/*
 * DCA dummy decoder
 * We retain some of the main logic for data extraction but
 * have removed all of the actual decoding code. The only reason
 * we still have this other logic is we need to do some minor stream
 * introspection to differntiate DTS-MA vs. DTS.
 */

#include <math.h>
#include <stddef.h>
#include <stdio.h>

#include "avcodec.h"
#include "dsputil.h"
#include "bitstream.h"

#include "dcadata.h"
#include "dcahuff.h"
#include "dca.h"

#define DCA_PRIM_CHANNELS_MAX (5)
#define DCA_SUBBANDS (32)
#define DCA_ABITS_MAX (32)      /* Should be 28 */
#define DCA_SUBSUBFAMES_MAX (4)
#define DCA_LFE_MAX (3)

enum DCAMode {
    DCA_MONO = 0,
    DCA_CHANNEL,
    DCA_STEREO,
    DCA_STEREO_SUMDIFF,
    DCA_STEREO_TOTAL,
    DCA_3F,
    DCA_2F1R,
    DCA_3F1R,
    DCA_2F2R,
    DCA_3F2R,
    DCA_4F2R
};

/* Tables for mapping dts channel configurations to libavcodec multichannel api.
 * Some compromises have been made for special configurations. Most configurations
 * are never used so complete accuracy is not needed.
 *
 * L = left, R = right, C = center, S = surround, F = front, R = rear, T = total, OV = overhead.
 * S  -> side, when both rear and back are configured move one of them to the side channel
 * OV -> center back
 * All 2 channel configurations -> CH_LAYOUT_STEREO
 */

static const int64_t dca_core_channel_layout[] = {
    CH_FRONT_CENTER,                                               ///< 1, A
    CH_LAYOUT_STEREO,                                              ///< 2, A + B (dual mono)
    CH_LAYOUT_STEREO,                                              ///< 2, L + R (stereo)
    CH_LAYOUT_STEREO,                                              ///< 2, (L+R) + (L-R) (sum-difference)
    CH_LAYOUT_STEREO,                                              ///< 2, LT +RT (left and right total)
    CH_LAYOUT_STEREO|CH_FRONT_CENTER,                              ///< 3, C+L+R
    CH_LAYOUT_STEREO|CH_BACK_CENTER,                               ///< 3, L+R+S
    CH_LAYOUT_STEREO|CH_FRONT_CENTER|CH_BACK_CENTER,               ///< 4, C + L + R+ S
    CH_LAYOUT_STEREO|CH_SIDE_LEFT|CH_SIDE_RIGHT,                   ///< 4, L + R +SL+ SR
    CH_LAYOUT_STEREO|CH_FRONT_CENTER|CH_SIDE_LEFT|CH_SIDE_RIGHT,   ///< 5, C + L + R+ SL+SR
    CH_LAYOUT_STEREO|CH_SIDE_LEFT|CH_SIDE_RIGHT|CH_FRONT_LEFT_OF_CENTER|CH_FRONT_RIGHT_OF_CENTER,                 ///< 6, CL + CR + L + R + SL + SR
    CH_LAYOUT_STEREO|CH_BACK_LEFT|CH_BACK_RIGHT|CH_FRONT_CENTER|CH_BACK_CENTER,                                   ///< 6, C + L + R+ LR + RR + OV
    CH_FRONT_CENTER|CH_FRONT_RIGHT_OF_CENTER|CH_FRONT_LEFT_OF_CENTER|CH_BACK_CENTER|CH_BACK_LEFT|CH_BACK_RIGHT,   ///< 6, CF+ CR+LF+ RF+LR + RR
    CH_FRONT_LEFT_OF_CENTER|CH_FRONT_CENTER|CH_FRONT_RIGHT_OF_CENTER|CH_LAYOUT_STEREO|CH_SIDE_LEFT|CH_SIDE_RIGHT, ///< 7, CL + C + CR + L + R + SL + SR
    CH_FRONT_LEFT_OF_CENTER|CH_FRONT_RIGHT_OF_CENTER|CH_LAYOUT_STEREO|CH_SIDE_LEFT|CH_SIDE_RIGHT|CH_BACK_LEFT|CH_BACK_RIGHT, ///< 8, CL + CR + L + R + SL1 + SL2+ SR1 + SR2
    CH_FRONT_LEFT_OF_CENTER|CH_FRONT_CENTER|CH_FRONT_RIGHT_OF_CENTER|CH_LAYOUT_STEREO|CH_SIDE_LEFT|CH_BACK_CENTER|CH_SIDE_RIGHT, ///< 8, CL + C+ CR + L + R + SL + S+ SR
};

