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aomedia / aom / 829a75702cd91ffa8b0532646bf6baad38ea33b7 / . / third_party / libyuv / source / scale_common.cc
blob: fd4cbd03867e028702933633fb1050f3b3ef6490 [file] [log] [blame]
/*
* Copyright 2013 The LibYuv 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 "libyuv/scale.h"
#include <assert.h>
#include <string.h>
#include "libyuv/cpu_id.h"
#include "libyuv/planar_functions.h" // For CopyARGB
#include "libyuv/row.h"
#include "libyuv/scale_row.h"
#ifdef __cplusplus
namespace libyuv {
extern "C" {
#endif
static __inline int Abs(int v) {
return v >= 0 ? v : -v;
}
// CPU agnostic row functions
void ScaleRowDown2_C(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst,
int dst_width) {
int x;
(void)src_stride;
for (x = 0; x < dst_width - 1; x += 2) {
dst[0] = src_ptr[1];
dst[1] = src_ptr[3];
dst += 2;
src_ptr += 4;
}
if (dst_width & 1) {
dst[0] = src_ptr[1];
}
}
void ScaleRowDown2_16_C(const uint16_t* src_ptr,
ptrdiff_t src_stride,
uint16_t* dst,
int dst_width) {
int x;
(void)src_stride;
for (x = 0; x < dst_width - 1; x += 2) {
dst[0] = src_ptr[1];
dst[1] = src_ptr[3];
dst += 2;
src_ptr += 4;
}
if (dst_width & 1) {
dst[0] = src_ptr[1];
}
}
void ScaleRowDown2Linear_C(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst,
int dst_width) {
const uint8_t* s = src_ptr;
int x;
(void)src_stride;
for (x = 0; x < dst_width - 1; x += 2) {
dst[0] = (s[0] + s[1] + 1) >> 1;
dst[1] = (s[2] + s[3] + 1) >> 1;
dst += 2;
s += 4;
}
if (dst_width & 1) {
dst[0] = (s[0] + s[1] + 1) >> 1;
}
}
void ScaleRowDown2Linear_16_C(const uint16_t* src_ptr,
ptrdiff_t src_stride,
uint16_t* dst,
int dst_width) {
const uint16_t* s = src_ptr;
int x;
(void)src_stride;
for (x = 0; x < dst_width - 1; x += 2) {
dst[0] = (s[0] + s[1] + 1) >> 1;
dst[1] = (s[2] + s[3] + 1) >> 1;
dst += 2;
s += 4;
}
if (dst_width & 1) {
dst[0] = (s[0] + s[1] + 1) >> 1;
}
}
void ScaleRowDown2Box_C(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst,
int dst_width) {
const uint8_t* s = src_ptr;
const uint8_t* t = src_ptr + src_stride;
int x;
for (x = 0; x < dst_width - 1; x += 2) {
dst[0] = (s[0] + s[1] + t[0] + t[1] + 2) >> 2;
dst[1] = (s[2] + s[3] + t[2] + t[3] + 2) >> 2;
dst += 2;
s += 4;
t += 4;
}
if (dst_width & 1) {
dst[0] = (s[0] + s[1] + t[0] + t[1] + 2) >> 2;
}
}
void ScaleRowDown2Box_Odd_C(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst,
int dst_width) {
const uint8_t* s = src_ptr;
const uint8_t* t = src_ptr + src_stride;
int x;
dst_width -= 1;
for (x = 0; x < dst_width - 1; x += 2) {
dst[0] = (s[0] + s[1] + t[0] + t[1] + 2) >> 2;
dst[1] = (s[2] + s[3] + t[2] + t[3] + 2) >> 2;
dst += 2;
s += 4;
t += 4;
}
if (dst_width & 1) {
dst[0] = (s[0] + s[1] + t[0] + t[1] + 2) >> 2;
dst += 1;
s += 2;
t += 2;
}
dst[0] = (s[0] + t[0] + 1) >> 1;
}
void ScaleRowDown2Box_16_C(const uint16_t* src_ptr,
ptrdiff_t src_stride,
uint16_t* dst,
int dst_width) {
const uint16_t* s = src_ptr;
const uint16_t* t = src_ptr + src_stride;
int x;
for (x = 0; x < dst_width - 1; x += 2) {
dst[0] = (s[0] + s[1] + t[0] + t[1] + 2) >> 2;
dst[1] = (s[2] + s[3] + t[2] + t[3] + 2) >> 2;
dst += 2;
s += 4;
t += 4;
}
if (dst_width & 1) {
dst[0] = (s[0] + s[1] + t[0] + t[1] + 2) >> 2;
}
}
void ScaleRowDown4_C(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst,
int dst_width) {
int x;
(void)src_stride;
for (x = 0; x < dst_width - 1; x += 2) {
dst[0] = src_ptr[2];
dst[1] = src_ptr[6];
dst += 2;
src_ptr += 8;
}
if (dst_width & 1) {
dst[0] = src_ptr[2];
}
}
void ScaleRowDown4_16_C(const uint16_t* src_ptr,
ptrdiff_t src_stride,
uint16_t* dst,
int dst_width) {
int x;
(void)src_stride;
for (x = 0; x < dst_width - 1; x += 2) {
dst[0] = src_ptr[2];
dst[1] = src_ptr[6];
dst += 2;
src_ptr += 8;
}
if (dst_width & 1) {
dst[0] = src_ptr[2];
}
}
void ScaleRowDown4Box_C(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst,
int dst_width) {
intptr_t stride = src_stride;
int x;
for (x = 0; x < dst_width - 1; x += 2) {
dst[0] = (src_ptr[0] + src_ptr[1] + src_ptr[2] + src_ptr[3] +
src_ptr[stride + 0] + src_ptr[stride + 1] + src_ptr[stride + 2] +
src_ptr[stride + 3] + src_ptr[stride * 2 + 0] +
src_ptr[stride * 2 + 1] + src_ptr[stride * 2 + 2] +
src_ptr[stride * 2 + 3] + src_ptr[stride * 3 + 0] +
src_ptr[stride * 3 + 1] + src_ptr[stride * 3 + 2] +
src_ptr[stride * 3 + 3] + 8) >>
4;
dst[1] = (src_ptr[4] + src_ptr[5] + src_ptr[6] + src_ptr[7] +
src_ptr[stride + 4] + src_ptr[stride + 5] + src_ptr[stride + 6] +
src_ptr[stride + 7] + src_ptr[stride * 2 + 4] +
src_ptr[stride * 2 + 5] + src_ptr[stride * 2 + 6] +
src_ptr[stride * 2 + 7] + src_ptr[stride * 3 + 4] +
src_ptr[stride * 3 + 5] + src_ptr[stride * 3 + 6] +
src_ptr[stride * 3 + 7] + 8) >>
4;
dst += 2;
src_ptr += 8;
}
if (dst_width & 1) {
dst[0] = (src_ptr[0] + src_ptr[1] + src_ptr[2] + src_ptr[3] +
src_ptr[stride + 0] + src_ptr[stride + 1] + src_ptr[stride + 2] +
src_ptr[stride + 3] + src_ptr[stride * 2 + 0] +
