ref: f9eee0cfbe67bbe20cfa5b3c5627b1eec18eaed9
dir: /vp8/encoder/arm/neon/denoising_neon.c/
/*
* Copyright (c) 2012 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 <arm_neon.h>
#include "vp8/encoder/denoising.h"
#include "vpx_mem/vpx_mem.h"
#include "./vp8_rtcd.h"
/*
* The filter function was modified to reduce the computational complexity.
*
* Step 1:
* Instead of applying tap coefficients for each pixel, we calculated the
* pixel adjustments vs. pixel diff value ahead of time.
* adjustment = filtered_value - current_raw
* = (filter_coefficient * diff + 128) >> 8
* where
* filter_coefficient = (255 << 8) / (256 + ((abs_diff * 330) >> 3));
* filter_coefficient += filter_coefficient /
* (3 + motion_magnitude_adjustment);
* filter_coefficient is clamped to 0 ~ 255.
*
* Step 2:
* The adjustment vs. diff curve becomes flat very quick when diff increases.
* This allowed us to use only several levels to approximate the curve without
* changing the filtering algorithm too much.
* The adjustments were further corrected by checking the motion magnitude.
* The levels used are:
* diff level adjustment w/o adjustment w/
* motion correction motion correction
* [-255, -16] 3 -6 -7
* [-15, -8] 2 -4 -5
* [-7, -4] 1 -3 -4
* [-3, 3] 0 diff diff
* [4, 7] 1 3 4
* [8, 15] 2 4 5
* [16, 255] 3 6 7
*/
int vp8_denoiser_filter_neon(unsigned char *mc_running_avg_y,
int mc_running_avg_y_stride,
unsigned char *running_avg_y,
int running_avg_y_stride, unsigned char *sig,
int sig_stride, unsigned int motion_magnitude,
int increase_denoising) {
/* If motion_magnitude is small, making the denoiser more aggressive by
* increasing the adjustment for each level, level1 adjustment is
* increased, the deltas stay the same.
*/
int shift_inc =
(increase_denoising && motion_magnitude <= MOTION_MAGNITUDE_THRESHOLD)
? 1
: 0;
const uint8x16_t v_level1_adjustment = vmovq_n_u8(
(motion_magnitude <= MOTION_MAGNITUDE_THRESHOLD) ? 4 + shift_inc : 3);
const uint8x16_t v_delta_level_1_and_2 = vdupq_n_u8(1);
const uint8x16_t v_delta_level_2_and_3 = vdupq_n_u8(2);
const uint8x16_t v_level1_threshold = vmovq_n_u8(4 + shift_inc);
const uint8x16_t v_level2_threshold = vdupq_n_u8(8);
const uint8x16_t v_level3_threshold = vdupq_n_u8(16);
int64x2_t v_sum_diff_total = vdupq_n_s64(0);
/* Go over lines. */
int r;
for (r = 0; r < 16; ++r) {
/* Load inputs. */
const uint8x16_t v_sig = vld1q_u8(sig);
const uint8x16_t v_mc_running_avg_y = vld1q_u8(mc_running_avg_y);
/* Calculate absolute difference and sign masks. */
const uint8x16_t v_abs_diff = vabdq_u8(v_sig, v_mc_running_avg_y);
const uint8x16_t v_diff_pos_mask = vcltq_u8(v_sig, v_mc_running_avg_y);
const uint8x16_t v_diff_neg_mask = vcgtq_u8(v_sig, v_mc_running_avg_y);
/* Figure out which level that put us in. */
const uint8x16_t v_level1_mask = vcleq_u8(v_level1_threshold, v_abs_diff);
const uint8x16_t v_level2_mask = vcleq_u8(v_level2_threshold, v_abs_diff);
const uint8x16_t v_level3_mask = vcleq_u8(v_level3_threshold, v_abs_diff);
/* Calculate absolute adjustments for level 1, 2 and 3. */
const uint8x16_t v_level2_adjustment =
vandq_u8(v_level2_mask, v_delta_level_1_and_2);
const uint8x16_t v_level3_adjustment =
vandq_u8(v_level3_mask, v_delta_level_2_and_3);
const uint8x16_t v_level1and2_adjustment =
vaddq_u8(v_level1_adjustment, v_level2_adjustment);
const uint8x16_t v_level1and2and3_adjustment =
vaddq_u8(v_level1and2_adjustment, v_level3_adjustment);
/* Figure adjustment absolute value by selecting between the absolute
* difference if in level0 or the value for level 1, 2 and 3.
