/*
  * SIPR / ACELP.NET decoder
  *
  * Copyright (c) 2008 Vladimir Voroshilov
  * Copyright (c) 2009 Vitor Sessak
  *
  * 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
  */
 
 #include <math.h>
 #include <stdint.h>

 #include <string.h>

 #include "libavutil/channel_layout.h"

 #include "libavutil/float_dsp.h"

 #include "libavutil/mathematics.h"

 #define BITSTREAM_READER_LE

 #include "avcodec.h"

 #include "get_bits.h"

 #include "internal.h"

 #include "lsp.h"
 #include "acelp_vectors.h"
 #include "acelp_pitch_delay.h"
 #include "acelp_filters.h"
 #include "celp_filters.h"
 

 #define MAX_SUBFRAME_COUNT   5
 

 #include "sipr.h"

 #include "siprdata.h"
 

 typedef struct SiprModeParam {

     const char *mode_name;
     uint16_t bits_per_frame;
     uint8_t subframe_count;
     uint8_t frames_per_packet;
     float pitch_sharp_factor;
 
     /* bitstream parameters */
     uint8_t number_of_fc_indexes;

     uint8_t ma_predictor_bits;  ///< size in bits of the switched MA predictor

 
     /** size in bits of the i-th stage vector of quantizer */
     uint8_t vq_indexes_bits[5];
 
     /** size in bits of the adaptive-codebook index for every subframe */
     uint8_t pitch_delay_bits[5];
 
     uint8_t gp_index_bits;
     uint8_t fc_index_bits[10]; ///< size in bits of the fixed codebook indexes
     uint8_t gc_index_bits;     ///< size in bits of the gain  codebook indexes
 } SiprModeParam;
 
 static const SiprModeParam modes[MODE_COUNT] = {

     [MODE_16k] = {
         .mode_name          = "16k",
         .bits_per_frame     = 160,
         .subframe_count     = SUBFRAME_COUNT_16k,
         .frames_per_packet  = 1,
         .pitch_sharp_factor = 0.00,
 
         .number_of_fc_indexes = 10,
         .ma_predictor_bits    = 1,
         .vq_indexes_bits      = {7, 8, 7, 7, 7},
         .pitch_delay_bits     = {9, 6},
         .gp_index_bits        = 4,
         .fc_index_bits        = {4, 5, 4, 5, 4, 5, 4, 5, 4, 5},
         .gc_index_bits        = 5
     },
 

     [MODE_8k5] = {
         .mode_name          = "8k5",
         .bits_per_frame     = 152,
         .subframe_count     = 3,
         .frames_per_packet  = 1,
         .pitch_sharp_factor = 0.8,
 
         .number_of_fc_indexes = 3,

         .ma_predictor_bits    = 0,

         .vq_indexes_bits      = {6, 7, 7, 7, 5},
         .pitch_delay_bits     = {8, 5, 5},
         .gp_index_bits        = 0,
         .fc_index_bits        = {9, 9, 9},
         .gc_index_bits        = 7
     },
 
     [MODE_6k5] = {
         .mode_name          = "6k5",
         .bits_per_frame     = 232,
         .subframe_count     = 3,
         .frames_per_packet  = 2,
         .pitch_sharp_factor = 0.8,
 
         .number_of_fc_indexes = 3,

         .ma_predictor_bits    = 0,

         .vq_indexes_bits      = {6, 7, 7, 7, 5},
         .pitch_delay_bits     = {8, 5, 5},
         .gp_index_bits        = 0,
         .fc_index_bits        = {5, 5, 5},
         .gc_index_bits        = 7
     },
 
     [MODE_5k0] = {
         .mode_name          = "5k0",
         .bits_per_frame     = 296,
         .subframe_count     = 5,
         .frames_per_packet  = 2,
         .pitch_sharp_factor = 0.85,
 
