/*
  * Opus encoder
  * Copyright (c) 2017 Rostislav Pehlivanov <atomnuker@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
  */
 
 #include "opusenc_psy.h"
 #include "opus_pvq.h"
 #include "opustab.h"
 #include "mdct15.h"
 #include "libavutil/qsort.h"
 

 static float pvq_band_cost(CeltPVQ *pvq, CeltFrame *f, OpusRangeCoder *rc, int band,
                            float *bits, float lambda)
 {
     int i, b = 0;
     uint32_t cm[2] = { (1 << f->blocks) - 1, (1 << f->blocks) - 1 };
     const int band_size = ff_celt_freq_range[band] << f->size;
     float buf[176 * 2], lowband_scratch[176], norm1[176], norm2[176];
     float dist, cost, err_x = 0.0f, err_y = 0.0f;
     float *X = buf;
     float *X_orig = f->block[0].coeffs + (ff_celt_freq_bands[band] << f->size);
     float *Y = (f->channels == 2) ? &buf[176] : NULL;
     float *Y_orig = f->block[1].coeffs + (ff_celt_freq_bands[band] << f->size);
     OPUS_RC_CHECKPOINT_SPAWN(rc);
 
     memcpy(X, X_orig, band_size*sizeof(float));
     if (Y)
         memcpy(Y, Y_orig, band_size*sizeof(float));
 
     f->remaining2 = ((f->framebits << 3) - f->anticollapse_needed) - opus_rc_tell_frac(rc) - 1;
     if (band <= f->coded_bands - 1) {
         int curr_balance = f->remaining / FFMIN(3, f->coded_bands - band);
         b = av_clip_uintp2(FFMIN(f->remaining2 + 1, f->pulses[band] + curr_balance), 14);
     }
 
     if (f->dual_stereo) {
         pvq->quant_band(pvq, f, rc, band, X, NULL, band_size, b / 2, f->blocks, NULL,
                         f->size, norm1, 0, 1.0f, lowband_scratch, cm[0]);
 
         pvq->quant_band(pvq, f, rc, band, Y, NULL, band_size, b / 2, f->blocks, NULL,
                         f->size, norm2, 0, 1.0f, lowband_scratch, cm[1]);
     } else {
         pvq->quant_band(pvq, f, rc, band, X, Y, band_size, b, f->blocks, NULL, f->size,
                         norm1, 0, 1.0f, lowband_scratch, cm[0] | cm[1]);
     }
 
     for (i = 0; i < band_size; i++) {
         err_x += (X[i] - X_orig[i])*(X[i] - X_orig[i]);
         if (Y)
             err_y += (Y[i] - Y_orig[i])*(Y[i] - Y_orig[i]);
     }
 
     dist = sqrtf(err_x) + sqrtf(err_y);
     cost = OPUS_RC_CHECKPOINT_BITS(rc)/8.0f;
     *bits += cost;
 
     OPUS_RC_CHECKPOINT_ROLLBACK(rc);
 
     return lambda*dist*cost;
 }
 

 /* Populate metrics without taking into consideration neighbouring steps */
 static void step_collect_psy_metrics(OpusPsyContext *s, int index)
 {
     int silence = 0, ch, i, j;
     OpusPsyStep *st = s->steps[index];
 
     st->index = index;
 
     for (ch = 0; ch < s->avctx->channels; ch++) {
         const int lap_size = (1 << s->bsize_analysis);
         for (i = 1; i <= FFMIN(lap_size, index); i++) {
             const int offset = i*120;
             AVFrame *cur = ff_bufqueue_peek(s->bufqueue, index - i);
             memcpy(&s->scratch[offset], cur->extended_data[ch], cur->nb_samples*sizeof(float));
         }
         for (i = 0; i < lap_size; i++) {
             const int offset = i*120 + lap_size;
             AVFrame *cur = ff_bufqueue_peek(s->bufqueue, index + i);
             memcpy(&s->scratch[offset], cur->extended_data[ch], cur->nb_samples*sizeof(float));
         }
 