*/
const uint8x16_t v_abs_adjustment =
vbslq_u8(v_level1_mask, v_level1and2and3_adjustment, v_abs_diff);
/* Calculate positive and negative adjustments. Apply them to the signal
* and accumulate them. Adjustments are less than eight and the maximum
* sum of them (7 * 16) can fit in a signed char.
*/
const uint8x16_t v_pos_adjustment =
vandq_u8(v_diff_pos_mask, v_abs_adjustment);
const uint8x16_t v_neg_adjustment =
vandq_u8(v_diff_neg_mask, v_abs_adjustment);
uint8x16_t v_running_avg_y = vqaddq_u8(v_sig, v_pos_adjustment);
v_running_avg_y = vqsubq_u8(v_running_avg_y, v_neg_adjustment);
/* Store results. */
vst1q_u8(running_avg_y, v_running_avg_y);
/* Sum all the accumulators to have the sum of all pixel differences
* for this macroblock.
*/
{
const int8x16_t v_sum_diff =
vqsubq_s8(vreinterpretq_s8_u8(v_pos_adjustment),
vreinterpretq_s8_u8(v_neg_adjustment));
const int16x8_t fe_dc_ba_98_76_54_32_10 = vpaddlq_s8(v_sum_diff);
const int32x4_t fedc_ba98_7654_3210 =
vpaddlq_s16(fe_dc_ba_98_76_54_32_10);
const int64x2_t fedcba98_76543210 = vpaddlq_s32(fedc_ba98_7654_3210);
v_sum_diff_total = vqaddq_s64(v_sum_diff_total, fedcba98_76543210);
}
/* Update pointers for next iteration. */
sig += sig_stride;
mc_running_avg_y += mc_running_avg_y_stride;
running_avg_y += running_avg_y_stride;
}
/* Too much adjustments => copy block. */
{
int64x1_t x = vqadd_s64(vget_high_s64(v_sum_diff_total),
vget_low_s64(v_sum_diff_total));
int sum_diff = vget_lane_s32(vabs_s32(vreinterpret_s32_s64(x)), 0);
int sum_diff_thresh = SUM_DIFF_THRESHOLD;
if (increase_denoising) sum_diff_thresh = SUM_DIFF_THRESHOLD_HIGH;
if (sum_diff > sum_diff_thresh) {
// Before returning to copy the block (i.e., apply no denoising),
// checK if we can still apply some (weaker) temporal filtering to
// this block, that would otherwise not be denoised at all. Simplest
// is to apply an additional adjustment to running_avg_y to bring it
// closer to sig. The adjustment is capped by a maximum delta, and
// chosen such that in most cases the resulting sum_diff will be
// within the accceptable range given by sum_diff_thresh.
// The delta is set by the excess of absolute pixel diff over the
// threshold.
int delta = ((sum_diff - sum_diff_thresh) >> 8) + 1;
// Only apply the adjustment for max delta up to 3.
if (delta < 4) {
const uint8x16_t k_delta = vmovq_n_u8(delta);
sig -= sig_stride * 16;
mc_running_avg_y -= mc_running_avg_y_stride * 16;
running_avg_y -= running_avg_y_stride * 16;
for (r = 0; r < 16; ++r) {
uint8x16_t v_running_avg_y = vld1q_u8(running_avg_y);
const uint8x16_t v_sig = vld1q_u8(sig);
const uint8x16_t v_mc_running_avg_y = vld1q_u8(mc_running_avg_y);
/* Calculate absolute difference and sign masks. */
const uint8x16_t v_abs_diff = vabdq_u8(v_sig, v_mc_running_avg_y);
const uint8x16_t v_diff_pos_mask =
vcltq_u8(v_sig, v_mc_running_avg_y);
const uint8x16_t v_diff_neg_mask =
vcgtq_u8(v_sig, v_mc_running_avg_y);
// Clamp absolute difference to delta to get the adjustment.
