ref: 68d79146ea791783ac7d89dcdbef8c11a93d2b12
dir: /vp9/common/vp9_convolve.c/
/*
* Copyright (c) 2013 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 "./vpx_config.h"
#include "./vp9_rtcd.h"
#include "vp9/common/vp9_common.h"
#include "vp9/common/vp9_convolve.h"
#include "vp9/common/vp9_filter.h"
#include "vpx/vpx_integer.h"
#include "vpx_ports/mem.h"
static void convolve_horiz(const uint8_t *src, ptrdiff_t src_stride,
uint8_t *dst, ptrdiff_t dst_stride,
const InterpKernel *x_filters,
int x0_q4, int x_step_q4, int w, int h) {
int x, y;
src -= SUBPEL_TAPS / 2 - 1;
for (y = 0; y < h; ++y) {
int x_q4 = x0_q4;
for (x = 0; x < w; ++x) {
const uint8_t *const src_x = &src[x_q4 >> SUBPEL_BITS];
const int16_t *const x_filter = x_filters[x_q4 & SUBPEL_MASK];
int k, sum = 0;
for (k = 0; k < SUBPEL_TAPS; ++k)
sum += src_x[k] * x_filter[k];
dst[x] = clip_pixel(ROUND_POWER_OF_TWO(sum, FILTER_BITS));
x_q4 += x_step_q4;
}
src += src_stride;
dst += dst_stride;
}
}
static void convolve_avg_horiz(const uint8_t *src, ptrdiff_t src_stride,
uint8_t *dst, ptrdiff_t dst_stride,
const InterpKernel *x_filters,
int x0_q4, int x_step_q4, int w, int h) {
int x, y;
src -= SUBPEL_TAPS / 2 - 1;
for (y = 0; y < h; ++y) {
int x_q4 = x0_q4;
for (x = 0; x < w; ++x) {
const uint8_t *const src_x = &src[x_q4 >> SUBPEL_BITS];
const int16_t *const x_filter = x_filters[x_q4 & SUBPEL_MASK];
int k, sum = 0;
for (k = 0; k < SUBPEL_TAPS; ++k)
sum += src_x[k] * x_filter[k];
dst[x] = ROUND_POWER_OF_TWO(dst[x] +
clip_pixel(ROUND_POWER_OF_TWO(sum, FILTER_BITS)), 1);
x_q4 += x_step_q4;
}
src += src_stride;
dst += dst_stride;
}
}
static void convolve_vert(const uint8_t *src, ptrdiff_t src_stride,
uint8_t *dst, ptrdiff_t dst_stride,
const InterpKernel *y_filters,
int y0_q4, int y_step_q4, int w, int h) {
int x, y;
src -= src_stride * (SUBPEL_TAPS / 2 - 1);
for (x = 0; x < w; ++x) {
int y_q4 = y0_q4;
for (y = 0; y < h; ++y) {
const unsigned char *src_y = &src[(y_q4 >> SUBPEL_BITS) * src_stride];
const int16_t *const y_filter = y_filters[y_q4 & SUBPEL_MASK];
int k, sum = 0;
for (k = 0; k < SUBPEL_TAPS; ++k)
sum += src_y[k * src_stride] * y_filter[k];
dst[y * dst_stride] = clip_pixel(ROUND_POWER_OF_TWO(sum, FILTER_BITS));
y_q4 += y_step_q4;
}
++src;
++dst;
}
}
static void convolve_avg_vert(const uint8_t *src, ptrdiff_t src_stride,
uint8_t *dst, ptrdiff_t dst_stride,
const InterpKernel *y_filters,
int y0_q4, int y_step_q4, int w, int h) {
int x, y;
src -= src_stride * (SUBPEL_TAPS / 2 - 1);
for (x = 0; x < w; ++x) {
int y_q4 = y0_q4;
for (y = 0; y < h; ++y) {
const unsigned char *src_y = &src[(y_q4 >> SUBPEL_BITS) * src_stride];
const int16_t *const y_filter = y_filters[y_q4 & SUBPEL_MASK];
int k, sum = 0;
for (k = 0; k < SUBPEL_TAPS; ++k)
sum += src_y[k * src_stride] * y_filter[k];
dst[y * dst_stride] = ROUND_POWER_OF_TWO(dst[y * dst_stride] +
clip_pixel(ROUND_POWER_OF_TWO(sum, FILTER_BITS)), 1);
y_q4 += y_step_q4;
}
++src;
++dst;
}
}
static void convolve(const uint8_t *src, ptrdiff_t src_stride,
uint8_t *dst, ptrdiff_t dst_stride,
const InterpKernel *const x_filters,
int x0_q4, int x_step_q4,
const InterpKernel *const y_filters,
int y0_q4, int y_step_q4,
int w, int h) {
// Note: Fixed size intermediate buffer, temp, places limits on parameters.
