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/*
* Copyright (c) 2020, Alliance for Open Media. All rights reserved.
*
* This source code is subject to the terms of the BSD 2 Clause License and
* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
* was not distributed with this source code in the LICENSE file, you can
* obtain it at www.aomedia.org/license/software. If the Alliance for Open
* Media Patent License 1.0 was not distributed with this source code in the
* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
*/
#include "av1/encoder/encoder_alloc.h"
#include "av1/encoder/superres_scale.h"
#include "av1/encoder/random.h"
// Compute the horizontal frequency components' energy in a frame
// by calculuating the 16x4 Horizontal DCT. This is to be used to
// decide the superresolution parameters.
static void analyze_hor_freq(const AV1_COMP *cpi, double *energy) {
uint64_t freq_energy[16] = { 0 };
const YV12_BUFFER_CONFIG *buf = cpi->source;
const int bd = cpi->td.mb.e_mbd.bd;
const int width = buf->y_crop_width;
const int height = buf->y_crop_height;
DECLARE_ALIGNED(16, int32_t, coeff[16 * 4]);
int n = 0;
memset(freq_energy, 0, sizeof(freq_energy));
if (buf->flags & YV12_FLAG_HIGHBITDEPTH) {
const int16_t *src16 = (const int16_t *)CONVERT_TO_SHORTPTR(buf->y_buffer);
for (int i = 0; i < height - 4; i += 4) {
for (int j = 0; j < width - 16; j += 16) {
av1_fwd_txfm2d_16x4(src16 + i * buf->y_stride + j, coeff, buf->y_stride,
H_DCT, bd);
for (int k = 1; k < 16; ++k) {
const uint64_t this_energy =
((int64_t)coeff[k] * coeff[k]) +
((int64_t)coeff[k + 16] * coeff[k + 16]) +
((int64_t)coeff[k + 32] * coeff[k + 32]) +
((int64_t)coeff[k + 48] * coeff[k + 48]);
freq_energy[k] += ROUND_POWER_OF_TWO(this_energy, 2 + 2 * (bd - 8));
}
n++;
}
}
} else {
assert(bd == 8);
DECLARE_ALIGNED(16, int16_t, src16[16 * 4]);
for (int i = 0; i < height - 4; i += 4) {
for (int j = 0; j < width - 16; j += 16) {
for (int ii = 0; ii < 4; ++ii)
for (int jj = 0; jj < 16; ++jj)
src16[ii * 16 + jj] =
buf->y_buffer[(i + ii) * buf->y_stride + (j + jj)];
av1_fwd_txfm2d_16x4(src16, coeff, 16, H_DCT, bd);
for (int k = 1; k < 16; ++k) {
const uint64_t this_energy =
((int64_t)coeff[k] * coeff[k]) +
((int64_t)coeff[k + 16] * coeff[k + 16]) +
((int64_t)coeff[k + 32] * coeff[k + 32]) +
((int64_t)coeff[k + 48] * coeff[k + 48]);
freq_energy[k] += ROUND_POWER_OF_TWO(this_energy, 2);
}
n++;
}
}
}
if (n) {
for (int k = 1; k < 16; ++k) energy[k] = (double)freq_energy[k] / n;
// Convert to cumulative energy
for (int k = 14; k > 0; --k) energy[k] += energy[k + 1];
} else {
for (int k = 1; k < 16; ++k) energy[k] = 1e+20;
}
}
static uint8_t calculate_next_resize_scale(const AV1_COMP *cpi) {
// Choose an arbitrary random number
static unsigned int seed = 56789;
const ResizeCfg *resize_cfg = &cpi->oxcf.resize_cfg;
if (is_stat_generation_stage(cpi)) return SCALE_NUMERATOR;
uint8_t new_denom = SCALE_NUMERATOR;
if (cpi->common.seq_params->reduced_still_picture_hdr) return SCALE_NUMERATOR;
switch (resize_cfg->resize_mode) {
case RESIZE_NONE: new_denom = SCALE_NUMERATOR; break;
case RESIZE_FIXED:
if (cpi->common.current_frame.frame_type == KEY_FRAME)
new_denom = resize_cfg->resize_kf_scale_denominator;
else
new_denom = resize_cfg->resize_scale_denominator;
break;
case RESIZE_RANDOM: new_denom = lcg_rand16(&seed) % 9 + 8; break;
default: assert(0);
}
return new_denom;
}
int av1_superres_in_recode_allowed(const AV1_COMP *const cpi) {
const AV1EncoderConfig *const oxcf = &cpi->oxcf;
// Empirically found to not be beneficial for image coding.
