rct.cc (5075B)
1 // Copyright (c) the JPEG XL Project Authors. All rights reserved. 2 // 3 // Use of this source code is governed by a BSD-style 4 // license that can be found in the LICENSE file. 5 6 #include "lib/jxl/modular/transform/rct.h" 7 #undef HWY_TARGET_INCLUDE 8 #define HWY_TARGET_INCLUDE "lib/jxl/modular/transform/rct.cc" 9 #include <hwy/foreach_target.h> 10 #include <hwy/highway.h> 11 HWY_BEFORE_NAMESPACE(); 12 namespace jxl { 13 namespace HWY_NAMESPACE { 14 15 // These templates are not found via ADL. 16 using hwy::HWY_NAMESPACE::Add; 17 using hwy::HWY_NAMESPACE::ShiftRight; 18 using hwy::HWY_NAMESPACE::Sub; 19 20 template <int transform_type> 21 void InvRCTRow(const pixel_type* in0, const pixel_type* in1, 22 const pixel_type* in2, pixel_type* out0, pixel_type* out1, 23 pixel_type* out2, size_t w) { 24 static_assert(transform_type >= 0 && transform_type < 7, 25 "Invalid transform type"); 26 int second = transform_type >> 1; 27 int third = transform_type & 1; 28 29 size_t x = 0; 30 const HWY_FULL(pixel_type) d; 31 const size_t N = Lanes(d); 32 for (; x + N - 1 < w; x += N) { 33 if (transform_type == 6) { 34 auto Y = Load(d, in0 + x); 35 auto Co = Load(d, in1 + x); 36 auto Cg = Load(d, in2 + x); 37 Y = Sub(Y, ShiftRight<1>(Cg)); 38 auto G = Add(Cg, Y); 39 Y = Sub(Y, ShiftRight<1>(Co)); 40 auto R = Add(Y, Co); 41 Store(R, d, out0 + x); 42 Store(G, d, out1 + x); 43 Store(Y, d, out2 + x); 44 } else { 45 auto First = Load(d, in0 + x); 46 auto Second = Load(d, in1 + x); 47 auto Third = Load(d, in2 + x); 48 if (third) Third = Add(Third, First); 49 if (second == 1) { 50 Second = Add(Second, First); 51 } else if (second == 2) { 52 Second = Add(Second, ShiftRight<1>(Add(First, Third))); 53 } 54 Store(First, d, out0 + x); 55 Store(Second, d, out1 + x); 56 Store(Third, d, out2 + x); 57 } 58 } 59 for (; x < w; x++) { 60 if (transform_type == 6) { 61 pixel_type Y = in0[x]; 62 pixel_type Co = in1[x]; 63 pixel_type Cg = in2[x]; 64 pixel_type tmp = PixelAdd(Y, -(Cg >> 1)); 65 pixel_type G = PixelAdd(Cg, tmp); 66 pixel_type B = PixelAdd(tmp, -(Co >> 1)); 67 pixel_type R = PixelAdd(B, Co); 68 out0[x] = R; 69 out1[x] = G; 70 out2[x] = B; 71 } else { 72 pixel_type First = in0[x]; 73 pixel_type Second = in1[x]; 74 pixel_type Third = in2[x]; 75 if (third) Third = PixelAdd(Third, First); 76 if (second == 1) { 77 Second = PixelAdd(Second, First); 78 } else if (second == 2) { 79 Second = PixelAdd(Second, (PixelAdd(First, Third) >> 1)); 80 } 81 out0[x] = First; 82 out1[x] = Second; 83 out2[x] = Third; 84 } 85 } 86 } 87 88 Status InvRCT(Image& input, size_t begin_c, size_t rct_type, ThreadPool* pool) { 89 JXL_RETURN_IF_ERROR(CheckEqualChannels(input, begin_c, begin_c + 2)); 90 size_t m = begin_c; 91 Channel& c0 = input.channel[m + 0]; 92 size_t w = c0.w; 93 size_t h = c0.h; 94 if (rct_type == 0) { // noop 95 return true; 96 } 97 // Permutation: 0=RGB, 1=GBR, 2=BRG, 3=RBG, 4=GRB, 5=BGR 98 int permutation = rct_type / 7; 99 JXL_ENSURE(permutation < 6); 100 // 0-5 values have the low bit corresponding to Third and the high bits 101 // corresponding to Second. 6 corresponds to YCoCg. 102 // 103 // Second: 0=nop, 1=SubtractFirst, 2=SubtractAvgFirstThird 104 // 105 // Third: 0=nop, 1=SubtractFirst 106 int custom = rct_type % 7; 107 // Special case: permute-only. Swap channels around. 108 if (custom == 0) { 109 Channel ch0 = std::move(input.channel[m]); 110 Channel ch1 = std::move(input.channel[m + 1]); 111 Channel ch2 = std::move(input.channel[m + 2]); 112 input.channel[m + (permutation % 3)] = std::move(ch0); 113 input.channel[m + ((permutation + 1 + permutation / 3) % 3)] = 114 std::move(ch1); 115 input.channel[m + ((permutation + 2 - permutation / 3) % 3)] = 116 std::move(ch2); 117 return true; 118 } 119 constexpr decltype(&InvRCTRow<0>) inv_rct_row[] = { 120 InvRCTRow<0>, InvRCTRow<1>, InvRCTRow<2>, InvRCTRow<3>, 121 InvRCTRow<4>, InvRCTRow<5>, InvRCTRow<6>}; 122 const auto process_row = [&](const uint32_t task, 123 size_t /* thread */) -> Status { 124 const size_t y = task; 125 const pixel_type* in0 = input.channel[m].Row(y); 126 const pixel_type* in1 = input.channel[m + 1].Row(y); 127 const pixel_type* in2 = input.channel[m + 2].Row(y); 128 pixel_type* out0 = input.channel[m + (permutation % 3)].Row(y); 129 pixel_type* out1 = 130 input.channel[m + ((permutation + 1 + permutation / 3) % 3)].Row(y); 131 pixel_type* out2 = 132 input.channel[m + ((permutation + 2 - permutation / 3) % 3)].Row(y); 133 inv_rct_row[custom](in0, in1, in2, out0, out1, out2, w); 134 return true; 135 }; 136 JXL_RETURN_IF_ERROR( 137 RunOnPool(pool, 0, h, ThreadPool::NoInit, process_row, "InvRCT")); 138 return true; 139 } 140 141 } // namespace HWY_NAMESPACE 142 } // namespace jxl 143 HWY_AFTER_NAMESPACE(); 144 145 #if HWY_ONCE 146 namespace jxl { 147 148 HWY_EXPORT(InvRCT); 149 Status InvRCT(Image& input, size_t begin_c, size_t rct_type, ThreadPool* pool) { 150 return HWY_DYNAMIC_DISPATCH(InvRCT)(input, begin_c, rct_type, pool); 151 } 152 153 } // namespace jxl 154 #endif