         .number_of_fc_indexes = 1,

         .ma_predictor_bits    = 0,

         .vq_indexes_bits      = {6, 7, 7, 7, 5},
         .pitch_delay_bits     = {8, 5, 8, 5, 5},
         .gp_index_bits        = 0,
         .fc_index_bits        = {10},
         .gc_index_bits        = 7
     }
 };
 

 const float ff_pow_0_5[] = {
     1.0/(1 <<  1), 1.0/(1 <<  2), 1.0/(1 <<  3), 1.0/(1 <<  4),
     1.0/(1 <<  5), 1.0/(1 <<  6), 1.0/(1 <<  7), 1.0/(1 <<  8),
     1.0/(1 <<  9), 1.0/(1 << 10), 1.0/(1 << 11), 1.0/(1 << 12),
     1.0/(1 << 13), 1.0/(1 << 14), 1.0/(1 << 15), 1.0/(1 << 16)
 };
 

 static void dequant(float *out, const int *idx, const float * const cbs[])

 {
     int i;
     int stride  = 2;
     int num_vec = 5;
 
     for (i = 0; i < num_vec; i++)
         memcpy(out + stride*i, cbs[i] + stride*idx[i], stride*sizeof(float));
 
 }
 
 static void lsf_decode_fp(float *lsfnew, float *lsf_history,
                           const SiprParameters *parm)
 {
     int i;
     float lsf_tmp[LP_FILTER_ORDER];
 
     dequant(lsf_tmp, parm->vq_indexes, lsf_codebooks);
 
     for (i = 0; i < LP_FILTER_ORDER; i++)
         lsfnew[i] = lsf_history[i] * 0.33 + lsf_tmp[i] + mean_lsf[i];
 
     ff_sort_nearly_sorted_floats(lsfnew, LP_FILTER_ORDER - 1);
 
     /* Note that a minimum distance is not enforced between the last value and
        the previous one, contrary to what is done in ff_acelp_reorder_lsf() */
     ff_set_min_dist_lsf(lsfnew, LSFQ_DIFF_MIN, LP_FILTER_ORDER - 1);
     lsfnew[9] = FFMIN(lsfnew[LP_FILTER_ORDER - 1], 1.3 * M_PI);
 
     memcpy(lsf_history, lsf_tmp, LP_FILTER_ORDER * sizeof(*lsf_history));
 
     for (i = 0; i < LP_FILTER_ORDER - 1; i++)
         lsfnew[i] = cos(lsfnew[i]);
     lsfnew[LP_FILTER_ORDER - 1] *= 6.153848 / M_PI;
 }
 
 /** Apply pitch lag to the fixed vector (AMR section 6.1.2). */
 static void pitch_sharpening(int pitch_lag_int, float beta,
                              float *fixed_vector)
 {
     int i;
 
     for (i = pitch_lag_int; i < SUBFR_SIZE; i++)
         fixed_vector[i] += beta * fixed_vector[i - pitch_lag_int];
 }
 
 /**

  * Extract decoding parameters from the input bitstream.

  * @param parms          parameters structure
  * @param pgb            pointer to initialized GetBitContext structure
  */
 static void decode_parameters(SiprParameters* parms, GetBitContext *pgb,
                               const SiprModeParam *p)
 {
     int i, j;
 

     if (p->ma_predictor_bits)
         parms->ma_pred_switch       = get_bits(pgb, p->ma_predictor_bits);

     for (i = 0; i < 5; i++)
         parms->vq_indexes[i]        = get_bits(pgb, p->vq_indexes_bits[i]);
 
     for (i = 0; i < p->subframe_count; i++) {
         parms->pitch_delay[i]       = get_bits(pgb, p->pitch_delay_bits[i]);

         if (p->gp_index_bits)
             parms->gp_index[i]      = get_bits(pgb, p->gp_index_bits);

 
         for (j = 0; j < p->number_of_fc_indexes; j++)
             parms->fc_indexes[i][j] = get_bits(pgb, p->fc_index_bits[j]);
 
