temporal_filter.h
/*
* 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.
*/
#ifndef AOM_AV1_ENCODER_TEMPORAL_FILTER_H_
#define AOM_AV1_ENCODER_TEMPORAL_FILTER_H_
#include <stdbool.h>
#include "aom_util/aom_pthread.h"
#ifdef __cplusplus
extern "C" {
#endif
struct AV1_COMP;
struct AV1EncoderConfig;
struct ThreadData;
// TODO(wtc): These two variables are only used in avx2, sse2, neon
// implementations, where the block size is still hard coded to TF_BLOCK_SIZE.
// This should be fixed to align with the c implementation.
#define BH 64
#define BW 64
// Block size used in temporal filtering.
#define TF_BLOCK_SIZE BLOCK_64X64
// Window size for temporal filtering.
#define TF_WINDOW_LENGTH 5
// Number of 16x16 blocks within one 64x64 TF block.
#define NUM_16X16 16
// A constant number, sqrt(pi / 2), used for noise estimation.
static const double SQRT_PI_BY_2 = 1.25331413732;
// Hyper-parameters used to compute filtering weight. These hyper-parameters can
// be tuned for a better performance.
// 0. A scale factor used in temporal filtering to raise the filter weight from
// `double` with range [0, 1] to `int` with range [0, 1000].
#define TF_WEIGHT_SCALE 1000
// 1. Weight factor used to balance the weighted-average between window error
// and block error. The weight is for window error while the weight for block
// error is always set as 1.
#define TF_WINDOW_BLOCK_BALANCE_WEIGHT 5
// 2. Threshold for using q to adjust the filtering weight. Concretely, when
// using a small q (high bitrate), we would like to reduce the filtering
// strength such that more detailed information can be preserved. Hence, when
// q is smaller than this threshold, we will adjust the filtering weight
// based on the q-value.
#define TF_Q_DECAY_THRESHOLD 20
// 3. Normalization factor used to normalize the motion search error. Since the
// motion search error can be large and uncontrollable, we will simply
// normalize it before using it to compute the filtering weight.
#define TF_SEARCH_ERROR_NORM_WEIGHT 20
// 4. Threshold for using `arnr_strength` to adjust the filtering strength.
// Concretely, users can use `arnr_strength` arguments to control the
// strength of temporal filtering. When `arnr_strength` is small enough (
// i.e., smaller than this threshold), we will adjust the filtering weight
// based on the strength value.
#define TF_STRENGTH_THRESHOLD 4
// 5. Threshold for using motion search distance to adjust the filtering weight.
// Concretely, larger motion search vector leads to a higher probability of
// unreliable search. Hence, we would like to reduce the filtering strength
// when the distance is large enough. Considering that the distance actually
// relies on the frame size, this threshold is also a resolution-based
// threshold. Taking 720p videos as an instance, if this field equals to 0.1,
// then the actual threshold will be 720 * 0.1 = 72. Similarly, the threshold
// for 360p videos will be 360 * 0.1 = 36.
#define TF_SEARCH_DISTANCE_THRESHOLD 0.1
// 6. Threshold to identify if the q is in a relative high range.
// Above this cutoff q, a stronger filtering is applied.
// For a high q, the quantization throws away more information, and thus a
// stronger filtering is less likely to distort the encoded quality, while a
// stronger filtering could reduce bit rates.
// Ror a low q, more details are expected to be retained. Filtering is thus
// more conservative.
#define TF_QINDEX_CUTOFF 128
#define NOISE_ESTIMATION_EDGE_THRESHOLD 50
// Sum and SSE source vs filtered frame difference returned by
// temporal filter.