         s->dsp->vector_fmul(s->scratch, s->scratch, s->window[s->bsize_analysis],
                             (OPUS_BLOCK_SIZE(s->bsize_analysis) << 1));
 
         s->mdct[s->bsize_analysis]->mdct(s->mdct[s->bsize_analysis], st->coeffs[ch], s->scratch, 1);
 
         for (i = 0; i < CELT_MAX_BANDS; i++)
             st->bands[ch][i] = &st->coeffs[ch][ff_celt_freq_bands[i] << s->bsize_analysis];
     }
 
     for (ch = 0; ch < s->avctx->channels; ch++) {
         for (i = 0; i < CELT_MAX_BANDS; i++) {
             float avg_c_s, energy = 0.0f, dist_dev = 0.0f;
             const int range = ff_celt_freq_range[i] << s->bsize_analysis;
             const float *coeffs = st->bands[ch][i];
             for (j = 0; j < range; j++)
                 energy += coeffs[j]*coeffs[j];
 
             st->energy[ch][i] += sqrtf(energy);
             silence |= !!st->energy[ch][i];
             avg_c_s = energy / range;
 
             for (j = 0; j < range; j++) {
                 const float c_s = coeffs[j]*coeffs[j];

                 dist_dev += (avg_c_s - c_s)*(avg_c_s - c_s);

             }
 
             st->tone[ch][i] += sqrtf(dist_dev);
         }
     }
 
     st->silence = !silence;
 
     if (s->avctx->channels > 1) {
         for (i = 0; i < CELT_MAX_BANDS; i++) {
             float incompat = 0.0f;
             const float *coeffs1 = st->bands[0][i];
             const float *coeffs2 = st->bands[1][i];
             const int range = ff_celt_freq_range[i] << s->bsize_analysis;
             for (j = 0; j < range; j++)
                 incompat += (coeffs1[j] - coeffs2[j])*(coeffs1[j] - coeffs2[j]);
             st->stereo[i] = sqrtf(incompat);
         }
     }
 
     for (ch = 0; ch < s->avctx->channels; ch++) {
         for (i = 0; i < CELT_MAX_BANDS; i++) {
             OpusBandExcitation *ex = &s->ex[ch][i];
             float bp_e = bessel_filter(&s->bfilter_lo[ch][i], st->energy[ch][i]);
             bp_e = bessel_filter(&s->bfilter_hi[ch][i], bp_e);
             bp_e *= bp_e;
             if (bp_e > ex->excitation) {
                 st->change_amp[ch][i] = bp_e - ex->excitation;
                 st->total_change += st->change_amp[ch][i];
                 ex->excitation = ex->excitation_init = bp_e;
                 ex->excitation_dist = 0.0f;
             }
             if (ex->excitation > 0.0f) {
                 ex->excitation -= av_clipf((1/expf(ex->excitation_dist)), ex->excitation_init/20, ex->excitation_init/1.09);
                 ex->excitation = FFMAX(ex->excitation, 0.0f);
                 ex->excitation_dist += 1.0f;
             }
         }
     }
 }
 
 static void search_for_change_points(OpusPsyContext *s, float tgt_change,
                                      int offset_s, int offset_e, int resolution,
                                      int level)
 {
     int i;
     float c_change = 0.0f;
     if ((offset_e - offset_s) <= resolution)
         return;
     for (i = offset_s; i < offset_e; i++) {
         c_change += s->steps[i]->total_change;
         if (c_change > tgt_change)
             break;
     }
     if (i == offset_e)
         return;
     search_for_change_points(s, tgt_change / 2.0f, offset_s, i + 0, resolution, level + 1);
     s->inflection_points[s->inflection_points_count++] = i;
     search_for_change_points(s, tgt_change / 2.0f, i + 1, offset_e, resolution, level + 1);
 }
 
 static int flush_silent_frames(OpusPsyContext *s)
 {
     int fsize, silent_frames;
 