         parms->gc_index[i]          = get_bits(pgb, p->gc_index_bits);
     }
 }
 
 static void sipr_decode_lp(float *lsfnew, const float *lsfold, float *Az,
                            int num_subfr)
 {
     double lsfint[LP_FILTER_ORDER];
     int i,j;
     float t, t0 = 1.0 / num_subfr;
 
     t = t0 * 0.5;
     for (i = 0; i < num_subfr; i++) {
         for (j = 0; j < LP_FILTER_ORDER; j++)
             lsfint[j] = lsfold[j] * (1 - t) + t * lsfnew[j];
 

         ff_amrwb_lsp2lpc(lsfint, Az, LP_FILTER_ORDER);

         Az += LP_FILTER_ORDER;
         t += t0;
     }
 }
 
 /**

  * Evaluate the adaptive impulse response.

  */
 static void eval_ir(const float *Az, int pitch_lag, float *freq,
                     float pitch_sharp_factor)
 {
     float tmp1[SUBFR_SIZE+1], tmp2[LP_FILTER_ORDER+1];
     int i;
 

     tmp1[0] = 1.0;

     for (i = 0; i < LP_FILTER_ORDER; i++) {
         tmp1[i+1] = Az[i] * ff_pow_0_55[i];
         tmp2[i  ] = Az[i] * ff_pow_0_7 [i];
     }
     memset(tmp1 + 11, 0, 37 * sizeof(float));
 
     ff_celp_lp_synthesis_filterf(freq, tmp2, tmp1, SUBFR_SIZE,
                                  LP_FILTER_ORDER);
 
     pitch_sharpening(pitch_lag, pitch_sharp_factor, freq);
 }
 
 /**

  * Evaluate the convolution of a vector with a sparse vector.

  */
 static void convolute_with_sparse(float *out, const AMRFixed *pulses,
                                   const float *shape, int length)
 {
     int i, j;
 
     memset(out, 0, length*sizeof(float));
     for (i = 0; i < pulses->n; i++)
         for (j = pulses->x[i]; j < length; j++)
             out[j] += pulses->y[i] * shape[j - pulses->x[i]];
 }
 
 /**
  * Apply postfilter, very similar to AMR one.
  */
 static void postfilter_5k0(SiprContext *ctx, const float *lpc, float *samples)
 {
     float buf[SUBFR_SIZE + LP_FILTER_ORDER];
     float *pole_out = buf + LP_FILTER_ORDER;
     float lpc_n[LP_FILTER_ORDER];
     float lpc_d[LP_FILTER_ORDER];
     int i;
 
     for (i = 0; i < LP_FILTER_ORDER; i++) {
         lpc_d[i] = lpc[i] * ff_pow_0_75[i];

         lpc_n[i] = lpc[i] * ff_pow_0_5 [i];

     };
 
     memcpy(pole_out - LP_FILTER_ORDER, ctx->postfilter_mem,
            LP_FILTER_ORDER*sizeof(float));
 
     ff_celp_lp_synthesis_filterf(pole_out, lpc_d, samples, SUBFR_SIZE,
                                  LP_FILTER_ORDER);
 
     memcpy(ctx->postfilter_mem, pole_out + SUBFR_SIZE - LP_FILTER_ORDER,
            LP_FILTER_ORDER*sizeof(float));
 
     ff_tilt_compensation(&ctx->tilt_mem, 0.4, pole_out, SUBFR_SIZE);
 
     memcpy(pole_out - LP_FILTER_ORDER, ctx->postfilter_mem5k0,
            LP_FILTER_ORDER*sizeof(*pole_out));
 
     memcpy(ctx->postfilter_mem5k0, pole_out + SUBFR_SIZE - LP_FILTER_ORDER,
            LP_FILTER_ORDER*sizeof(*pole_out));
 
     ff_celp_lp_zero_synthesis_filterf(samples, lpc_n, pole_out, SUBFR_SIZE,
                                       LP_FILTER_ORDER);
 
