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VP9: Estimate noise level for denoiser.

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Periodically estiamte noise level in source, and only denoise
if estimated noise level is above threshold.

Change-Id: I54f967b3003b0c14d0b1d3dc83cb82ce8cc2d381
This commit is contained in:
Marco 2015-10-16 16:14:22 -07:00
parent f4af1a9af4
commit d162934bdc
3 changed files with 173 additions and 6 deletions
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159
vp9/encoder/vp9_denoiser.c
View File

@ -10,6 +10,8 @@
#include <assert.h>
#include <limits.h>
#include <math.h>
#include "./vpx_dsp_rtcd.h"
#include "vpx_dsp/vpx_dsp_common.h"
#include "vpx_scale/yv12config.h"
@ -17,6 +19,7 @@
#include "vp9/common/vp9_reconinter.h"
#include "vp9/encoder/vp9_context_tree.h"
#include "vp9/encoder/vp9_denoiser.h"
#include "vp9/encoder/vp9_encoder.h"
/* The VP9 denoiser is a work-in-progress. It currently is only designed to work
* with speed 6, though it (inexplicably) seems to also work with speed 5 (one
@ -325,7 +328,7 @@ void vp9_denoiser_denoise(VP9_DENOISER *denoiser, MACROBLOCK *mb,
struct buf_2d src = mb->plane[0].src;
int is_skin = 0;
if (bs <= BLOCK_16X16) {
if (bs <= BLOCK_16X16 && !denoiser->no_denoising) {
// Take center pixel in block to determine is_skin.
const int y_width_shift = (4 << b_width_log2_lookup[bs]) >> 1;
const int y_height_shift = (4 << b_height_log2_lookup[bs]) >> 1;
@ -342,11 +345,12 @@ void vp9_denoiser_denoise(VP9_DENOISER *denoiser, MACROBLOCK *mb,
is_skin = vp9_skin_pixel(ysource, usource, vsource);
}
decision = perform_motion_compensation(denoiser, mb, bs,
denoiser->increase_denoising,
mi_row, mi_col, ctx,
&motion_magnitude,
is_skin);
if (!denoiser->no_denoising)
decision = perform_motion_compensation(denoiser, mb, bs,
denoiser->increase_denoising,
mi_row, mi_col, ctx,
&motion_magnitude,
is_skin);
if (decision == FILTER_BLOCK) {
decision = vp9_denoiser_filter(src.buf, src.stride,
@ -493,6 +497,17 @@ int vp9_denoiser_alloc(VP9_DENOISER *denoiser, int width, int height,
ssx, ssy,
#if CONFIG_VP9_HIGHBITDEPTH
use_highbitdepth,
#endif
border, legacy_byte_alignment);
if (fail) {
vp9_denoiser_free(denoiser);
return 1;
}
fail = vpx_alloc_frame_buffer(&denoiser->last_source, width, height,
ssx, ssy,
#if CONFIG_VP9_HIGHBITDEPTH
use_highbitdepth,
#endif
border, legacy_byte_alignment);
if (fail) {
@ -504,9 +519,27 @@ int vp9_denoiser_alloc(VP9_DENOISER *denoiser, int width, int height,
#endif
denoiser->increase_denoising = 0;
denoiser->frame_buffer_initialized = 1;
vp9_denoiser_init_noise_estimate(denoiser, width, height);
return 0;
}
void vp9_denoiser_init_noise_estimate(VP9_DENOISER *denoiser,
int width,
int height) {
// Denoiser is off by default, i.e., no denoising is performed.
// Noise level is measured periodically, and if observed to be above
// thresh_noise_estimate, then denoising is performed, i.e., no_denoising = 0.
denoiser->no_denoising = 1;
denoiser->noise_estimate = 0;
denoiser->noise_estimate_count = 0;
denoiser->thresh_noise_estimate = 20;
if (width * height >= 1920 * 1080) {
denoiser->thresh_noise_estimate = 70;
} else if (width * height >= 1280 * 720) {
denoiser->thresh_noise_estimate = 40;
}
}
void vp9_denoiser_free(VP9_DENOISER *denoiser) {
int i;
denoiser->frame_buffer_initialized = 0;
@ -517,6 +550,120 @@ void vp9_denoiser_free(VP9_DENOISER *denoiser) {
vpx_free_frame_buffer(&denoiser->running_avg_y[i]);
}
vpx_free_frame_buffer(&denoiser->mc_running_avg_y);
vpx_free_frame_buffer(&denoiser->last_source);
}
void vp9_denoiser_update_noise_estimate(VP9_COMP *const cpi) {
const VP9_COMMON *const cm = &cpi->common;
CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
int frame_period = 10;
int thresh_consec_zeromv = 8;
unsigned int thresh_sum_diff = 128;
int num_frames_estimate = 20;
int min_blocks_estimate = cm->mi_rows * cm->mi_cols >> 7;
// Estimate of noise level every frame_period frames.
// Estimate is between current source and last source.