src_ptr[stride * 2 + 1] + src_ptr[stride * 2 + 2] +
src_ptr[stride * 2 + 3] + src_ptr[stride * 3 + 0] +
src_ptr[stride * 3 + 1] + src_ptr[stride * 3 + 2] +
src_ptr[stride * 3 + 3] + 8) >>
4;
}
}
void ScaleRowDown4Box_16_C(const uint16_t* src_ptr,
ptrdiff_t src_stride,
uint16_t* dst,
int dst_width) {
intptr_t stride = src_stride;
int x;
for (x = 0; x < dst_width - 1; x += 2) {
dst[0] = (src_ptr[0] + src_ptr[1] + src_ptr[2] + src_ptr[3] +
src_ptr[stride + 0] + src_ptr[stride + 1] + src_ptr[stride + 2] +
src_ptr[stride + 3] + src_ptr[stride * 2 + 0] +
src_ptr[stride * 2 + 1] + src_ptr[stride * 2 + 2] +
src_ptr[stride * 2 + 3] + src_ptr[stride * 3 + 0] +
src_ptr[stride * 3 + 1] + src_ptr[stride * 3 + 2] +
src_ptr[stride * 3 + 3] + 8) >>
4;
dst[1] = (src_ptr[4] + src_ptr[5] + src_ptr[6] + src_ptr[7] +
src_ptr[stride + 4] + src_ptr[stride + 5] + src_ptr[stride + 6] +
src_ptr[stride + 7] + src_ptr[stride * 2 + 4] +
src_ptr[stride * 2 + 5] + src_ptr[stride * 2 + 6] +
src_ptr[stride * 2 + 7] + src_ptr[stride * 3 + 4] +
src_ptr[stride * 3 + 5] + src_ptr[stride * 3 + 6] +
src_ptr[stride * 3 + 7] + 8) >>
4;
dst += 2;
src_ptr += 8;
}
if (dst_width & 1) {
dst[0] = (src_ptr[0] + src_ptr[1] + src_ptr[2] + src_ptr[3] +
src_ptr[stride + 0] + src_ptr[stride + 1] + src_ptr[stride + 2] +
src_ptr[stride + 3] + src_ptr[stride * 2 + 0] +
src_ptr[stride * 2 + 1] + src_ptr[stride * 2 + 2] +
src_ptr[stride * 2 + 3] + src_ptr[stride * 3 + 0] +
src_ptr[stride * 3 + 1] + src_ptr[stride * 3 + 2] +
src_ptr[stride * 3 + 3] + 8) >>
4;
}
}
void ScaleRowDown34_C(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst,
int dst_width) {
int x;
(void)src_stride;
assert((dst_width % 3 == 0) && (dst_width > 0));
for (x = 0; x < dst_width; x += 3) {
dst[0] = src_ptr[0];
dst[1] = src_ptr[1];
dst[2] = src_ptr[3];
dst += 3;
src_ptr += 4;
}
}
void ScaleRowDown34_16_C(const uint16_t* src_ptr,
ptrdiff_t src_stride,
uint16_t* dst,
int dst_width) {
int x;
(void)src_stride;
assert((dst_width % 3 == 0) && (dst_width > 0));
for (x = 0; x < dst_width; x += 3) {
dst[0] = src_ptr[0];
dst[1] = src_ptr[1];
dst[2] = src_ptr[3];
dst += 3;
src_ptr += 4;
}
}
// Filter rows 0 and 1 together, 3 : 1
void ScaleRowDown34_0_Box_C(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* d,
int dst_width) {
const uint8_t* s = src_ptr;
const uint8_t* t = src_ptr + src_stride;
int x;
assert((dst_width % 3 == 0) && (dst_width > 0));
for (x = 0; x < dst_width; x += 3) {
uint8_t a0 = (s[0] * 3 + s[1] * 1 + 2) >> 2;
uint8_t a1 = (s[1] * 1 + s[2] * 1 + 1) >> 1;
uint8_t a2 = (s[2] * 1 + s[3] * 3 + 2) >> 2;
uint8_t b0 = (t[0] * 3 + t[1] * 1 + 2) >> 2;
uint8_t b1 = (t[1] * 1 + t[2] * 1 + 1) >> 1;
uint8_t b2 = (t[2] * 1 + t[3] * 3 + 2) >> 2;
d[0] = (a0 * 3 + b0 + 2) >> 2;
d[1] = (a1 * 3 + b1 + 2) >> 2;
d[2] = (a2 * 3 + b2 + 2) >> 2;
d += 3;
s += 4;
t += 4;
}
}
void ScaleRowDown34_0_Box_16_C(const uint16_t* src_ptr,
ptrdiff_t src_stride,
uint16_t* d,
int dst_width) {
const uint16_t* s = src_ptr;
const uint16_t* t = src_ptr + src_stride;
int x;
assert((dst_width % 3 == 0) && (dst_width > 0));
for (x = 0; x < dst_width; x += 3) {
uint16_t a0 = (s[0] * 3 + s[1] * 1 + 2) >> 2;
uint16_t a1 = (s[1] * 1 + s[2] * 1 + 1) >> 1;
uint16_t a2 = (s[2] * 1 + s[3] * 3 + 2) >> 2;
uint16_t b0 = (t[0] * 3 + t[1] * 1 + 2) >> 2;
uint16_t b1 = (t[1] * 1 + t[2] * 1 + 1) >> 1;
uint16_t b2 = (t[2] * 1 + t[3] * 3 + 2) >> 2;
d[0] = (a0 * 3 + b0 + 2) >> 2;
d[1] = (a1 * 3 + b1 + 2) >> 2;
d[2] = (a2 * 3 + b2 + 2) >> 2;
d += 3;
s += 4;
t += 4;
}
}
// Filter rows 1 and 2 together, 1 : 1
void ScaleRowDown34_1_Box_C(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* d,
int dst_width) {
const uint8_t* s = src_ptr;
const uint8_t* t = src_ptr + src_stride;
int x;
assert((dst_width % 3 == 0) && (dst_width > 0));
for (x = 0; x < dst_width; x += 3) {
uint8_t a0 = (s[0] * 3 + s[1] * 1 + 2) >> 2;
uint8_t a1 = (s[1] * 1 + s[2] * 1 + 1) >> 1;
uint8_t a2 = (s[2] * 1 + s[3] * 3 + 2) >> 2;
uint8_t b0 = (t[0] * 3 + t[1] * 1 + 2) >> 2;
uint8_t b1 = (t[1] * 1 + t[2] * 1 + 1) >> 1;
uint8_t b2 = (t[2] * 1 + t[3] * 3 + 2) >> 2;
d[0] = (a0 + b0 + 1) >> 1;
d[1] = (a1 + b1 + 1) >> 1;
d[2] = (a2 + b2 + 1) >> 1;
d += 3;
s += 4;
t += 4;
}
}
void ScaleRowDown34_1_Box_16_C(const uint16_t* src_ptr,
ptrdiff_t src_stride,
uint16_t* d,
int dst_width) {
const uint16_t* s = src_ptr;
const uint16_t* t = src_ptr + src_stride;
int x;
assert((dst_width % 3 == 0) && (dst_width > 0));
for (x = 0; x < dst_width; x += 3) {
uint16_t a0 = (s[0] * 3 + s[1] * 1 + 2) >> 2;
uint16_t a1 = (s[1] * 1 + s[2] * 1 + 1) >> 1;
uint16_t a2 = (s[2] * 1 + s[3] * 3 + 2) >> 2;
uint16_t b0 = (t[0] * 3 + t[1] * 1 + 2) >> 2;
uint16_t b1 = (t[1] * 1 + t[2] * 1 + 1) >> 1;
uint16_t b2 = (t[2] * 1 + t[3] * 3 + 2) >> 2;
d[0] = (a0 + b0 + 1) >> 1;
d[1] = (a1 + b1 + 1) >> 1;
d[2] = (a2 + b2 + 1) >> 1;
d += 3;
s += 4;
t += 4;
}
}
// Scales a single row of pixels using point sampling.
