/*
  * ATRAC3+ compatible decoder
  *
  * Copyright (c) 2010-2013 Maxim Poliakovski
  *
  * 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
  * Sony ATRAC3+ compatible decoder.
  *
  * Container formats used to store its data:
  * RIFF WAV (.at3) and Sony OpenMG (.oma, .aa3).
  *
  * Technical description of this codec can be found here:
  * http://wiki.multimedia.cx/index.php?title=ATRAC3plus
  *
  * Kudos to Benjamin Larsson and Michael Karcher
  * for their precious technical help!
  */
 
 #include <stdint.h>
 #include <string.h>
 
 #include "libavutil/channel_layout.h"
 #include "libavutil/float_dsp.h"
 #include "avcodec.h"
 #include "get_bits.h"
 #include "internal.h"
 #include "atrac.h"
 #include "atrac3plus.h"
 
 typedef struct ATRAC3PContext {
     GetBitContext gb;

     AVFloatDSPContext *fdsp;

 
     DECLARE_ALIGNED(32, float, samples)[2][ATRAC3P_FRAME_SAMPLES];  ///< quantized MDCT spectrum
     DECLARE_ALIGNED(32, float, mdct_buf)[2][ATRAC3P_FRAME_SAMPLES]; ///< output of the IMDCT
     DECLARE_ALIGNED(32, float, time_buf)[2][ATRAC3P_FRAME_SAMPLES]; ///< output of the gain compensation
     DECLARE_ALIGNED(32, float, outp_buf)[2][ATRAC3P_FRAME_SAMPLES];
 
     AtracGCContext gainc_ctx;   ///< gain compensation context
     FFTContext mdct_ctx;
     FFTContext ipqf_dct_ctx;    ///< IDCT context used by IPQF
 
     Atrac3pChanUnitCtx *ch_units;   ///< global channel units
 
     int num_channel_blocks;     ///< number of channel blocks
     uint8_t channel_blocks[5];  ///< channel configuration descriptor
     uint64_t my_channel_layout; ///< current channel layout
 } ATRAC3PContext;
 
 static av_cold int atrac3p_decode_close(AVCodecContext *avctx)
 {

     ATRAC3PContext *ctx = avctx->priv_data;
 
     av_freep(&ctx->ch_units);
     av_freep(&ctx->fdsp);

     ff_mdct_end(&ctx->mdct_ctx);
     ff_mdct_end(&ctx->ipqf_dct_ctx);
 

     return 0;
 }
 
 static av_cold int set_channel_params(ATRAC3PContext *ctx,
                                       AVCodecContext *avctx)
 {
     memset(ctx->channel_blocks, 0, sizeof(ctx->channel_blocks));
 

     switch (avctx->channels) {
     case 1:
         if (avctx->channel_layout != AV_CH_FRONT_LEFT)
             avctx->channel_layout = AV_CH_LAYOUT_MONO;
 

         ctx->num_channel_blocks = 1;
         ctx->channel_blocks[0]  = CH_UNIT_MONO;
         break;

     case 2:
         avctx->channel_layout   = AV_CH_LAYOUT_STEREO;

         ctx->num_channel_blocks = 1;
         ctx->channel_blocks[0]  = CH_UNIT_STEREO;
         break;

     case 3:
         avctx->channel_layout   = AV_CH_LAYOUT_SURROUND;

         ctx->num_channel_blocks = 2;
         ctx->channel_blocks[0]  = CH_UNIT_STEREO;
         ctx->channel_blocks[1]  = CH_UNIT_MONO;
         break;

     case 4:
         avctx->channel_layout   = AV_CH_LAYOUT_4POINT0;

         ctx->num_channel_blocks = 3;
         ctx->channel_blocks[0]  = CH_UNIT_STEREO;
         ctx->channel_blocks[1]  = CH_UNIT_MONO;
         ctx->channel_blocks[2]  = CH_UNIT_MONO;
         break;