 }
 
 static void decode_fixed_sparse(AMRFixed *fixed_sparse, const int16_t *pulses,
                                 SiprMode mode, int low_gain)
 {
     int i;
 
     switch (mode) {
     case MODE_6k5:
         for (i = 0; i < 3; i++) {
             fixed_sparse->x[i] = 3 * (pulses[i] & 0xf) + i;
             fixed_sparse->y[i] = pulses[i] & 0x10 ? -1 : 1;
         }
         fixed_sparse->n = 3;
         break;
     case MODE_8k5:
         for (i = 0; i < 3; i++) {
             fixed_sparse->x[2*i    ] = 3 * ((pulses[i] >> 4) & 0xf) + i;
             fixed_sparse->x[2*i + 1] = 3 * ( pulses[i]       & 0xf) + i;
 
             fixed_sparse->y[2*i    ] = (pulses[i] & 0x100) ? -1.0: 1.0;
 
             fixed_sparse->y[2*i + 1] =
                 (fixed_sparse->x[2*i + 1] < fixed_sparse->x[2*i]) ?
                 -fixed_sparse->y[2*i    ] : fixed_sparse->y[2*i];
         }
 
         fixed_sparse->n = 6;
         break;
     case MODE_5k0:
     default:
         if (low_gain) {
             int offset = (pulses[0] & 0x200) ? 2 : 0;
             int val = pulses[0];
 
             for (i = 0; i < 3; i++) {
                 int index = (val & 0x7) * 6 + 4 - i*2;
 
                 fixed_sparse->y[i] = (offset + index) & 0x3 ? -1 : 1;
                 fixed_sparse->x[i] = index;
 
                 val >>= 3;
             }
             fixed_sparse->n = 3;
         } else {
             int pulse_subset = (pulses[0] >> 8) & 1;
 
             fixed_sparse->x[0] = ((pulses[0] >> 4) & 15) * 3 + pulse_subset;
             fixed_sparse->x[1] = ( pulses[0]       & 15) * 3 + pulse_subset + 1;
 
             fixed_sparse->y[0] = pulses[0] & 0x200 ? -1 : 1;
             fixed_sparse->y[1] = -fixed_sparse->y[0];
             fixed_sparse->n = 2;
         }
         break;
     }
 }
 
 static void decode_frame(SiprContext *ctx, SiprParameters *params,
                          float *out_data)
 {
     int i, j;

     int subframe_count = modes[ctx->mode].subframe_count;
     int frame_size = subframe_count * SUBFR_SIZE;

     float Az[LP_FILTER_ORDER * MAX_SUBFRAME_COUNT];

     float *excitation;
     float ir_buf[SUBFR_SIZE + LP_FILTER_ORDER];
     float lsf_new[LP_FILTER_ORDER];
     float *impulse_response = ir_buf + LP_FILTER_ORDER;
     float *synth = ctx->synth_buf + 16; // 16 instead of LP_FILTER_ORDER for
                                         // memory alignment
     int t0_first = 0;
     AMRFixed fixed_cb;
 
     memset(ir_buf, 0, LP_FILTER_ORDER * sizeof(float));
     lsf_decode_fp(lsf_new, ctx->lsf_history, params);
 

     sipr_decode_lp(lsf_new, ctx->lsp_history, Az, subframe_count);

 
     memcpy(ctx->lsp_history, lsf_new, LP_FILTER_ORDER * sizeof(float));
 
     excitation = ctx->excitation + PITCH_DELAY_MAX + L_INTERPOL;
 

     for (i = 0; i < subframe_count; i++) {

         float *pAz = Az + i*LP_FILTER_ORDER;
         float fixed_vector[SUBFR_SIZE];
         int T0,T0_frac;
         float pitch_gain, gain_code, avg_energy;
 
         ff_decode_pitch_lag(&T0, &T0_frac, params->pitch_delay[i], t0_first, i,
                             ctx->mode == MODE_5k0, 6);
 
         if (i == 0 || (i == 2 && ctx->mode == MODE_5k0))
             t0_first = T0;
 
