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: 2017-03-25 17:02:41 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             : /* prototypes for static functions in ac3enc_fixed.c and ac3enc_float.c */
      40             : 
      41             : static void scale_coefficients(AC3EncodeContext *s);
      42             : 
      43             : static int normalize_samples(AC3EncodeContext *s);
      44             : 
      45             : static void clip_coefficients(AudioDSPContext *adsp, CoefType *coef,
      46             :                               unsigned int len);
      47             : 
      48             : static CoefType calc_cpl_coord(CoefSumType energy_ch, CoefSumType energy_cpl);
      49             : 
      50             : static void sum_square_butterfly(AC3EncodeContext *s, CoefSumType sum[4],
      51             :                                  const CoefType *coef0, const CoefType *coef1,
      52             :                                  int len);
      53             : 
      54           5 : int AC3_NAME(allocate_sample_buffers)(AC3EncodeContext *s)
      55             : {
      56             :     int ch;
      57             : 
      58           5 :     FF_ALLOC_OR_GOTO(s->avctx, s->windowed_samples, AC3_WINDOW_SIZE *
      59             :                      sizeof(*s->windowed_samples), alloc_fail);
      60           5 :     FF_ALLOC_ARRAY_OR_GOTO(s->avctx, s->planar_samples, s->channels, sizeof(*s->planar_samples),
      61             :                      alloc_fail);
      62          13 :     for (ch = 0; ch < s->channels; ch++) {
      63           8 :         FF_ALLOCZ_OR_GOTO(s->avctx, s->planar_samples[ch],
      64             :                           (AC3_FRAME_SIZE+AC3_BLOCK_SIZE) * sizeof(**s->planar_samples),
      65             :                           alloc_fail);
      66             :     }
      67             : 
      68           5 :     return 0;
      69             : alloc_fail:
      70           0 :     return AVERROR(ENOMEM);
      71             : }
      72             : 
      73             : 
      74             : /*
      75             :  * Copy input samples.
      76             :  * Channels are reordered from FFmpeg's default order to AC-3 order.
      77             :  */
      78        1093 : static void copy_input_samples(AC3EncodeContext *s, SampleType **samples)
      79             : {
      80             :     int ch;
      81             : 
      82             :     /* copy and remap input samples */
      83        2905 :     for (ch = 0; ch < s->channels; ch++) {
      84             :         /* copy last 256 samples of previous frame to the start of the current frame */
      85        1812 :         memcpy(&s->planar_samples[ch][0], &s->planar_samples[ch][AC3_BLOCK_SIZE * s->num_blocks],
      86             :                AC3_BLOCK_SIZE * sizeof(s->planar_samples[0][0]));
      87             : 
      88             :         /* copy new samples for current frame */
      89        3624 :         memcpy(&s->planar_samples[ch][AC3_BLOCK_SIZE],
      90        1812 :                samples[s->channel_map[ch]],
      91        1812 :                AC3_BLOCK_SIZE * s->num_blocks * sizeof(s->planar_samples[0][0]));
      92             :     }
      93        1093 : }
      94             : 
      95             : 
      96             : /*
      97             :  * Apply the MDCT to input samples to generate frequency coefficients.
      98             :  * This applies the KBD window and normalizes the input to reduce precision
      99             :  * loss due to fixed-point calculations.
     100             :  */
     101        1093 : static void apply_mdct(AC3EncodeContext *s)
     102             : {
     103             :     int blk, ch;
     104             : 
     105        2905 :     for (ch = 0; ch < s->channels; ch++) {
     106       12684 :         for (blk = 0; blk < s->num_blocks; blk++) {
     107       10872 :             AC3Block *block = &s->blocks[blk];
     108       10872 :             const SampleType *input_samples = &s->planar_samples[ch][blk * AC3_BLOCK_SIZE];
     109             : 
     110             : #if CONFIG_AC3ENC_FLOAT
     111       13104 :             s->fdsp->vector_fmul(s->windowed_samples, input_samples,
     112        6552 :                                 s->mdct_window, AC3_WINDOW_SIZE);
     113             : #else
     114        8640 :             s->ac3dsp.apply_window_int16(s->windowed_samples, input_samples,
     115        4320 :                                          s->mdct_window, AC3_WINDOW_SIZE);
     116             : #endif
     117             : 
     118       10872 :             if (s->fixed_point)
     119        4320 :                 block->coeff_shift[ch+1] = normalize_samples(s);
     120             : 
     121       21744 :             s->mdct.mdct_calcw(&s->mdct, block->mdct_coef[ch+1],
     122       10872 :                                s->windowed_samples);
     123             :         }
     124             :     }
     125        1093 : }
     126             : 
     127             : 
     128             : /*
     129             :  * Calculate coupling channel and coupling coordinates.