     case 6:
         avctx->channel_layout   = AV_CH_LAYOUT_5POINT1_BACK;

         ctx->num_channel_blocks = 4;
         ctx->channel_blocks[0]  = CH_UNIT_STEREO;
         ctx->channel_blocks[1]  = CH_UNIT_MONO;
         ctx->channel_blocks[2]  = CH_UNIT_STEREO;
         ctx->channel_blocks[3]  = CH_UNIT_MONO;
         break;

     case 7:
         avctx->channel_layout   = AV_CH_LAYOUT_6POINT1_BACK;

         ctx->num_channel_blocks = 5;
         ctx->channel_blocks[0]  = CH_UNIT_STEREO;
         ctx->channel_blocks[1]  = CH_UNIT_MONO;
         ctx->channel_blocks[2]  = CH_UNIT_STEREO;
         ctx->channel_blocks[3]  = CH_UNIT_MONO;
         ctx->channel_blocks[4]  = CH_UNIT_MONO;
         break;

     case 8:
         avctx->channel_layout   = AV_CH_LAYOUT_7POINT1;

         ctx->num_channel_blocks = 5;
         ctx->channel_blocks[0]  = CH_UNIT_STEREO;
         ctx->channel_blocks[1]  = CH_UNIT_MONO;
         ctx->channel_blocks[2]  = CH_UNIT_STEREO;
         ctx->channel_blocks[3]  = CH_UNIT_STEREO;
         ctx->channel_blocks[4]  = CH_UNIT_MONO;
         break;
     default:
         av_log(avctx, AV_LOG_ERROR,

                "Unsupported channel count: %d!\n", avctx->channels);

         return AVERROR_INVALIDDATA;
     }
 
     return 0;
 }
 
 static av_cold int atrac3p_decode_init(AVCodecContext *avctx)
 {
     ATRAC3PContext *ctx = avctx->priv_data;
     int i, ch, ret;
 

     if (!avctx->block_align) {
         av_log(avctx, AV_LOG_ERROR, "block_align is not set\n");
         return AVERROR(EINVAL);
     }
 

     ff_atrac3p_init_vlcs();
 
     /* initialize IPQF */
     ff_mdct_init(&ctx->ipqf_dct_ctx, 5, 1, 32.0 / 32768.0);
 
     ff_atrac3p_init_imdct(avctx, &ctx->mdct_ctx);
 
     ff_atrac_init_gain_compensation(&ctx->gainc_ctx, 6, 2);
 
     ff_atrac3p_init_wave_synth();
 
     if ((ret = set_channel_params(ctx, avctx)) < 0)
         return ret;
 
     ctx->my_channel_layout = avctx->channel_layout;
 

     ctx->ch_units = av_mallocz_array(ctx->num_channel_blocks, sizeof(*ctx->ch_units));

     ctx->fdsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT);

     if (!ctx->ch_units || !ctx->fdsp) {

         atrac3p_decode_close(avctx);
         return AVERROR(ENOMEM);
     }
 
     for (i = 0; i < ctx->num_channel_blocks; i++) {
         for (ch = 0; ch < 2; ch++) {
             ctx->ch_units[i].channels[ch].ch_num          = ch;
             ctx->ch_units[i].channels[ch].wnd_shape       = &ctx->ch_units[i].channels[ch].wnd_shape_hist[0][0];
             ctx->ch_units[i].channels[ch].wnd_shape_prev  = &ctx->ch_units[i].channels[ch].wnd_shape_hist[1][0];
             ctx->ch_units[i].channels[ch].gain_data       = &ctx->ch_units[i].channels[ch].gain_data_hist[0][0];
             ctx->ch_units[i].channels[ch].gain_data_prev  = &ctx->ch_units[i].channels[ch].gain_data_hist[1][0];
             ctx->ch_units[i].channels[ch].tones_info      = &ctx->ch_units[i].channels[ch].tones_info_hist[0][0];
             ctx->ch_units[i].channels[ch].tones_info_prev = &ctx->ch_units[i].channels[ch].tones_info_hist[1][0];
         }
 
         ctx->ch_units[i].waves_info      = &ctx->ch_units[i].wave_synth_hist[0];
         ctx->ch_units[i].waves_info_prev = &ctx->ch_units[i].wave_synth_hist[1];
     }
 
     avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
 
     return 0;
 }
 

 static void decode_residual_spectrum(ATRAC3PContext *ctx, Atrac3pChanUnitCtx *ch_unit,