void ScaleCols_C(uint8_t* dst_ptr,
const uint8_t* src_ptr,
int dst_width,
int x,
int dx) {
int j;
for (j = 0; j < dst_width - 1; j += 2) {
dst_ptr[0] = src_ptr[x >> 16];
x += dx;
dst_ptr[1] = src_ptr[x >> 16];
x += dx;
dst_ptr += 2;
}
if (dst_width & 1) {
dst_ptr[0] = src_ptr[x >> 16];
}
}
void ScaleCols_16_C(uint16_t* dst_ptr,
const uint16_t* src_ptr,
int dst_width,
int x,
int dx) {
int j;
for (j = 0; j < dst_width - 1; j += 2) {
dst_ptr[0] = src_ptr[x >> 16];
x += dx;
dst_ptr[1] = src_ptr[x >> 16];
x += dx;
dst_ptr += 2;
}
if (dst_width & 1) {
dst_ptr[0] = src_ptr[x >> 16];
}
}
// Scales a single row of pixels up by 2x using point sampling.
void ScaleColsUp2_C(uint8_t* dst_ptr,
const uint8_t* src_ptr,
int dst_width,
int x,
int dx) {
int j;
(void)x;
(void)dx;
for (j = 0; j < dst_width - 1; j += 2) {
dst_ptr[1] = dst_ptr[0] = src_ptr[0];
src_ptr += 1;
dst_ptr += 2;
}
if (dst_width & 1) {
dst_ptr[0] = src_ptr[0];
}
}
void ScaleColsUp2_16_C(uint16_t* dst_ptr,
const uint16_t* src_ptr,
int dst_width,
int x,
int dx) {
int j;
(void)x;
(void)dx;
for (j = 0; j < dst_width - 1; j += 2) {
dst_ptr[1] = dst_ptr[0] = src_ptr[0];
src_ptr += 1;
dst_ptr += 2;
}
if (dst_width & 1) {
dst_ptr[0] = src_ptr[0];
}
}
// (1-f)a + fb can be replaced with a + f(b-a)
#if defined(__arm__) || defined(__aarch64__)
#define BLENDER(a, b, f) \
(uint8_t)((int)(a) + ((((int)((f)) * ((int)(b) - (int)(a))) + 0x8000) >> 16))
#else
// Intel uses 7 bit math with rounding.
#define BLENDER(a, b, f) \
(uint8_t)((int)(a) + (((int)((f) >> 9) * ((int)(b) - (int)(a)) + 0x40) >> 7))
#endif
void ScaleFilterCols_C(uint8_t* dst_ptr,
const uint8_t* src_ptr,
int dst_width,
int x,
int dx) {
int j;
for (j = 0; j < dst_width - 1; j += 2) {
int xi = x >> 16;
int a = src_ptr[xi];
int b = src_ptr[xi + 1];
dst_ptr[0] = BLENDER(a, b, x & 0xffff);
x += dx;
xi = x >> 16;
a = src_ptr[xi];
b = src_ptr[xi + 1];
dst_ptr[1] = BLENDER(a, b, x & 0xffff);
x += dx;
dst_ptr += 2;
}
if (dst_width & 1) {
int xi = x >> 16;
int a = src_ptr[xi];
int b = src_ptr[xi + 1];
dst_ptr[0] = BLENDER(a, b, x & 0xffff);
}
}
void ScaleFilterCols64_C(uint8_t* dst_ptr,
const uint8_t* src_ptr,
int dst_width,
int x32,
int dx) {
int64_t x = (int64_t)(x32);
int j;
for (j = 0; j < dst_width - 1; j += 2) {
int64_t xi = x >> 16;
int a = src_ptr[xi];
int b = src_ptr[xi + 1];
dst_ptr[0] = BLENDER(a, b, x & 0xffff);
x += dx;
xi = x >> 16;
a = src_ptr[xi];
b = src_ptr[xi + 1];
dst_ptr[1] = BLENDER(a, b, x & 0xffff);
x += dx;
dst_ptr += 2;
}
if (dst_width & 1) {
int64_t xi = x >> 16;
int a = src_ptr[xi];
int b = src_ptr[xi + 1];
dst_ptr[0] = BLENDER(a, b, x & 0xffff);
}
}
#undef BLENDER
// Same as 8 bit arm blender but return is cast to uint16_t
#define BLENDER(a, b, f) \
(uint16_t)( \
(int)(a) + \
(int)((((int64_t)((f)) * ((int64_t)(b) - (int)(a))) + 0x8000) >> 16))
void ScaleFilterCols_16_C(uint16_t* dst_ptr,
const uint16_t* src_ptr,
int dst_width,
int x,
int dx) {
int j;
for (j = 0; j < dst_width - 1; j += 2) {
int xi = x >> 16;
int a = src_ptr[xi];
int b = src_ptr[xi + 1];
dst_ptr[0] = BLENDER(a, b, x & 0xffff);
x += dx;
xi = x >> 16;
a = src_ptr[xi];
b = src_ptr[xi + 1];
dst_ptr[1] = BLENDER(a, b, x & 0xffff);
x += dx;
dst_ptr += 2;
}
if (dst_width & 1) {
int xi = x >> 16;
int a = src_ptr[xi];
int b = src_ptr[xi + 1];
dst_ptr[0] = BLENDER(a, b, x & 0xffff);
}
}
void ScaleFilterCols64_16_C(uint16_t* dst_ptr,
const uint16_t* src_ptr,
int dst_width,
int x32,
int dx) {
int64_t x = (int64_t)(x32);
int j;
for (j = 0; j < dst_width - 1; j += 2) {
int64_t xi = x >> 16;
int a = src_ptr[xi];
int b = src_ptr[xi + 1];
dst_ptr[0] = BLENDER(a, b, x & 0xffff);
x += dx;
xi = x >> 16;
a = src_ptr[xi];
b = src_ptr[xi + 1];
dst_ptr[1] = BLENDER(a, b, x & 0xffff);
x += dx;
dst_ptr += 2;
}
if (dst_width & 1) {
int64_t xi = x >> 16;
int a = src_ptr[xi];
int b = src_ptr[xi + 1];
dst_ptr[0] = BLENDER(a, b, x & 0xffff);
}
}
#undef BLENDER
