/*
  * E-AC-3 encoder
  * Copyright (c) 2011 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
  */
 
 /**
  * @file
  * E-AC-3 encoder
  */
 
 #define CONFIG_AC3ENC_FLOAT 1

 
 #include "libavutil/attributes.h"

 #include "ac3enc.h"
 #include "eac3enc.h"

 #include "eac3_data.h"

 
 #define AC3ENC_TYPE AC3ENC_TYPE_EAC3
 #include "ac3enc_opts_template.c"
 

 static const AVClass eac3enc_class = {
     .class_name = "E-AC-3 Encoder",
     .item_name  = av_default_item_name,

     .option     = ac3_options,

     .version    = LIBAVUTIL_VERSION_INT,
 };

 /**
  * LUT for finding a matching frame exponent strategy index from a set of
  * exponent strategies for a single channel across all 6 blocks.
  */
 static int8_t eac3_frame_expstr_index_tab[3][4][4][4][4][4];
 
 

 av_cold void ff_eac3_exponent_init(void)

 {
     int i;
 
     memset(eac3_frame_expstr_index_tab, -1, sizeof(eac3_frame_expstr_index_tab));
     for (i = 0; i < 32; i++) {
         eac3_frame_expstr_index_tab[ff_eac3_frm_expstr[i][0]-1]
                                    [ff_eac3_frm_expstr[i][1]]
                                    [ff_eac3_frm_expstr[i][2]]
                                    [ff_eac3_frm_expstr[i][3]]
                                    [ff_eac3_frm_expstr[i][4]]
                                    [ff_eac3_frm_expstr[i][5]] = i;
     }
 }
 
 
 void ff_eac3_get_frame_exp_strategy(AC3EncodeContext *s)
 {
     int ch;
 

     if (s->num_blocks < 6) {
         s->use_frame_exp_strategy = 0;
         return;
     }
 

     s->use_frame_exp_strategy = 1;
     for (ch = !s->cpl_on; ch <= s->fbw_channels; ch++) {
         int expstr = eac3_frame_expstr_index_tab[s->exp_strategy[ch][0]-1]
                                                 [s->exp_strategy[ch][1]]
                                                 [s->exp_strategy[ch][2]]
                                                 [s->exp_strategy[ch][3]]
                                                 [s->exp_strategy[ch][4]]
                                                 [s->exp_strategy[ch][5]];
         if (expstr < 0) {
             s->use_frame_exp_strategy = 0;
             break;
         }
         s->frame_exp_strategy[ch] = expstr;
     }
 }
 
 
 

 void ff_eac3_set_cpl_states(AC3EncodeContext *s)
 {
     int ch, blk;
     int first_cpl_coords[AC3_MAX_CHANNELS];
 
     /* set first cpl coords */
     for (ch = 1; ch <= s->fbw_channels; ch++)
         first_cpl_coords[ch] = 1;

     for (blk = 0; blk < s->num_blocks; blk++) {

         AC3Block *block = &s->blocks[blk];
         for (ch = 1; ch <= s->fbw_channels; ch++) {
             if (block->channel_in_cpl[ch]) {
                 if (first_cpl_coords[ch]) {

                     block->new_cpl_coords[ch] = 2;

                     first_cpl_coords[ch]  = 0;
                 }
             } else {
                 first_cpl_coords[ch] = 1;
             }
         }
     }
 
     /* set first cpl leak */

     for (blk = 0; blk < s->num_blocks; blk++) {

         AC3Block *block = &s->blocks[blk];
         if (block->cpl_in_use) {
             block->new_cpl_leak = 2;
             break;
         }
     }
 }
 
 
 void ff_eac3_output_frame_header(AC3EncodeContext *s)
 {
     int blk, ch;
     AC3EncOptions *opt = &s->options;
 
     put_bits(&s->pb, 16, 0x0b77);                   /* sync word */
 
     /* BSI header */
     put_bits(&s->pb,  2, 0);                        /* stream type = independent */
     put_bits(&s->pb,  3, 0);                        /* substream id = 0 */
     put_bits(&s->pb, 11, (s->frame_size / 2) - 1);  /* frame size */
     if (s->bit_alloc.sr_shift) {
         put_bits(&s->pb, 2, 0x3);                   /* fscod2 */
         put_bits(&s->pb, 2, s->bit_alloc.sr_code);  /* sample rate code */
     } else {
         put_bits(&s->pb, 2, s->bit_alloc.sr_code);  /* sample rate code */

         put_bits(&s->pb, 2, s->num_blks_code);      /* number of blocks */

     }
     put_bits(&s->pb, 3, s->channel_mode);           /* audio coding mode */
     put_bits(&s->pb, 1, s->lfe_on);                 /* LFE channel indicator */
     put_bits(&s->pb, 5, s->bitstream_id);           /* bitstream id (EAC3=16) */
     put_bits(&s->pb, 5, -opt->dialogue_level);      /* dialogue normalization level */
     put_bits(&s->pb, 1, 0);                         /* no compression gain */