static const int8_t dca_lfe_index[] = {
    1,2,2,2,2,3,2,3,2,3,2,3,1,3,2,3
};

static const int8_t dca_channel_reorder_lfe[][8] = {
    { 0, -1, -1, -1, -1, -1, -1, -1},
    { 0,  1, -1, -1, -1, -1, -1, -1},
    { 0,  1, -1, -1, -1, -1, -1, -1},
    { 0,  1, -1, -1, -1, -1, -1, -1},
    { 0,  1, -1, -1, -1, -1, -1, -1},
    { 2,  0,  1, -1, -1, -1, -1, -1},
    { 0,  1,  3, -1, -1, -1, -1, -1},
    { 2,  0,  1,  4, -1, -1, -1, -1},
    { 0,  1,  3,  4, -1, -1, -1, -1},
    { 2,  0,  1,  4,  5, -1, -1, -1},
    { 3,  4,  0,  1,  5,  6, -1, -1},
    { 2,  0,  1,  4,  5,  6, -1, -1},
    { 0,  6,  4,  5,  2,  3, -1, -1},
    { 4,  2,  5,  0,  1,  6,  7, -1},
    { 5,  6,  0,  1,  7,  3,  8,  4},
    { 4,  2,  5,  0,  1,  6,  8,  7},
};

static const int8_t dca_channel_reorder_nolfe[][8] = {
    { 0, -1, -1, -1, -1, -1, -1, -1},
    { 0,  1, -1, -1, -1, -1, -1, -1},
    { 0,  1, -1, -1, -1, -1, -1, -1},
    { 0,  1, -1, -1, -1, -1, -1, -1},
    { 0,  1, -1, -1, -1, -1, -1, -1},
    { 2,  0,  1, -1, -1, -1, -1, -1},
    { 0,  1,  2, -1, -1, -1, -1, -1},
    { 2,  0,  1,  3, -1, -1, -1, -1},
    { 0,  1,  2,  3, -1, -1, -1, -1},
    { 2,  0,  1,  3,  4, -1, -1, -1},
    { 2,  3,  0,  1,  4,  5, -1, -1},
    { 2,  0,  1,  3,  4,  5, -1, -1},
    { 0,  5,  3,  4,  1,  2, -1, -1},
    { 3,  2,  4,  0,  1,  5,  6, -1},
    { 4,  5,  0,  1,  6,  2,  7,  3},
    { 3,  2,  4,  0,  1,  5,  7,  6},
};


#define DCA_DOLBY 101           /* FIXME */

#define DCA_CHANNEL_BITS 6
#define DCA_CHANNEL_MASK 0x3F

#define DCA_LFE 0x80

#define HEADER_SIZE 14

#define DCA_MAX_FRAME_SIZE 16384

/** Bit allocation */
typedef struct {
    int offset;                 ///< code values offset
    int maxbits[8];             ///< max bits in VLC
    int wrap;                   ///< wrap for get_vlc2()
    VLC vlc[8];                 ///< actual codes
} BitAlloc;

static BitAlloc dca_bitalloc_index;    ///< indexes for samples VLC select
static BitAlloc dca_tmode;             ///< transition mode VLCs
static BitAlloc dca_scalefactor;       ///< scalefactor VLCs
static BitAlloc dca_smpl_bitalloc[11]; ///< samples VLCs

static av_always_inline int get_bitalloc(GetBitContext *gb, BitAlloc *ba, int idx)
{
    return get_vlc2(gb, ba->vlc[idx].table, ba->vlc[idx].bits, ba->wrap) + ba->offset;
}

typedef struct {
    AVCodecContext *avctx;
    /* Frame header */
    int frame_type;             ///< type of the current frame
    int samples_deficit;        ///< deficit sample count
    int crc_present;            ///< crc is present in the bitstream
    int sample_blocks;          ///< number of PCM sample blocks
    int frame_size;             ///< primary frame byte size
    int amode;                  ///< audio channels arrangement
    int sample_rate;            ///< audio sampling rate
    int bit_rate;               ///< transmission bit rate
    int bit_rate_index;         ///< transmission bit rate index