                                      float out[2][ATRAC3P_FRAME_SAMPLES],
                                      int num_channels,
                                      AVCodecContext *avctx)
 {
     int i, sb, ch, qu, nspeclines, RNG_index;
     float *dst, q;
     int16_t *src;
     /* calculate RNG table index for each subband */
     int sb_RNG_index[ATRAC3P_SUBBANDS] = { 0 };
 

     if (ch_unit->mute_flag) {

         for (ch = 0; ch < num_channels; ch++)
             memset(out[ch], 0, ATRAC3P_FRAME_SAMPLES * sizeof(*out[ch]));
         return;
     }
 

     for (qu = 0, RNG_index = 0; qu < ch_unit->used_quant_units; qu++)
         RNG_index += ch_unit->channels[0].qu_sf_idx[qu] +
                      ch_unit->channels[1].qu_sf_idx[qu];

     for (sb = 0; sb < ch_unit->num_coded_subbands; sb++, RNG_index += 128)

         sb_RNG_index[sb] = RNG_index & 0x3FC;
 
     /* inverse quant and power compensation */
     for (ch = 0; ch < num_channels; ch++) {
         /* clear channel's residual spectrum */
         memset(out[ch], 0, ATRAC3P_FRAME_SAMPLES * sizeof(*out[ch]));
 

         for (qu = 0; qu < ch_unit->used_quant_units; qu++) {
             src        = &ch_unit->channels[ch].spectrum[ff_atrac3p_qu_to_spec_pos[qu]];

             dst        = &out[ch][ff_atrac3p_qu_to_spec_pos[qu]];
             nspeclines = ff_atrac3p_qu_to_spec_pos[qu + 1] -
                          ff_atrac3p_qu_to_spec_pos[qu];
 

             if (ch_unit->channels[ch].qu_wordlen[qu] > 0) {
                 q = ff_atrac3p_sf_tab[ch_unit->channels[ch].qu_sf_idx[qu]] *
                     ff_atrac3p_mant_tab[ch_unit->channels[ch].qu_wordlen[qu]];

                 for (i = 0; i < nspeclines; i++)
                     dst[i] = src[i] * q;
             }
         }
 

         for (sb = 0; sb < ch_unit->num_coded_subbands; sb++)
             ff_atrac3p_power_compensation(ch_unit, ctx->fdsp, ch, &out[ch][0],

                                           sb_RNG_index[sb], sb);
     }
 

     if (ch_unit->unit_type == CH_UNIT_STEREO) {
         for (sb = 0; sb < ch_unit->num_coded_subbands; sb++) {
             if (ch_unit->swap_channels[sb]) {

                 for (i = 0; i < ATRAC3P_SUBBAND_SAMPLES; i++)
                     FFSWAP(float, out[0][sb * ATRAC3P_SUBBAND_SAMPLES + i],
                                   out[1][sb * ATRAC3P_SUBBAND_SAMPLES + i]);
             }
 
