diff options
Diffstat (limited to 'media/libvpx/libvpx/vp9/encoder/vp9_noise_estimate.c')
| -rw-r--r-- | media/libvpx/libvpx/vp9/encoder/vp9_noise_estimate.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/media/libvpx/libvpx/vp9/encoder/vp9_noise_estimate.c b/media/libvpx/libvpx/vp9/encoder/vp9_noise_estimate.c new file mode 100644 index 0000000000..9696529c50 --- /dev/null +++ b/media/libvpx/libvpx/vp9/encoder/vp9_noise_estimate.c @@ -0,0 +1,302 @@ +/* + * Copyright (c) 2015 The WebM project authors. All Rights Reserved. + * + * Use of this source code is governed by a BSD-style license + * that can be found in the LICENSE file in the root of the source + * tree. An additional intellectual property rights grant can be found + * in the file PATENTS. All contributing project authors may + * be found in the AUTHORS file in the root of the source tree. + */ + +#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" +#include "vpx/vpx_integer.h" +#include "vp9/common/vp9_reconinter.h" +#include "vp9/encoder/vp9_context_tree.h" +#include "vp9/encoder/vp9_noise_estimate.h" +#include "vp9/encoder/vp9_encoder.h" + +#if CONFIG_VP9_TEMPORAL_DENOISING +// For SVC: only do noise estimation on top spatial layer. +static INLINE int noise_est_svc(const struct VP9_COMP *const cpi) { + return (!cpi->use_svc || + (cpi->use_svc && + cpi->svc.spatial_layer_id == cpi->svc.number_spatial_layers - 1)); +} +#endif + +void vp9_noise_estimate_init(NOISE_ESTIMATE *const ne, int width, int height) { + ne->enabled = 0; + ne->level = (width * height < 1280 * 720) ? kLowLow : kLow; + ne->value = 0; + ne->count = 0; + ne->thresh = 90; + ne->last_w = 0; + ne->last_h = 0; + if (width * height >= 1920 * 1080) { + ne->thresh = 200; + } else if (width * height >= 1280 * 720) { + ne->thresh = 140; + } else if (width * height >= 640 * 360) { + ne->thresh = 115; + } + ne->num_frames_estimate = 15; + ne->adapt_thresh = (3 * ne->thresh) >> 1; +} + +static int enable_noise_estimation(VP9_COMP *const cpi) { +#if CONFIG_VP9_HIGHBITDEPTH + if (cpi->common.use_highbitdepth) return 0; +#endif +// Enable noise estimation if denoising is on. +#if CONFIG_VP9_TEMPORAL_DENOISING + if (cpi->oxcf.noise_sensitivity > 0 && noise_est_svc(cpi) && + cpi->common.width >= 320 && cpi->common.height >= 180) + return 1; +#endif + // Only allow noise estimate under certain encoding mode. + // Enabled for 1 pass CBR, speed >=5, and if resolution is same as original. + // Not enabled for SVC mode and screen_content_mode. + // Not enabled for low resolutions. + if (cpi->oxcf.pass == 0 && cpi->oxcf.rc_mode == VPX_CBR && + cpi->oxcf.aq_mode == CYCLIC_REFRESH_AQ && cpi->oxcf.speed >= 5 && + cpi->resize_state == ORIG && cpi->resize_pending == 0 && !cpi->use_svc && + cpi->oxcf.content != VP9E_CONTENT_SCREEN && + cpi->common.width * cpi->common.height >= 640 * 360) + return 1; + else + return 0; +} + +#if CONFIG_VP9_TEMPORAL_DENOISING +static void copy_frame(YV12_BUFFER_CONFIG *const dest, + const YV12_BUFFER_CONFIG *const src) { + int r; + const uint8_t *srcbuf = src->y_buffer; + uint8_t *destbuf = dest->y_buffer; + + assert(dest->y_width == src->y_width); + assert(dest->y_height == src->y_height); + + for (r = 0; r < dest->y_height; ++r) { + memcpy(destbuf, srcbuf, dest->y_width); + destbuf += dest->y_stride; + srcbuf += src->y_stride; + } +} +#endif // CONFIG_VP9_TEMPORAL_DENOISING + +NOISE_LEVEL vp9_noise_estimate_extract_level(NOISE_ESTIMATE *const ne) { + int noise_level = kLowLow; + if (ne->value > (ne->thresh << 1)) { + noise_level = kHigh; + } else { + if (ne->value > ne->thresh) + noise_level = kMedium; + else if (ne->value > (ne->thresh >> 1)) + noise_level = kLow; + else + noise_level = kLowLow; + } + return noise_level; +} + +void vp9_update_noise_estimate(VP9_COMP *const cpi) { + const VP9_COMMON *const cm = &cpi->common; + NOISE_ESTIMATE *const ne = &cpi->noise_estimate; + const int low_res = (cm->width <= 352 && cm->height <= 288); + // Estimate of noise level every frame_period frames. + int frame_period = 8; + int thresh_consec_zeromv = 6; + int frame_counter = cm->current_video_frame; + // Estimate is between current source and last source. + YV12_BUFFER_CONFIG *last_source = cpi->Last_Source; +#if CONFIG_VP9_TEMPORAL_DENOISING + if (cpi->oxcf.noise_sensitivity > 0 && noise_est_svc(cpi)) { + last_source = &cpi->denoiser.last_source; + // Tune these thresholds for different resolutions when denoising is + // enabled. + if (cm->width > 640 && cm->width <= 1920) { + thresh_consec_zeromv = 2; + } + } +#endif + ne->enabled = enable_noise_estimation(cpi); + if (cpi->svc.number_spatial_layers > 1) + frame_counter = cpi->svc.current_superframe; + if (!ne->enabled || frame_counter % frame_period != 0 || + last_source == NULL || + (cpi->svc.number_spatial_layers == 1 && + (ne->last_w != cm->width || ne->last_h != cm->height))) { +#if CONFIG_VP9_TEMPORAL_DENOISING + if (cpi->oxcf.noise_sensitivity > 0 && noise_est_svc(cpi)) + copy_frame(&cpi->denoiser.last_source, cpi->Source); +#endif + if (last_source != NULL) { + ne->last_w = cm->width; + ne->last_h = cm->height; + } + return; + } else if (frame_counter > 60 && cpi->svc.num_encoded_top_layer > 1 && + cpi->rc.frames_since_key > cpi->svc.number_spatial_layers && + cpi->svc.spatial_layer_id == cpi->svc.number_spatial_layers - 1 && + cpi->rc.avg_frame_low_motion < (low_res ? 60 : 40)) { + // Force noise estimation to 0 and denoiser off if content has high motion. + ne->level = kLowLow; + ne->count = 0; + ne->num_frames_estimate = 10; +#if CONFIG_VP9_TEMPORAL_DENOISING + if (cpi->oxcf.noise_sensitivity > 0 && noise_est_svc(cpi) && + cpi->svc.current_superframe > 1) { + vp9_denoiser_set_noise_level(cpi, ne->level); + copy_frame(&cpi->denoiser.last_source, cpi->Source); + } +#endif + return; + } else { + unsigned int bin_size = 100; + unsigned int hist[MAX_VAR_HIST_BINS] = { 0 }; + unsigned int hist_avg[MAX_VAR_HIST_BINS]; + unsigned int max_bin = 0; + unsigned int max_bin_count = 0; + unsigned int bin_cnt; + int bsize = BLOCK_16X16; + // 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 = last_source->y_buffer; + const int last_src_ystride = 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; + int mi_row, mi_col; + int num_low_motion = 0; + int frame_low_motion = 1; + for (mi_row = 0; mi_row < cm->mi_rows; mi_row++) { + for (mi_col = 0; mi_col < cm->mi_cols; mi_col++) { + int bl_index = mi_row * cm->mi_cols + mi_col; + if (cpi->consec_zero_mv[bl_index] > thresh_consec_zeromv) + num_low_motion++; + } + } + if (num_low_motion < ((3 * cm->mi_rows * cm->mi_cols) >> 3)) + frame_low_motion = 0; + 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 && mi_row < cm->mi_rows - 1 && + mi_col < cm->mi_cols - 1) { + 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; + int consec_zeromv = + VPXMIN(cpi->consec_zero_mv[bl_index], + VPXMIN(cpi->consec_zero_mv[bl_index1], + VPXMIN(cpi->consec_zero_mv[bl_index2], + cpi->consec_zero_mv[bl_index3]))); + // 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. And exclude this frame if + // high_source_sad is true (i.e., scene/content change). + if (frame_low_motion && consec_zeromv > thresh_consec_zeromv && + !cpi->rc.high_source_sad && + !cpi->svc.high_source_sad_superframe) { + int is_skin = 0; + if (cpi->use_skin_detection) { + is_skin = + vp9_compute_skin_block(src_y, src_u, src_v, src_ystride, + src_uvstride, bsize, consec_zeromv, 0); + } + if (!is_skin) { + unsigned int sse; + // Compute variance between co-located blocks from current and + // last input frames. + unsigned int variance = cpi->fn_ptr[bsize].vf( + src_y, src_ystride, last_src_y, last_src_ystride, &sse); + unsigned int hist_index = variance / bin_size; + if (hist_index < MAX_VAR_HIST_BINS) + hist[hist_index]++; + else if (hist_index < 3 * (MAX_VAR_HIST_BINS >> 1)) + hist[MAX_VAR_HIST_BINS - 1]++; // Account for the tail + } + } + } + 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); + } + ne->last_w = cm->width; + ne->last_h = cm->height; + // Adjust histogram to account for effect that histogram flattens + // and shifts to zero as scene darkens. + if (hist[0] > 10 && (hist[MAX_VAR_HIST_BINS - 1] > hist[0] >> 2)) { + hist[0] = 0; + hist[1] >>= 2; + hist[2] >>= 2; + hist[3] >>= 2; + hist[4] >>= 1; + hist[5] >>= 1; + hist[6] = 3 * hist[6] >> 1; + hist[MAX_VAR_HIST_BINS - 1] >>= 1; + } + + // Average hist[] and find largest bin + for (bin_cnt = 0; bin_cnt < MAX_VAR_HIST_BINS; bin_cnt++) { + if (bin_cnt == 0) + hist_avg[bin_cnt] = (hist[0] + hist[1] + hist[2]) / 3; + else if (bin_cnt == MAX_VAR_HIST_BINS - 1) + hist_avg[bin_cnt] = hist[MAX_VAR_HIST_BINS - 1] >> 2; + else if (bin_cnt == MAX_VAR_HIST_BINS - 2) + hist_avg[bin_cnt] = (hist[bin_cnt - 1] + 2 * hist[bin_cnt] + + (hist[bin_cnt + 1] >> 1) + 2) >> + 2; + else + hist_avg[bin_cnt] = + (hist[bin_cnt - 1] + 2 * hist[bin_cnt] + hist[bin_cnt + 1] + 2) >> + 2; + + if (hist_avg[bin_cnt] > max_bin_count) { + max_bin_count = hist_avg[bin_cnt]; + max_bin = bin_cnt; + } + } + + // Scale by 40 to work with existing thresholds + ne->value = (int)((3 * ne->value + max_bin * 40) >> 2); + // Quickly increase VNR strength when the noise level increases suddenly. + if (ne->level < kMedium && ne->value > ne->adapt_thresh) { + ne->count = ne->num_frames_estimate; + } else { + ne->count++; + } + if (ne->count == ne->num_frames_estimate) { + // Reset counter and check noise level condition. + ne->num_frames_estimate = 30; + ne->count = 0; + ne->level = vp9_noise_estimate_extract_level(ne); +#if CONFIG_VP9_TEMPORAL_DENOISING + if (cpi->oxcf.noise_sensitivity > 0 && noise_est_svc(cpi)) + vp9_denoiser_set_noise_level(cpi, ne->level); +#endif + } + } +#if CONFIG_VP9_TEMPORAL_DENOISING + if (cpi->oxcf.noise_sensitivity > 0 && noise_est_svc(cpi)) + copy_frame(&cpi->denoiser.last_source, cpi->Source); +#endif +} |