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Diffstat (limited to 'media/libaom/src/av1/encoder/aq_complexity.c')
| -rw-r--r-- | media/libaom/src/av1/encoder/aq_complexity.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/media/libaom/src/av1/encoder/aq_complexity.c b/media/libaom/src/av1/encoder/aq_complexity.c new file mode 100644 index 000000000..80f8e2e66 --- /dev/null +++ b/media/libaom/src/av1/encoder/aq_complexity.c @@ -0,0 +1,172 @@ +/* + * 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; + } + } +} |