    int downmix;                ///< embedded downmix enabled
    int dynrange;               ///< embedded dynamic range flag
    int timestamp;              ///< embedded time stamp flag
    int aux_data;               ///< auxiliary data flag
    int hdcd;                   ///< source material is mastered in HDCD
    int ext_descr;              ///< extension audio descriptor flag
    int ext_coding;             ///< extended coding flag
    int aspf;                   ///< audio sync word insertion flag
    int lfe;                    ///< low frequency effects flag
    int predictor_history;      ///< predictor history flag
    int header_crc;             ///< header crc check bytes
    int multirate_inter;        ///< multirate interpolator switch
    int version;                ///< encoder software revision
    int copy_history;           ///< copy history
    int source_pcm_res;         ///< source pcm resolution
    int front_sum;              ///< front sum/difference flag
    int surround_sum;           ///< surround sum/difference flag
    int dialog_norm;            ///< dialog normalisation parameter

    /* Primary audio coding header */
    int subframes;              ///< number of subframes
    int total_channels;         ///< number of channels including extensions
    int prim_channels;          ///< number of primary audio channels
    int subband_activity[DCA_PRIM_CHANNELS_MAX];    ///< subband activity count
    int vq_start_subband[DCA_PRIM_CHANNELS_MAX];    ///< high frequency vq start subband
    int joint_intensity[DCA_PRIM_CHANNELS_MAX];     ///< joint intensity coding index
    int transient_huffman[DCA_PRIM_CHANNELS_MAX];   ///< transient mode code book
    int scalefactor_huffman[DCA_PRIM_CHANNELS_MAX]; ///< scale factor code book
    int bitalloc_huffman[DCA_PRIM_CHANNELS_MAX];    ///< bit allocation quantizer select
    int quant_index_huffman[DCA_PRIM_CHANNELS_MAX][DCA_ABITS_MAX]; ///< quantization index codebook select
    float scalefactor_adj[DCA_PRIM_CHANNELS_MAX][DCA_ABITS_MAX];   ///< scale factor adjustment

    /* Primary audio coding side information */
    int subsubframes;           ///< number of subsubframes
    int partial_samples;        ///< partial subsubframe samples count
    int prediction_mode[DCA_PRIM_CHANNELS_MAX][DCA_SUBBANDS];    ///< prediction mode (ADPCM used or not)
    int prediction_vq[DCA_PRIM_CHANNELS_MAX][DCA_SUBBANDS];      ///< prediction VQ coefs
    int bitalloc[DCA_PRIM_CHANNELS_MAX][DCA_SUBBANDS];           ///< bit allocation index
    int transition_mode[DCA_PRIM_CHANNELS_MAX][DCA_SUBBANDS];    ///< transition mode (transients)
    int scale_factor[DCA_PRIM_CHANNELS_MAX][DCA_SUBBANDS][2];    ///< scale factors (2 if transient)
    int joint_huff[DCA_PRIM_CHANNELS_MAX];                       ///< joint subband scale factors codebook
    int joint_scale_factor[DCA_PRIM_CHANNELS_MAX][DCA_SUBBANDS]; ///< joint subband scale factors
    int downmix_coef[DCA_PRIM_CHANNELS_MAX][2];                  ///< stereo downmix coefficients
    int dynrange_coef;                                           ///< dynamic range coefficient

    int high_freq_vq[DCA_PRIM_CHANNELS_MAX][DCA_SUBBANDS];       ///< VQ encoded high frequency subbands

    float lfe_data[2 * DCA_SUBSUBFAMES_MAX * DCA_LFE_MAX *
                   2 /*history */ ];    ///< Low frequency effect data
    int lfe_scale_factor;

    /* Subband samples history (for ADPCM) */
    float subband_samples_hist[DCA_PRIM_CHANNELS_MAX][DCA_SUBBANDS][4];
    DECLARE_ALIGNED_16(float, subband_fir_hist[DCA_PRIM_CHANNELS_MAX][512]);
    float subband_fir_noidea[DCA_PRIM_CHANNELS_MAX][32];
    int hist_index[DCA_PRIM_CHANNELS_MAX];

    int output;                 ///< type of output
    float add_bias;             ///< output bias
    float scale_bias;           ///< output scale