return oxcf->superres_cfg.superres_mode == AOM_SUPERRES_AUTO &&
cpi->sf.hl_sf.superres_auto_search_type != SUPERRES_AUTO_SOLO &&
cpi->rc.frames_to_key > 1;
}
#define SUPERRES_ENERGY_BY_Q2_THRESH_KEYFRAME_SOLO 0.012
#define SUPERRES_ENERGY_BY_Q2_THRESH_KEYFRAME 0.008
#define SUPERRES_ENERGY_BY_Q2_THRESH_ARFFRAME 0.008
#define SUPERRES_ENERGY_BY_AC_THRESH 0.2
static double get_energy_by_q2_thresh(const GF_GROUP *gf_group,
const RATE_CONTROL *rc,
int gf_frame_index) {
// TODO(now): Return keyframe thresh * factor based on frame type / pyramid
// level.
if (gf_group->update_type[gf_frame_index] == ARF_UPDATE) {
return SUPERRES_ENERGY_BY_Q2_THRESH_ARFFRAME;
} else if (gf_group->update_type[gf_frame_index] == KF_UPDATE) {
if (rc->frames_to_key <= 1)
return SUPERRES_ENERGY_BY_Q2_THRESH_KEYFRAME_SOLO;
else
return SUPERRES_ENERGY_BY_Q2_THRESH_KEYFRAME;
} else {
assert(0);
}
return 0;
}
static uint8_t get_superres_denom_from_qindex_energy(int qindex, double *energy,
double threshq,
double threshp) {
const double q = av1_convert_qindex_to_q(qindex, AOM_BITS_8);
const double tq = threshq * q * q;
const double tp = threshp * energy[1];
const double thresh = AOMMIN(tq, tp);
int k;
for (k = SCALE_NUMERATOR * 2; k > SCALE_NUMERATOR; --k) {
if (energy[k - 1] > thresh) break;
}
return 3 * SCALE_NUMERATOR - k;
}
static uint8_t get_superres_denom_for_qindex(const AV1_COMP *cpi, int qindex,
int sr_kf, int sr_arf) {
// Use superres for Key-frames and Alt-ref frames only.
const GF_GROUP *gf_group = &cpi->ppi->gf_group;
if (gf_group->update_type[cpi->gf_frame_index] != KF_UPDATE &&
gf_group->update_type[cpi->gf_frame_index] != ARF_UPDATE) {
return SCALE_NUMERATOR;
}
if (gf_group->update_type[cpi->gf_frame_index] == KF_UPDATE && !sr_kf) {
return SCALE_NUMERATOR;
}
if (gf_group->update_type[cpi->gf_frame_index] == ARF_UPDATE && !sr_arf) {
return SCALE_NUMERATOR;
}
double energy[16];
analyze_hor_freq(cpi, energy);
const double energy_by_q2_thresh =
get_energy_by_q2_thresh(gf_group, &cpi->rc, cpi->gf_frame_index);
int denom = get_superres_denom_from_qindex_energy(
qindex, energy, energy_by_q2_thresh, SUPERRES_ENERGY_BY_AC_THRESH);
/*
printf("\nenergy = [");
for (int k = 1; k < 16; ++k) printf("%f, ", energy[k]);
printf("]\n");
printf("boost = %d\n",
(gf_group->update_type[cpi->gf_frame_index] == KF_UPDATE)
? cpi->ppi->p_rc.kf_boost
: cpi->rc.gfu_boost);
printf("denom = %d\n", denom);
*/
if (av1_superres_in_recode_allowed(cpi)) {
assert(cpi->superres_mode != AOM_SUPERRES_NONE);
// Force superres to be tried in the recode loop, as full-res is also going
// to be tried anyway.