// 2d filtering proceeds in 2 steps:
// (1) Interpolate horizontally into an intermediate buffer, temp.
// (2) Interpolate temp vertically to derive the sub-pixel result.
// Deriving the maximum number of rows in the temp buffer (135):
// --Smallest scaling factor is x1/2 ==> y_step_q4 = 32 (Normative).
// --Largest block size is 64x64 pixels.
// --64 rows in the downscaled frame span a distance of (64 - 1) * 32 in the
// original frame (in 1/16th pixel units).
// --Must round-up because block may be located at sub-pixel position.
// --Require an additional SUBPEL_TAPS rows for the 8-tap filter tails.
// --((64 - 1) * 32 + 15) >> 4 + 8 = 135.
uint8_t temp[135 * 64];
int intermediate_height = (((h - 1) * y_step_q4 + 15) >> 4) + SUBPEL_TAPS;
assert(w <= 64);
assert(h <= 64);
assert(y_step_q4 <= 32);
assert(x_step_q4 <= 32);
if (intermediate_height < h)
intermediate_height = h;
convolve_horiz(src - src_stride * (SUBPEL_TAPS / 2 - 1), src_stride, temp, 64,
x_filters, x0_q4, x_step_q4, w, intermediate_height);
convolve_vert(temp + 64 * (SUBPEL_TAPS / 2 - 1), 64, dst, dst_stride,
y_filters, y0_q4, y_step_q4, w, h);
}
static const InterpKernel *get_filter_base(const int16_t *filter) {
// NOTE: This assumes that the filter table is 256-byte aligned.
// TODO(agrange) Modify to make independent of table alignment.
return (const InterpKernel *)(((intptr_t)filter) & ~((intptr_t)0xFF));
}
static int get_filter_offset(const int16_t *f, const InterpKernel *base) {
return (int)((const InterpKernel *)(intptr_t)f - base);
}
void vp9_convolve8_horiz_c(const uint8_t *src, ptrdiff_t src_stride,
uint8_t *dst, ptrdiff_t dst_stride,
const int16_t *filter_x, int x_step_q4,
const int16_t *filter_y, int y_step_q4,
int w, int h) {
const InterpKernel *const filters_x = get_filter_base(filter_x);
const int x0_q4 = get_filter_offset(filter_x, filters_x);
(void)filter_y;
(void)y_step_q4;
convolve_horiz(src, src_stride, dst, dst_stride, filters_x,
x0_q4, x_step_q4, w, h);
}
void vp9_convolve8_avg_horiz_c(const uint8_t *src, ptrdiff_t src_stride,
uint8_t *dst, ptrdiff_t dst_stride,
const int16_t *filter_x, int x_step_q4,
const int16_t *filter_y, int y_step_q4,
int w, int h) {
const InterpKernel *const filters_x = get_filter_base(filter_x);
const int x0_q4 = get_filter_offset(filter_x, filters_x);
(void)filter_y;
(void)y_step_q4;
convolve_avg_horiz(src, src_stride, dst, dst_stride, filters_x,
x0_q4, x_step_q4, w, h);
}
void vp9_convolve8_vert_c(const uint8_t *src, ptrdiff_t src_stride,
uint8_t *dst, ptrdiff_t dst_stride,
const int16_t *filter_x, int x_step_q4,
const int16_t *filter_y, int y_step_q4,
