ref: a2127236ae4742f329e5571d76b84de08cd3b8ea
dir: /vpx_dsp/arm/vpx_scaled_convolve8_neon.c/
/*
* Copyright (c) 2017 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 <assert.h>
#include <string.h>
#include "./vpx_config.h"
#include "./vpx_dsp_rtcd.h"
#include "vpx/vpx_integer.h"
#include "vpx_dsp/arm/transpose_neon.h"
#include "vpx_dsp/arm/vpx_convolve8_neon.h"
#include "vpx_ports/mem.h"
static INLINE void scaledconvolve_horiz_w4(
const uint8_t *src, const ptrdiff_t src_stride, uint8_t *dst,
const ptrdiff_t dst_stride, const InterpKernel *const x_filters,
const int x0_q4, const int x_step_q4, const int w, const int h) {
DECLARE_ALIGNED(16, uint8_t, temp[4 * 4]);
int x, y, z;
src -= SUBPEL_TAPS / 2 - 1;
y = h;
do {
int x_q4 = x0_q4;
x = 0;
do {
// process 4 src_x steps
for (z = 0; z < 4; ++z) {
const uint8_t *const src_x = &src[x_q4 >> SUBPEL_BITS];
if (x_q4 & SUBPEL_MASK) {
const int16x8_t filters = vld1q_s16(x_filters[x_q4 & SUBPEL_MASK]);
const int16x4_t filter3 = vdup_lane_s16(vget_low_s16(filters), 3);
const int16x4_t filter4 = vdup_lane_s16(vget_high_s16(filters), 0);
uint8x8_t s[8], d;
int16x8_t ss[4];
int16x4_t t[8], tt;
load_u8_8x4(src_x, src_stride, &s[0], &s[1], &s[2], &s[3]);
transpose_u8_8x4(&s[0], &s[1], &s[2], &s[3]);
ss[0] = vreinterpretq_s16_u16(vmovl_u8(s[0]));
ss[1] = vreinterpretq_s16_u16(vmovl_u8(s[1]));
ss[2] = vreinterpretq_s16_u16(vmovl_u8(s[2]));
ss[3] = vreinterpretq_s16_u16(vmovl_u8(s[3]));
t[0] = vget_low_s16(ss[0]);
t[1] = vget_low_s16(ss[1]);
t[2] = vget_low_s16(ss[2]);
t[3] = vget_low_s16(ss[3]);
t[4] = vget_high_s16(ss[0]);
t[5] = vget_high_s16(ss[1]);
t[6] = vget_high_s16(ss[2]);
t[7] = vget_high_s16(ss[3]);
tt = convolve8_4(t[0], t[1], t[2], t[3], t[4], t[5], t[6], t[7],
filters, filter3, filter4);
d = vqrshrun_n_s16(vcombine_s16(tt, tt), 7);
vst1_lane_u32((uint32_t *)&temp[4 * z], vreinterpret_u32_u8(d), 0);
} else {
int i;
for (i = 0; i < 4; ++i) {
temp[z * 4 + i] = src_x[i * src_stride + 3];
}
}
x_q4 += x_step_q4;
}
// transpose the 4x4 filters values back to dst
{
const uint8x8x4_t d4 = vld4_u8(temp);
vst1_lane_u32((uint32_t *)&dst[x + 0 * dst_stride],
vreinterpret_u32_u8(d4.val[0]), 0);
vst1_lane_u32((uint32_t *)&dst[x + 1 * dst_stride],
vreinterpret_u32_u8(d4.val[1]), 0);
vst1_lane_u32((uint32_t *)&dst[x + 2 * dst_stride],
vreinterpret_u32_u8(d4.val[2]), 0);
vst1_lane_u32((uint32_t *)&dst[x + 3 * dst_stride],
vreinterpret_u32_u8(d4.val[3]), 0);
}
x += 4;
} while (x < w);
src += src_stride * 4;
dst += dst_stride * 4;
y -= 4;
} while (y > 0);
}
static INLINE void scaledconvolve_horiz_w8(
const uint8_t *src, const ptrdiff_t src_stride, uint8_t *dst,
const ptrdiff_t dst_stride, const InterpKernel *const x_filters,
const int x0_q4, const int x_step_q4, const int w, const int h) {
DECLARE_ALIGNED(16, uint8_t, temp[8 * 8]);
int x, y, z;
src -= SUBPEL_TAPS / 2 - 1;
// This function processes 8x8 areas. The intermediate height is not always
// a multiple of 8, so force it to be a multiple of 8 here.