     130             :  */
     131         719 : static void apply_channel_coupling(AC3EncodeContext *s)
     132             : {
     133         719 :     LOCAL_ALIGNED_16(CoefType, cpl_coords,      [AC3_MAX_BLOCKS], [AC3_MAX_CHANNELS][16]);
     134             : #if CONFIG_AC3ENC_FLOAT
     135         546 :     LOCAL_ALIGNED_16(int32_t, fixed_cpl_coords, [AC3_MAX_BLOCKS], [AC3_MAX_CHANNELS][16]);
     136             : #else
     137         173 :     int32_t (*fixed_cpl_coords)[AC3_MAX_CHANNELS][16] = cpl_coords;
     138             : #endif
     139         719 :     int av_uninit(blk), ch, bnd, i, j;
     140         719 :     CoefSumType energy[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][16] = {{{0}}};
     141             :     int cpl_start, num_cpl_coefs;
     142             : 
     143         719 :     memset(cpl_coords,       0, AC3_MAX_BLOCKS * sizeof(*cpl_coords));
     144             : #if CONFIG_AC3ENC_FLOAT
     145         546 :     memset(fixed_cpl_coords, 0, AC3_MAX_BLOCKS * sizeof(*cpl_coords));
     146             : #endif
     147             : 
     148             :     /* align start to 16-byte boundary. align length to multiple of 32.
     149             :         note: coupling start bin % 4 will always be 1 */
     150         719 :     cpl_start     = s->start_freq[CPL_CH] - 1;
     151         719 :     num_cpl_coefs = FFALIGN(s->num_cpl_subbands * 12 + 1, 32);
     152         719 :     cpl_start     = FFMIN(256, cpl_start + num_cpl_coefs) - num_cpl_coefs;
     153             : 
     154             :     /* calculate coupling channel from fbw channels */
     155        5033 :     for (blk = 0; blk < s->num_blocks; blk++) {
     156        4314 :         AC3Block *block = &s->blocks[blk];
     157        4314 :         CoefType *cpl_coef = &block->mdct_coef[CPL_CH][cpl_start];
     158        4314 :         if (!block->cpl_in_use)
     159           0 :             continue;
     160        4314 :         memset(cpl_coef, 0, num_cpl_coefs * sizeof(*cpl_coef));
     161       12942 :         for (ch = 1; ch <= s->fbw_channels; ch++) {
     162        8628 :             CoefType *ch_coef = &block->mdct_coef[ch][cpl_start];
     163        8628 :             if (!block->channel_in_cpl[ch])
     164           0 :                 continue;
     165      560820 :             for (i = 0; i < num_cpl_coefs; i++)
     166      552192 :                 cpl_coef[i] += ch_coef[i];
     167             :         }
     168             : 
     169             :         /* coefficients must be clipped in order to be encoded */
     170        4314 :         clip_coefficients(&s->adsp, cpl_coef, num_cpl_coefs);
     171             :     }
     172             : 
     173             :     /* calculate energy in each band in coupling channel and each fbw channel */
     174             :     /* TODO: possibly use SIMD to speed up energy calculation */
     175         719 :     bnd = 0;
     176         719 :     i = s->start_freq[CPL_CH];
     177        4314 :     while (i < s->cpl_end_freq) {
     178        2876 :         int band_size = s->cpl_band_sizes[bnd];
     179       11504 :         for (ch = CPL_CH; ch <= s->fbw_channels; ch++) {
     180       60396 :             for (blk = 0; blk < s->num_blocks; blk++) {
     181       51768 :                 AC3Block *block = &s->blocks[blk];
     182       51768 :                 if (!block->cpl_in_use || (ch > CPL_CH && !block->channel_in_cpl[ch]))
     183           0 :                     continue;
     184      828288 :                 for (j = 0; j < band_size; j++) {
     185      776520 :                     CoefType v = block->mdct_coef[ch][i+j];
     186      776520 :                     MAC_COEF(energy[blk][ch][bnd], v, v);
     187             :                 }
     188             :             }
     189             :         }
     190        2876 :         i += band_size;
     191        2876 :         bnd++;
     192             :     }
     193             : 
     194             :     /* calculate coupling coordinates for all blocks for all channels */
     195        5033 :     for (blk = 0; blk < s->num_blocks; blk++) {
     196        4314 :         AC3Block *block  = &s->blocks[blk];
     197        4314 :         if (!block->cpl_in_use)
     198           0 :             continue;