if (cm->current_video_frame % frame_period != 0 ||
cpi->denoiser.last_source.y_buffer == NULL) {
copy_frame(&cpi->denoiser.last_source, cpi->Source);
return;
} else {
int num_samples = 0;
uint64_t avg_est = 0;
int bsize = BLOCK_16X16;
static const unsigned char const_source[16] = {
128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
128, 128};
// Loop over sub-sample of 16x16 blocks of frame, and for blocks that have
// been encoded as zero/small mv at least x consecutive frames, compute
// the variance to update estimate of noise in the source.
const uint8_t *src_y = cpi->Source->y_buffer;
const int src_ystride = cpi->Source->y_stride;
const uint8_t *last_src_y = cpi->denoiser.last_source.y_buffer;
const int last_src_ystride = cpi->denoiser.last_source.y_stride;
const uint8_t *src_u = cpi->Source->u_buffer;
const uint8_t *src_v = cpi->Source->v_buffer;
const int src_uvstride = cpi->Source->uv_stride;
const int y_width_shift = (4 << b_width_log2_lookup[bsize]) >> 1;
const int y_height_shift = (4 << b_height_log2_lookup[bsize]) >> 1;
const int uv_width_shift = y_width_shift >> 1;
const int uv_height_shift = y_height_shift >> 1;
int mi_row, mi_col;
for (mi_row = 0; mi_row < cm->mi_rows; mi_row ++) {
for (mi_col = 0; mi_col < cm->mi_cols; mi_col ++) {
// 16x16 blocks, 1/4 sample of frame.
if (mi_row % 4 == 0 && mi_col % 4 == 0) {
int bl_index = mi_row * cm->mi_cols + mi_col;
int bl_index1 = bl_index + 1;
int bl_index2 = bl_index + cm->mi_cols;
int bl_index3 = bl_index2 + 1;
// Only consider blocks that are likely steady background. i.e, have
// been encoded as zero/low motion x (= thresh_consec_zeromv) frames
// in a row. consec_zero_mv[] defined for 8x8 blocks, so consider all
// 4 sub-blocks for 16x16 block. Also, avoid skin blocks.
const uint8_t ysource =
src_y[y_height_shift * src_ystride + y_width_shift];
const uint8_t usource =
src_u[uv_height_shift * src_uvstride + uv_width_shift];
const uint8_t vsource =
src_v[uv_height_shift * src_uvstride + uv_width_shift];
int is_skin = vp9_skin_pixel(ysource, usource, vsource);
if (cr->consec_zero_mv[bl_index] > thresh_consec_zeromv &&
cr->consec_zero_mv[bl_index1] > thresh_consec_zeromv &&
cr->consec_zero_mv[bl_index2] > thresh_consec_zeromv &&
cr->consec_zero_mv[bl_index3] > thresh_consec_zeromv &&
!is_skin) {
// Compute variance.
unsigned int sse;
unsigned int variance = cpi->fn_ptr[bsize].vf(src_y,
src_ystride,
last_src_y,
last_src_ystride,
&sse);
// Only consider this block as valid for noise measurement if the
// average term (sse - variance = N * avg^{2}, N = 16X16) of the
// temporal residual is small (avoid effects from lighting change).
if ((sse - variance) < thresh_sum_diff) {
unsigned int sse2;
const unsigned int spatial_variance =
cpi->fn_ptr[bsize].vf(src_y, src_ystride, const_source,
0, &sse2);
avg_est += variance / (10 + spatial_variance);
num_samples++;
}
}
}
src_y += 8;
last_src_y += 8;
src_u += 4;
src_v += 4;
}
src_y += (src_ystride << 3) - (cm->mi_cols << 3);
last_src_y += (last_src_ystride << 3) - (cm->mi_cols << 3);
src_u += (src_uvstride << 2) - (cm->mi_cols << 2);
src_v += (src_uvstride << 2) - (cm->mi_cols << 2);
}
// Update noise estimate if we have at a minimum number of block samples,
// and avg_est > 0 (avg_est == 0 can happen if the application inputs
// duplicate frames).
if (num_samples > min_blocks_estimate && avg_est > 0) {
// Normalize.
avg_est = (avg_est << 8) / num_samples;
// Update noise estimate.
cpi->denoiser.noise_estimate = (3 * cpi->denoiser.noise_estimate +
avg_est) >> 2;
cpi->denoiser.noise_estimate_count++;
if (cpi->denoiser.noise_estimate_count == num_frames_estimate) {
// Reset counter and check noise level condition.
cpi->denoiser.noise_estimate_count = 0;
if (cpi->denoiser.noise_estimate > cpi->denoiser.thresh_noise_estimate)
cpi->denoiser.no_denoising = 0;
else
cpi->denoiser.no_denoising = 1;
}
}
}
copy_frame(&cpi->denoiser.last_source, cpi->Source);
}
#ifdef OUTPUT_YUV_DENOISED