         ff_acelp_interpolatef(excitation, excitation - T0 + (T0_frac <= 0),
                               ff_b60_sinc, 6,
                               2 * ((2 + T0_frac)%3 + 1), LP_FILTER_ORDER,
                               SUBFR_SIZE);
 
         decode_fixed_sparse(&fixed_cb, params->fc_indexes[i], ctx->mode,
                             ctx->past_pitch_gain < 0.8);
 

         eval_ir(pAz, T0, impulse_response, modes[ctx->mode].pitch_sharp_factor);

 
         convolute_with_sparse(fixed_vector, &fixed_cb, impulse_response,
                               SUBFR_SIZE);
 

         avg_energy = (0.01 + avpriv_scalarproduct_float_c(fixed_vector,
                                                           fixed_vector,
                                                           SUBFR_SIZE)) /
                      SUBFR_SIZE;

 
         ctx->past_pitch_gain = pitch_gain = gain_cb[params->gc_index[i]][0];
 
         gain_code = ff_amr_set_fixed_gain(gain_cb[params->gc_index[i]][1],
                                           avg_energy, ctx->energy_history,

                                           34 - 15.0/(0.05*M_LN10/M_LN2),

                                           pred);
 
         ff_weighted_vector_sumf(excitation, excitation, fixed_vector,
                                 pitch_gain, gain_code, SUBFR_SIZE);
 
         pitch_gain *= 0.5 * pitch_gain;
         pitch_gain = FFMIN(pitch_gain, 0.4);
 
         ctx->gain_mem = 0.7 * ctx->gain_mem + 0.3 * pitch_gain;
         ctx->gain_mem = FFMIN(ctx->gain_mem, pitch_gain);
         gain_code *= ctx->gain_mem;
 
         for (j = 0; j < SUBFR_SIZE; j++)
             fixed_vector[j] = excitation[j] - gain_code * fixed_vector[j];
 
         if (ctx->mode == MODE_5k0) {
             postfilter_5k0(ctx, pAz, fixed_vector);
 
             ff_celp_lp_synthesis_filterf(ctx->postfilter_syn5k0 + LP_FILTER_ORDER + i*SUBFR_SIZE,
                                          pAz, excitation, SUBFR_SIZE,
                                          LP_FILTER_ORDER);
         }
 
         ff_celp_lp_synthesis_filterf(synth + i*SUBFR_SIZE, pAz, fixed_vector,
                                      SUBFR_SIZE, LP_FILTER_ORDER);
 
         excitation += SUBFR_SIZE;
     }
 
     memcpy(synth - LP_FILTER_ORDER, synth + frame_size - LP_FILTER_ORDER,
            LP_FILTER_ORDER * sizeof(float));
 
     if (ctx->mode == MODE_5k0) {

         for (i = 0; i < subframe_count; i++) {

             float energy = avpriv_scalarproduct_float_c(ctx->postfilter_syn5k0 + LP_FILTER_ORDER + i * SUBFR_SIZE,
                                                         ctx->postfilter_syn5k0 + LP_FILTER_ORDER + i * SUBFR_SIZE,
                                                         SUBFR_SIZE);

             ff_adaptive_gain_control(&synth[i * SUBFR_SIZE],
                                      &synth[i * SUBFR_SIZE], energy,

                                      SUBFR_SIZE, 0.9, &ctx->postfilter_agc);