    DECLARE_ALIGNED_16(float, samples[1536]);  /* 6 * 256 = 1536, might only need 5 */
    const float *samples_chanptr[6];

    uint8_t dca_buffer[DCA_MAX_FRAME_SIZE];
    int dca_buffer_size;        ///< how much data is in the dca_buffer

    const int8_t* channel_order_tab;                             ///< channel reordering table, lfe and non lfe
    GetBitContext gb;
    /* Current position in DCA frame */
    int current_subframe;
    int current_subsubframe;

    int debug_flag;             ///< used for suppressing repeated error messages output
    DSPContext dsp;
    MDCTContext imdct;
} DCAContext;

static av_cold void dca_init_vlcs(void)
{
    static int vlcs_initialized = 0;
    int i, j;

    if (vlcs_initialized)
        return;

    dca_bitalloc_index.offset = 1;
    dca_bitalloc_index.wrap = 2;
    for (i = 0; i < 5; i++)
        init_vlc(&dca_bitalloc_index.vlc[i], bitalloc_12_vlc_bits[i], 12,
                 bitalloc_12_bits[i], 1, 1,
                 bitalloc_12_codes[i], 2, 2, 1);
    dca_scalefactor.offset = -64;
    dca_scalefactor.wrap = 2;
    for (i = 0; i < 5; i++)
        init_vlc(&dca_scalefactor.vlc[i], SCALES_VLC_BITS, 129,
                 scales_bits[i], 1, 1,
                 scales_codes[i], 2, 2, 1);
    dca_tmode.offset = 0;
    dca_tmode.wrap = 1;
    for (i = 0; i < 4; i++)
        init_vlc(&dca_tmode.vlc[i], tmode_vlc_bits[i], 4,
                 tmode_bits[i], 1, 1,
                 tmode_codes[i], 2, 2, 1);

    for(i = 0; i < 10; i++)
        for(j = 0; j < 7; j++){
            if(!bitalloc_codes[i][j]) break;
            dca_smpl_bitalloc[i+1].offset = bitalloc_offsets[i];
            dca_smpl_bitalloc[i+1].wrap = 1 + (j > 4);
            init_vlc(&dca_smpl_bitalloc[i+1].vlc[j], bitalloc_maxbits[i][j],
                     bitalloc_sizes[i],
                     bitalloc_bits[i][j], 1, 1,
                     bitalloc_codes[i][j], 2, 2, 1);
        }
    vlcs_initialized = 1;
}

static inline void get_array(GetBitContext *gb, int *dst, int len, int bits)
{
    while(len--)
        *dst++ = get_bits(gb, bits);
}

static int dca_parse_frame_header(DCAContext * s)
{
    int i, j;
    static const float adj_table[4] = { 1.0, 1.1250, 1.2500, 1.4375 };
    static const int bitlen[11] = { 0, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3 };
    static const int thr[11] = { 0, 1, 3, 3, 3, 3, 7, 7, 7, 7, 7 };
    uint32_t syncword = 0;

    init_get_bits(&s->gb, s->dca_buffer, s->dca_buffer_size * 8);

    /* Sync code */
    syncword = get_bits(&s->gb, 32);

    /* Frame header */
    s->frame_type        = get_bits(&s->gb, 1);
    s->samples_deficit   = get_bits(&s->gb, 5) + 1;
    s->crc_present       = get_bits(&s->gb, 1);
    s->sample_blocks     = get_bits(&s->gb, 7) + 1;
    s->frame_size        = get_bits(&s->gb, 14) + 1;
    if (s->frame_size < 95)
        return -1;
    s->amode             = get_bits(&s->gb, 6);
    s->sample_rate       = dca_sample_rates[get_bits(&s->gb, 4)];
    if (!s->sample_rate)
        return -1;
    s->bit_rate_index    = get_bits(&s->gb, 5);
    s->bit_rate          = dca_bit_rates[s->bit_rate_index];
    if (!s->bit_rate)
        return -1;

    s->downmix           = get_bits(&s->gb, 1);
    s->dynrange          = get_bits(&s->gb, 1);
    s->timestamp         = get_bits(&s->gb, 1);
    s->aux_data          = get_bits(&s->gb, 1);
    s->hdcd              = get_bits(&s->gb, 1);
    s->ext_descr         = get_bits(&s->gb, 3);
    s->ext_coding        = get_bits(&s->gb, 1);
    s->aspf              = get_bits(&s->gb, 1);
    s->lfe               = get_bits(&s->gb, 2);
    s->predictor_history = get_bits(&s->gb, 1);

