ref: 656f9c41260c376a6e34e6fef6d586f8ebeae325
dir: /vp8/encoder/picklpf.c/
/*
* Copyright (c) 2010 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 "./vpx_dsp_rtcd.h"
#include "./vpx_scale_rtcd.h"
#include "vp8/common/onyxc_int.h"
#include "onyx_int.h"
#include "vp8/encoder/quantize.h"
#include "vpx_mem/vpx_mem.h"
#include "vpx_scale/vpx_scale.h"
#include "vp8/common/alloccommon.h"
#include "vp8/common/loopfilter.h"
#if ARCH_ARM
#include "vpx_ports/arm.h"
#endif
extern int vp8_calc_ss_err(YV12_BUFFER_CONFIG *source, YV12_BUFFER_CONFIG *dest);
static void yv12_copy_partial_frame(YV12_BUFFER_CONFIG *src_ybc,
YV12_BUFFER_CONFIG *dst_ybc)
{
unsigned char *src_y, *dst_y;
int yheight;
int ystride;
int yoffset;
int linestocopy;
yheight = src_ybc->y_height;
ystride = src_ybc->y_stride;
/* number of MB rows to use in partial filtering */
linestocopy = (yheight >> 4) / PARTIAL_FRAME_FRACTION;
linestocopy = linestocopy ? linestocopy << 4 : 16; /* 16 lines per MB */
/* Copy extra 4 so that full filter context is available if filtering done
* on the copied partial frame and not original. Partial filter does mb
* filtering for top row also, which can modify3 pixels above.
*/
linestocopy += 4;
/* partial image starts at ~middle of frame (macroblock border)*/
yoffset = ystride * (((yheight >> 5) * 16) - 4);
src_y = src_ybc->y_buffer + yoffset;
dst_y = dst_ybc->y_buffer + yoffset;
memcpy(dst_y, src_y, ystride * linestocopy);
}
static int calc_partial_ssl_err(YV12_BUFFER_CONFIG *source,
YV12_BUFFER_CONFIG *dest)
{
int i, j;
int Total = 0;
int srcoffset, dstoffset;
unsigned char *src = source->y_buffer;
unsigned char *dst = dest->y_buffer;
int linestocopy;
/* number of MB rows to use in partial filtering */
linestocopy = (source->y_height >> 4) / PARTIAL_FRAME_FRACTION;
linestocopy = linestocopy ? linestocopy << 4 : 16; /* 16 lines per MB */
/* partial image starts at ~middle of frame (macroblock border)*/
srcoffset = source->y_stride * ((dest->y_height >> 5) * 16);
dstoffset = dest->y_stride * ((dest->y_height >> 5) * 16);
src += srcoffset;
dst += dstoffset;
/* Loop through the Y plane raw and reconstruction data summing
* (square differences)
*/
for (i = 0; i < linestocopy; i += 16)
{
for (j = 0; j < source->y_width; j += 16)
{
unsigned int sse;
Total += vpx_mse16x16(src + j, source->y_stride,
dst + j, dest->y_stride,
&sse);
}
src += 16 * source->y_stride;
dst += 16 * dest->y_stride;
}
return Total;
}
/* Enforce a minimum filter level based upon baseline Q */
static int get_min_filter_level(VP8_COMP *cpi, int base_qindex)
{
int min_filter_level;
if (cpi->source_alt_ref_active && cpi->common.refresh_golden_frame &&
!cpi->common.refresh_alt_ref_frame)
min_filter_level = 0;
else
{
if (base_qindex <= 6)
min_filter_level = 0;
else if (base_qindex <= 16)
min_filter_level = 1;
else
min_filter_level = (base_qindex / 8);
}
return min_filter_level;
}
/* Enforce a maximum filter level based upon baseline Q */
static int get_max_filter_level(VP8_COMP *cpi, int base_qindex)
{
/* PGW August 2006: Highest filter values almost always a bad idea */
/* jbb chg: 20100118 - not so any more with this overquant stuff allow
* high values with lots of intra coming in.