y = (h + 7) & ~7;
do {
int x_q4 = x0_q4;
x = 0;
do {
uint8x8_t d[8];
// process 8 src_x steps
for (z = 0; z < 8; ++z) {
const uint8_t *const src_x = &src[x_q4 >> SUBPEL_BITS];
if (x_q4 & SUBPEL_MASK) {
const int16x8_t filters = vld1q_s16(x_filters[x_q4 & SUBPEL_MASK]);
uint8x8_t s[8];
load_u8_8x8(src_x, src_stride, &s[0], &s[1], &s[2], &s[3], &s[4],
&s[5], &s[6], &s[7]);
transpose_u8_8x8(&s[0], &s[1], &s[2], &s[3], &s[4], &s[5], &s[6],
&s[7]);
d[0] = scale_filter_8(s, filters);
vst1_u8(&temp[8 * z], d[0]);
} else {
int i;
for (i = 0; i < 8; ++i) {
temp[z * 8 + i] = src_x[i * src_stride + 3];
}
}
x_q4 += x_step_q4;
}
// transpose the 8x8 filters values back to dst
load_u8_8x8(temp, 8, &d[0], &d[1], &d[2], &d[3], &d[4], &d[5], &d[6],
&d[7]);
transpose_u8_8x8(&d[0], &d[1], &d[2], &d[3], &d[4], &d[5], &d[6], &d[7]);
vst1_u8(&dst[x + 0 * dst_stride], d[0]);
vst1_u8(&dst[x + 1 * dst_stride], d[1]);
vst1_u8(&dst[x + 2 * dst_stride], d[2]);
vst1_u8(&dst[x + 3 * dst_stride], d[3]);
vst1_u8(&dst[x + 4 * dst_stride], d[4]);
vst1_u8(&dst[x + 5 * dst_stride], d[5]);
vst1_u8(&dst[x + 6 * dst_stride], d[6]);
vst1_u8(&dst[x + 7 * dst_stride], d[7]);
x += 8;
} while (x < w);
src += src_stride * 8;
dst += dst_stride * 8;
} while (y -= 8);
}
static INLINE void scaledconvolve_vert_w4(
const uint8_t *src, const ptrdiff_t src_stride, uint8_t *dst,
const ptrdiff_t dst_stride, const InterpKernel *const y_filters,
const int y0_q4, const int y_step_q4, const int w, const int h) {
int y;
int y_q4 = y0_q4;
src -= src_stride * (SUBPEL_TAPS / 2 - 1);
y = h;
do {
const unsigned char *src_y = &src[(y_q4 >> SUBPEL_BITS) * src_stride];
if (y_q4 & SUBPEL_MASK) {
const int16x8_t filters = vld1q_s16(y_filters[y_q4 & SUBPEL_MASK]);
const int16x4_t filter3 = vdup_lane_s16(vget_low_s16(filters), 3);
const int16x4_t filter4 = vdup_lane_s16(vget_high_s16(filters), 0);
uint8x8_t s[8], d;
int16x4_t t[8], tt;
load_u8_8x8(src_y, src_stride, &s[0], &s[1], &s[2], &s[3], &s[4], &s[5],
&s[6], &s[7]);
t[0] = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(s[0])));
t[1] = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(s[1])));
t[2] = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(s[2])));
t[3] = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(s[3])));
t[4] = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(s[4])));
t[5] = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(s[5])));
t[6] = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(s[6])));
t[7] = vget_low_s16(vreinterpretq_s16_u16(vmovl_u8(s[7])));
tt = convolve8_4(t[0], t[1], t[2], t[3], t[4], t[5], t[6], t[7], filters,
filter3, filter4);
d = vqrshrun_n_s16(vcombine_s16(tt, tt), 7);
vst1_lane_u32((uint32_t *)dst, vreinterpret_u32_u8(d), 0);
} else {
memcpy(dst, &src_y[3 * src_stride], w);
}
dst += dst_stride;
y_q4 += y_step_q4;
} while (--y);
}
static INLINE void scaledconvolve_vert_w8(
const uint8_t *src, const ptrdiff_t src_stride, uint8_t *dst,
const ptrdiff_t dst_stride, const InterpKernel *const y_filters,
const int y0_q4, const int y_step_q4, const int w, const int h) {
int y;
int y_q4 = y0_q4;
src -= src_stride * (SUBPEL_TAPS / 2 - 1);
y = h;
do {