    /* TODO: check CRC */
    if (s->crc_present)
        s->header_crc    = get_bits(&s->gb, 16);

    s->multirate_inter   = get_bits(&s->gb, 1);
    s->version           = get_bits(&s->gb, 4);
    s->copy_history      = get_bits(&s->gb, 2);
    s->source_pcm_res    = get_bits(&s->gb, 3);
    s->front_sum         = get_bits(&s->gb, 1);
    s->surround_sum      = get_bits(&s->gb, 1);
    s->dialog_norm       = get_bits(&s->gb, 4);

    /* FIXME: channels mixing levels */
    s->output = s->amode;
    if(s->lfe) s->output |= DCA_LFE;

#ifdef TRACE
    av_log(s->avctx, AV_LOG_DEBUG, "frame type: %i\n", s->frame_type);
    av_log(s->avctx, AV_LOG_DEBUG, "samples deficit: %i\n", s->samples_deficit);
    av_log(s->avctx, AV_LOG_DEBUG, "crc present: %i\n", s->crc_present);
    av_log(s->avctx, AV_LOG_DEBUG, "sample blocks: %i (%i samples)\n",
           s->sample_blocks, s->sample_blocks * 32);
    av_log(s->avctx, AV_LOG_DEBUG, "frame size: %i bytes\n", s->frame_size);
    av_log(s->avctx, AV_LOG_DEBUG, "amode: %i (%i channels)\n",
           s->amode, dca_channels[s->amode]);
    av_log(s->avctx, AV_LOG_DEBUG, "sample rate: %i Hz\n",
           s->sample_rate);
    av_log(s->avctx, AV_LOG_DEBUG, "bit rate: %i bits/s\n",
           s->bit_rate);
    av_log(s->avctx, AV_LOG_DEBUG, "downmix: %i\n", s->downmix);
    av_log(s->avctx, AV_LOG_DEBUG, "dynrange: %i\n", s->dynrange);
    av_log(s->avctx, AV_LOG_DEBUG, "timestamp: %i\n", s->timestamp);
    av_log(s->avctx, AV_LOG_DEBUG, "aux_data: %i\n", s->aux_data);
    av_log(s->avctx, AV_LOG_DEBUG, "hdcd: %i\n", s->hdcd);
    av_log(s->avctx, AV_LOG_DEBUG, "ext descr: %i\n", s->ext_descr);
    av_log(s->avctx, AV_LOG_DEBUG, "ext coding: %i\n", s->ext_coding);
    av_log(s->avctx, AV_LOG_DEBUG, "aspf: %i\n", s->aspf);
    av_log(s->avctx, AV_LOG_DEBUG, "lfe: %i\n", s->lfe);
    av_log(s->avctx, AV_LOG_DEBUG, "predictor history: %i\n",
           s->predictor_history);
    av_log(s->avctx, AV_LOG_DEBUG, "header crc: %i\n", s->header_crc);
    av_log(s->avctx, AV_LOG_DEBUG, "multirate inter: %i\n",
           s->multirate_inter);
    av_log(s->avctx, AV_LOG_DEBUG, "version number: %i\n", s->version);
    av_log(s->avctx, AV_LOG_DEBUG, "copy history: %i\n", s->copy_history);
    av_log(s->avctx, AV_LOG_DEBUG,
           "source pcm resolution: %i (%i bits/sample)\n",
           s->source_pcm_res, dca_bits_per_sample[s->source_pcm_res]);
    av_log(s->avctx, AV_LOG_DEBUG, "front sum: %i\n", s->front_sum);
    av_log(s->avctx, AV_LOG_DEBUG, "surround sum: %i\n", s->surround_sum);
    av_log(s->avctx, AV_LOG_DEBUG, "dialog norm: %i\n", s->dialog_norm);
    av_log(s->avctx, AV_LOG_DEBUG, "\n");
#endif