const uint8x16_t v_abs_adjustment = vminq_u8(v_abs_diff, (k_delta));
const uint8x16_t v_pos_adjustment =
vandq_u8(v_diff_pos_mask, v_abs_adjustment);
const uint8x16_t v_neg_adjustment =
vandq_u8(v_diff_neg_mask, v_abs_adjustment);
v_running_avg_y = vqsubq_u8(v_running_avg_y, v_pos_adjustment);
v_running_avg_y = vqaddq_u8(v_running_avg_y, v_neg_adjustment);
/* Store results. */
vst1q_u8(running_avg_y, v_running_avg_y);
{
const int8x16_t v_sum_diff =
vqsubq_s8(vreinterpretq_s8_u8(v_neg_adjustment),
vreinterpretq_s8_u8(v_pos_adjustment));
const int16x8_t fe_dc_ba_98_76_54_32_10 = vpaddlq_s8(v_sum_diff);
const int32x4_t fedc_ba98_7654_3210 =
vpaddlq_s16(fe_dc_ba_98_76_54_32_10);
const int64x2_t fedcba98_76543210 =
vpaddlq_s32(fedc_ba98_7654_3210);
v_sum_diff_total = vqaddq_s64(v_sum_diff_total, fedcba98_76543210);
}
/* Update pointers for next iteration. */
sig += sig_stride;
mc_running_avg_y += mc_running_avg_y_stride;
running_avg_y += running_avg_y_stride;
}
{
// Update the sum of all pixel differences of this MB.
x = vqadd_s64(vget_high_s64(v_sum_diff_total),
vget_low_s64(v_sum_diff_total));
sum_diff = vget_lane_s32(vabs_s32(vreinterpret_s32_s64(x)), 0);
if (sum_diff > sum_diff_thresh) {
return COPY_BLOCK;
}
}
} else {
return COPY_BLOCK;
}
}
}
/* Tell above level that block was filtered. */
running_avg_y -= running_avg_y_stride * 16;
sig -= sig_stride * 16;
vp8_copy_mem16x16(running_avg_y, running_avg_y_stride, sig, sig_stride);
return FILTER_BLOCK;
}
int vp8_denoiser_filter_uv_neon(unsigned char *mc_running_avg,
int mc_running_avg_stride,
unsigned char *running_avg,
int running_avg_stride, unsigned char *sig,
int sig_stride, unsigned int motion_magnitude,
int increase_denoising) {
/* If motion_magnitude is small, making the denoiser more aggressive by
* increasing the adjustment for each level, level1 adjustment is
* increased, the deltas stay the same.
*/
int shift_inc =
(increase_denoising && motion_magnitude <= MOTION_MAGNITUDE_THRESHOLD_UV)
? 1
: 0;
const uint8x16_t v_level1_adjustment = vmovq_n_u8(
(motion_magnitude <= MOTION_MAGNITUDE_THRESHOLD_UV) ? 4 + shift_inc : 3);
const uint8x16_t v_delta_level_1_and_2 = vdupq_n_u8(1);
const uint8x16_t v_delta_level_2_and_3 = vdupq_n_u8(2);
const uint8x16_t v_level1_threshold = vmovq_n_u8(4 + shift_inc);
const uint8x16_t v_level2_threshold = vdupq_n_u8(8);
const uint8x16_t v_level3_threshold = vdupq_n_u8(16);
int64x2_t v_sum_diff_total = vdupq_n_s64(0);
int r;
{
uint16x4_t v_sum_block = vdup_n_u16(0);
// Avoid denoising color signal if its close to average level.
