LCOV - code coverage report
Current view: top level - src/libavcodec - ac3enc_fixed.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 37 37 100.0 %
Date: 2017-01-24 04:42:20 Functions: 8 8 100.0 %

          Line data    Source code
       1             : /*
       2             :  * The simplest AC-3 encoder
       3             :  * Copyright (c) 2000 Fabrice Bellard
       4             :  * Copyright (c) 2006-2010 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             :  * fixed-point AC-3 encoder.
      27             :  */
      28             : 
      29             : #define FFT_FLOAT 0
      30             : #undef CONFIG_AC3ENC_FLOAT
      31             : #include "internal.h"
      32             : #include "audiodsp.h"
      33             : #include "ac3enc.h"
      34             : #include "eac3enc.h"
      35             : 
      36             : #define AC3ENC_TYPE AC3ENC_TYPE_AC3_FIXED
      37             : #include "ac3enc_opts_template.c"
      38             : 
      39             : static const AVClass ac3enc_class = {
      40             :     .class_name = "Fixed-Point AC-3 Encoder",
      41             :     .item_name  = av_default_item_name,
      42             :     .option     = ac3_options,
      43             :     .version    = LIBAVUTIL_VERSION_INT,
      44             : };
      45             : 
      46             : #include "ac3enc_template.c"
      47             : 
      48             : 
      49             : /**
      50             :  * Finalize MDCT and free allocated memory.
      51             :  *
      52             :  * @param s  AC-3 encoder private context
      53             :  */
      54           3 : av_cold void AC3_NAME(mdct_end)(AC3EncodeContext *s)
      55             : {
      56           3 :     ff_mdct_end(&s->mdct);
      57           3 : }
      58             : 
      59             : 
      60             : /**
      61             :  * Initialize MDCT tables.
      62             :  *
      63             :  * @param s  AC-3 encoder private context
      64             :  * @return   0 on success, negative error code on failure
      65             :  */
      66           3 : av_cold int AC3_NAME(mdct_init)(AC3EncodeContext *s)
      67             : {
      68           3 :     int ret = ff_mdct_init(&s->mdct, 9, 0, -1.0);
      69           3 :     s->mdct_window = ff_ac3_window;
      70           3 :     return ret;
      71             : }
      72             : 
      73             : 
      74             : /*
      75             :  * Normalize the input samples to use the maximum available precision.
      76             :  * This assumes signed 16-bit input samples.
      77             :  */
      78        4320 : static int normalize_samples(AC3EncodeContext *s)
      79             : {
      80        4320 :     int v = s->ac3dsp.ac3_max_msb_abs_int16(s->windowed_samples, AC3_WINDOW_SIZE);
      81        4320 :     v = 14 - av_log2(v);
      82        4320 :     if (v > 0)
      83        3972 :         s->ac3dsp.ac3_lshift_int16(s->windowed_samples, AC3_WINDOW_SIZE, v);
      84             :     /* +6 to right-shift from 31-bit to 25-bit */
      85        4320 :     return v + 6;
      86             : }
      87             : 
      88             : 
      89             : /*
      90             :  * Scale MDCT coefficients to 25-bit signed fixed-point.
      91             :  */
      92         547 : static void scale_coefficients(AC3EncodeContext *s)
      93             : {
      94             :     int blk, ch;
      95             : 
      96        3829 :     for (blk = 0; blk < s->num_blocks; blk++) {
      97        3282 :         AC3Block *block = &s->blocks[blk];
      98        7602 :         for (ch = 1; ch <= s->channels; ch++) {
      99        8640 :             s->ac3dsp.ac3_rshift_int32(block->mdct_coef[ch], AC3_MAX_COEFS,
     100        4320 :                                        block->coeff_shift[ch]);
     101             :         }
     102             :     }
     103         547 : }
     104             : 
     105        4152 : static void sum_square_butterfly(AC3EncodeContext *s, int64_t sum[4],
     106             :                                  const int32_t *coef0, const int32_t *coef1,
     107             :                                  int len)
     108             : {
     109        4152 :     s->ac3dsp.sum_square_butterfly_int32(sum, coef0, coef1, len);
     110        4152 : }
     111             : 
     112             : /*
     113             :  * Clip MDCT coefficients to allowable range.
     114             :  */
     115        1585 : static void clip_coefficients(AudioDSPContext *adsp, int32_t *coef,
     116             :                               unsigned int len)
     117             : {
     118        1585 :     adsp->vector_clip_int32(coef, coef, COEF_MIN, COEF_MAX, len);
     119        1585 : }
     120             : 
     121             : 
     122             : /*
     123             :  * Calculate a single coupling coordinate.
     124             :  */
     125        9704 : static CoefType calc_cpl_coord(CoefSumType energy_ch, CoefSumType energy_cpl)
     126             : {
     127        9704 :     if (energy_cpl <= COEF_MAX) {
     128        7882 :         return 1048576;
     129             :     } else {
     130        1822 :         uint64_t coord   = energy_ch / (energy_cpl >> 24);
     131        1822 :         uint32_t coord32 = FFMIN(coord, 1073741824);
     132        1822 :         coord32          = ff_sqrt(coord32) << 9;
     133        1822 :         return FFMIN(coord32, COEF_MAX);
     134             :     }
     135             : }
     136             : 
     137             : 
     138           3 : static av_cold int ac3_fixed_encode_init(AVCodecContext *avctx)
     139             : {
     140           3 :     AC3EncodeContext *s = avctx->priv_data;
     141           3 :     s->fixed_point = 1;
     142           3 :     return ff_ac3_encode_init(avctx);
     143             : }
     144             : 
     145             : 
     146             : AVCodec ff_ac3_fixed_encoder = {
     147             :     .name            = "ac3_fixed",
     148             :     .long_name       = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"),
     149             :     .type            = AVMEDIA_TYPE_AUDIO,
     150             :     .id              = AV_CODEC_ID_AC3,
     151             :     .priv_data_size  = sizeof(AC3EncodeContext),
     152             :     .init            = ac3_fixed_encode_init,
     153             :     .encode2         = ff_ac3_fixed_encode_frame,
     154             :     .close           = ff_ac3_encode_close,
     155             :     .sample_fmts     = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16P,
     156             :                                                       AV_SAMPLE_FMT_NONE },
     157             :     .priv_class      = &ac3enc_class,
     158             :     .channel_layouts = ff_ac3_channel_layouts,
     159             :     .defaults        = ac3_defaults,
     160             : };

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