             /* flip coefficients' sign if requested */

             if (ch_unit->negate_coeffs[sb])

                 for (i = 0; i < ATRAC3P_SUBBAND_SAMPLES; i++)
                     out[1][sb * ATRAC3P_SUBBAND_SAMPLES + i] = -(out[1][sb * ATRAC3P_SUBBAND_SAMPLES + i]);
         }
     }
 }
 
 static void reconstruct_frame(ATRAC3PContext *ctx, Atrac3pChanUnitCtx *ch_unit,
                               int num_channels, AVCodecContext *avctx)
 {
     int ch, sb;
 
     for (ch = 0; ch < num_channels; ch++) {
         for (sb = 0; sb < ch_unit->num_subbands; sb++) {
             /* inverse transform and windowing */

             ff_atrac3p_imdct(ctx->fdsp, &ctx->mdct_ctx,

                              &ctx->samples[ch][sb * ATRAC3P_SUBBAND_SAMPLES],
                              &ctx->mdct_buf[ch][sb * ATRAC3P_SUBBAND_SAMPLES],
                              (ch_unit->channels[ch].wnd_shape_prev[sb] << 1) +
                              ch_unit->channels[ch].wnd_shape[sb], sb);
 
             /* gain compensation and overlapping */
             ff_atrac_gain_compensation(&ctx->gainc_ctx,
                                        &ctx->mdct_buf[ch][sb * ATRAC3P_SUBBAND_SAMPLES],
                                        &ch_unit->prev_buf[ch][sb * ATRAC3P_SUBBAND_SAMPLES],
                                        &ch_unit->channels[ch].gain_data_prev[sb],
                                        &ch_unit->channels[ch].gain_data[sb],
                                        ATRAC3P_SUBBAND_SAMPLES,
                                        &ctx->time_buf[ch][sb * ATRAC3P_SUBBAND_SAMPLES]);
         }
 
         /* zero unused subbands in both output and overlapping buffers */
         memset(&ch_unit->prev_buf[ch][ch_unit->num_subbands * ATRAC3P_SUBBAND_SAMPLES],
                0,
                (ATRAC3P_SUBBANDS - ch_unit->num_subbands) *
                ATRAC3P_SUBBAND_SAMPLES *
                sizeof(ch_unit->prev_buf[ch][ch_unit->num_subbands * ATRAC3P_SUBBAND_SAMPLES]));
         memset(&ctx->time_buf[ch][ch_unit->num_subbands * ATRAC3P_SUBBAND_SAMPLES],
                0,
                (ATRAC3P_SUBBANDS - ch_unit->num_subbands) *
                ATRAC3P_SUBBAND_SAMPLES *
                sizeof(ctx->time_buf[ch][ch_unit->num_subbands * ATRAC3P_SUBBAND_SAMPLES]));
 
         /* resynthesize and add tonal signal */
         if (ch_unit->waves_info->tones_present ||
             ch_unit->waves_info_prev->tones_present) {
             for (sb = 0; sb < ch_unit->num_subbands; sb++)
                 if (ch_unit->channels[ch].tones_info[sb].num_wavs ||
                     ch_unit->channels[ch].tones_info_prev[sb].num_wavs) {

                     ff_atrac3p_generate_tones(ch_unit, ctx->fdsp, ch, sb,

                                               &ctx->time_buf[ch][sb * 128]);
                 }
         }
 
         /* subband synthesis and acoustic signal output */
         ff_atrac3p_ipqf(&ctx->ipqf_dct_ctx, &ch_unit->ipqf_ctx[ch],
                         &ctx->time_buf[ch][0], &ctx->outp_buf[ch][0]);
     }
 
     /* swap window shape and gain control buffers. */
     for (ch = 0; ch < num_channels; ch++) {
         FFSWAP(uint8_t *, ch_unit->channels[ch].wnd_shape,
                ch_unit->channels[ch].wnd_shape_prev);
         FFSWAP(AtracGainInfo *, ch_unit->channels[ch].gain_data,
                ch_unit->channels[ch].gain_data_prev);
         FFSWAP(Atrac3pWavesData *, ch_unit->channels[ch].tones_info,
                ch_unit->channels[ch].tones_info_prev);
     }
 