void ScaleRowDown38_C(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst,
int dst_width) {
int x;
(void)src_stride;
assert(dst_width % 3 == 0);
for (x = 0; x < dst_width; x += 3) {
dst[0] = src_ptr[0];
dst[1] = src_ptr[3];
dst[2] = src_ptr[6];
dst += 3;
src_ptr += 8;
}
}
void ScaleRowDown38_16_C(const uint16_t* src_ptr,
ptrdiff_t src_stride,
uint16_t* dst,
int dst_width) {
int x;
(void)src_stride;
assert(dst_width % 3 == 0);
for (x = 0; x < dst_width; x += 3) {
dst[0] = src_ptr[0];
dst[1] = src_ptr[3];
dst[2] = src_ptr[6];
dst += 3;
src_ptr += 8;
}
}
// 8x3 -> 3x1
void ScaleRowDown38_3_Box_C(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst_ptr,
int dst_width) {
intptr_t stride = src_stride;
int i;
assert((dst_width % 3 == 0) && (dst_width > 0));
for (i = 0; i < dst_width; i += 3) {
dst_ptr[0] =
(src_ptr[0] + src_ptr[1] + src_ptr[2] + src_ptr[stride + 0] +
src_ptr[stride + 1] + src_ptr[stride + 2] + src_ptr[stride * 2 + 0] +
src_ptr[stride * 2 + 1] + src_ptr[stride * 2 + 2]) *
(65536 / 9) >>
16;
dst_ptr[1] =
(src_ptr[3] + src_ptr[4] + src_ptr[5] + src_ptr[stride + 3] +
src_ptr[stride + 4] + src_ptr[stride + 5] + src_ptr[stride * 2 + 3] +
src_ptr[stride * 2 + 4] + src_ptr[stride * 2 + 5]) *
(65536 / 9) >>
16;
dst_ptr[2] =
(src_ptr[6] + src_ptr[7] + src_ptr[stride + 6] + src_ptr[stride + 7] +
src_ptr[stride * 2 + 6] + src_ptr[stride * 2 + 7]) *
(65536 / 6) >>
16;
src_ptr += 8;
dst_ptr += 3;
}
}
void ScaleRowDown38_3_Box_16_C(const uint16_t* src_ptr,
ptrdiff_t src_stride,
uint16_t* dst_ptr,
int dst_width) {
intptr_t stride = src_stride;
int i;
assert((dst_width % 3 == 0) && (dst_width > 0));
for (i = 0; i < dst_width; i += 3) {
dst_ptr[0] =
(src_ptr[0] + src_ptr[1] + src_ptr[2] + src_ptr[stride + 0] +
src_ptr[stride + 1] + src_ptr[stride + 2] + src_ptr[stride * 2 + 0] +
src_ptr[stride * 2 + 1] + src_ptr[stride * 2 + 2]) *
(65536 / 9) >>
16;
dst_ptr[1] =
(src_ptr[3] + src_ptr[4] + src_ptr[5] + src_ptr[stride + 3] +
src_ptr[stride + 4] + src_ptr[stride + 5] + src_ptr[stride * 2 + 3] +
src_ptr[stride * 2 + 4] + src_ptr[stride * 2 + 5]) *
(65536 / 9) >>
16;
dst_ptr[2] =
(src_ptr[6] + src_ptr[7] + src_ptr[stride + 6] + src_ptr[stride + 7] +
src_ptr[stride * 2 + 6] + src_ptr[stride * 2 + 7]) *
(65536 / 6) >>
16;
src_ptr += 8;
dst_ptr += 3;
}
}
// 8x2 -> 3x1
void ScaleRowDown38_2_Box_C(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst_ptr,
int dst_width) {
intptr_t stride = src_stride;
int i;
assert((dst_width % 3 == 0) && (dst_width > 0));
for (i = 0; i < dst_width; i += 3) {
dst_ptr[0] = (src_ptr[0] + src_ptr[1] + src_ptr[2] + src_ptr[stride + 0] +
src_ptr[stride + 1] + src_ptr[stride + 2]) *
(65536 / 6) >>
16;
dst_ptr[1] = (src_ptr[3] + src_ptr[4] + src_ptr[5] + src_ptr[stride + 3] +
src_ptr[stride + 4] + src_ptr[stride + 5]) *
(65536 / 6) >>
16;
dst_ptr[2] =
(src_ptr[6] + src_ptr[7] + src_ptr[stride + 6] + src_ptr[stride + 7]) *
(65536 / 4) >>
16;
src_ptr += 8;
dst_ptr += 3;
}
}
void ScaleRowDown38_2_Box_16_C(const uint16_t* src_ptr,
ptrdiff_t src_stride,
uint16_t* dst_ptr,
int dst_width) {
intptr_t stride = src_stride;
int i;
assert((dst_width % 3 == 0) && (dst_width > 0));
for (i = 0; i < dst_width; i += 3) {
dst_ptr[0] = (src_ptr[0] + src_ptr[1] + src_ptr[2] + src_ptr[stride + 0] +
src_ptr[stride + 1] + src_ptr[stride + 2]) *
(65536 / 6) >>
16;
dst_ptr[1] = (src_ptr[3] + src_ptr[4] + src_ptr[5] + src_ptr[stride + 3] +
src_ptr[stride + 4] + src_ptr[stride + 5]) *
(65536 / 6) >>
16;
dst_ptr[2] =
(src_ptr[6] + src_ptr[7] + src_ptr[stride + 6] + src_ptr[stride + 7]) *
(65536 / 4) >>
16;
src_ptr += 8;
dst_ptr += 3;
}
}
void ScaleAddRow_C(const uint8_t* src_ptr, uint16_t* dst_ptr, int src_width) {
int x;
assert(src_width > 0);
for (x = 0; x < src_width - 1; x += 2) {
dst_ptr[0] += src_ptr[0];
dst_ptr[1] += src_ptr[1];
src_ptr += 2;
dst_ptr += 2;
}
if (src_width & 1) {
dst_ptr[0] += src_ptr[0];
}
}
void ScaleAddRow_16_C(const uint16_t* src_ptr,
uint32_t* dst_ptr,
int src_width) {