for (r = 0; r < 8; ++r) {
const uint8x8_t v_sig = vld1_u8(sig);
const uint16x4_t _76_54_32_10 = vpaddl_u8(v_sig);
v_sum_block = vqadd_u16(v_sum_block, _76_54_32_10);
sig += sig_stride;
}
sig -= sig_stride * 8;
{
const uint32x2_t _7654_3210 = vpaddl_u16(v_sum_block);
const uint64x1_t _76543210 = vpaddl_u32(_7654_3210);
const int sum_block = vget_lane_s32(vreinterpret_s32_u64(_76543210), 0);
if (abs(sum_block - (128 * 8 * 8)) < SUM_DIFF_FROM_AVG_THRESH_UV) {
return COPY_BLOCK;
}
}
}
/* Go over lines. */
for (r = 0; r < 4; ++r) {
/* Load inputs. */
const uint8x8_t v_sig_lo = vld1_u8(sig);
const uint8x8_t v_sig_hi = vld1_u8(&sig[sig_stride]);
const uint8x16_t v_sig = vcombine_u8(v_sig_lo, v_sig_hi);
const uint8x8_t v_mc_running_avg_lo = vld1_u8(mc_running_avg);
const uint8x8_t v_mc_running_avg_hi =
vld1_u8(&mc_running_avg[mc_running_avg_stride]);
const uint8x16_t v_mc_running_avg =
vcombine_u8(v_mc_running_avg_lo, v_mc_running_avg_hi);
/* Calculate absolute difference and sign masks. */
const uint8x16_t v_abs_diff = vabdq_u8(v_sig, v_mc_running_avg);
const uint8x16_t v_diff_pos_mask = vcltq_u8(v_sig, v_mc_running_avg);
const uint8x16_t v_diff_neg_mask = vcgtq_u8(v_sig, v_mc_running_avg);
/* Figure out which level that put us in. */
const uint8x16_t v_level1_mask = vcleq_u8(v_level1_threshold, v_abs_diff);
const uint8x16_t v_level2_mask = vcleq_u8(v_level2_threshold, v_abs_diff);
const uint8x16_t v_level3_mask = vcleq_u8(v_level3_threshold, v_abs_diff);
/* Calculate absolute adjustments for level 1, 2 and 3. */
const uint8x16_t v_level2_adjustment =
vandq_u8(v_level2_mask, v_delta_level_1_and_2);
const uint8x16_t v_level3_adjustment =
vandq_u8(v_level3_mask, v_delta_level_2_and_3);
const uint8x16_t v_level1and2_adjustment =
vaddq_u8(v_level1_adjustment, v_level2_adjustment);
const uint8x16_t v_level1and2and3_adjustment =
vaddq_u8(v_level1and2_adjustment, v_level3_adjustment);
/* Figure adjustment absolute value by selecting between the absolute
* difference if in level0 or the value for level 1, 2 and 3.
*/
const uint8x16_t v_abs_adjustment =
vbslq_u8(v_level1_mask, v_level1and2and3_adjustment, v_abs_diff);
/* Calculate positive and negative adjustments. Apply them to the signal
* and accumulate them. Adjustments are less than eight and the maximum
* sum of them (7 * 16) can fit in a signed char.
*/
const uint8x16_t v_pos_adjustment =
vandq_u8(v_diff_pos_mask, v_abs_adjustment);
const uint8x16_t v_neg_adjustment =
vandq_u8(v_diff_neg_mask, v_abs_adjustment);
uint8x16_t v_running_avg = vqaddq_u8(v_sig, v_pos_adjustment);
v_running_avg = vqsubq_u8(v_running_avg, v_neg_adjustment);
/* Store results. */
vst1_u8(running_avg, vget_low_u8(v_running_avg));
vst1_u8(&running_avg[running_avg_stride], vget_high_u8(v_running_avg));
/* Sum all the accumulators to have the sum of all pixel differences
* for this macroblock.
*/
{
const int8x16_t v_sum_diff =
vqsubq_s8(vreinterpretq_s8_u8(v_pos_adjustment),
vreinterpretq_s8_u8(v_neg_adjustment));
const int16x8_t fe_dc_ba_98_76_54_32_10 = vpaddlq_s8(v_sum_diff);
const int32x4_t fedc_ba98_7654_3210 =
vpaddlq_s16(fe_dc_ba_98_76_54_32_10);
const int64x2_t fedcba98_76543210 = vpaddlq_s32(fedc_ba98_7654_3210);
v_sum_diff_total = vqaddq_s64(v_sum_diff_total, fedcba98_76543210);
}
/* Update pointers for next iteration. */
sig += sig_stride * 2;
mc_running_avg += mc_running_avg_stride * 2;
running_avg += running_avg_stride * 2;
}
/* Too much adjustments => copy block. */
{
int64x1_t x = vqadd_s64(vget_high_s64(v_sum_diff_total),
vget_low_s64(v_sum_diff_total));
int sum_diff = vget_lane_s32(vabs_s32(vreinterpret_s32_s64(x)), 0);
int sum_diff_thresh = SUM_DIFF_THRESHOLD_UV;
if (increase_denoising) sum_diff_thresh = SUM_DIFF_THRESHOLD_HIGH_UV;
if (sum_diff > sum_diff_thresh) {
// Before returning to copy the block (i.e., apply no denoising),
// checK if we can still apply some (weaker) temporal filtering to
// this block, that would otherwise not be denoised at all. Simplest
// is to apply an additional adjustment to running_avg_y to bring it
// closer to sig. The adjustment is capped by a maximum delta, and
// chosen such that in most cases the resulting sum_diff will be
// within the accceptable range given by sum_diff_thresh.