*/
int max_filter_level = MAX_LOOP_FILTER;
(void)base_qindex;
if (cpi->twopass.section_intra_rating > 8)
max_filter_level = MAX_LOOP_FILTER * 3 / 4;
return max_filter_level;
}
void vp8cx_pick_filter_level_fast(YV12_BUFFER_CONFIG *sd, VP8_COMP *cpi)
{
VP8_COMMON *cm = &cpi->common;
int best_err = 0;
int filt_err = 0;
int min_filter_level = get_min_filter_level(cpi, cm->base_qindex);
int max_filter_level = get_max_filter_level(cpi, cm->base_qindex);
int filt_val;
int best_filt_val;
YV12_BUFFER_CONFIG * saved_frame = cm->frame_to_show;
/* Replace unfiltered frame buffer with a new one */
cm->frame_to_show = &cpi->pick_lf_lvl_frame;
if (cm->frame_type == KEY_FRAME)
cm->sharpness_level = 0;
else
cm->sharpness_level = cpi->oxcf.Sharpness;
if (cm->sharpness_level != cm->last_sharpness_level)
{
vp8_loop_filter_update_sharpness(&cm->lf_info, cm->sharpness_level);
cm->last_sharpness_level = cm->sharpness_level;
}
/* Start the search at the previous frame filter level unless it is
* now out of range.
*/
if (cm->filter_level < min_filter_level)
cm->filter_level = min_filter_level;
else if (cm->filter_level > max_filter_level)
cm->filter_level = max_filter_level;
filt_val = cm->filter_level;
best_filt_val = filt_val;
/* Get the err using the previous frame's filter value. */
/* Copy the unfiltered / processed recon buffer to the new buffer */
yv12_copy_partial_frame(saved_frame, cm->frame_to_show);
vp8_loop_filter_partial_frame(cm, &cpi->mb.e_mbd, filt_val);
best_err = calc_partial_ssl_err(sd, cm->frame_to_show);
filt_val -= 1 + (filt_val > 10);
/* Search lower filter levels */
while (filt_val >= min_filter_level)
{
/* Apply the loop filter */
yv12_copy_partial_frame(saved_frame, cm->frame_to_show);
vp8_loop_filter_partial_frame(cm, &cpi->mb.e_mbd, filt_val);
/* Get the err for filtered frame */
filt_err = calc_partial_ssl_err(sd, cm->frame_to_show);
/* Update the best case record or exit loop. */
if (filt_err < best_err)
{
best_err = filt_err;
best_filt_val = filt_val;
}
else
break;
/* Adjust filter level */
filt_val -= 1 + (filt_val > 10);
}
/* Search up (note that we have already done filt_val = cm->filter_level) */
filt_val = cm->filter_level + 1 + (filt_val > 10);
if (best_filt_val == cm->filter_level)
{
/* Resist raising filter level for very small gains */
best_err -= (best_err >> 10);
while (filt_val < max_filter_level)
{
/* Apply the loop filter */
yv12_copy_partial_frame(saved_frame, cm->frame_to_show);
vp8_loop_filter_partial_frame(cm, &cpi->mb.e_mbd, filt_val);
/* Get the err for filtered frame */
filt_err = calc_partial_ssl_err(sd, cm->frame_to_show);
/* Update the best case record or exit loop. */
if (filt_err < best_err)
{
/* Do not raise filter level if improvement is < 1 part
* in 4096
*/
best_err = filt_err - (filt_err >> 10);
best_filt_val = filt_val;
}
else
break;
/* Adjust filter level */
filt_val += 1 + (filt_val > 10);
}
}
cm->filter_level = best_filt_val;
if (cm->filter_level < min_filter_level)
cm->filter_level = min_filter_level;
if (cm->filter_level > max_filter_level)
cm->filter_level = max_filter_level;
/* restore unfiltered frame pointer */
cm->frame_to_show = saved_frame;
}
/* Stub function for now Alt LF not used */
void vp8cx_set_alt_lf_level(VP8_COMP *cpi, int filt_val)
{
MACROBLOCKD *mbd = &cpi->mb.e_mbd;
(void) filt_val;
mbd->segment_feature_data[MB_LVL_ALT_LF][0] = cpi->segment_feature_data[MB_LVL_ALT_LF][0];
mbd->segment_feature_data[MB_LVL_ALT_LF][1] = cpi->segment_feature_data[MB_LVL_ALT_LF][1];
mbd->segment_feature_data[MB_LVL_ALT_LF][2] = cpi->segment_feature_data[MB_LVL_ALT_LF][2];
mbd->segment_feature_data[MB_LVL_ALT_LF][3] = cpi->segment_feature_data[MB_LVL_ALT_LF][3];
}
void vp8cx_pick_filter_level(YV12_BUFFER_CONFIG *sd, VP8_COMP *cpi)
{
VP8_COMMON *cm = &cpi->common;
int best_err = 0;
int filt_err = 0;
int min_filter_level = get_min_filter_level(cpi, cm->base_qindex);
int max_filter_level = get_max_filter_level(cpi, cm->base_qindex);
int filter_step;
int filt_high = 0;
int filt_mid;
int filt_low = 0;
int filt_best;
int filt_direction = 0;
/* Bias against raising loop filter and in favor of lowering it */
int Bias = 0;
int ss_err[MAX_LOOP_FILTER + 1];
YV12_BUFFER_CONFIG * saved_frame = cm->frame_to_show;
memset(ss_err, 0, sizeof(ss_err));
/* Replace unfiltered frame buffer with a new one */
cm->frame_to_show = &cpi->pick_lf_lvl_frame;
if (cm->frame_type == KEY_FRAME)
cm->sharpness_level = 0;
else
cm->sharpness_level = cpi->oxcf.Sharpness;
/* Start the search at the previous frame filter level unless it is
* now out of range.
