| /* |
| * 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/planar_functions.h" // For CopyARGB |
| #include "libyuv/row.h" |
| #include "libyuv/scale_row.h" |
| |
| static __inline int Abs(int v) { |
| return v >= 0 ? v : -v; |
| } |
| |
| // Sample position: (O is src sample position, X is dst sample position) |
| // |
| // v dst_ptr at here v stop at here |
| // X O X X O X X O X X O X X O X |
| // ^ src_ptr at here |
| void ScaleRowUp2_Linear_C(const uint8_t* src_ptr, |
| uint8_t* dst_ptr, |
| int dst_width) { |
| int src_width = dst_width >> 1; |
| int x; |
| assert((dst_width % 2 == 0) && (dst_width >= 0)); |
| for (x = 0; x < src_width; ++x) { |
| dst_ptr[2 * x + 0] = (src_ptr[x + 0] * 3 + src_ptr[x + 1] * 1 + 2) >> 2; |
| dst_ptr[2 * x + 1] = (src_ptr[x + 0] * 1 + src_ptr[x + 1] * 3 + 2) >> 2; |
| } |
| } |
| |
| // Sample position: (O is src sample position, X is dst sample position) |
| // |
| // src_ptr at here |
| // X v X X X X X X X X X |
| // O O O O O |
| // X X X X X X X X X X |
| // ^ dst_ptr at here ^ stop at here |
| // X X X X X X X X X X |
| // O O O O O |
| // X X X X X X X X X X |
| void ScaleRowUp2_Bilinear_C(const uint8_t* src_ptr, |
| ptrdiff_t src_stride, |
| uint8_t* dst_ptr, |
| ptrdiff_t dst_stride, |
| int dst_width) { |
| const uint8_t* s = src_ptr; |
| const uint8_t* t = src_ptr + src_stride; |
| uint8_t* d = dst_ptr; |
| uint8_t* e = dst_ptr + dst_stride; |
| int src_width = dst_width >> 1; |
| int x; |
| assert((dst_width % 2 == 0) && (dst_width >= 0)); |
| for (x = 0; x < src_width; ++x) { |
| d[2 * x + 0] = |
| (s[x + 0] * 9 + s[x + 1] * 3 + t[x + 0] * 3 + t[x + 1] * 1 + 8) >> 4; |
| d[2 * x + 1] = |
| (s[x + 0] * 3 + s[x + 1] * 9 + t[x + 0] * 1 + t[x + 1] * 3 + 8) >> 4; |
| e[2 * x + 0] = |
| (s[x + 0] * 3 + s[x + 1] * 1 + t[x + 0] * 9 + t[x + 1] * 3 + 8) >> 4; |
| e[2 * x + 1] = |
| (s[x + 0] * 1 + s[x + 1] * 3 + t[x + 0] * 3 + t[x + 1] * 9 + 8) >> 4; |
| } |
| } |
| |
| // Only suitable for at most 14 bit range. |
| void ScaleRowUp2_Linear_16_C(const uint16_t* src_ptr, |
| uint16_t* dst_ptr, |
| int dst_width) { |
| int src_width = dst_width >> 1; |
| int x; |
| assert((dst_width % 2 == 0) && (dst_width >= 0)); |
| for (x = 0; x < src_width; ++x) { |
| dst_ptr[2 * x + 0] = (src_ptr[x + 0] * 3 + src_ptr[x + 1] * 1 + 2) >> 2; |
| dst_ptr[2 * x + 1] = (src_ptr[x + 0] * 1 + src_ptr[x + 1] * 3 + 2) >> 2; |
| } |
| } |
| |
| // Only suitable for at most 12bit range. |
| void ScaleRowUp2_Bilinear_16_C(const uint16_t* src_ptr, |
| ptrdiff_t src_stride, |
| uint16_t* dst_ptr, |
| ptrdiff_t dst_stride, |
| int dst_width) { |
| const uint16_t* s = src_ptr; |
| const uint16_t* t = src_ptr + src_stride; |
| uint16_t* d = dst_ptr; |
| uint16_t* e = dst_ptr + dst_stride; |
| int src_width = dst_width >> 1; |
| int x; |
| assert((dst_width % 2 == 0) && (dst_width >= 0)); |
| for (x = 0; x < src_width; ++x) { |
| d[2 * x + 0] = |
| (s[x + 0] * 9 + s[x + 1] * 3 + t[x + 0] * 3 + t[x + 1] * 1 + 8) >> 4; |
| d[2 * x + 1] = |
| (s[x + 0] * 3 + s[x + 1] * 9 + t[x + 0] * 1 + t[x + 1] * 3 + 8) >> 4; |
| e[2 * x + 0] = |
| (s[x + 0] * 3 + s[x + 1] * 1 + t[x + 0] * 9 + t[x + 1] * 3 + 8) >> 4; |
| e[2 * x + 1] = |
| (s[x + 0] * 1 + s[x + 1] * 3 + t[x + 0] * 3 + t[x + 1] * 9 + 8) >> 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 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]; |
| } |
| } |
| |
| |
| // 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, // bytes per pixel. 4 for ARGB. |
| 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; |
| |
| 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, /* words per pixel. normally 1 */ |
| 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; |
| 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 either 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 - 1 by div - 1 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 (src_width > 1 && 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 (src_height > 1 && 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 (src_width > 1 && 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 |