denom = AOMMAX(denom, SCALE_NUMERATOR + 1);
}
return denom;
}
static uint8_t calculate_next_superres_scale(AV1_COMP *cpi) {
// Choose an arbitrary random number
static unsigned int seed = 34567;
const AV1EncoderConfig *oxcf = &cpi->oxcf;
const SuperResCfg *const superres_cfg = &oxcf->superres_cfg;
const FrameDimensionCfg *const frm_dim_cfg = &oxcf->frm_dim_cfg;
const RateControlCfg *const rc_cfg = &oxcf->rc_cfg;
if (is_stat_generation_stage(cpi)) return SCALE_NUMERATOR;
uint8_t new_denom = SCALE_NUMERATOR;
// Make sure that superres mode of the frame is consistent with the
// sequence-level flag.
assert(IMPLIES(superres_cfg->superres_mode != AOM_SUPERRES_NONE,
cpi->common.seq_params->enable_superres));
assert(IMPLIES(!cpi->common.seq_params->enable_superres,
superres_cfg->superres_mode == AOM_SUPERRES_NONE));
// Make sure that superres mode for current encoding is consistent with user
// provided superres mode.
assert(IMPLIES(superres_cfg->superres_mode != AOM_SUPERRES_AUTO,
cpi->superres_mode == superres_cfg->superres_mode));
// Note: we must look at the current superres_mode to be tried in 'cpi' here,
// not the user given mode in 'oxcf'.
switch (cpi->superres_mode) {
case AOM_SUPERRES_NONE: new_denom = SCALE_NUMERATOR; break;
case AOM_SUPERRES_FIXED:
if (cpi->common.current_frame.frame_type == KEY_FRAME)
new_denom = superres_cfg->superres_kf_scale_denominator;
else
new_denom = superres_cfg->superres_scale_denominator;
break;
case AOM_SUPERRES_RANDOM: new_denom = lcg_rand16(&seed) % 9 + 8; break;
case AOM_SUPERRES_QTHRESH: {
// Do not use superres when screen content tools are used.
if (cpi->common.features.allow_screen_content_tools) break;
if (rc_cfg->mode == AOM_VBR || rc_cfg->mode == AOM_CQ)
av1_set_target_rate(cpi, frm_dim_cfg->width, frm_dim_cfg->height);
// Now decide the use of superres based on 'q'.
int bottom_index, top_index;
const int q = av1_rc_pick_q_and_bounds(
cpi, frm_dim_cfg->width, frm_dim_cfg->height, cpi->gf_frame_index,
&bottom_index, &top_index);
const int qthresh = (frame_is_intra_only(&cpi->common))
? superres_cfg->superres_kf_qthresh
: superres_cfg->superres_qthresh;
if (q <= qthresh) {
new_denom = SCALE_NUMERATOR;
} else {
new_denom = get_superres_denom_for_qindex(cpi, q, 1, 1);
}
break;
}
case AOM_SUPERRES_AUTO: {
if (cpi->common.features.allow_screen_content_tools) break;
if (rc_cfg->mode == AOM_VBR || rc_cfg->mode == AOM_CQ)
av1_set_target_rate(cpi, frm_dim_cfg->width, frm_dim_cfg->height);
// Now decide the use of superres based on 'q'.
int bottom_index, top_index;
const int q = av1_rc_pick_q_and_bounds(
cpi, frm_dim_cfg->width, frm_dim_cfg->height, cpi->gf_frame_index,
&bottom_index, &top_index);
const SUPERRES_AUTO_SEARCH_TYPE sr_search_type =
cpi->sf.hl_sf.superres_auto_search_type;
const int qthresh = (sr_search_type == SUPERRES_AUTO_SOLO) ? 128 : 0;
if (q <= qthresh) {
new_denom = SCALE_NUMERATOR; // Don't use superres.