13
vp9/encoder/vp9_denoiser.h
View File

@ -29,10 +29,17 @@ typedef enum vp9_denoiser_decision {
typedef struct vp9_denoiser {
YV12_BUFFER_CONFIG running_avg_y[MAX_REF_FRAMES];
YV12_BUFFER_CONFIG mc_running_avg_y;
YV12_BUFFER_CONFIG last_source;
int increase_denoising;
int frame_buffer_initialized;
int no_denoising;
int noise_estimate;
int thresh_noise_estimate;
int noise_estimate_count;
} VP9_DENOISER;
struct VP9_COMP;
void vp9_denoiser_update_frame_info(VP9_DENOISER *denoiser,
YV12_BUFFER_CONFIG src,
FRAME_TYPE frame_type,
@ -69,6 +76,12 @@ static int total_adj_strong_thresh(BLOCK_SIZE bs, int increase_denoising) {
void vp9_denoiser_free(VP9_DENOISER *denoiser);
void vp9_denoiser_init_noise_estimate(VP9_DENOISER *denoiser,
int width,
int height);
void vp9_denoiser_update_noise_estimate(struct VP9_COMP *const cpi);
#ifdef __cplusplus
} // extern "C"
#endif

7
vp9/encoder/vp9_encoder.c
View File

@ -3250,6 +3250,13 @@ static void encode_without_recode_loop(VP9_COMP *cpi,
&cpi->scaled_last_source,
(cpi->oxcf.pass == 0));
#if CONFIG_VP9_TEMPORAL_DENOISING
if (cpi->oxcf.noise_sensitivity > 0 &&
cpi->oxcf.aq_mode == CYCLIC_REFRESH_AQ) {
vp9_denoiser_update_noise_estimate(cpi);
}
#endif
if (cpi->oxcf.pass == 0 &&
cpi->oxcf.rc_mode == VPX_CBR &&
cpi->resize_state == 0 &&