     199       12942 :         for (ch = 1; ch <= s->fbw_channels; ch++) {
     200        8628 :             if (!block->channel_in_cpl[ch])
     201           0 :                 continue;
     202       43140 :             for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
     203       34512 :                 cpl_coords[blk][ch][bnd] = calc_cpl_coord(energy[blk][ch][bnd],
     204             :                                                           energy[blk][CPL_CH][bnd]);
     205             :             }
     206             :         }
     207             :     }
     208             : 
     209             :     /* determine which blocks to send new coupling coordinates for */
     210        5033 :     for (blk = 0; blk < s->num_blocks; blk++) {
     211        4314 :         AC3Block *block  = &s->blocks[blk];
     212        4314 :         AC3Block *block0 = blk ? &s->blocks[blk-1] : NULL;
     213             : 
     214        4314 :         memset(block->new_cpl_coords, 0, sizeof(block->new_cpl_coords));
     215             : 
     216        4314 :         if (block->cpl_in_use) {
     217             :             /* send new coordinates if this is the first block, if previous
     218             :              * block did not use coupling but this block does, the channels
     219             :              * using coupling has changed from the previous block, or the
     220             :              * coordinate difference from the last block for any channel is
     221             :              * greater than a threshold value. */
     222        5033 :             if (blk == 0 || !block0->cpl_in_use) {
     223        2157 :                 for (ch = 1; ch <= s->fbw_channels; ch++)
     224        1438 :                     block->new_cpl_coords[ch] = 1;
     225             :             } else {
     226       10785 :                 for (ch = 1; ch <= s->fbw_channels; ch++) {
     227        7190 :                     if (!block->channel_in_cpl[ch])
     228           0 :                         continue;
     229        7190 :                     if (!block0->channel_in_cpl[ch]) {
     230           0 :                         block->new_cpl_coords[ch] = 1;
     231             :                     } else {
     232        7190 :                         CoefSumType coord_diff = 0;
     233       35950 :                         for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
     234       28760 :                             coord_diff += FFABS(cpl_coords[blk-1][ch][bnd] -
     235             :                                                 cpl_coords[blk  ][ch][bnd]);
     236             :                         }
     237        7190 :                         coord_diff /= s->num_cpl_bands;
     238        7190 :                         if (coord_diff > NEW_CPL_COORD_THRESHOLD)
     239          32 :                             block->new_cpl_coords[ch] = 1;
     240             :                     }
     241             :                 }
     242             :             }
     243             :         }
     244             :     }
     245             : 
     246             :     /* calculate final coupling coordinates, taking into account reusing of
     247             :        coordinates in successive blocks */
     248        3595 :     for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
     249        2876 :         blk = 0;
     250        8716 :         while (blk < s->num_blocks) {
     251        2964 :             int av_uninit(blk1);
     252        2964 :             AC3Block *block  = &s->blocks[blk];
     253             : 
     254        2964 :             if (!block->cpl_in_use) {
     255           0 :                 blk++;
     256           0 :                 continue;
     257             :             }
     258             : 
     259        8892 :             for (ch = 1; ch <= s->fbw_channels; ch++) {
     260             :                 CoefSumType energy_ch, energy_cpl;
     261        5928 :                 if (!block->channel_in_cpl[ch])
     262           0 :                     continue;
     263        5928 :                 energy_cpl = energy[blk][CPL_CH][bnd];
     264        5928 :                 energy_ch = energy[blk][ch][bnd];