         }
 
         memcpy(ctx->postfilter_syn5k0, ctx->postfilter_syn5k0 + frame_size,
                LP_FILTER_ORDER*sizeof(float));
     }

     memmove(ctx->excitation, excitation - PITCH_DELAY_MAX - L_INTERPOL,

            (PITCH_DELAY_MAX + L_INTERPOL) * sizeof(float));
 

     ff_acelp_apply_order_2_transfer_function(out_data, synth,

                                              (const float[2]) {-1.99997   , 1.000000000},
                                              (const float[2]) {-1.93307352, 0.935891986},
                                              0.939805806,
                                              ctx->highpass_filt_mem,
                                              frame_size);
 }
 
 static av_cold int sipr_decoder_init(AVCodecContext * avctx)
 {
     SiprContext *ctx = avctx->priv_data;
     int i;
 

     switch (avctx->block_align) {
     case 20: ctx->mode = MODE_16k; break;
     case 19: ctx->mode = MODE_8k5; break;
     case 29: ctx->mode = MODE_6k5; break;
     case 37: ctx->mode = MODE_5k0; break;
     default:

         if      (avctx->bit_rate > 12200) ctx->mode = MODE_16k;
         else if (avctx->bit_rate > 7500 ) ctx->mode = MODE_8k5;
         else if (avctx->bit_rate > 5750 ) ctx->mode = MODE_6k5;
         else                              ctx->mode = MODE_5k0;

         av_log(avctx, AV_LOG_WARNING,

                "Invalid block_align: %d. Mode %s guessed based on bitrate: %"PRId64"\n",

                avctx->block_align, modes[ctx->mode].mode_name, avctx->bit_rate);

     }

     av_log(avctx, AV_LOG_DEBUG, "Mode: %s\n", modes[ctx->mode].mode_name);

     if (ctx->mode == MODE_16k) {

         ff_sipr_init_16k(ctx);

         ctx->decode_frame = ff_sipr_decode_frame_16k;
     } else {
         ctx->decode_frame = decode_frame;
     }

     for (i = 0; i < LP_FILTER_ORDER; i++)
         ctx->lsp_history[i] = cos((i+1) * M_PI / (LP_FILTER_ORDER + 1));
 
     for (i = 0; i < 4; i++)
         ctx->energy_history[i] = -14;
 

     avctx->channels       = 1;
     avctx->channel_layout = AV_CH_LAYOUT_MONO;
     avctx->sample_fmt     = AV_SAMPLE_FMT_FLT;

 
     return 0;
 }
 

 static int sipr_decode_frame(AVCodecContext *avctx, void *data,
                              int *got_frame_ptr, AVPacket *avpkt)

 {
     SiprContext *ctx = avctx->priv_data;

     AVFrame *frame   = data;

     const uint8_t *buf=avpkt->data;
     SiprParameters parm;

     const SiprModeParam *mode_par = &modes[ctx->mode];

     GetBitContext gb;

     float *samples;

     int subframe_size = ctx->mode == MODE_16k ? L_SUBFR_16k : SUBFR_SIZE;

     int i, ret;

 
     ctx->avctx = avctx;

     if (avpkt->size < (mode_par->bits_per_frame >> 3)) {

         av_log(avctx, AV_LOG_ERROR,
                "Error processing packet: packet size (%d) too small\n",
                avpkt->size);

         return AVERROR_INVALIDDATA;

     }

     /* get output buffer */

     frame->nb_samples = mode_par->frames_per_packet * subframe_size *
                         mode_par->subframe_count;

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

         return ret;

     samples = (float *)frame->data[0];

     init_get_bits(&gb, buf, mode_par->bits_per_frame);

     for (i = 0; i < mode_par->frames_per_packet; i++) {
         decode_parameters(&parm, &gb, mode_par);

         ctx->decode_frame(ctx, &parm, samples);

         samples += subframe_size * mode_par->subframe_count;

     }
 

     *got_frame_ptr = 1;

     return mode_par->bits_per_frame >> 3;

 }

 AVCodec ff_sipr_decoder = {

     .name           = "sipr",

     .long_name      = NULL_IF_CONFIG_SMALL("RealAudio SIPR / ACELP.NET"),

     .type           = AVMEDIA_TYPE_AUDIO,

     .id             = AV_CODEC_ID_SIPR,

     .priv_data_size = sizeof(SiprContext),
     .init           = sipr_decoder_init,
     .decode         = sipr_decode_frame,

     .capabilities   = AV_CODEC_CAP_DR1,

 };