     for (silent_frames = 0; silent_frames < s->buffered_steps; silent_frames++)
         if (!s->steps[silent_frames]->silence)
             break;
     if (--silent_frames < 0)
         return 0;
 
     for (fsize = CELT_BLOCK_960; fsize > CELT_BLOCK_120; fsize--) {
         if ((1 << fsize) > silent_frames)
             continue;
         s->p.frames = FFMIN(silent_frames / (1 << fsize), 48 >> fsize);
         s->p.framesize = fsize;
         return 1;
     }
 
     return 0;
 }
 
 /* Main function which decides frame size and frames per current packet */
 static void psy_output_groups(OpusPsyContext *s)
 {
     int max_delay_samples = (s->options->max_delay_ms*s->avctx->sample_rate)/1000;
     int max_bsize = FFMIN(OPUS_SAMPLES_TO_BLOCK_SIZE(max_delay_samples), CELT_BLOCK_960);
 
     /* These don't change for now */
     s->p.mode      = OPUS_MODE_CELT;
     s->p.bandwidth = OPUS_BANDWIDTH_FULLBAND;
 
     /* Flush silent frames ASAP */
     if (s->steps[0]->silence && flush_silent_frames(s))
         return;
 
     s->p.framesize = FFMIN(max_bsize, CELT_BLOCK_960);
     s->p.frames    = 1;
 }
 
 int ff_opus_psy_process(OpusPsyContext *s, OpusPacketInfo *p)
 {
     int i;
     float total_energy_change = 0.0f;
 
     if (s->buffered_steps < s->max_steps && !s->eof) {
         const int awin = (1 << s->bsize_analysis);
         if (++s->steps_to_process >= awin) {
             step_collect_psy_metrics(s, s->buffered_steps - awin + 1);
             s->steps_to_process = 0;
         }
         if ((++s->buffered_steps) < s->max_steps)
             return 1;
     }
 
     for (i = 0; i < s->buffered_steps; i++)
         total_energy_change += s->steps[i]->total_change;
 
     search_for_change_points(s, total_energy_change / 2.0f, 0,
                              s->buffered_steps, 1, 0);
 
     psy_output_groups(s);
 
     p->frames    = s->p.frames;
     p->framesize = s->p.framesize;
     p->mode      = s->p.mode;
     p->bandwidth = s->p.bandwidth;
 
     return 0;
 }
 
 void ff_opus_psy_celt_frame_init(OpusPsyContext *s, CeltFrame *f, int index)
 {
     int i, neighbouring_points = 0, start_offset = 0;
     int radius = (1 << s->p.framesize), step_offset = radius*index;
     int silence = 1;
 
     f->start_band = (s->p.mode == OPUS_MODE_HYBRID) ? 17 : 0;
     f->end_band   = ff_celt_band_end[s->p.bandwidth];
     f->channels   = s->avctx->channels;
     f->size       = s->p.framesize;
 
     for (i = 0; i < (1 << f->size); i++)
         silence &= s->steps[index*(1 << f->size) + i]->silence;
 
     f->silence = silence;
     if (f->silence) {
         f->framebits = 0; /* Otherwise the silence flag eats up 16(!) bits */
         return;
     }
 
     for (i = 0; i < s->inflection_points_count; i++) {
         if (s->inflection_points[i] >= step_offset) {
             start_offset = i;
             break;
         }
     }
 
     for (i = start_offset; i < FFMIN(radius, s->inflection_points_count - start_offset); i++) {
         if (s->inflection_points[i] < (step_offset + radius)) {
             neighbouring_points++;
         }
     }
 
     /* Transient flagging */
     f->transient = neighbouring_points > 0;
     f->blocks = f->transient ? OPUS_BLOCK_SIZE(s->p.framesize)/CELT_OVERLAP : 1;
 
     /* Some sane defaults */
     f->pfilter   = 0;
     f->pf_gain   = 0.5f;
     f->pf_octave = 2;
     f->pf_period = 1;
     f->pf_tapset = 2;
 
