1 /* 2 * Copyright 2020 The libgav1 Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef LIBGAV1_SRC_UTILS_REFERENCE_INFO_H_ 18 #define LIBGAV1_SRC_UTILS_REFERENCE_INFO_H_ 19 20 #include <array> 21 #include <cstdint> 22 23 #include "src/utils/array_2d.h" 24 #include "src/utils/compiler_attributes.h" 25 #include "src/utils/constants.h" 26 #include "src/utils/types.h" 27 28 namespace libgav1 { 29 30 // This struct collects some members related to reference frames in one place to 31 // make it easier to pass them as parameters to some dsp functions. 32 struct ReferenceInfo { 33 // Initialize |motion_field_reference_frame| so that 34 // Tile::StoreMotionFieldMvsIntoCurrentFrame() can skip some updates when 35 // the updates are the same as the initialized value. 36 // Set to kReferenceFrameIntra instead of kReferenceFrameNone to simplify 37 // branch conditions in motion field projection. 38 // The following memory initialization of contiguous memory is very fast. It 39 // is not recommended to make the initialization multi-threaded, unless the 40 // memory which needs to be initialized in each thread is still contiguous. ResetReferenceInfo41 LIBGAV1_MUST_USE_RESULT bool Reset(int rows, int columns) { 42 return motion_field_reference_frame.Reset(rows, columns, 43 /*zero_initialize=*/true) && 44 motion_field_mv.Reset( 45 rows, columns, 46 #if LIBGAV1_MSAN 47 // It is set in Tile::StoreMotionFieldMvsIntoCurrentFrame() only 48 // for qualified blocks. In MotionFieldProjectionKernel() dsp 49 // optimizations, it is read no matter it was set or not. 50 /*zero_initialize=*/true 51 #else 52 /*zero_initialize=*/false 53 #endif 54 ); 55 } 56 57 // All members are used by inter frames only. 58 // For intra frames, they are not initialized. 59 60 std::array<uint8_t, kNumReferenceFrameTypes> order_hint; 61 62 // An example when |relative_distance_from| does not equal 63 // -|relative_distance_to|: 64 // |relative_distance_from| = GetRelativeDistance(7, 71, 25) = -64 65 // -|relative_distance_to| = -GetRelativeDistance(71, 7, 25) = 64 66 // This is why we need both |relative_distance_from| and 67 // |relative_distance_to|. 68 // |relative_distance_from|: Relative distances from reference frames to this 69 // frame. 70 std::array<int8_t, kNumReferenceFrameTypes> relative_distance_from; 71 // |relative_distance_to|: Relative distances to reference frames. 72 std::array<int8_t, kNumReferenceFrameTypes> relative_distance_to; 73 74 // Skip motion field projection of specific types of frames if their 75 // |relative_distance_to| is negative or too large. 76 std::array<bool, kNumReferenceFrameTypes> skip_references; 77 // Lookup table to get motion field projection division multiplier of specific 78 // types of frames. Derived from kProjectionMvDivisionLookup. 79 std::array<int16_t, kNumReferenceFrameTypes> projection_divisions; 80 81 // The current frame's |motion_field_reference_frame| and |motion_field_mv_| 82 // are guaranteed to be allocated only when refresh_frame_flags is not 0. 83 // Array of size (rows4x4 / 2) x (columns4x4 / 2). Entry at i, j corresponds 84 // to MfRefFrames[i * 2 + 1][j * 2 + 1] in the spec. 85 Array2D<ReferenceFrameType> motion_field_reference_frame; 86 // Array of size (rows4x4 / 2) x (columns4x4 / 2). Entry at i, j corresponds 87 // to MfMvs[i * 2 + 1][j * 2 + 1] in the spec. 88 Array2D<MotionVector> motion_field_mv; 89 }; 90 91 } // namespace libgav1 92 93 #endif // LIBGAV1_SRC_UTILS_REFERENCE_INFO_H_ 94