int x;
assert(src_width > 0);
for (x = 0; x < src_width - 1; x += 2) {
dst_ptr[0] += src_ptr[0];
dst_ptr[1] += src_ptr[1];
src_ptr += 2;
dst_ptr += 2;
}
if (src_width & 1) {
dst_ptr[0] += src_ptr[0];
}
}
// ARGB scale row functions
void ScaleARGBRowDown2_C(const uint8_t* src_argb,
ptrdiff_t src_stride,
uint8_t* dst_argb,
int dst_width) {
const uint32_t* src = (const uint32_t*)(src_argb);
uint32_t* dst = (uint32_t*)(dst_argb);
int x;
(void)src_stride;
for (x = 0; x < dst_width - 1; x += 2) {
dst[0] = src[1];
dst[1] = src[3];
src += 4;
dst += 2;
}
if (dst_width & 1) {
dst[0] = src[1];
}
}
void ScaleARGBRowDown2Linear_C(const uint8_t* src_argb,
ptrdiff_t src_stride,
uint8_t* dst_argb,
int dst_width) {
int x;
(void)src_stride;
for (x = 0; x < dst_width; ++x) {
dst_argb[0] = (src_argb[0] + src_argb[4] + 1) >> 1;
dst_argb[1] = (src_argb[1] + src_argb[5] + 1) >> 1;
dst_argb[2] = (src_argb[2] + src_argb[6] + 1) >> 1;
dst_argb[3] = (src_argb[3] + src_argb[7] + 1) >> 1;
src_argb += 8;
dst_argb += 4;
}
}
void ScaleARGBRowDown2Box_C(const uint8_t* src_argb,
ptrdiff_t src_stride,
uint8_t* dst_argb,
int dst_width) {
int x;
for (x = 0; x < dst_width; ++x) {
dst_argb[0] = (src_argb[0] + src_argb[4] + src_argb[src_stride] +
src_argb[src_stride + 4] + 2) >>
2;
dst_argb[1] = (src_argb[1] + src_argb[5] + src_argb[src_stride + 1] +
src_argb[src_stride + 5] + 2) >>
2;
dst_argb[2] = (src_argb[2] + src_argb[6] + src_argb[src_stride + 2] +
src_argb[src_stride + 6] + 2) >>
2;
dst_argb[3] = (src_argb[3] + src_argb[7] + src_argb[src_stride + 3] +
src_argb[src_stride + 7] + 2) >>
2;
src_argb += 8;
dst_argb += 4;
}
}
void ScaleARGBRowDownEven_C(const uint8_t* src_argb,
ptrdiff_t src_stride,
int src_stepx,
uint8_t* dst_argb,
int dst_width) {
const uint32_t* src = (const uint32_t*)(src_argb);
uint32_t* dst = (uint32_t*)(dst_argb);
(void)src_stride;
int x;
for (x = 0; x < dst_width - 1; x += 2) {
dst[0] = src[0];
dst[1] = src[src_stepx];
src += src_stepx * 2;
dst += 2;
}
if (dst_width & 1) {
dst[0] = src[0];
}
}
void ScaleARGBRowDownEvenBox_C(const uint8_t* src_argb,
ptrdiff_t src_stride,
int src_stepx,
uint8_t* dst_argb,
int dst_width) {
int x;
for (x = 0; x < dst_width; ++x) {
dst_argb[0] = (src_argb[0] + src_argb[4] + src_argb[src_stride] +
src_argb[src_stride + 4] + 2) >>
2;
dst_argb[1] = (src_argb[1] + src_argb[5] + src_argb[src_stride + 1] +
src_argb[src_stride + 5] + 2) >>
2;
dst_argb[2] = (src_argb[2] + src_argb[6] + src_argb[src_stride + 2] +
src_argb[src_stride + 6] + 2) >>
2;
dst_argb[3] = (src_argb[3] + src_argb[7] + src_argb[src_stride + 3] +
src_argb[src_stride + 7] + 2) >>
2;
src_argb += src_stepx * 4;
dst_argb += 4;
}
}
// Scales a single row of pixels using point sampling.
void ScaleARGBCols_C(uint8_t* dst_argb,
const uint8_t* src_argb,
int dst_width,
int x,
int dx) {
const uint32_t* src = (const uint32_t*)(src_argb);
uint32_t* dst = (uint32_t*)(dst_argb);
int j;
for (j = 0; j < dst_width - 1; j += 2) {
dst[0] = src[x >> 16];
x += dx;
dst[1] = src[x >> 16];
x += dx;
dst += 2;
}
if (dst_width & 1) {
dst[0] = src[x >> 16];
}
}
void ScaleARGBCols64_C(uint8_t* dst_argb,
const uint8_t* src_argb,
int dst_width,
int x32,
int dx) {
int64_t x = (int64_t)(x32);
const uint32_t* src = (const uint32_t*)(src_argb);
uint32_t* dst = (uint32_t*)(dst_argb);
int j;
for (j = 0; j < dst_width - 1; j += 2) {
dst[0] = src[x >> 16];
x += dx;
dst[1] = src[x >> 16];
x += dx;
dst += 2;
}
if (dst_width & 1) {
dst[0] = src[x >> 16];
}
}
// Scales a single row of pixels up by 2x using point sampling.
void ScaleARGBColsUp2_C(uint8_t* dst_argb,
const uint8_t* src_argb,
int dst_width,
int x,
int dx) {
const uint32_t* src = (const uint32_t*)(src_argb);
uint32_t* dst = (uint32_t*)(dst_argb);
int j;
(void)x;
(void)dx;
for (j = 0; j < dst_width - 1; j += 2) {
dst[1] = dst[0] = src[0];
src += 1;
dst += 2;
}
if (dst_width & 1) {
dst[0] = src[0];
}
}
// TODO(fbarchard): Replace 0x7f ^ f with 128-f. bug=607.