     /* More sane defaults */
     f->tf_select = 0;
     f->anticollapse = 1;
     f->alloc_trim = 5;
     f->skip_band_floor = f->end_band;
     f->intensity_stereo = f->end_band;
     f->dual_stereo = 0;
     f->spread = CELT_SPREAD_NORMAL;
     memset(f->tf_change, 0, sizeof(int)*CELT_MAX_BANDS);
     memset(f->alloc_boost, 0, sizeof(int)*CELT_MAX_BANDS);
 }
 
 static void celt_gauge_psy_weight(OpusPsyContext *s, OpusPsyStep **start,
                                   CeltFrame *f_out)
 {
     int i, f, ch;
     int frame_size = OPUS_BLOCK_SIZE(s->p.framesize);
     float rate, frame_bits = 0;
 
     /* Used for the global ROTATE flag */
     float tonal = 0.0f;
 
     /* Pseudo-weights */
     float band_score[CELT_MAX_BANDS] = { 0 };
     float max_score = 1.0f;
 
     /* Pass one - one loop around each band, computing unquant stuff */
     for (i = 0; i < CELT_MAX_BANDS; i++) {
         float weight = 0.0f;
         float tonal_contrib = 0.0f;
         for (f = 0; f < (1 << s->p.framesize); f++) {
             weight = start[f]->stereo[i];
             for (ch = 0; ch < s->avctx->channels; ch++) {
                 weight += start[f]->change_amp[ch][i] + start[f]->tone[ch][i] + start[f]->energy[ch][i];
                 tonal_contrib += start[f]->tone[ch][i];
             }
         }
         tonal += tonal_contrib;
         band_score[i] = weight;
     }
 
     tonal /= (float)CELT_MAX_BANDS;
 
     for (i = 0; i < CELT_MAX_BANDS; i++) {
         if (band_score[i] > max_score)
             max_score = band_score[i];
     }
 
     for (i = 0; i < CELT_MAX_BANDS; i++) {
         f_out->alloc_boost[i] = (int)((band_score[i]/max_score)*3.0f);
         frame_bits += band_score[i]*8.0f;
     }
 
     tonal /= 1333136.0f;

     f_out->spread = av_clip_uintp2(lrintf(tonal), 2);

 
     rate = ((float)s->avctx->bit_rate) + frame_bits*frame_size*16;
     rate *= s->lambda;
     rate /= s->avctx->sample_rate/frame_size;
 
     f_out->framebits = lrintf(rate);
     f_out->framebits = FFMIN(f_out->framebits, OPUS_MAX_PACKET_SIZE*8);
     f_out->framebits = FFALIGN(f_out->framebits, 8);
 }
 
 static int bands_dist(OpusPsyContext *s, CeltFrame *f, float *total_dist)
 {
     int i, tdist = 0.0f;
     OpusRangeCoder dump;
 
     ff_opus_rc_enc_init(&dump);

     ff_celt_bitalloc(f, &dump, 1);

 
     for (i = 0; i < CELT_MAX_BANDS; i++) {
         float bits = 0.0f;

         float dist = pvq_band_cost(f->pvq, f, &dump, i, &bits, s->lambda);

         tdist += dist;
     }
 
     *total_dist = tdist;
 
     return 0;
 }
 
 static void celt_search_for_dual_stereo(OpusPsyContext *s, CeltFrame *f)
 {
     float td1, td2;
     f->dual_stereo = 0;

 
     if (s->avctx->channels < 2)
         return;
 

     bands_dist(s, f, &td1);
     f->dual_stereo = 1;
     bands_dist(s, f, &td2);
 
     f->dual_stereo = td2 < td1;
     s->dual_stereo_used += td2 < td1;
 }
 
 static void celt_search_for_intensity(OpusPsyContext *s, CeltFrame *f)
 {
     int i, best_band = CELT_MAX_BANDS - 1;
     float dist, best_dist = FLT_MAX;