typedef struct {
int64_t sum;
int64_t sse;
} FRAME_DIFF;
typedef struct {
YV12_BUFFER_CONFIG *frames[MAX_LAG_BUFFERS];
int num_frames;
YV12_BUFFER_CONFIG *output_frame;
int filter_frame_idx;
int compute_frame_diff;
struct scale_factors sf;
double noise_levels[MAX_MB_PLANE];
int num_pels;
int mb_rows;
int mb_cols;
int is_highbitdepth;
int q_factor;
} TemporalFilterCtx;
#define TF_INFO_BUF_COUNT 2
typedef struct TEMPORAL_FILTER_INFO {
int is_temporal_filter_on;
YV12_BUFFER_CONFIG tf_buf[TF_INFO_BUF_COUNT];
YV12_BUFFER_CONFIG tf_buf_second_arf;
FRAME_DIFF frame_diff[TF_INFO_BUF_COUNT];
int tf_buf_gf_index[TF_INFO_BUF_COUNT];
int tf_buf_display_index_offset[TF_INFO_BUF_COUNT];
int tf_buf_valid[TF_INFO_BUF_COUNT];
} TEMPORAL_FILTER_INFO;
int av1_is_temporal_filter_on(const struct AV1EncoderConfig *oxcf);
bool av1_tf_info_alloc(TEMPORAL_FILTER_INFO *tf_info,
const struct AV1_COMP *cpi);
void av1_tf_info_free(TEMPORAL_FILTER_INFO *tf_info);
void av1_tf_info_reset(TEMPORAL_FILTER_INFO *tf_info);
void av1_tf_info_filtering(TEMPORAL_FILTER_INFO *tf_info, struct AV1_COMP *cpi,
const GF_GROUP *gf_group);
YV12_BUFFER_CONFIG *av1_tf_info_get_filtered_buf(TEMPORAL_FILTER_INFO *tf_info,
int gf_index,
FRAME_DIFF *frame_diff);
// Data related to temporal filtering.
typedef struct {
// Source vs filtered frame error.
FRAME_DIFF diff;
// Pointer to temporary block info used to store state in temporal filtering
// process.
MB_MODE_INFO *tmp_mbmi;
// Pointer to accumulator buffer used in temporal filtering process.
uint32_t *accum;
// Pointer to count buffer used in temporal filtering process.
uint16_t *count;
// Pointer to predictor used in temporal filtering process.
uint8_t *pred;
} TemporalFilterData;
// Data related to temporal filter multi-thread synchronization.
typedef struct {
#if CONFIG_MULTITHREAD
// Mutex lock used for dispatching jobs.
pthread_mutex_t *mutex_;
#endif // CONFIG_MULTITHREAD
// Next temporal filter block row to be filtered.
int next_tf_row;
// Initialized to false, set to true by the worker thread that encounters an
// error in order to abort the processing of other worker threads.
bool tf_mt_exit;
} AV1TemporalFilterSync;
// Estimates noise level from a given frame using a single plane (Y, U, or V).
// This is an adaptation of the mehtod in the following paper:
// Shen-Chuan Tai, Shih-Ming Yang, "A fast method for image noise
// estimation using Laplacian operator and adaptive edge detection",
// Proc. 3rd International Symposium on Communications, Control and
// Signal Processing, 2008, St Julians, Malta.
// Inputs:
// frame: Pointer to the frame to estimate noise level from.
// noise_level: Pointer to store the estimated noise.
// plane_from: Index of the starting plane used for noise estimation.
// Commonly, 0 for Y-plane, 1 for U-plane, and 2 for V-plane.
// plane_to: Index of the end plane used for noise estimation.
// bit_depth: Actual bit-depth instead of the encoding bit-depth of the frame.
// edge_thresh: Edge threshold.
void av1_estimate_noise_level(const YV12_BUFFER_CONFIG *frame,
double *noise_level, int plane_from, int plane_to,
int bit_depth, int edge_thresh);
void av1_tf_do_filtering_row(struct AV1_COMP *cpi, struct ThreadData *td,
int mb_row);
void av1_temporal_filter(struct AV1_COMP *cpi,
const int filter_frame_lookahead_idx,
int gf_frame_index, FRAME_DIFF *frame_diff,
YV12_BUFFER_CONFIG *output_frame);
int av1_check_show_filtered_frame(const YV12_BUFFER_CONFIG *frame,
const FRAME_DIFF *frame_diff, int q_index,
aom_bit_depth_t bit_depth, int enable_overlay,
int is_second_arf);
// Allocates memory for members of TemporalFilterData.
// Inputs:
// tf_data: Pointer to the structure containing temporal filter related data.
// num_pels: Number of pixels in the block across all planes.
// is_high_bitdepth: Whether the frame is high-bitdepth or not.