*/
filt_mid = cm->filter_level;
if (filt_mid < min_filter_level)
filt_mid = min_filter_level;
else if (filt_mid > max_filter_level)
filt_mid = max_filter_level;
/* Define the initial step size */
filter_step = (filt_mid < 16) ? 4 : filt_mid / 4;
/* Get baseline error score */
/* Copy the unfiltered / processed recon buffer to the new buffer */
vpx_yv12_copy_y(saved_frame, cm->frame_to_show);
vp8cx_set_alt_lf_level(cpi, filt_mid);
vp8_loop_filter_frame_yonly(cm, &cpi->mb.e_mbd, filt_mid);
best_err = vp8_calc_ss_err(sd, cm->frame_to_show);
ss_err[filt_mid] = best_err;
filt_best = filt_mid;
while (filter_step > 0)
{
Bias = (best_err >> (15 - (filt_mid / 8))) * filter_step;
if (cpi->twopass.section_intra_rating < 20)
Bias = Bias * cpi->twopass.section_intra_rating / 20;
filt_high = ((filt_mid + filter_step) > max_filter_level) ? max_filter_level : (filt_mid + filter_step);
filt_low = ((filt_mid - filter_step) < min_filter_level) ? min_filter_level : (filt_mid - filter_step);
if ((filt_direction <= 0) && (filt_low != filt_mid))
{
if(ss_err[filt_low] == 0)
{
/* Get Low filter error score */
vpx_yv12_copy_y(saved_frame, cm->frame_to_show);
vp8cx_set_alt_lf_level(cpi, filt_low);
vp8_loop_filter_frame_yonly(cm, &cpi->mb.e_mbd, filt_low);
filt_err = vp8_calc_ss_err(sd, cm->frame_to_show);
ss_err[filt_low] = filt_err;
}
else
filt_err = ss_err[filt_low];
/* If value is close to the best so far then bias towards a
* lower loop filter value.
*/
if ((filt_err - Bias) < best_err)
{
/* Was it actually better than the previous best? */
if (filt_err < best_err)
best_err = filt_err;
filt_best = filt_low;
}
}
/* Now look at filt_high */
if ((filt_direction >= 0) && (filt_high != filt_mid))
{
if(ss_err[filt_high] == 0)
{
vpx_yv12_copy_y(saved_frame, cm->frame_to_show);
vp8cx_set_alt_lf_level(cpi, filt_high);
vp8_loop_filter_frame_yonly(cm, &cpi->mb.e_mbd, filt_high);
filt_err = vp8_calc_ss_err(sd, cm->frame_to_show);
ss_err[filt_high] = filt_err;
}
else
filt_err = ss_err[filt_high];
/* Was it better than the previous best? */
if (filt_err < (best_err - Bias))
{
best_err = filt_err;
filt_best = filt_high;
}
}
/* Half the step distance if the best filter value was the same
* as last time
*/
if (filt_best == filt_mid)
{
filter_step = filter_step / 2;
filt_direction = 0;
}
else
{
filt_direction = (filt_best < filt_mid) ? -1 : 1;
filt_mid = filt_best;
}
}
cm->filter_level = filt_best;
/* restore unfiltered frame pointer */
cm->frame_to_show = saved_frame;
}