    /* Primary audio coding header */
    s->subframes         = get_bits(&s->gb, 4) + 1;
    s->total_channels    = get_bits(&s->gb, 3) + 1;
    s->prim_channels     = s->total_channels;
    if (s->prim_channels > DCA_PRIM_CHANNELS_MAX)
        s->prim_channels = DCA_PRIM_CHANNELS_MAX;   /* We only support DTS core */


    for (i = 0; i < s->prim_channels; i++) {
        s->subband_activity[i] = get_bits(&s->gb, 5) + 2;
        if (s->subband_activity[i] > DCA_SUBBANDS)
            s->subband_activity[i] = DCA_SUBBANDS;
    }
    for (i = 0; i < s->prim_channels; i++) {
        s->vq_start_subband[i] = get_bits(&s->gb, 5) + 1;
        if (s->vq_start_subband[i] > DCA_SUBBANDS)
            s->vq_start_subband[i] = DCA_SUBBANDS;
    }
    get_array(&s->gb, s->joint_intensity,     s->prim_channels, 3);
    get_array(&s->gb, s->transient_huffman,   s->prim_channels, 2);
    get_array(&s->gb, s->scalefactor_huffman, s->prim_channels, 3);
    get_array(&s->gb, s->bitalloc_huffman,    s->prim_channels, 3);

    /* Get codebooks quantization indexes */
    memset(s->quant_index_huffman, 0, sizeof(s->quant_index_huffman));
    for (j = 1; j < 11; j++)
        for (i = 0; i < s->prim_channels; i++)
            s->quant_index_huffman[i][j] = get_bits(&s->gb, bitlen[j]);

    /* Get scale factor adjustment */
    for (j = 0; j < 11; j++)
        for (i = 0; i < s->prim_channels; i++)
            s->scalefactor_adj[i][j] = 1;

    for (j = 1; j < 11; j++)
        for (i = 0; i < s->prim_channels; i++)
            if (s->quant_index_huffman[i][j] < thr[j])
                s->scalefactor_adj[i][j] = adj_table[get_bits(&s->gb, 2)];

    if (s->crc_present) {
        /* Audio header CRC check */
        get_bits(&s->gb, 16);
    }

    s->current_subframe = 0;
    s->current_subsubframe = 0;

#ifdef TRACE
    av_log(s->avctx, AV_LOG_DEBUG, "subframes: %i\n", s->subframes);
    av_log(s->avctx, AV_LOG_DEBUG, "prim channels: %i\n", s->prim_channels);
    for(i = 0; i < s->prim_channels; i++){
        av_log(s->avctx, AV_LOG_DEBUG, "subband activity: %i\n", s->subband_activity[i]);
        av_log(s->avctx, AV_LOG_DEBUG, "vq start subband: %i\n", s->vq_start_subband[i]);
        av_log(s->avctx, AV_LOG_DEBUG, "joint intensity: %i\n", s->joint_intensity[i]);
        av_log(s->avctx, AV_LOG_DEBUG, "transient mode codebook: %i\n", s->transient_huffman[i]);
        av_log(s->avctx, AV_LOG_DEBUG, "scale factor codebook: %i\n", s->scalefactor_huffman[i]);
        av_log(s->avctx, AV_LOG_DEBUG, "bit allocation quantizer: %i\n", s->bitalloc_huffman[i]);
        av_log(s->avctx, AV_LOG_DEBUG, "quant index huff:");
        for (j = 0; j < 11; j++)
            av_log(s->avctx, AV_LOG_DEBUG, " %i",
                   s->quant_index_huffman[i][j]);
        av_log(s->avctx, AV_LOG_DEBUG, "\n");
        av_log(s->avctx, AV_LOG_DEBUG, "scalefac adj:");
        for (j = 0; j < 11; j++)
            av_log(s->avctx, AV_LOG_DEBUG, " %1.3f", s->scalefactor_adj[i][j]);
        av_log(s->avctx, AV_LOG_DEBUG, "\n");
    }
#endif

    return 0;
}


static inline int get_scale(GetBitContext *gb, int level, int value)
{
   if (level < 5) {
       /* huffman encoded */
       value += get_bitalloc(gb, &dca_scalefactor, level);
   } else if(level < 8)
       value = get_bits(gb, level + 1);
   return value;
}

static const uint8_t abits_sizes[7] = { 7, 10, 12, 13, 15, 17, 19 };
static const uint8_t abits_levels[7] = { 3, 5, 7, 9, 13, 17, 25 };