// Mimics SSSE3 blender
#define BLENDER1(a, b, f) ((a) * (0x7f ^ f) + (b)*f) >> 7
#define BLENDERC(a, b, f, s) \
(uint32_t)(BLENDER1(((a) >> s) & 255, ((b) >> s) & 255, f) << s)
#define BLENDER(a, b, f) \
BLENDERC(a, b, f, 24) | BLENDERC(a, b, f, 16) | BLENDERC(a, b, f, 8) | \
BLENDERC(a, b, f, 0)
void ScaleARGBFilterCols_C(uint8_t* dst_argb,
const uint8_t* src_argb,
int dst_width,
int x,
int dx) {
const uint32_t* src = (const uint32_t*)(src_argb);
uint32_t* dst = (uint32_t*)(dst_argb);
int j;
for (j = 0; j < dst_width - 1; j += 2) {
int xi = x >> 16;
int xf = (x >> 9) & 0x7f;
uint32_t a = src[xi];
uint32_t b = src[xi + 1];
dst[0] = BLENDER(a, b, xf);
x += dx;
xi = x >> 16;
xf = (x >> 9) & 0x7f;
a = src[xi];
b = src[xi + 1];
dst[1] = BLENDER(a, b, xf);
x += dx;
dst += 2;
}
if (dst_width & 1) {
int xi = x >> 16;
int xf = (x >> 9) & 0x7f;
uint32_t a = src[xi];
uint32_t b = src[xi + 1];
dst[0] = BLENDER(a, b, xf);
}
}
void ScaleARGBFilterCols64_C(uint8_t* dst_argb,
const uint8_t* src_argb,
int dst_width,
int x32,
int dx) {
int64_t x = (int64_t)(x32);
const uint32_t* src = (const uint32_t*)(src_argb);
uint32_t* dst = (uint32_t*)(dst_argb);
int j;
for (j = 0; j < dst_width - 1; j += 2) {
int64_t xi = x >> 16;
int xf = (x >> 9) & 0x7f;
uint32_t a = src[xi];
uint32_t b = src[xi + 1];
dst[0] = BLENDER(a, b, xf);
x += dx;
xi = x >> 16;
xf = (x >> 9) & 0x7f;
a = src[xi];
b = src[xi + 1];
dst[1] = BLENDER(a, b, xf);
x += dx;
dst += 2;
}
if (dst_width & 1) {
int64_t xi = x >> 16;
int xf = (x >> 9) & 0x7f;
uint32_t a = src[xi];
uint32_t b = src[xi + 1];
dst[0] = BLENDER(a, b, xf);
}
}
#undef BLENDER1
#undef BLENDERC
#undef BLENDER
// UV scale row functions
// same as ARGB but 2 channels
void ScaleUVRowDown2_C(const uint8_t* src_uv,
ptrdiff_t src_stride,
uint8_t* dst_uv,
int dst_width) {
const uint16_t* src = (const uint16_t*)(src_uv);
uint16_t* dst = (uint16_t*)(dst_uv);
int x;
(void)src_stride;
for (x = 0; x < dst_width - 1; x += 2) {
dst[0] = src[1];
dst[1] = src[3];
src += 2;
dst += 2;
}
if (dst_width & 1) {
dst[0] = src[1];
}
}
void ScaleUVRowDown2Linear_C(const uint8_t* src_uv,
ptrdiff_t src_stride,
uint8_t* dst_uv,
int dst_width) {
int x;
(void)src_stride;
for (x = 0; x < dst_width; ++x) {
dst_uv[0] = (src_uv[0] + src_uv[2] + 1) >> 1;
dst_uv[1] = (src_uv[1] + src_uv[3] + 1) >> 1;
src_uv += 4;
dst_uv += 2;
}
}
void ScaleUVRowDown2Box_C(const uint8_t* src_uv,
ptrdiff_t src_stride,
uint8_t* dst_uv,
int dst_width) {
int x;
for (x = 0; x < dst_width; ++x) {
dst_uv[0] = (src_uv[0] + src_uv[2] + src_uv[src_stride] +
src_uv[src_stride + 2] + 2) >>
2;
dst_uv[1] = (src_uv[1] + src_uv[3] + src_uv[src_stride + 1] +
src_uv[src_stride + 3] + 2) >>
2;
src_uv += 4;
dst_uv += 2;
}
}
void ScaleUVRowDownEven_C(const uint8_t* src_uv,
ptrdiff_t src_stride,
int src_stepx,
uint8_t* dst_uv,
int dst_width) {
const uint16_t* src = (const uint16_t*)(src_uv);
uint16_t* dst = (uint16_t*)(dst_uv);
(void)src_stride;
int x;
for (x = 0; x < dst_width - 1; x += 2) {
dst[0] = src[0];
dst[1] = src[src_stepx];
src += src_stepx * 2;
dst += 2;
}
if (dst_width & 1) {
dst[0] = src[0];
}
}
void ScaleUVRowDownEvenBox_C(const uint8_t* src_uv,
ptrdiff_t src_stride,
int src_stepx,
uint8_t* dst_uv,
int dst_width) {
int x;
for (x = 0; x < dst_width; ++x) {
dst_uv[0] = (src_uv[0] + src_uv[2] + src_uv[src_stride] +
src_uv[src_stride + 2] + 2) >>
2;
dst_uv[1] = (src_uv[1] + src_uv[3] + src_uv[src_stride + 1] +
src_uv[src_stride + 3] + 2) >>
2;
src_uv += src_stepx * 2;
dst_uv += 2;
}
}
// Scales a single row of pixels using point sampling.
void ScaleUVCols_C(uint8_t* dst_uv,
const uint8_t* src_uv,
int dst_width,
int x,
int dx) {
const uint16_t* src = (const uint16_t*)(src_uv);
uint16_t* dst = (uint16_t*)(dst_uv);
int j;
for (j = 0; j < dst_width - 1; j += 2) {
dst[0] = src[x >> 16];
x += dx;
dst[1] = src[x >> 16];
x += dx;
dst += 2;
}
if (dst_width & 1) {
dst[0] = src[x >> 16];
}
}
void ScaleUVCols64_C(uint8_t* dst_uv,
const uint8_t* src_uv,
int dst_width,
int x32,
int dx) {
int64_t x = (int64_t)(x32);
const uint16_t* src = (const uint16_t*)(src_uv);
uint16_t* dst = (uint16_t*)(dst_uv);
int j;
for (j = 0; j < dst_width - 1; j += 2) {
dst[0] = src[x >> 16];
x += dx;
dst[1] = src[x >> 16];
x += dx;
dst += 2;
}
if (dst_width & 1) {
dst[0] = src[x >> 16];
}
}
// Scales a single row of pixels up by 2x using point sampling.
void ScaleUVColsUp2_C(uint8_t* dst_uv,
const uint8_t* src_uv,
int dst_width,
int x,
int dx) {
const uint16_t* src = (const uint16_t*)(src_uv);
uint16_t* dst = (uint16_t*)(dst_uv);
int j;
(void)x;
(void)dx;
for (j = 0; j < dst_width - 1; j += 2) {
dst[1] = dst[0] = src[0];
src += 1;
dst += 2;
}
if (dst_width & 1) {
dst[0] = src[0];
}
}
// TODO(fbarchard): Replace 0x7f ^ f with 128-f. bug=607.