     265        5928 :                 blk1 = blk+1;
     266       40624 :                 while (blk1 < s->num_blocks && !s->blocks[blk1].new_cpl_coords[ch]) {
     267       28768 :                     if (s->blocks[blk1].cpl_in_use) {
     268       28768 :                         energy_cpl += energy[blk1][CPL_CH][bnd];
     269       28768 :                         energy_ch += energy[blk1][ch][bnd];
     270             :                     }
     271       28768 :                     blk1++;
     272             :                 }
     273        5928 :                 cpl_coords[blk][ch][bnd] = calc_cpl_coord(energy_ch, energy_cpl);
     274             :             }
     275        2964 :             blk = blk1;
     276             :         }
     277             :     }
     278             : 
     279             :     /* calculate exponents/mantissas for coupling coordinates */
     280        5033 :     for (blk = 0; blk < s->num_blocks; blk++) {
     281        4314 :         AC3Block *block = &s->blocks[blk];
     282        4314 :         if (!block->cpl_in_use)
     283           0 :             continue;
     284             : 
     285             : #if CONFIG_AC3ENC_FLOAT
     286        9828 :         s->ac3dsp.float_to_fixed24(fixed_cpl_coords[blk][1],
     287        3276 :                                    cpl_coords[blk][1],
     288        3276 :                                    s->fbw_channels * 16);
     289             : #endif
     290       12942 :         s->ac3dsp.extract_exponents(block->cpl_coord_exp[1],
     291        4314 :                                     fixed_cpl_coords[blk][1],
     292        4314 :                                     s->fbw_channels * 16);
     293             : 
     294       12942 :         for (ch = 1; ch <= s->fbw_channels; ch++) {
     295             :             int bnd, min_exp, max_exp, master_exp;
     296             : 
     297        8628 :             if (!block->new_cpl_coords[ch])
     298        7158 :                 continue;
     299             : 
     300             :             /* determine master exponent */
     301        1470 :             min_exp = max_exp = block->cpl_coord_exp[ch][0];
     302        5880 :             for (bnd = 1; bnd < s->num_cpl_bands; bnd++) {
     303        4410 :                 int exp = block->cpl_coord_exp[ch][bnd];
     304        4410 :                 min_exp = FFMIN(exp, min_exp);
     305        4410 :                 max_exp = FFMAX(exp, max_exp);
     306             :             }
     307        1470 :             master_exp = ((max_exp - 15) + 2) / 3;
     308        1470 :             master_exp = FFMAX(master_exp, 0);
     309        2940 :             while (min_exp < master_exp * 3)
     310           0 :                 master_exp--;
     311        7350 :             for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
     312       11760 :                 block->cpl_coord_exp[ch][bnd] = av_clip(block->cpl_coord_exp[ch][bnd] -
     313        5880 :                                                         master_exp * 3, 0, 15);
     314             :             }
     315        1470 :             block->cpl_master_exp[ch] = master_exp;
     316             : 
     317             :             /* quantize mantissas */
     318        7350 :             for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
     319        5880 :                 int cpl_exp  = block->cpl_coord_exp[ch][bnd];
     320        5880 :                 int cpl_mant = (fixed_cpl_coords[blk][ch][bnd] << (5 + cpl_exp + master_exp * 3)) >> 24;
     321        5880 :                 if (cpl_exp == 15)
     322           0 :                     cpl_mant >>= 1;
     323             :                 else
     324        5880 :                     cpl_mant -= 16;
     325             : 
     326        5880 :                 block->cpl_coord_mant[ch][bnd] = cpl_mant;
     327             :             }
     328             :         }
     329             :     }
     330             : 
     331         719 :     if (CONFIG_EAC3_ENCODER && s->eac3)
     332         273 :         ff_eac3_set_cpl_states(s);
     333         719 : }
     334             : 
     335             : 
     336             : /*
     337             :  * Determine rematrixing flags for each block and band.