} else {
if (sr_search_type == SUPERRES_AUTO_ALL) {
if (cpi->common.current_frame.frame_type == KEY_FRAME)
new_denom = superres_cfg->superres_kf_scale_denominator;
else
new_denom = superres_cfg->superres_scale_denominator;
} else {
new_denom = get_superres_denom_for_qindex(cpi, q, 1, 1);
}
}
break;
}
default: assert(0);
}
return new_denom;
}
static int dimension_is_ok(int orig_dim, int resized_dim, int denom) {
return (resized_dim * SCALE_NUMERATOR >= orig_dim * denom / 2);
}
static int dimensions_are_ok(int owidth, int oheight, size_params_type *rsz) {
// Only need to check the width, as scaling is horizontal only.
(void)oheight;
return dimension_is_ok(owidth, rsz->resize_width, rsz->superres_denom);
}
static int validate_size_scales(RESIZE_MODE resize_mode,
aom_superres_mode superres_mode, int owidth,
int oheight, size_params_type *rsz) {
if (dimensions_are_ok(owidth, oheight, rsz)) { // Nothing to do.
return 1;
}
// Calculate current resize scale.
int resize_denom =
AOMMAX(DIVIDE_AND_ROUND(owidth * SCALE_NUMERATOR, rsz->resize_width),
DIVIDE_AND_ROUND(oheight * SCALE_NUMERATOR, rsz->resize_height));
if (resize_mode != RESIZE_RANDOM && superres_mode == AOM_SUPERRES_RANDOM) {
// Alter superres scale as needed to enforce conformity.
rsz->superres_denom =
(2 * SCALE_NUMERATOR * SCALE_NUMERATOR) / resize_denom;
if (!dimensions_are_ok(owidth, oheight, rsz)) {
if (rsz->superres_denom > SCALE_NUMERATOR) --rsz->superres_denom;
}
} else if (resize_mode == RESIZE_RANDOM &&
superres_mode != AOM_SUPERRES_RANDOM) {
// Alter resize scale as needed to enforce conformity.
resize_denom =
(2 * SCALE_NUMERATOR * SCALE_NUMERATOR) / rsz->superres_denom;
rsz->resize_width = owidth;
rsz->resize_height = oheight;
av1_calculate_scaled_size(&rsz->resize_width, &rsz->resize_height,
resize_denom);
if (!dimensions_are_ok(owidth, oheight, rsz)) {
if (resize_denom > SCALE_NUMERATOR) {
--resize_denom;
rsz->resize_width = owidth;
rsz->resize_height = oheight;
av1_calculate_scaled_size(&rsz->resize_width, &rsz->resize_height,
resize_denom);
}
}
} else if (resize_mode == RESIZE_RANDOM &&
superres_mode == AOM_SUPERRES_RANDOM) {
// Alter both resize and superres scales as needed to enforce conformity.
do {
if (resize_denom > rsz->superres_denom)
--resize_denom;
else
--rsz->superres_denom;
rsz->resize_width = owidth;
rsz->resize_height = oheight;
av1_calculate_scaled_size(&rsz->resize_width, &rsz->resize_height,
resize_denom);
} while (!dimensions_are_ok(owidth, oheight, rsz) &&
(resize_denom > SCALE_NUMERATOR ||
rsz->superres_denom > SCALE_NUMERATOR));
} else { // We are allowed to alter neither resize scale nor superres
// scale.