/**
 * Convert bitstream to one representation based on sync marker
 */
static int dca_convert_bitstream(const uint8_t * src, int src_size, uint8_t * dst,
                          int max_size)
{
    uint32_t mrk;
    int i, tmp;
    const uint16_t *ssrc = (const uint16_t *) src;
    uint16_t *sdst = (uint16_t *) dst;
    PutBitContext pb;

    if((unsigned)src_size > (unsigned)max_size) {
//        av_log(NULL, AV_LOG_ERROR, "Input frame size larger then DCA_MAX_FRAME_SIZE!\n");
//        return -1;
        src_size = max_size;
    }

    mrk = AV_RB32(src);
    switch (mrk) {
    case DCA_MARKER_RAW_BE:
        memcpy(dst, src, src_size);
        return src_size;
    case DCA_MARKER_RAW_LE:
        for (i = 0; i < (src_size + 1) >> 1; i++)
            *sdst++ = bswap_16(*ssrc++);
        return src_size;
    case DCA_MARKER_14B_BE:
    case DCA_MARKER_14B_LE:
        init_put_bits(&pb, dst, max_size);
        for (i = 0; i < (src_size + 1) >> 1; i++, src += 2) {
            tmp = ((mrk == DCA_MARKER_14B_BE) ? AV_RB16(src) : AV_RL16(src)) & 0x3FFF;
            put_bits(&pb, 14, tmp);
        }
        flush_put_bits(&pb);
        return (put_bits_count(&pb) + 7) >> 3;
    default:
        return -1;
    }
}

/**
 * Main frame decoding function
 * FIXME add arguments
 */
static int dca_decode_dummy_frame(AVCodecContext * avctx,
                            void *data, int *data_size,
                            const uint8_t * buf, int buf_size)
{

    int i;
    int16_t *samples = data;
    DCAContext *s = avctx->priv_data;
    int channels;
    uint32_t mrk=0;


    s->dca_buffer_size = dca_convert_bitstream(buf, buf_size, s->dca_buffer, DCA_MAX_FRAME_SIZE);
    if (s->dca_buffer_size == -1) {
        av_log(avctx, AV_LOG_ERROR, "Not a valid DCA frame\n");
        return -1;
    }

    init_get_bits(&s->gb, s->dca_buffer, s->dca_buffer_size * 8);
    if (dca_parse_frame_header(s) < 0) {
        //seems like the frame is corrupt, try with the next one
        *data_size=0;
        return buf_size;
    }
    //set AVCodec values with parsed data
    avctx->sample_rate = s->sample_rate;
    avctx->bit_rate = s->bit_rate;
    // JFT, so we only look at 1 frame when looking for DTS-HD/DTS-MA
    avctx->frame_size = s->sample_blocks*32;

    channels = s->prim_channels + !!s->lfe;

    if (s->amode<16) {
        avctx->channel_layout = dca_core_channel_layout[s->amode];

        if (s->lfe) {
            avctx->channel_layout |= CH_LOW_FREQUENCY;
            s->channel_order_tab = dca_channel_reorder_lfe[s->amode];
        } else
            s->channel_order_tab = dca_channel_reorder_nolfe[s->amode];

        if(avctx->request_channels == 2 && s->prim_channels > 2) {
            channels = 2;
            s->output = DCA_STEREO;
            avctx->channel_layout = CH_LAYOUT_STEREO;
        }
    } else {
        av_log(avctx, AV_LOG_ERROR, "Non standard configuration %d !\n",s->amode);
        return -1;
    }


    /* There is nothing that prevents a dts frame to change channel configuration
       but FFmpeg doesn't support that so only set the channels if it is previously
       unset. Ideally during the first probe for channels the crc should be checked
       and only set avctx->channels when the crc is ok. Right now the decoder could
       set the channels based on a broken first frame.*/
    if (!avctx->channels)
        avctx->channels = channels;