// Returns:
// True if allocation is successful and false otherwise.
static inline bool tf_alloc_and_reset_data(TemporalFilterData *tf_data,
int num_pels, int is_high_bitdepth) {
tf_data->tmp_mbmi = (MB_MODE_INFO *)aom_calloc(1, sizeof(*tf_data->tmp_mbmi));
tf_data->accum =
(uint32_t *)aom_memalign(16, num_pels * sizeof(*tf_data->accum));
tf_data->count =
(uint16_t *)aom_memalign(16, num_pels * sizeof(*tf_data->count));
if (is_high_bitdepth)
tf_data->pred = CONVERT_TO_BYTEPTR(
aom_memalign(32, num_pels * 2 * sizeof(*tf_data->pred)));
else
tf_data->pred =
(uint8_t *)aom_memalign(32, num_pels * sizeof(*tf_data->pred));
// In case of an allocation failure, other successfully allocated buffers will
// be freed by the tf_dealloc_data() call in encoder_destroy().
if (!(tf_data->tmp_mbmi && tf_data->accum && tf_data->count && tf_data->pred))
return false;
memset(&tf_data->diff, 0, sizeof(tf_data->diff));
return true;
}
// Setup macroblockd params for temporal filtering process.
// Inputs:
// mbd: Pointer to the block for filtering.
// tf_data: Pointer to the structure containing temporal filter related data.
// scale: Scaling factor.
// Returns:
// Nothing will be returned. Contents of mbd will be modified.
static inline void tf_setup_macroblockd(MACROBLOCKD *mbd,
TemporalFilterData *tf_data,
const struct scale_factors *scale) {
mbd->block_ref_scale_factors[0] = scale;
mbd->block_ref_scale_factors[1] = scale;
mbd->mi = &tf_data->tmp_mbmi;
mbd->mi[0]->motion_mode = SIMPLE_TRANSLATION;
}
// Deallocates the memory allocated for members of TemporalFilterData.
// Inputs:
// tf_data: Pointer to the structure containing temporal filter related data.
// is_high_bitdepth: Whether the frame is high-bitdepth or not.
// Returns:
// Nothing will be returned.
static inline void tf_dealloc_data(TemporalFilterData *tf_data,
int is_high_bitdepth) {
if (is_high_bitdepth)
tf_data->pred = (uint8_t *)CONVERT_TO_SHORTPTR(tf_data->pred);
aom_free(tf_data->tmp_mbmi);
tf_data->tmp_mbmi = NULL;
aom_free(tf_data->accum);
tf_data->accum = NULL;
aom_free(tf_data->count);
tf_data->count = NULL;
aom_free(tf_data->pred);
tf_data->pred = NULL;
}
// Saves the state prior to temporal filter process.
// Inputs:
// mbd: Pointer to the block for filtering.
// input_mbmi: Backup block info to save input state.
// input_buffer: Backup buffer pointer to save input state.
// num_planes: Number of planes.
// Returns:
// Nothing will be returned. Contents of input_mbmi and input_buffer will be
// modified.
static inline void tf_save_state(MACROBLOCKD *mbd, MB_MODE_INFO ***input_mbmi,
uint8_t **input_buffer, int num_planes) {
for (int i = 0; i < num_planes; i++) {
input_buffer[i] = mbd->plane[i].pre[0].buf;
}
*input_mbmi = mbd->mi;
}
// Restores the initial state after temporal filter process.
// Inputs:
// mbd: Pointer to the block for filtering.
// input_mbmi: Backup block info from where input state is restored.
// input_buffer: Backup buffer pointer from where input state is restored.
// num_planes: Number of planes.
// Returns:
// Nothing will be returned. Contents of mbd will be modified.
static inline void tf_restore_state(MACROBLOCKD *mbd, MB_MODE_INFO **input_mbmi,
uint8_t **input_buffer, int num_planes) {
for (int i = 0; i < num_planes; i++) {
mbd->plane[i].pre[0].buf = input_buffer[i];
}
mbd->mi = input_mbmi;
}
#ifdef __cplusplus
} // extern "C"
#endif
#endif // AOM_AV1_ENCODER_TEMPORAL_FILTER_H_
aom_bit_depth_t
enum aom_bit_depth aom_bit_depth_t
Bit depth for codecThis enumeration determines the bit depth of the codec.
