/*
* 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"
/* 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_enc_bitalloc(&dump, f);
for (i = 0; i < CELT_MAX_BANDS; i++) {
float bits = 0.0f;
float dist = f->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;
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;
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;
int i;
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;
}