    /* REMOVED DECODING CALLS
    if(*data_size < (s->sample_blocks / 8) * 256 * sizeof(int16_t) * channels)
        return -1;
    *data_size = 256 / 8 * s->sample_blocks * sizeof(int16_t) * channels;
    for (i = 0; i < (s->sample_blocks / 8); i++) {
        dca_decode_block(s);
        s->dsp.float_to_int16_interleave(samples, s->samples_chanptr, 256, channels);
        samples += 256 * channels;
    }
    */
    // See if there is a HD extension

    /* extensions start at 32-bit boundaries into bitstream */
    skip_bits_long(&s->gb, (-get_bits_count(&s->gb)) & 31);
    /*align_get_bits(&s->gb);
    while(get_bits_count(&s->gb)<(s->dca_buffer_size * 8))
    {
        mrk=get_bits_long(&s->gb, 8);
        if(mrk!=0)
        {
            mrk=(mrk<<24)|get_bits_long(&s->gb, 24);
            break;
        }
    }
    av_log(avctx, AV_LOG_ERROR, "Marker %X\n",mrk);
    if(mrk==DCA_HD_MARKER)
    {
        avctx->codec_id=CODEC_ID_DTS_MA;
    }*/
    while(get_bits_count(&s->gb)<(s->dca_buffer_size * 8-31))
    {
        uint32_t bits = get_bits_long(&s->gb, 32);
        switch(bits) {
        case DCA_HD_MARKER:
            avctx->codec_id=CODEC_ID_DTS_MA;
            break;
        }

        skip_bits_long(&s->gb, (-get_bits_count(&s->gb)) & 31);
    }

    return 0;
}


/**
 * DCA initialization
 *
 * @param avctx     pointer to the AVCodecContext
 */

static av_cold int dca_decode_dummy_init(AVCodecContext * avctx)
{
    DCAContext *s = avctx->priv_data;
    int i;

    s->avctx = avctx;
    dca_init_vlcs();

    dsputil_init(&s->dsp, avctx);
    ff_mdct_init(&s->imdct, 6, 1);

    for(i = 0; i < 6; i++)
        s->samples_chanptr[i] = s->samples + i * 256;
    avctx->sample_fmt = SAMPLE_FMT_S16;

    if(s->dsp.float_to_int16 == ff_float_to_int16_c) {
        s->add_bias = 385.0f;
        s->scale_bias = 1.0 / 32768.0;
    } else {
        s->add_bias = 0.0f;
        s->scale_bias = 1.0;

        /* allow downmixing to stereo */
        if (avctx->channels > 0 && avctx->request_channels < avctx->channels &&
                avctx->request_channels == 2) {
            avctx->channels = avctx->request_channels;
        }
    }
    return 0;
}

static av_cold int dca_decode_dummy_end(AVCodecContext * avctx)
{
   DCAContext *s = avctx->priv_data;
   ff_mdct_end(&s->imdct);
   return 0;
}

AVCodec dcadummy_decoder = {
    .name = "dca",
    .type = CODEC_TYPE_AUDIO,
    .id = CODEC_ID_DTS,
    .priv_data_size = sizeof(DCAContext),
    .init = dca_decode_dummy_init,
    .decode = dca_decode_dummy_frame,
    .close = dca_decode_dummy_end,
    .long_name = NULL_IF_CONFIG_SMALL("DCA (DTS Coherent Acoustics)-Dummy"),
};

AVCodec dts_hddummy_decoder = {
    .name = "dts_hd",
    .type = CODEC_TYPE_AUDIO,
    .id = CODEC_ID_DTS_HD,
    .priv_data_size = sizeof(DCAContext),
    .init = dca_decode_dummy_init,
    .decode = dca_decode_dummy_frame,
    .close = dca_decode_dummy_end,
    .long_name = NULL_IF_CONFIG_SMALL("DTS-HD-Dummy"),
};

AVCodec dts_madummy_decoder = {
    .name = "dts_ma",
    .type = CODEC_TYPE_AUDIO,
    .id = CODEC_ID_DTS_MA,
    .priv_data_size = sizeof(DCAContext),
    .init = dca_decode_dummy_init,
    .decode = dca_decode_dummy_frame,
    .close = dca_decode_dummy_end,
    .long_name = NULL_IF_CONFIG_SMALL("DTS-MA-Dummy"),
};