     338             :  */
     339        1093 : static void compute_rematrixing_strategy(AC3EncodeContext *s)
     340             : {
     341             :     int nb_coefs;
     342             :     int blk, bnd;
     343        1093 :     AC3Block *block, *block0 = NULL;
     344             : 
     345        1093 :     if (s->channel_mode != AC3_CHMODE_STEREO)
     346         374 :         return;
     347             : 
     348        5033 :     for (blk = 0; blk < s->num_blocks; blk++) {
     349        4314 :         block = &s->blocks[blk];
     350        4314 :         block->new_rematrixing_strategy = !blk;
     351             : 
     352        4314 :         block->num_rematrixing_bands = 4;
     353        4314 :         if (block->cpl_in_use) {
     354        4314 :             block->num_rematrixing_bands -= (s->start_freq[CPL_CH] <= 61);
     355        4314 :             block->num_rematrixing_bands -= (s->start_freq[CPL_CH] == 37);
     356        4314 :             if (blk && block->num_rematrixing_bands != block0->num_rematrixing_bands)
     357           0 :                 block->new_rematrixing_strategy = 1;
     358             :         }
     359        4314 :         nb_coefs = FFMIN(block->end_freq[1], block->end_freq[2]);
     360             : 
     361        4314 :         if (!s->rematrixing_enabled) {
     362           0 :             block0 = block;
     363           0 :             continue;
     364             :         }
     365             : 
     366       21570 :         for (bnd = 0; bnd < block->num_rematrixing_bands; bnd++) {
     367             :             /* calculate sum of squared coeffs for one band in one block */
     368       17256 :             int start = ff_ac3_rematrix_band_tab[bnd];
     369       17256 :             int end   = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]);
     370             :             CoefSumType sum[4];
     371       34512 :             sum_square_butterfly(s, sum, block->mdct_coef[1] + start,
     372       17256 :                                  block->mdct_coef[2] + start, end - start);
     373             : 
     374             :             /* compare sums to determine if rematrixing will be used for this band */
     375       17256 :             if (FFMIN(sum[2], sum[3]) < FFMIN(sum[0], sum[1]))
     376        9589 :                 block->rematrixing_flags[bnd] = 1;
     377             :             else
     378        7667 :                 block->rematrixing_flags[bnd] = 0;
     379             : 
     380             :             /* determine if new rematrixing flags will be sent */
     381       31636 :             if (blk &&
     382       14380 :                 block->rematrixing_flags[bnd] != block0->rematrixing_flags[bnd]) {
     383        1932 :                 block->new_rematrixing_strategy = 1;
     384             :             }
     385             :         }
     386        4314 :         block0 = block;
     387             :     }
     388             : }
     389             : 
     390             : 
     391        1093 : int AC3_NAME(encode_frame)(AVCodecContext *avctx, AVPacket *avpkt,
     392             :                            const AVFrame *frame, int *got_packet_ptr)
     393             : {
     394        1093 :     AC3EncodeContext *s = avctx->priv_data;
     395             :     int ret;
     396             : 
     397        1093 :     if (s->options.allow_per_frame_metadata) {
     398           0 :         ret = ff_ac3_validate_metadata(s);
     399           0 :         if (ret)
     400           0 :             return ret;
     401             :     }
     402             : 
     403        1093 :     if (s->bit_alloc.sr_code == 1 || s->eac3)
     404        1093 :         ff_ac3_adjust_frame_size(s);
     405             : 
     406        1093 :     copy_input_samples(s, (SampleType **)frame->extended_data);
     407             : 
     408        1093 :     apply_mdct(s);
     409             : 
     410        1093 :     if (s->fixed_point)
     411         547 :         scale_coefficients(s);
     412             : 
     413        1093 :     clip_coefficients(&s->adsp, s->blocks[0].mdct_coef[1],
     414        1093 :                       AC3_MAX_COEFS * s->num_blocks * s->channels);
     415             : 
     416        1093 :     s->cpl_on = s->cpl_enabled;
     417        1093 :     ff_ac3_compute_coupling_strategy(s);
     418             : 
     419        1093 :     if (s->cpl_on)
     420         719 :         apply_channel_coupling(s);
     421             : 
     422        1093 :     compute_rematrixing_strategy(s);
     423             : 
     424        1093 :     if (!s->fixed_point)
     425         546 :         scale_coefficients(s);
     426             : 
     427        1093 :     ff_ac3_apply_rematrixing(s);
     428             : 
     429        1093 :     ff_ac3_process_exponents(s);
     430             : 
     431        1093 :     ret = ff_ac3_compute_bit_allocation(s);
     432        1093 :     if (ret) {
     433           0 :         av_log(avctx, AV_LOG_ERROR, "Bit allocation failed. Try increasing the bitrate.\n");
     434           0 :         return ret;
     435             :     }
     436             : 
     437        1093 :     ff_ac3_group_exponents(s);
     438             : 
     439        1093 :     ff_ac3_quantize_mantissas(s);
     440             : 
     441        1093 :     if ((ret = ff_alloc_packet2(avctx, avpkt, s->frame_size, 0)) < 0)
     442           0 :         return ret;
     443        1093 :     ff_ac3_output_frame(s, avpkt->data);
     444             : 
     445        1093 :     if (frame->pts != AV_NOPTS_VALUE)
     446        1093 :         avpkt->pts = frame->pts - ff_samples_to_time_base(avctx, avctx->initial_padding);
     447             : 
     448        1093 :     *got_packet_ptr = 1;
     449        1093 :     return 0;
     450             : }

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