     /* mixing metadata*/
     put_bits(&s->pb, 1, opt->eac3_mixing_metadata);
     if (opt->eac3_mixing_metadata) {
         if (s->channel_mode > AC3_CHMODE_STEREO)
             put_bits(&s->pb, 2, opt->preferred_stereo_downmix);
         if (s->has_center) {
             put_bits(&s->pb, 3, s->ltrt_center_mix_level);
             put_bits(&s->pb, 3, s->loro_center_mix_level);
         }
         if (s->has_surround) {
             put_bits(&s->pb, 3, s->ltrt_surround_mix_level);
             put_bits(&s->pb, 3, s->loro_surround_mix_level);
         }
         if (s->lfe_on)
             put_bits(&s->pb, 1, 0);
         put_bits(&s->pb, 1, 0);                     /* no program scale */
         put_bits(&s->pb, 1, 0);                     /* no ext program scale */
         put_bits(&s->pb, 2, 0);                     /* no mixing parameters */
         if (s->channel_mode < AC3_CHMODE_STEREO)
             put_bits(&s->pb, 1, 0);                 /* no pan info */
         put_bits(&s->pb, 1, 0);                     /* no frame mix config info */
     }
     /* info metadata*/
     put_bits(&s->pb, 1, opt->eac3_info_metadata);
     if (opt->eac3_info_metadata) {
         put_bits(&s->pb, 3, s->bitstream_mode);
         put_bits(&s->pb, 1, opt->copyright);
         put_bits(&s->pb, 1, opt->original);
         if (s->channel_mode == AC3_CHMODE_STEREO) {
             put_bits(&s->pb, 2, opt->dolby_surround_mode);
             put_bits(&s->pb, 2, opt->dolby_headphone_mode);
         }
         if (s->channel_mode >= AC3_CHMODE_2F2R)
             put_bits(&s->pb, 2, opt->dolby_surround_ex_mode);
         put_bits(&s->pb, 1, opt->audio_production_info);
         if (opt->audio_production_info) {
             put_bits(&s->pb, 5, opt->mixing_level - 80);
             put_bits(&s->pb, 2, opt->room_type);
             put_bits(&s->pb, 1, opt->ad_converter_type);
         }
         put_bits(&s->pb, 1, 0);
     }

     if (s->num_blocks != 6)
         put_bits(&s->pb, 1, !(s->avctx->frame_number % 6)); /* converter sync flag */

     put_bits(&s->pb, 1, 0);                         /* no additional bit stream info */
 
     /* frame header */

     if (s->num_blocks == 6) {

     put_bits(&s->pb, 1, !s->use_frame_exp_strategy);/* exponent strategy syntax */

     put_bits(&s->pb, 1, 0);                         /* aht enabled = no */

     }

     put_bits(&s->pb, 2, 0);                         /* snr offset strategy = 1 */
     put_bits(&s->pb, 1, 0);                         /* transient pre-noise processing enabled = no */
     put_bits(&s->pb, 1, 0);                         /* block switch syntax enabled = no */
     put_bits(&s->pb, 1, 0);                         /* dither flag syntax enabled = no */
     put_bits(&s->pb, 1, 0);                         /* bit allocation model syntax enabled = no */
     put_bits(&s->pb, 1, 0);                         /* fast gain codes enabled = no */
     put_bits(&s->pb, 1, 0);                         /* dba syntax enabled = no */
     put_bits(&s->pb, 1, 0);                         /* skip field syntax enabled = no */
     put_bits(&s->pb, 1, 0);                         /* spx enabled = no */
     /* coupling strategy use flags */
     if (s->channel_mode > AC3_CHMODE_MONO) {
         put_bits(&s->pb, 1, s->blocks[0].cpl_in_use);

         for (blk = 1; blk < s->num_blocks; blk++) {

             AC3Block *block = &s->blocks[blk];
             put_bits(&s->pb, 1, block->new_cpl_strategy);
             if (block->new_cpl_strategy)
                 put_bits(&s->pb, 1, block->cpl_in_use);
         }
     }
     /* exponent strategy */

     if (s->use_frame_exp_strategy) {
         for (ch = !s->cpl_on; ch <= s->fbw_channels; ch++)
             put_bits(&s->pb, 5, s->frame_exp_strategy[ch]);
     } else {

         for (blk = 0; blk < s->num_blocks; blk++)

             for (ch = !s->blocks[blk].cpl_in_use; ch <= s->fbw_channels; ch++)
                 put_bits(&s->pb, 2, s->exp_strategy[ch][blk]);

     }

     if (s->lfe_on) {

         for (blk = 0; blk < s->num_blocks; blk++)

             put_bits(&s->pb, 1, s->exp_strategy[s->lfe_channel][blk]);
     }

     /* E-AC-3 to AC-3 converter exponent strategy (not optional when num blocks == 6) */
     if (s->num_blocks != 6) {
         put_bits(&s->pb, 1, 0);
     } else {

     for (ch = 1; ch <= s->fbw_channels; ch++) {
         if (s->use_frame_exp_strategy)
             put_bits(&s->pb, 5, s->frame_exp_strategy[ch]);
         else
             put_bits(&s->pb, 5, 0);
     }

     }

     /* snr offsets */
     put_bits(&s->pb, 6, s->coarse_snr_offset);
     put_bits(&s->pb, 4, s->fine_snr_offset[1]);
     /* block start info */

     if (s->num_blocks > 1)
         put_bits(&s->pb, 1, 0);

 }

 
 
 #if CONFIG_EAC3_ENCODER
 AVCodec ff_eac3_encoder = {
     .name            = "eac3",

     .long_name       = NULL_IF_CONFIG_SMALL("ATSC A/52 E-AC-3"),

     .type            = AVMEDIA_TYPE_AUDIO,

     .id              = AV_CODEC_ID_EAC3,

     .priv_data_size  = sizeof(AC3EncodeContext),
     .init            = ff_ac3_encode_init,

     .encode2         = ff_ac3_float_encode_frame,

     .close           = ff_ac3_encode_close,

     .sample_fmts     = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLTP,

                                                       AV_SAMPLE_FMT_NONE },

     .priv_class      = &eac3enc_class,
     .channel_layouts = ff_ac3_channel_layouts,

     .defaults        = ac3_defaults,

 };
 #endif