ref: d162934bdca89b156194732226746993356344ef
parent: f4af1a9af48c972da1d5d8f04b84fed1017a25b5
author: Marco <marpan@chromium.org>
date: Fri Oct 16 12:14:22 EDT 2015
VP9: Estimate noise level for denoiser. Periodically estiamte noise level in source, and only denoise if estimated noise level is above threshold. Change-Id: I54f967b3003b0c14d0b1d3dc83cb82ce8cc2d381
--- a/vp9/encoder/vp9_denoiser.c
+++ b/vp9/encoder/vp9_denoiser.c
@@ -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 @@
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 @@
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,
@@ -499,14 +503,43 @@
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) {+ vp9_denoiser_free(denoiser);
+ return 1;
+ }
#ifdef OUTPUT_YUV_DENOISED
make_grayscale(&denoiser->running_avg_y[i]);
#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 @@
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
--- a/vp9/encoder/vp9_denoiser.h
+++ b/vp9/encoder/vp9_denoiser.h
@@ -29,10 +29,17 @@
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,
@@ -68,6 +75,12 @@
#endif
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"
--- a/vp9/encoder/vp9_encoder.c
+++ b/vp9/encoder/vp9_encoder.c
@@ -3250,6 +3250,13 @@
&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 &&