// The delta is set by the excess of absolute pixel diff over the
// threshold.
int delta = ((sum_diff - sum_diff_thresh) >> 8) + 1;
// Only apply the adjustment for max delta up to 3.
if (delta < 4) {
const uint8x16_t k_delta = vmovq_n_u8(delta);
sig -= sig_stride * 8;
mc_running_avg -= mc_running_avg_stride * 8;
running_avg -= running_avg_stride * 8;
for (r = 0; r < 4; ++r) {
const uint8x8_t v_sig_lo = vld1_u8(sig);
const uint8x8_t v_sig_hi = vld1_u8(&sig[sig_stride]);
const uint8x16_t v_sig = vcombine_u8(v_sig_lo, v_sig_hi);
const uint8x8_t v_mc_running_avg_lo = vld1_u8(mc_running_avg);
const uint8x8_t v_mc_running_avg_hi =
vld1_u8(&mc_running_avg[mc_running_avg_stride]);
const uint8x16_t v_mc_running_avg =
vcombine_u8(v_mc_running_avg_lo, v_mc_running_avg_hi);
/* Calculate absolute difference and sign masks. */
const uint8x16_t v_abs_diff = vabdq_u8(v_sig, v_mc_running_avg);
const uint8x16_t v_diff_pos_mask = vcltq_u8(v_sig, v_mc_running_avg);
const uint8x16_t v_diff_neg_mask = vcgtq_u8(v_sig, v_mc_running_avg);
// Clamp absolute difference to delta to get the adjustment.
const uint8x16_t v_abs_adjustment = vminq_u8(v_abs_diff, (k_delta));
const uint8x16_t v_pos_adjustment =
vandq_u8(v_diff_pos_mask, v_abs_adjustment);
const uint8x16_t v_neg_adjustment =
vandq_u8(v_diff_neg_mask, v_abs_adjustment);
const uint8x8_t v_running_avg_lo = vld1_u8(running_avg);
const uint8x8_t v_running_avg_hi =
vld1_u8(&running_avg[running_avg_stride]);
uint8x16_t v_running_avg =
vcombine_u8(v_running_avg_lo, v_running_avg_hi);
v_running_avg = vqsubq_u8(v_running_avg, v_pos_adjustment);
v_running_avg = vqaddq_u8(v_running_avg, v_neg_adjustment);
/* Store results. */
vst1_u8(running_avg, vget_low_u8(v_running_avg));
vst1_u8(&running_avg[running_avg_stride],
vget_high_u8(v_running_avg));
{
const int8x16_t v_sum_diff =
vqsubq_s8(vreinterpretq_s8_u8(v_neg_adjustment),
vreinterpretq_s8_u8(v_pos_adjustment));
const int16x8_t fe_dc_ba_98_76_54_32_10 = vpaddlq_s8(v_sum_diff);
const int32x4_t fedc_ba98_7654_3210 =
vpaddlq_s16(fe_dc_ba_98_76_54_32_10);
const int64x2_t fedcba98_76543210 =
vpaddlq_s32(fedc_ba98_7654_3210);
v_sum_diff_total = vqaddq_s64(v_sum_diff_total, fedcba98_76543210);
}
/* Update pointers for next iteration. */
sig += sig_stride * 2;
mc_running_avg += mc_running_avg_stride * 2;
running_avg += running_avg_stride * 2;
}
{
// Update the sum of all pixel differences of this MB.
x = vqadd_s64(vget_high_s64(v_sum_diff_total),
vget_low_s64(v_sum_diff_total));
sum_diff = vget_lane_s32(vabs_s32(vreinterpret_s32_s64(x)), 0);
if (sum_diff > sum_diff_thresh) {
return COPY_BLOCK;
}
}
} else {
return COPY_BLOCK;
}
}
}
/* Tell above level that block was filtered. */
running_avg -= running_avg_stride * 8;
sig -= sig_stride * 8;
vp8_copy_mem8x8(running_avg, running_avg_stride, sig, sig_stride);
return FILTER_BLOCK;
}