ref: d9ca52452bff9481ec1ed4684985a86fb7fc3c3e
dir: /vp8/common/mfqe.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.
*/
/* MFQE: Multiframe Quality Enhancement
* In rate limited situations keyframes may cause significant visual artifacts
* commonly referred to as "popping." This file implements a postproccesing
* algorithm which blends data from the preceeding frame when there is no
* motion and the q from the previous frame is lower which indicates that it is
* higher quality.
*/
#include "postproc.h"
#include "variance.h"
#include "vpx_mem/vpx_mem.h"
#include "vpx_rtcd.h"
#include "vpx_scale/yv12config.h"
#include <limits.h>
#include <stdlib.h>
static void filter_by_weight(unsigned char *src, int src_stride,
unsigned char *dst, int dst_stride,
int block_size, int src_weight)
{
int dst_weight = (1 << MFQE_PRECISION) - src_weight;
int rounding_bit = 1 << (MFQE_PRECISION - 1);
int r, c;
for (r = 0; r < block_size; r++)
{
for (c = 0; c < block_size; c++)
{
dst[c] = (src[c] * src_weight +
dst[c] * dst_weight +
rounding_bit) >> MFQE_PRECISION;
}
src += src_stride;
dst += dst_stride;
}
}
void vp8_filter_by_weight16x16_c(unsigned char *src, int src_stride,
unsigned char *dst, int dst_stride,
int src_weight)
{
filter_by_weight(src, src_stride, dst, dst_stride, 16, src_weight);
}
void vp8_filter_by_weight8x8_c(unsigned char *src, int src_stride,
unsigned char *dst, int dst_stride,
int src_weight)
{
filter_by_weight(src, src_stride, dst, dst_stride, 8, src_weight);
}
void vp8_filter_by_weight4x4_c(unsigned char *src, int src_stride,
unsigned char *dst, int dst_stride,
int src_weight)
{
filter_by_weight(src, src_stride, dst, dst_stride, 4, src_weight);
}
static void apply_ifactor(unsigned char *y_src,
int y_src_stride,
unsigned char *y_dst,
int y_dst_stride,
unsigned char *u_src,
unsigned char *v_src,
int uv_src_stride,
unsigned char *u_dst,
unsigned char *v_dst,
int uv_dst_stride,
int block_size,
int src_weight)
{
if (block_size == 16)
{
vp8_filter_by_weight16x16(y_src, y_src_stride, y_dst, y_dst_stride, src_weight);
vp8_filter_by_weight8x8(u_src, uv_src_stride, u_dst, uv_dst_stride, src_weight);
vp8_filter_by_weight8x8(v_src, uv_src_stride, v_dst, uv_dst_stride, src_weight);
}
else /* if (block_size == 8) */
{
vp8_filter_by_weight8x8(y_src, y_src_stride, y_dst, y_dst_stride, src_weight);
vp8_filter_by_weight4x4(u_src, uv_src_stride, u_dst, uv_dst_stride, src_weight);
vp8_filter_by_weight4x4(v_src, uv_src_stride, v_dst, uv_dst_stride, src_weight);
}
}
static void multiframe_quality_enhance_block
(
int blksize, /* Currently only values supported are 16 and 8 */
int qcurr,
int qprev,
unsigned char *y,
unsigned char *u,
unsigned char *v,
int y_stride,
int uv_stride,
unsigned char *yd,
unsigned char *ud,
unsigned char *vd,
int yd_stride,
int uvd_stride
)
{
static const unsigned char VP8_ZEROS[16]=
{
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
};
int uvblksize = blksize >> 1;
int qdiff = qcurr - qprev;
int i;
unsigned char *up;
unsigned char *udp;
unsigned char *vp;
unsigned char *vdp;
unsigned int act, sad, thr, sse;
if (blksize == 16)
{
act = (vp8_variance16x16(yd, yd_stride, VP8_ZEROS, 0, &sse)+128)>>8;
sad = (vp8_sad16x16(y, y_stride, yd, yd_stride, INT_MAX)+128)>>8;
}
else /* if (blksize == 8) */
{