// Mimics SSSE3 blender
#define BLENDER1(a, b, f) ((a) * (0x7f ^ f) + (b)*f) >> 7
#define BLENDERC(a, b, f, s) \
(uint16_t)(BLENDER1(((a) >> s) & 255, ((b) >> s) & 255, f) << s)
#define BLENDER(a, b, f) BLENDERC(a, b, f, 8) | BLENDERC(a, b, f, 0)
void ScaleUVFilterCols_C(uint8_t* dst_uv,
const uint8_t* src_uv,
int dst_width,
int x,
int dx) {
const uint16_t* src = (const uint16_t*)(src_uv);
uint16_t* dst = (uint16_t*)(dst_uv);
int j;
for (j = 0; j < dst_width - 1; j += 2) {
int xi = x >> 16;
int xf = (x >> 9) & 0x7f;
uint16_t a = src[xi];
uint16_t b = src[xi + 1];
dst[0] = BLENDER(a, b, xf);
x += dx;
xi = x >> 16;
xf = (x >> 9) & 0x7f;
a = src[xi];
b = src[xi + 1];
dst[1] = BLENDER(a, b, xf);
x += dx;
dst += 2;
}
if (dst_width & 1) {
int xi = x >> 16;
int xf = (x >> 9) & 0x7f;
uint16_t a = src[xi];
uint16_t b = src[xi + 1];
dst[0] = BLENDER(a, b, xf);
}
}
void ScaleUVFilterCols64_C(uint8_t* dst_uv,
const uint8_t* src_uv,
int dst_width,
int x32,
int dx) {
int64_t x = (int64_t)(x32);
const uint16_t* src = (const uint16_t*)(src_uv);
uint16_t* dst = (uint16_t*)(dst_uv);
int j;
for (j = 0; j < dst_width - 1; j += 2) {
int64_t xi = x >> 16;
int xf = (x >> 9) & 0x7f;
uint16_t a = src[xi];
uint16_t b = src[xi + 1];
dst[0] = BLENDER(a, b, xf);
x += dx;
xi = x >> 16;
xf = (x >> 9) & 0x7f;
a = src[xi];
b = src[xi + 1];
dst[1] = BLENDER(a, b, xf);
x += dx;
dst += 2;
}
if (dst_width & 1) {
int64_t xi = x >> 16;
int xf = (x >> 9) & 0x7f;
uint16_t a = src[xi];
uint16_t b = src[xi + 1];
dst[0] = BLENDER(a, b, xf);
}
}
#undef BLENDER1
#undef BLENDERC
#undef BLENDER
// Scale plane vertically with bilinear interpolation.
void ScalePlaneVertical(int src_height,
int dst_width,
int dst_height,
int src_stride,
int dst_stride,
const uint8_t* src_argb,
uint8_t* dst_argb,
int x,
int y,
int dy,
int bpp,
enum FilterMode filtering) {
// TODO(fbarchard): Allow higher bpp.
int dst_width_bytes = dst_width * bpp;
void (*InterpolateRow)(uint8_t * dst_argb, const uint8_t* src_argb,
ptrdiff_t src_stride, int dst_width,
int source_y_fraction) = InterpolateRow_C;
const int max_y = (src_height > 1) ? ((src_height - 1) << 16) - 1 : 0;
int j;
assert(bpp >= 1 && bpp <= 4);
assert(src_height != 0);
assert(dst_width > 0);
assert(dst_height > 0);
src_argb += (x >> 16) * bpp;
#if defined(HAS_INTERPOLATEROW_SSSE3)
if (TestCpuFlag(kCpuHasSSSE3)) {
InterpolateRow = InterpolateRow_Any_SSSE3;
if (IS_ALIGNED(dst_width_bytes, 16)) {
InterpolateRow = InterpolateRow_SSSE3;
}
}
#endif
#if defined(HAS_INTERPOLATEROW_AVX2)
if (TestCpuFlag(kCpuHasAVX2)) {
InterpolateRow = InterpolateRow_Any_AVX2;
if (IS_ALIGNED(dst_width_bytes, 32)) {
InterpolateRow = InterpolateRow_AVX2;
}
}
#endif
#if defined(HAS_INTERPOLATEROW_NEON)
if (TestCpuFlag(kCpuHasNEON)) {
InterpolateRow = InterpolateRow_Any_NEON;
if (IS_ALIGNED(dst_width_bytes, 16)) {
InterpolateRow = InterpolateRow_NEON;
}
}
#endif
#if defined(HAS_INTERPOLATEROW_MMI)
if (TestCpuFlag(kCpuHasMMI)) {
InterpolateRow = InterpolateRow_Any_MMI;
if (IS_ALIGNED(dst_width_bytes, 8)) {
InterpolateRow = InterpolateRow_MMI;
}
}
#endif
#if defined(HAS_INTERPOLATEROW_MSA)
if (TestCpuFlag(kCpuHasMSA)) {
InterpolateRow = InterpolateRow_Any_MSA;
if (IS_ALIGNED(dst_width_bytes, 32)) {
InterpolateRow = InterpolateRow_MSA;
}
}
#endif
for (j = 0; j < dst_height; ++j) {
int yi;
int yf;
if (y > max_y) {
y = max_y;
}
yi = y >> 16;
yf = filtering ? ((y >> 8) & 255) : 0;
InterpolateRow(dst_argb, src_argb + yi * src_stride, src_stride,
dst_width_bytes, yf);
dst_argb += dst_stride;
y += dy;
}
}
void ScalePlaneVertical_16(int src_height,
int dst_width,
int dst_height,
int src_stride,
int dst_stride,
const uint16_t* src_argb,
uint16_t* dst_argb,
int x,
int y,
int dy,
int wpp,
enum FilterMode filtering) {
// TODO(fbarchard): Allow higher wpp.
int dst_width_words = dst_width * wpp;
void (*InterpolateRow)(uint16_t * dst_argb, const uint16_t* src_argb,
ptrdiff_t src_stride, int dst_width,
int source_y_fraction) = InterpolateRow_16_C;
const int max_y = (src_height > 1) ? ((src_height - 1) << 16) - 1 : 0;
int j;
assert(wpp >= 1 && wpp <= 2);
assert(src_height != 0);
assert(dst_width > 0);
assert(dst_height > 0);
src_argb += (x >> 16) * wpp;
#if defined(HAS_INTERPOLATEROW_16_SSE2)
if (TestCpuFlag(kCpuHasSSE2)) {
InterpolateRow = InterpolateRow_Any_16_SSE2;
if (IS_ALIGNED(dst_width_bytes, 16)) {
InterpolateRow = InterpolateRow_16_SSE2;
}
}
#endif
#if defined(HAS_INTERPOLATEROW_16_SSSE3)
if (TestCpuFlag(kCpuHasSSSE3)) {
InterpolateRow = InterpolateRow_Any_16_SSSE3;
if (IS_ALIGNED(dst_width_bytes, 16)) {
InterpolateRow = InterpolateRow_16_SSSE3;
}
}
#endif
#if defined(HAS_INTERPOLATEROW_16_AVX2)
if (TestCpuFlag(kCpuHasAVX2)) {
InterpolateRow = InterpolateRow_Any_16_AVX2;
if (IS_ALIGNED(dst_width_bytes, 32)) {
InterpolateRow = InterpolateRow_16_AVX2;
}
}
#endif
#if defined(HAS_INTERPOLATEROW_16_NEON)
if (TestCpuFlag(kCpuHasNEON)) {
InterpolateRow = InterpolateRow_Any_16_NEON;
if (IS_ALIGNED(dst_width_bytes, 16)) {
InterpolateRow = InterpolateRow_16_NEON;
}
}
#endif
for (j = 0; j < dst_height; ++j) {
int yi;
int yf;
if (y > max_y) {
y = max_y;
}
yi = y >> 16;
yf = filtering ? ((y >> 8) & 255) : 0;
InterpolateRow(dst_argb, src_argb + yi * src_stride, src_stride,
dst_width_words, yf);
dst_argb += dst_stride;
y += dy;
}
}
// Simplify the filtering based on scale factors.