const unsigned char *src_y = &src[(y_q4 >> SUBPEL_BITS) * src_stride];
if (y_q4 & SUBPEL_MASK) {
const int16x8_t filters = vld1q_s16(y_filters[y_q4 & SUBPEL_MASK]);
uint8x8_t s[8], d;
load_u8_8x8(src_y, src_stride, &s[0], &s[1], &s[2], &s[3], &s[4], &s[5],
&s[6], &s[7]);
d = scale_filter_8(s, filters);
vst1_u8(dst, d);
} else {
memcpy(dst, &src_y[3 * src_stride], w);
}
dst += dst_stride;
y_q4 += y_step_q4;
} while (--y);
}
static INLINE void scaledconvolve_vert_w16(
const uint8_t *src, const ptrdiff_t src_stride, uint8_t *dst,
const ptrdiff_t dst_stride, const InterpKernel *const y_filters,
const int y0_q4, const int y_step_q4, const int w, const int h) {
int x, y;
int y_q4 = y0_q4;
src -= src_stride * (SUBPEL_TAPS / 2 - 1);
y = h;
do {
const unsigned char *src_y = &src[(y_q4 >> SUBPEL_BITS) * src_stride];
if (y_q4 & SUBPEL_MASK) {
x = 0;
do {
const int16x8_t filters = vld1q_s16(y_filters[y_q4 & SUBPEL_MASK]);
uint8x16_t ss[8];
uint8x8_t s[8], d[2];
load_u8_16x8(src_y, src_stride, &ss[0], &ss[1], &ss[2], &ss[3], &ss[4],
&ss[5], &ss[6], &ss[7]);
s[0] = vget_low_u8(ss[0]);
s[1] = vget_low_u8(ss[1]);
s[2] = vget_low_u8(ss[2]);
s[3] = vget_low_u8(ss[3]);
s[4] = vget_low_u8(ss[4]);
s[5] = vget_low_u8(ss[5]);
s[6] = vget_low_u8(ss[6]);
s[7] = vget_low_u8(ss[7]);
d[0] = scale_filter_8(s, filters);
s[0] = vget_high_u8(ss[0]);
s[1] = vget_high_u8(ss[1]);
s[2] = vget_high_u8(ss[2]);
s[3] = vget_high_u8(ss[3]);
s[4] = vget_high_u8(ss[4]);
s[5] = vget_high_u8(ss[5]);
s[6] = vget_high_u8(ss[6]);
s[7] = vget_high_u8(ss[7]);
d[1] = scale_filter_8(s, filters);
vst1q_u8(&dst[x], vcombine_u8(d[0], d[1]));
src_y += 16;
x += 16;
} while (x < w);
} else {
memcpy(dst, &src_y[3 * src_stride], w);
}
dst += dst_stride;
y_q4 += y_step_q4;
} while (--y);
}
void vpx_scaled_2d_neon(const uint8_t *src, ptrdiff_t src_stride, uint8_t *dst,
ptrdiff_t dst_stride, const InterpKernel *filter,
int x0_q4, int x_step_q4, 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.
// --Require an additional 8 rows for the horiz_w8 transpose tail.
// When calling in frame scaling function, the smallest scaling factor is x1/4
// ==> y_step_q4 = 64. Since w and h are at most 16, the temp buffer is still
// big enough.
DECLARE_ALIGNED(16, uint8_t, temp[(135 + 8) * 64]);
const int intermediate_height =
(((h - 1) * y_step_q4 + y0_q4) >> SUBPEL_BITS) + SUBPEL_TAPS;
assert(w <= 64);
assert(h <= 64);
assert(y_step_q4 <= 32 || (y_step_q4 <= 64 && h <= 32));
assert(x_step_q4 <= 64);
if (w >= 8) {
scaledconvolve_horiz_w8(src - src_stride * (SUBPEL_TAPS / 2 - 1),
src_stride, temp, 64, filter, x0_q4, x_step_q4, w,
intermediate_height);
} else {
scaledconvolve_horiz_w4(src - src_stride * (SUBPEL_TAPS / 2 - 1),
src_stride, temp, 64, filter, x0_q4, x_step_q4, w,
intermediate_height);
}
if (w >= 16) {
scaledconvolve_vert_w16(temp + 64 * (SUBPEL_TAPS / 2 - 1), 64, dst,
dst_stride, filter, y0_q4, y_step_q4, w, h);
} else if (w == 8) {
scaledconvolve_vert_w8(temp + 64 * (SUBPEL_TAPS / 2 - 1), 64, dst,
dst_stride, filter, y0_q4, y_step_q4, w, h);
} else {
scaledconvolve_vert_w4(temp + 64 * (SUBPEL_TAPS / 2 - 1), 64, dst,
dst_stride, filter, y0_q4, y_step_q4, w, h);
}
}