     FFSWAP(Atrac3pWaveSynthParams *, ch_unit->waves_info, ch_unit->waves_info_prev);
 }
 
 static int atrac3p_decode_frame(AVCodecContext *avctx, void *data,
                                 int *got_frame_ptr, AVPacket *avpkt)
 {
     ATRAC3PContext *ctx = avctx->priv_data;
     AVFrame *frame      = data;
     int i, ret, ch_unit_id, ch_block = 0, out_ch_index = 0, channels_to_process;
     float **samples_p = (float **)frame->extended_data;
 
     frame->nb_samples = ATRAC3P_FRAME_SAMPLES;

     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)

         return ret;
 
     if ((ret = init_get_bits8(&ctx->gb, avpkt->data, avpkt->size)) < 0)
         return ret;
 
     if (get_bits1(&ctx->gb)) {
         av_log(avctx, AV_LOG_ERROR, "Invalid start bit!\n");
         return AVERROR_INVALIDDATA;
     }
 
     while (get_bits_left(&ctx->gb) >= 2 &&
            (ch_unit_id = get_bits(&ctx->gb, 2)) != CH_UNIT_TERMINATOR) {
         if (ch_unit_id == CH_UNIT_EXTENSION) {
             avpriv_report_missing_feature(avctx, "Channel unit extension");
             return AVERROR_PATCHWELCOME;
         }
         if (ch_block >= ctx->num_channel_blocks ||
             ctx->channel_blocks[ch_block] != ch_unit_id) {
             av_log(avctx, AV_LOG_ERROR,
                    "Frame data doesn't match channel configuration!\n");
             return AVERROR_INVALIDDATA;
         }
 
         ctx->ch_units[ch_block].unit_type = ch_unit_id;
         channels_to_process               = ch_unit_id + 1;
 
         if ((ret = ff_atrac3p_decode_channel_unit(&ctx->gb,
                                                   &ctx->ch_units[ch_block],
                                                   channels_to_process,
                                                   avctx)) < 0)
             return ret;
 

         decode_residual_spectrum(ctx, &ctx->ch_units[ch_block], ctx->samples,

                                  channels_to_process, avctx);
         reconstruct_frame(ctx, &ctx->ch_units[ch_block],
                           channels_to_process, avctx);
 
         for (i = 0; i < channels_to_process; i++)
             memcpy(samples_p[out_ch_index + i], ctx->outp_buf[i],
                    ATRAC3P_FRAME_SAMPLES * sizeof(**samples_p));
 
         ch_block++;
         out_ch_index += channels_to_process;
     }
 
     *got_frame_ptr = 1;
 

     return avctx->codec_id == AV_CODEC_ID_ATRAC3P ? FFMIN(avctx->block_align, avpkt->size) : avpkt->size;

 }
 
 AVCodec ff_atrac3p_decoder = {
     .name           = "atrac3plus",
     .long_name      = NULL_IF_CONFIG_SMALL("ATRAC3+ (Adaptive TRansform Acoustic Coding 3+)"),
     .type           = AVMEDIA_TYPE_AUDIO,
     .id             = AV_CODEC_ID_ATRAC3P,

     .capabilities   = AV_CODEC_CAP_DR1,

     .priv_data_size = sizeof(ATRAC3PContext),
     .init           = atrac3p_decode_init,
     .close          = atrac3p_decode_close,
     .decode         = atrac3p_decode_frame,
 };

 
 AVCodec ff_atrac3pal_decoder = {
     .name           = "atrac3plusal",
     .long_name      = NULL_IF_CONFIG_SMALL("ATRAC3+ AL (Adaptive TRansform Acoustic Coding 3+ Advanced Lossless)"),
     .type           = AVMEDIA_TYPE_AUDIO,
     .id             = AV_CODEC_ID_ATRAC3PAL,
     .capabilities   = AV_CODEC_CAP_DR1,
     .priv_data_size = sizeof(ATRAC3PContext),
     .init           = atrac3p_decode_init,
     .close          = atrac3p_decode_close,
     .decode         = atrac3p_decode_frame,
 };