return 0;
}
return dimensions_are_ok(owidth, oheight, rsz);
}
// Calculates resize and superres params for next frame
static size_params_type calculate_next_size_params(AV1_COMP *cpi) {
const AV1EncoderConfig *oxcf = &cpi->oxcf;
ResizePendingParams *resize_pending_params = &cpi->resize_pending_params;
const FrameDimensionCfg *const frm_dim_cfg = &oxcf->frm_dim_cfg;
size_params_type rsz = { frm_dim_cfg->width, frm_dim_cfg->height,
SCALE_NUMERATOR };
int resize_denom = SCALE_NUMERATOR;
if (has_no_stats_stage(cpi) && cpi->ppi->use_svc &&
(cpi->common.width != cpi->oxcf.frm_dim_cfg.width ||
cpi->common.height != cpi->oxcf.frm_dim_cfg.height)) {
rsz.resize_width = cpi->common.width;
rsz.resize_height = cpi->common.height;
return rsz;
}
if (is_stat_generation_stage(cpi)) return rsz;
if (resize_pending_params->width && resize_pending_params->height) {
rsz.resize_width = resize_pending_params->width;
rsz.resize_height = resize_pending_params->height;
resize_pending_params->width = resize_pending_params->height = 0;
if (oxcf->superres_cfg.superres_mode == AOM_SUPERRES_NONE) return rsz;
} else {
resize_denom = calculate_next_resize_scale(cpi);
rsz.resize_width = frm_dim_cfg->width;
rsz.resize_height = frm_dim_cfg->height;
av1_calculate_scaled_size(&rsz.resize_width, &rsz.resize_height,
resize_denom);
}
rsz.superres_denom = calculate_next_superres_scale(cpi);
if (!validate_size_scales(oxcf->resize_cfg.resize_mode, cpi->superres_mode,
frm_dim_cfg->width, frm_dim_cfg->height, &rsz))
assert(0 && "Invalid scale parameters");
return rsz;
}
static void setup_frame_size_from_params(AV1_COMP *cpi,
const size_params_type *rsz) {
int encode_width = rsz->resize_width;
int encode_height = rsz->resize_height;
AV1_COMMON *cm = &cpi->common;
cm->superres_upscaled_width = encode_width;
cm->superres_upscaled_height = encode_height;
cm->superres_scale_denominator = rsz->superres_denom;
av1_calculate_scaled_superres_size(&encode_width, &encode_height,
rsz->superres_denom);
av1_set_frame_size(cpi, encode_width, encode_height);
}
void av1_setup_frame_size(AV1_COMP *cpi) {
AV1_COMMON *cm = &cpi->common;
// Reset superres params from previous frame.
cm->superres_scale_denominator = SCALE_NUMERATOR;
const size_params_type rsz = calculate_next_size_params(cpi);
setup_frame_size_from_params(cpi, &rsz);
assert(av1_is_min_tile_width_satisfied(cm));
}
void av1_superres_post_encode(AV1_COMP *cpi) {
AV1_COMMON *cm = &cpi->common;
assert(cpi->oxcf.superres_cfg.enable_superres);
assert(!is_lossless_requested(&cpi->oxcf.rc_cfg));
assert(!cm->features.all_lossless);
av1_superres_upscale(cm, NULL, cpi->alloc_pyramid);
// If regular resizing is occurring the source will need to be downscaled to
// match the upscaled superres resolution. Otherwise the original source is
// used.
if (!av1_resize_scaled(cm)) {
cpi->source = cpi->unscaled_source;
if (cpi->last_source != NULL) cpi->last_source = cpi->unscaled_last_source;
} else {
assert(cpi->unscaled_source->y_crop_width != cm->superres_upscaled_width);
assert(cpi->unscaled_source->y_crop_height != cm->superres_upscaled_height);
// Do downscale. cm->(width|height) has been updated by
// av1_superres_upscale
cpi->source = realloc_and_scale_source(cpi, cm->superres_upscaled_width,
cm->superres_upscaled_height);
}
}