     /* TODO: fix, make some heuristic up here using the lambda value */
     float end_band = 0;

     if (s->avctx->channels < 2)
         return;
 

     for (i = f->end_band; i >= end_band; i--) {
         f->intensity_stereo = i;
         bands_dist(s, f, &dist);
         if (best_dist > dist) {
             best_dist = dist;
             best_band = i;
         }
     }
 
     f->intensity_stereo = best_band;
     s->avg_is_band = (s->avg_is_band + f->intensity_stereo)/2.0f;
 }
 
 static int celt_search_for_tf(OpusPsyContext *s, OpusPsyStep **start, CeltFrame *f)
 {
     int i, j, k, cway, config[2][CELT_MAX_BANDS] = { { 0 } };
     float score[2] = { 0 };
 
     for (cway = 0; cway < 2; cway++) {
         int mag[2];
         int base = f->transient ? 120 : 960;
 

         for (i = 0; i < 2; i++) {

             int c = ff_celt_tf_select[f->size][f->transient][cway][i];
             mag[i] = c < 0 ? base >> FFABS(c) : base << FFABS(c);
         }
 
         for (i = 0; i < CELT_MAX_BANDS; i++) {
             float iscore0 = 0.0f;
             float iscore1 = 0.0f;
             for (j = 0; j < (1 << f->size); j++) {
                 for (k = 0; k < s->avctx->channels; k++) {
                     iscore0 += start[j]->tone[k][i]*start[j]->change_amp[k][i]/mag[0];
                     iscore1 += start[j]->tone[k][i]*start[j]->change_amp[k][i]/mag[1];
                 }
             }
             config[cway][i] = FFABS(iscore0 - 1.0f) < FFABS(iscore1 - 1.0f);
             score[cway] += config[cway][i] ? iscore1 : iscore0;
         }
     }
 
     f->tf_select = score[0] < score[1];
     memcpy(f->tf_change, config[f->tf_select], sizeof(int)*CELT_MAX_BANDS);
 
     return 0;
 }
 
 int ff_opus_psy_celt_frame_process(OpusPsyContext *s, CeltFrame *f, int index)
 {
     int start_transient_flag = f->transient;
     OpusPsyStep **start = &s->steps[index * (1 << s->p.framesize)];
 
     if (f->silence)
         return 0;
 
     celt_gauge_psy_weight(s, start, f);
     celt_search_for_intensity(s, f);
     celt_search_for_dual_stereo(s, f);
     celt_search_for_tf(s, start, f);
 
     if (f->transient != start_transient_flag) {
         f->blocks = f->transient ? OPUS_BLOCK_SIZE(s->p.framesize)/CELT_OVERLAP : 1;
         s->redo_analysis = 1;
         return 1;
     }
 
     s->redo_analysis = 0;
 
     return 0;
 }
 
 void ff_opus_psy_postencode_update(OpusPsyContext *s, CeltFrame *f, OpusRangeCoder *rc)
 {
     int i, frame_size = OPUS_BLOCK_SIZE(s->p.framesize);
     int steps_out = s->p.frames*(frame_size/120);
     void *tmp[FF_BUFQUEUE_SIZE];
     float ideal_fbits;
 
     for (i = 0; i < steps_out; i++)
         memset(s->steps[i], 0, sizeof(OpusPsyStep));
 
     for (i = 0; i < s->max_steps; i++)
         tmp[i] = s->steps[i];
 
     for (i = 0; i < s->max_steps; i++) {
         const int i_new = i - steps_out;
         s->steps[i_new < 0 ? s->max_steps + i_new : i_new] = tmp[i];
     }
 
     for (i = steps_out; i < s->buffered_steps; i++)
         s->steps[i]->index -= steps_out;
 
     ideal_fbits = s->avctx->bit_rate/(s->avctx->sample_rate/frame_size);
 
