/* * Copyright (c) 2016, 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 <limits.h> #include <math.h> #include "av1/encoder/aq_complexity.h" #include "av1/encoder/aq_variance.h" #include "av1/encoder/encodeframe.h" #include "av1/common/seg_common.h" #include "av1/encoder/segmentation.h" #include "aom_dsp/aom_dsp_common.h" #include "aom_ports/system_state.h" #define AQ_C_SEGMENTS 5 #define DEFAULT_AQ2_SEG 3 // Neutral Q segment #define AQ_C_STRENGTHS 3 static const double aq_c_q_adj_factor[AQ_C_STRENGTHS][AQ_C_SEGMENTS] = { { 1.75, 1.25, 1.05, 1.00, 0.90 }, { 2.00, 1.50, 1.15, 1.00, 0.85 }, { 2.50, 1.75, 1.25, 1.00, 0.80 } }; static const double aq_c_transitions[AQ_C_STRENGTHS][AQ_C_SEGMENTS] = { { 0.15, 0.30, 0.55, 2.00, 100.0 }, { 0.20, 0.40, 0.65, 2.00, 100.0 }, { 0.25, 0.50, 0.75, 2.00, 100.0 } }; static const double aq_c_var_thresholds[AQ_C_STRENGTHS][AQ_C_SEGMENTS] = { { -4.0, -3.0, -2.0, 100.00, 100.0 }, { -3.5, -2.5, -1.5, 100.00, 100.0 }, { -3.0, -2.0, -1.0, 100.00, 100.0 } }; static int get_aq_c_strength(int q_index, aom_bit_depth_t bit_depth) { // Approximate base quatizer (truncated to int) const int base_quant = av1_ac_quant_Q3(q_index, 0, bit_depth) / 4; return (base_quant > 10) + (base_quant > 25); } void av1_setup_in_frame_q_adj(AV1_COMP *cpi) { AV1_COMMON *const cm = &cpi->common; struct segmentation *const seg = &cm->seg; int resolution_change = cm->prev_frame && (cm->width != cm->prev_frame->width || cm->height != cm->prev_frame->height); // Make SURE use of floating point in this function is safe. aom_clear_system_state(); if (resolution_change) { memset(cpi->segmentation_map, 0, cm->mi_rows * cm->mi_cols); av1_clearall_segfeatures(seg); av1_disable_segmentation(seg); return; } if (frame_is_intra_only(cm) || cm->error_resilient_mode || cpi->refresh_alt_ref_frame || (cpi->refresh_golden_frame && !cpi->rc.is_src_frame_alt_ref)) { int segment; const int aq_strength = get_aq_c_strength(cm->base_qindex, cm->seq_params.bit_depth); // Clear down the segment map. memset(cpi->segmentation_map, DEFAULT_AQ2_SEG, cm->mi_rows * cm->mi_cols); av1_clearall_segfeatures(seg); // Segmentation only makes sense if the target bits per SB is above a // threshold. Below this the overheads will usually outweigh any benefit. if (cpi->rc.sb64_target_rate < 256) { av1_disable_segmentation(seg); return; } av1_enable_segmentation(seg); // Default segment "Q" feature is disabled so it defaults to the baseline Q. av1_disable_segfeature(seg, DEFAULT_AQ2_SEG, SEG_LVL_ALT_Q); // Use some of the segments for in frame Q adjustment. for (segment = 0; segment < AQ_C_SEGMENTS; ++segment) { int qindex_delta; if (segment == DEFAULT_AQ2_SEG) continue; qindex_delta = av1_compute_qdelta_by_rate( &cpi->rc, cm->frame_type, cm->base_qindex, aq_c_q_adj_factor[aq_strength][segment], cm->seq_params.bit_depth); // For AQ complexity mode, we dont allow Q0 in a segment if the base // Q is not 0. Q0 (lossless) implies 4x4 only and in AQ mode 2 a segment // Q delta is sometimes applied without going back around the rd loop. // This could lead to an illegal combination of partition size and q. if ((cm->base_qindex != 0) && ((cm->base_qindex + qindex_delta) == 0)) { qindex_delta = -cm->base_qindex + 1; } if ((cm->base_qindex + qindex_delta) > 0) { av1_enable_segfeature(seg, segment, SEG_LVL_ALT_Q); av1_set_segdata(seg, segment, SEG_LVL_ALT_Q, qindex_delta); } } } } #define DEFAULT_LV_THRESH 10.0 #define MIN_DEFAULT_LV_THRESH 8.0 // Select a segment for the current block. // The choice of segment for a block depends on the ratio of the projected // bits for the block vs a target average and its spatial complexity. void av1_caq_select_segment(const AV1_COMP *cpi, MACROBLOCK *mb, BLOCK_SIZE bs, int mi_row, int mi_col, int projected_rate) { const AV1_COMMON *const cm = &cpi->common; const int num_planes = av1_num_planes(cm); const int mi_offset = mi_row * cm->mi_cols + mi_col; const int xmis = AOMMIN(cm->mi_cols - mi_col, mi_size_wide[bs]); const int ymis = AOMMIN(cm->mi_rows - mi_row, mi_size_high[bs]); int x, y; int i; unsigned char segment; if (0) { segment = DEFAULT_AQ2_SEG; } else { // Rate depends on fraction of a SB64 in frame (xmis * ymis / bw * bh). // It is converted to bits << AV1_PROB_COST_SHIFT units. const int64_t num = (int64_t)(cpi->rc.sb64_target_rate * xmis * ymis) << AV1_PROB_COST_SHIFT; const int denom = cm->seq_params.mib_size * cm->seq_params.mib_size; const int target_rate = (int)(num / denom); double logvar; double low_var_thresh; const int aq_strength = get_aq_c_strength(cm->base_qindex, cm->seq_params.bit_depth); aom_clear_system_state(); low_var_thresh = (cpi->oxcf.pass == 2) ? AOMMAX(exp(cpi->twopass.mb_av_energy), MIN_DEFAULT_LV_THRESH) : DEFAULT_LV_THRESH; av1_setup_src_planes(mb, cpi->source, mi_row, mi_col, num_planes); logvar = av1_log_block_var(cpi, mb, bs); segment = AQ_C_SEGMENTS - 1; // Just in case no break out below. for (i = 0; i < AQ_C_SEGMENTS; ++i) { // Test rate against a threshold value and variance against a threshold. // Increasing segment number (higher variance and complexity) = higher Q. if ((projected_rate < target_rate * aq_c_transitions[aq_strength][i]) && (logvar < (low_var_thresh + aq_c_var_thresholds[aq_strength][i]))) { segment = i; break; } } } // Fill in the entires in the segment map corresponding to this SB64. for (y = 0; y < ymis; y++) { for (x = 0; x < xmis; x++) { cpi->segmentation_map[mi_offset + y * cm->mi_cols + x] = segment; } } }