av1_temporal_filter
void av1_temporal_filter(struct AV1_COMP *cpi, const int filter_frame_lookahead_idx, int gf_frame_index, FRAME_DIFF *frame_diff, YV12_BUFFER_CONFIG *output_frame)
Performs temporal filtering if needed on a source frame. For example to create a filtered alternate r...
av1_check_show_filtered_frame
int av1_check_show_filtered_frame(const YV12_BUFFER_CONFIG *frame, const FRAME_DIFF *frame_diff, int q_index, aom_bit_depth_t bit_depth, int enable_overlay, int is_second_arf)
Check whether a filtered frame can be show directly.
av1_tf_do_filtering_row
void av1_tf_do_filtering_row(struct AV1_COMP *cpi, struct ThreadData *td, int mb_row)
Does temporal filter for a given macroblock row.
Definition temporal_filter.c:1034
AV1EncoderConfig
Main encoder configuration data structure.
Definition encoder.h:934
AV1_COMP
Top level encoder structure.
Definition encoder.h:2897
GF_GROUP
Data related to the current GF/ARF group and the individual frames within the group.
Definition firstpass.h:343
MB_MODE_INFO
Stores the prediction/txfm mode of the current coding block.
Definition blockd.h:222
MB_MODE_INFO::motion_mode
MOTION_MODE motion_mode
The motion mode used by the inter prediction.
Definition blockd.h:250
TEMPORAL_FILTER_INFO
Temporal filter info for a gop.
Definition temporal_filter.h:164
TEMPORAL_FILTER_INFO::tf_buf_display_index_offset
int tf_buf_display_index_offset[2]
Definition temporal_filter.h:195
TEMPORAL_FILTER_INFO::tf_buf
YV12_BUFFER_CONFIG tf_buf[2]
Definition temporal_filter.h:175
TEMPORAL_FILTER_INFO::tf_buf_gf_index
int tf_buf_gf_index[2]
Definition temporal_filter.h:191
TEMPORAL_FILTER_INFO::frame_diff
FRAME_DIFF frame_diff[2]
Definition temporal_filter.h:187
TEMPORAL_FILTER_INFO::is_temporal_filter_on
int is_temporal_filter_on
Definition temporal_filter.h:170
TEMPORAL_FILTER_INFO::tf_buf_valid
int tf_buf_valid[2]
Definition temporal_filter.h:199
TEMPORAL_FILTER_INFO::tf_buf_second_arf
YV12_BUFFER_CONFIG tf_buf_second_arf
Definition temporal_filter.h:183
TemporalFilterCtx
Parameters related to temporal filtering.
Definition temporal_filter.h:101
TemporalFilterCtx::sf
struct scale_factors sf
Definition temporal_filter.h:127
TemporalFilterCtx::output_frame
YV12_BUFFER_CONFIG * output_frame
Definition temporal_filter.h:114
TemporalFilterCtx::q_factor
int q_factor
Definition temporal_filter.h:151
TemporalFilterCtx::num_pels
int num_pels
Definition temporal_filter.h:135
TemporalFilterCtx::num_frames
int num_frames
Definition temporal_filter.h:109
TemporalFilterCtx::compute_frame_diff
int compute_frame_diff
Definition temporal_filter.h:123
TemporalFilterCtx::mb_rows
int mb_rows
Definition temporal_filter.h:139
TemporalFilterCtx::mb_cols
int mb_cols
Definition temporal_filter.h:143
TemporalFilterCtx::noise_levels
double noise_levels[MAX_MB_PLANE]
Definition temporal_filter.h:131
TemporalFilterCtx::is_highbitdepth
int is_highbitdepth
Definition temporal_filter.h:147
TemporalFilterCtx::filter_frame_idx
int filter_frame_idx
Definition temporal_filter.h:119
TemporalFilterCtx::frames
YV12_BUFFER_CONFIG * frames[MAX_LAG_BUFFERS]
Definition temporal_filter.h:105
macroblockd::plane
struct macroblockd_plane plane[3]
Definition blockd.h:606
macroblockd::block_ref_scale_factors
const struct scale_factors * block_ref_scale_factors[2]
Definition blockd.h:687
macroblockd::mi
MB_MODE_INFO ** mi
Definition blockd.h:617