;
     421             :     }
     422             : 
     423        1093 :     ff_ac3_group_exponents(s);
     424             : 
     425        1093 :     ff_ac3_quantize_mantissas(s);
     426             : 
     427        1093 :     if ((ret = ff_alloc_packet2(avctx, avpkt, s->frame_size, 0)) < 0)
     428           0 :         return ret;
     429        1093 :     ff_ac3_output_frame(s, avpkt->data);
     430             : 
     431        1093 :     if (frame->pts != AV_NOPTS_VALUE)
     432        1093 :         avpkt->pts = frame->pts - ff_samples_to_time_base(avctx, avctx->initial_padding);
     433             : 
     434        1093 :     *got_packet_ptr = 1;
     435        1093 :     return 0;
     436             : }

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