coeff_order.h (2030B)
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 #ifndef LIB_JXL_COEFF_ORDER_H_ 7 #define LIB_JXL_COEFF_ORDER_H_ 8 9 #include <jxl/memory_manager.h> 10 11 #include <array> 12 #include <cstddef> 13 #include <cstdint> 14 15 #include "lib/jxl/base/compiler_specific.h" 16 #include "lib/jxl/base/status.h" 17 #include "lib/jxl/coeff_order_fwd.h" 18 #include "lib/jxl/frame_dimensions.h" 19 20 namespace jxl { 21 22 class BitReader; 23 24 // Those offsets get multiplied by kDCTBlockSize. 25 26 static constexpr size_t kCoeffOrderLimit = 6156; 27 28 static constexpr std::array<size_t, 3 * kNumOrders + 1> JXL_MAYBE_UNUSED 29 kCoeffOrderOffset = { 30 0, 1, 2, 3, 4, 5, 6, 10, 14, 18, 31 34, 50, 66, 68, 70, 72, 76, 80, 84, 92, 32 100, 108, 172, 236, 300, 332, 364, 396, 652, 908, 33 1164, 1292, 1420, 1548, 2572, 3596, 4620, 5132, 5644, kCoeffOrderLimit}; 34 35 // TODO(eustas): rollback to constexpr once modern C++ becomes required. 36 #define CoeffOrderOffset(O, C) \ 37 (kCoeffOrderOffset[3 * (O) + (C)] * kDCTBlockSize) 38 39 static JXL_MAYBE_UNUSED constexpr size_t kCoeffOrderMaxSize = 40 kCoeffOrderLimit * kDCTBlockSize; 41 42 // Mapping from AC strategy to order bucket. Strategies with different natural 43 // orders must have different buckets. 44 constexpr std::array<uint8_t, 27> kStrategyOrder = { 45 0, 1, 1, 1, 2, 3, 4, 4, 5, 5, 6, 6, 1, 1, 46 1, 1, 1, 1, 7, 8, 8, 9, 10, 10, 11, 12, 12, 47 }; 48 49 constexpr JXL_MAYBE_UNUSED uint32_t kPermutationContexts = 8; 50 51 uint32_t CoeffOrderContext(uint32_t val); 52 53 Status DecodeCoeffOrders(JxlMemoryManager* memory_manager, uint16_t used_orders, 54 uint32_t used_acs, coeff_order_t* order, 55 BitReader* br); 56 57 Status DecodePermutation(JxlMemoryManager* memory_manager, size_t skip, 58 size_t size, coeff_order_t* order, BitReader* br); 59 60 } // namespace jxl 61 62 #endif // LIB_JXL_COEFF_ORDER_H_