int w, int h) {
const InterpKernel *const filters_y = get_filter_base(filter_y);
const int y0_q4 = get_filter_offset(filter_y, filters_y);
(void)filter_x;
(void)x_step_q4;
convolve_vert(src, src_stride, dst, dst_stride, filters_y,
y0_q4, y_step_q4, w, h);
}
void vp9_convolve8_avg_vert_c(const uint8_t *src, ptrdiff_t src_stride,
uint8_t *dst, ptrdiff_t dst_stride,
const int16_t *filter_x, int x_step_q4,
const int16_t *filter_y, int y_step_q4,
int w, int h) {
const InterpKernel *const filters_y = get_filter_base(filter_y);
const int y0_q4 = get_filter_offset(filter_y, filters_y);
(void)filter_x;
(void)x_step_q4;
convolve_avg_vert(src, src_stride, dst, dst_stride, filters_y,
y0_q4, y_step_q4, w, h);
}
void vp9_convolve8_c(const uint8_t *src, ptrdiff_t src_stride,
uint8_t *dst, ptrdiff_t dst_stride,
const int16_t *filter_x, int x_step_q4,
const int16_t *filter_y, int y_step_q4,
int w, int h) {
const InterpKernel *const filters_x = get_filter_base(filter_x);
const int x0_q4 = get_filter_offset(filter_x, filters_x);
const InterpKernel *const filters_y = get_filter_base(filter_y);
const int y0_q4 = get_filter_offset(filter_y, filters_y);
convolve(src, src_stride, dst, dst_stride,
filters_x, x0_q4, x_step_q4,
filters_y, y0_q4, y_step_q4, w, h);
}
void vp9_convolve8_avg_c(const uint8_t *src, ptrdiff_t src_stride,
uint8_t *dst, ptrdiff_t dst_stride,
const int16_t *filter_x, int x_step_q4,
const int16_t *filter_y, int y_step_q4,
int w, int h) {
/* Fixed size intermediate buffer places limits on parameters. */
DECLARE_ALIGNED_ARRAY(16, uint8_t, temp, 64 * 64);
assert(w <= 64);
assert(h <= 64);
vp9_convolve8_c(src, src_stride, temp, 64,
filter_x, x_step_q4, filter_y, y_step_q4, w, h);
vp9_convolve_avg_c(temp, 64, dst, dst_stride, NULL, 0, NULL, 0, w, h);
}
void vp9_convolve_copy_c(const uint8_t *src, ptrdiff_t src_stride,
uint8_t *dst, ptrdiff_t dst_stride,
const int16_t *filter_x, int filter_x_stride,
const int16_t *filter_y, int filter_y_stride,
int w, int h) {
int r;
(void)filter_x; (void)filter_x_stride;
(void)filter_y; (void)filter_y_stride;
for (r = h; r > 0; --r) {
vpx_memcpy(dst, src, w);
src += src_stride;
dst += dst_stride;
}
}
void vp9_convolve_avg_c(const uint8_t *src, ptrdiff_t src_stride,
uint8_t *dst, ptrdiff_t dst_stride,
const int16_t *filter_x, int filter_x_stride,
const int16_t *filter_y, int filter_y_stride,
int w, int h) {
int x, y;
(void)filter_x; (void)filter_x_stride;
(void)filter_y; (void)filter_y_stride;
for (y = 0; y < h; ++y) {
for (x = 0; x < w; ++x)
dst[x] = ROUND_POWER_OF_TWO(dst[x] + src[x], 1);
src += src_stride;
dst += dst_stride;
}
}