     for (i = 0; i < s->p.frames; i++) {
         s->avg_is_band += f[i].intensity_stereo;
         s->lambda *= ideal_fbits / f[i].framebits;
     }
 
     s->avg_is_band /= (s->p.frames + 1);
 
     s->cs_num = 0;
     s->steps_to_process = 0;
     s->buffered_steps -= steps_out;
     s->total_packets_out += s->p.frames;
     s->inflection_points_count = 0;
 }
 
 av_cold int ff_opus_psy_init(OpusPsyContext *s, AVCodecContext *avctx,
                              struct FFBufQueue *bufqueue, OpusEncOptions *options)
 {
     int i, ch, ret;
 
     s->redo_analysis = 0;
     s->lambda = 1.0f;
     s->options = options;
     s->avctx = avctx;
     s->bufqueue = bufqueue;
     s->max_steps = ceilf(s->options->max_delay_ms/2.5f);
     s->bsize_analysis = CELT_BLOCK_960;
     s->avg_is_band = CELT_MAX_BANDS - 1;
     s->inflection_points_count = 0;
 
     s->inflection_points = av_mallocz(sizeof(*s->inflection_points)*s->max_steps);
     if (!s->inflection_points) {
         ret = AVERROR(ENOMEM);
         goto fail;
     }
 
     s->dsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT);
     if (!s->dsp) {
         ret = AVERROR(ENOMEM);
         goto fail;
     }
 
     for (ch = 0; ch < s->avctx->channels; ch++) {
         for (i = 0; i < CELT_MAX_BANDS; i++) {
             bessel_init(&s->bfilter_hi[ch][i], 1.0f, 19.0f, 100.0f, 1);
             bessel_init(&s->bfilter_lo[ch][i], 1.0f, 20.0f, 100.0f, 0);
         }
     }
 
     for (i = 0; i < s->max_steps; i++) {
         s->steps[i] = av_mallocz(sizeof(OpusPsyStep));
         if (!s->steps[i]) {
             ret = AVERROR(ENOMEM);
             goto fail;
         }
     }
 
     for (i = 0; i < CELT_BLOCK_NB; i++) {
         float tmp;
         const int len = OPUS_BLOCK_SIZE(i);
         s->window[i] = av_malloc(2*len*sizeof(float));
         if (!s->window[i]) {
             ret = AVERROR(ENOMEM);
             goto fail;
         }

         generate_window_func(s->window[i], 2*len, WFUNC_SINE, &tmp);

         if ((ret = ff_mdct15_init(&s->mdct[i], 0, i + 3, 68 << (CELT_BLOCK_NB - 1 - i))))
             goto fail;
     }
 
     return 0;
 
 fail:
     av_freep(&s->inflection_points);
     av_freep(&s->dsp);
 
     for (i = 0; i < CELT_BLOCK_NB; i++) {
         ff_mdct15_uninit(&s->mdct[i]);
         av_freep(&s->window[i]);
     }
 
     for (i = 0; i < s->max_steps; i++)
         av_freep(&s->steps[i]);
 
     return ret;
 }
 
 void ff_opus_psy_signal_eof(OpusPsyContext *s)
 {
     s->eof = 1;
 }
 
 av_cold int ff_opus_psy_end(OpusPsyContext *s)
 {
     int i;
 
     av_freep(&s->inflection_points);
     av_freep(&s->dsp);
 
     for (i = 0; i < CELT_BLOCK_NB; i++) {
         ff_mdct15_uninit(&s->mdct[i]);
         av_freep(&s->window[i]);
     }
 
     for (i = 0; i < s->max_steps; i++)
         av_freep(&s->steps[i]);
 
     av_log(s->avctx, AV_LOG_INFO, "Average Intensity Stereo band: %0.1f\n", s->avg_is_band);
     av_log(s->avctx, AV_LOG_INFO, "Dual Stereo used: %0.2f%%\n", ((float)s->dual_stereo_used/s->total_packets_out)*100.0f);
 
     return 0;
 }