enum FilterMode ScaleFilterReduce(int src_width,
int src_height,
int dst_width,
int dst_height,
enum FilterMode filtering) {
if (src_width < 0) {
src_width = -src_width;
}
if (src_height < 0) {
src_height = -src_height;
}
if (filtering == kFilterBox) {
// If scaling both axis to 0.5 or larger, switch from Box to Bilinear.
if (dst_width * 2 >= src_width && dst_height * 2 >= src_height) {
filtering = kFilterBilinear;
}
}
if (filtering == kFilterBilinear) {
if (src_height == 1) {
filtering = kFilterLinear;
}
// TODO(fbarchard): Detect any odd scale factor and reduce to Linear.
if (dst_height == src_height || dst_height * 3 == src_height) {
filtering = kFilterLinear;
}
// TODO(fbarchard): Remove 1 pixel wide filter restriction, which is to
// avoid reading 2 pixels horizontally that causes memory exception.
if (src_width == 1) {
filtering = kFilterNone;
}
}
if (filtering == kFilterLinear) {
if (src_width == 1) {
filtering = kFilterNone;
}
// TODO(fbarchard): Detect any odd scale factor and reduce to None.
if (dst_width == src_width || dst_width * 3 == src_width) {
filtering = kFilterNone;
}
}
return filtering;
}
// Divide num by div and return as 16.16 fixed point result.
int FixedDiv_C(int num, int div) {
return (int)(((int64_t)(num) << 16) / div);
}
// Divide num by div and return as 16.16 fixed point result.
int FixedDiv1_C(int num, int div) {
return (int)((((int64_t)(num) << 16) - 0x00010001) / (div - 1));
}
#define CENTERSTART(dx, s) (dx < 0) ? -((-dx >> 1) + s) : ((dx >> 1) + s)
// Compute slope values for stepping.
void ScaleSlope(int src_width,
int src_height,
int dst_width,
int dst_height,
enum FilterMode filtering,
int* x,
int* y,
int* dx,
int* dy) {
assert(x != NULL);
assert(y != NULL);
assert(dx != NULL);
assert(dy != NULL);
assert(src_width != 0);
assert(src_height != 0);
assert(dst_width > 0);
assert(dst_height > 0);
// Check for 1 pixel and avoid FixedDiv overflow.
if (dst_width == 1 && src_width >= 32768) {
dst_width = src_width;
}
if (dst_height == 1 && src_height >= 32768) {
dst_height = src_height;
}
if (filtering == kFilterBox) {
// Scale step for point sampling duplicates all pixels equally.
*dx = FixedDiv(Abs(src_width), dst_width);
*dy = FixedDiv(src_height, dst_height);
*x = 0;
*y = 0;
} else if (filtering == kFilterBilinear) {
// Scale step for bilinear sampling renders last pixel once for upsample.
if (dst_width <= Abs(src_width)) {
*dx = FixedDiv(Abs(src_width), dst_width);
*x = CENTERSTART(*dx, -32768); // Subtract 0.5 (32768) to center filter.
} else if (dst_width > 1) {
*dx = FixedDiv1(Abs(src_width), dst_width);
*x = 0;
}
if (dst_height <= src_height) {
*dy = FixedDiv(src_height, dst_height);
*y = CENTERSTART(*dy, -32768); // Subtract 0.5 (32768) to center filter.
} else if (dst_height > 1) {
*dy = FixedDiv1(src_height, dst_height);
*y = 0;
}
} else if (filtering == kFilterLinear) {
// Scale step for bilinear sampling renders last pixel once for upsample.
if (dst_width <= Abs(src_width)) {
*dx = FixedDiv(Abs(src_width), dst_width);
*x = CENTERSTART(*dx, -32768); // Subtract 0.5 (32768) to center filter.
} else if (dst_width > 1) {
*dx = FixedDiv1(Abs(src_width), dst_width);
*x = 0;
}
*dy = FixedDiv(src_height, dst_height);
*y = *dy >> 1;
} else {
// Scale step for point sampling duplicates all pixels equally.
*dx = FixedDiv(Abs(src_width), dst_width);
*dy = FixedDiv(src_height, dst_height);
*x = CENTERSTART(*dx, 0);
*y = CENTERSTART(*dy, 0);
}
// Negative src_width means horizontally mirror.
if (src_width < 0) {
*x += (dst_width - 1) * *dx;
*dx = -*dx;
// src_width = -src_width; // Caller must do this.
}
}
#undef CENTERSTART
// Read 8x2 upsample with filtering and write 16x1.
// actually reads an extra pixel, so 9x2.
void ScaleRowUp2_16_C(const uint16_t* src_ptr,
ptrdiff_t src_stride,
uint16_t* dst,
int dst_width) {
const uint16_t* src2 = src_ptr + src_stride;
int x;
for (x = 0; x < dst_width - 1; x += 2) {
uint16_t p0 = src_ptr[0];
uint16_t p1 = src_ptr[1];
uint16_t p2 = src2[0];
uint16_t p3 = src2[1];
dst[0] = (p0 * 9 + p1 * 3 + p2 * 3 + p3 + 8) >> 4;
dst[1] = (p0 * 3 + p1 * 9 + p2 + p3 * 3 + 8) >> 4;
++src_ptr;
++src2;
dst += 2;
}
if (dst_width & 1) {
uint16_t p0 = src_ptr[0];
uint16_t p1 = src_ptr[1];
uint16_t p2 = src2[0];
uint16_t p3 = src2[1];
dst[0] = (p0 * 9 + p1 * 3 + p2 * 3 + p3 + 8) >> 4;
}
}
#ifdef __cplusplus
} // extern "C"
} // namespace libyuv
#endif