act = (vp8_variance8x8(yd, yd_stride, VP8_ZEROS, 0, &sse)+32)>>6;
sad = (vp8_sad8x8(y, y_stride, yd, yd_stride, INT_MAX)+32)>>6;
}
/* thr = qdiff/8 + log2(act) + log4(qprev) */
thr = (qdiff>>3);
while (act>>=1) thr++;
while (qprev>>=2) thr++;
if (sad < thr)
{
int ifactor = (sad << MFQE_PRECISION) / thr;
ifactor >>= (qdiff >> 5);
if (ifactor)
{
apply_ifactor(y, y_stride, yd, yd_stride,
u, v, uv_stride,
ud, vd, uvd_stride,
blksize, ifactor);
}
/* else implicitly copy from previous frame */
}
else
{
if (blksize == 16)
{
vp8_copy_mem16x16(y, y_stride, yd, yd_stride);
vp8_copy_mem8x8(u, uv_stride, ud, uvd_stride);
vp8_copy_mem8x8(v, uv_stride, vd, uvd_stride);
}
else /* if (blksize == 8) */
{
vp8_copy_mem8x8(y, y_stride, yd, yd_stride);
for (up = u, udp = ud, i = 0; i < uvblksize; ++i, up += uv_stride, udp += uvd_stride)
vpx_memcpy(udp, up, uvblksize);
for (vp = v, vdp = vd, i = 0; i < uvblksize; ++i, vp += uv_stride, vdp += uvd_stride)
vpx_memcpy(vdp, vp, uvblksize);
}
}
}
void vp8_multiframe_quality_enhance
(
VP8_COMMON *cm
)
{
YV12_BUFFER_CONFIG *show = cm->frame_to_show;
YV12_BUFFER_CONFIG *dest = &cm->post_proc_buffer;
FRAME_TYPE frame_type = cm->frame_type;
/* Point at base of Mb MODE_INFO list has motion vectors etc */
const MODE_INFO *mode_info_context = cm->mi;
int mb_row;
int mb_col;
int qcurr = cm->base_qindex;
int qprev = cm->postproc_state.last_base_qindex;
unsigned char *y_ptr, *u_ptr, *v_ptr;
unsigned char *yd_ptr, *ud_ptr, *vd_ptr;
/* Set up the buffer pointers */
y_ptr = show->y_buffer;
u_ptr = show->u_buffer;
v_ptr = show->v_buffer;
yd_ptr = dest->y_buffer;
ud_ptr = dest->u_buffer;
vd_ptr = dest->v_buffer;
/* postprocess each macro block */
for (mb_row = 0; mb_row < cm->mb_rows; mb_row++)
{
for (mb_col = 0; mb_col < cm->mb_cols; mb_col++)
{
/* if motion is high there will likely be no benefit */
if (((frame_type == INTER_FRAME &&
abs(mode_info_context->mbmi.mv.as_mv.row) <= 10 &&
abs(mode_info_context->mbmi.mv.as_mv.col) <= 10) ||
(frame_type == KEY_FRAME)))
{
if (mode_info_context->mbmi.mode == B_PRED || mode_info_context->mbmi.mode == SPLITMV)
{
int i, j;
for (i=0; i<2; ++i)
for (j=0; j<2; ++j)
multiframe_quality_enhance_block(8, qcurr, qprev,
y_ptr + 8*(i*show->y_stride+j),
u_ptr + 4*(i*show->uv_stride+j),
v_ptr + 4*(i*show->uv_stride+j),
show->y_stride,
show->uv_stride,
yd_ptr + 8*(i*dest->y_stride+j),
ud_ptr + 4*(i*dest->uv_stride+j),
vd_ptr + 4*(i*dest->uv_stride+j),
dest->y_stride,
dest->uv_stride);
}
else
{
multiframe_quality_enhance_block(16, qcurr, qprev, y_ptr,
u_ptr, v_ptr,
show->y_stride,
show->uv_stride,
yd_ptr, ud_ptr, vd_ptr,
dest->y_stride,
dest->uv_stride);
}
}
else
{
vp8_copy_mem16x16(y_ptr, show->y_stride, yd_ptr, dest->y_stride);
vp8_copy_mem8x8(u_ptr, show->uv_stride, ud_ptr, dest->uv_stride);
vp8_copy_mem8x8(v_ptr, show->uv_stride, vd_ptr, dest->uv_stride);
}
y_ptr += 16;
u_ptr += 8;
v_ptr += 8;
yd_ptr += 16;
ud_ptr += 8;
vd_ptr += 8;
mode_info_context++; /* step to next MB */
}
y_ptr += show->y_stride * 16 - 16 * cm->mb_cols;
u_ptr += show->uv_stride * 8 - 8 * cm->mb_cols;
v_ptr += show->uv_stride * 8 - 8 * cm->mb_cols;
yd_ptr += dest->y_stride * 16 - 16 * cm->mb_cols;
ud_ptr += dest->uv_stride * 8 - 8 * cm->mb_cols;
vd_ptr += dest->uv_stride * 8 - 8 * cm->mb_cols;
mode_info_context++; /* Skip border mb */
}
}