text: /*
   * AC-3 Audio Decoder
   * This code was developed as part of Google Summer of Code 2006.
   * E-AC-3 support was added as part of Google Summer of Code 2007.
   *
   * Copyright (c) 2006 Kartikey Mahendra BHATT (bhattkm at gmail dot com)
   * Copyright (c) 2007-2008 Bartlomiej Wolowiec <bartek.wolowiec@gmail.com>
   * Copyright (c) 2007 Justin Ruggles <justin.ruggles@gmail.com>
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  /**
   * Upmix delay samples from stereo to original channel layout.
   */
  #include "ac3dec.h"
  #include "eac3dec.c"
  #include "ac3dec.c"
  
  static const AVOption options[] = {
      { "cons_noisegen", "enable consistent noise generation", OFFSET(consistent_noise_generation), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, PAR },
      { "drc_scale", "percentage of dynamic range compression to apply", OFFSET(drc_scale), AV_OPT_TYPE_FLOAT, {.dbl = 1.0}, 0.0, 6.0, PAR },
      { "heavy_compr", "enable heavy dynamic range compression", OFFSET(heavy_compression), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, PAR },
      { "target_level", "target level in -dBFS (0 not applied)", OFFSET(target_level), AV_OPT_TYPE_INT, {.i64 = 0 }, -31, 0, PAR },
  
  {"dmix_mode", "Preferred Stereo Downmix Mode", OFFSET(preferred_stereo_downmix), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, 2, 0, "dmix_mode"},
  {"ltrt_cmixlev",   "Lt/Rt Center Mix Level",   OFFSET(ltrt_center_mix_level),    AV_OPT_TYPE_FLOAT, {.dbl = -1.0 }, -1.0, 2.0, 0},
  {"ltrt_surmixlev", "Lt/Rt Surround Mix Level", OFFSET(ltrt_surround_mix_level),  AV_OPT_TYPE_FLOAT, {.dbl = -1.0 }, -1.0, 2.0, 0},
  {"loro_cmixlev",   "Lo/Ro Center Mix Level",   OFFSET(loro_center_mix_level),    AV_OPT_TYPE_FLOAT, {.dbl = -1.0 }, -1.0, 2.0, 0},
  {"loro_surmixlev", "Lo/Ro Surround Mix Level", OFFSET(loro_surround_mix_level),  AV_OPT_TYPE_FLOAT, {.dbl = -1.0 }, -1.0, 2.0, 0},
  
      { NULL},
  };
  
  static const AVClass ac3_decoder_class = {
      .class_name = "AC3 decoder",
      .item_name  = av_default_item_name,
      .option     = options,
      .version    = LIBAVUTIL_VERSION_INT,
  };
  
  AVCodec ff_ac3_decoder = {
      .name           = "ac3",
      .type           = AVMEDIA_TYPE_AUDIO,
      .id             = AV_CODEC_ID_AC3,
      .priv_data_size = sizeof (AC3DecodeContext),
      .init           = ac3_decode_init,
      .close          = ac3_decode_end,
      .decode         = ac3_decode_frame,
      .capabilities   = AV_CODEC_CAP_DR1,
      .long_name      = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"),
      .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
                                                        AV_SAMPLE_FMT_NONE },
      .priv_class     = &ac3_decoder_class,
  };
  
  #if CONFIG_EAC3_DECODER
  static const AVClass eac3_decoder_class = {
      .class_name = "E-AC3 decoder",
      .item_name  = av_default_item_name,
      .option     = options,
      .version    = LIBAVUTIL_VERSION_INT,
  };
  
  AVCodec ff_eac3_decoder = {
      .name           = "eac3",
      .type           = AVMEDIA_TYPE_AUDIO,
      .id             = AV_CODEC_ID_EAC3,
      .priv_data_size = sizeof (AC3DecodeContext),
      .init           = ac3_decode_init,
      .close          = ac3_decode_end,
      .decode         = ac3_decode_frame,
      .capabilities   = AV_CODEC_CAP_DR1,
      .long_name      = NULL_IF_CONFIG_SMALL("ATSC A/52B (AC-3, E-AC-3)"),
      .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
                                                        AV_SAMPLE_FMT_NONE },
      .priv_class     = &eac3_decoder_class,
  };
  #endif
  