Quelle  enc_coeff_order.h   Sprache: C

// Copyright (c) the JPEG XL 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.

#ifndef LIB_JXL_ENC_COEFF_ORDER_H_
#define LIB_JXL_ENC_COEFF_ORDER_H_

#include <cstddef>
#include <cstdint>
#include <utility>

#include "lib/jxl/base/compiler_specific.h"
#include "lib/jxl/base/rect.h"
#include "lib/jxl/base/status.h"
#include "lib/jxl/coeff_order_fwd.h"
#include "lib/jxl/common.h"
#include "lib/jxl/dct_util.h"
#include "lib/jxl/enc_bit_writer.h"
#include "lib/jxl/frame_dimensions.h"

namespace jxl {

struct AuxOut;
class AcStrategyImage;
enum class LayerType : uint8_t;

// Orders that are actually used in part of image. `rect` is in block units.
// Returns {orders that are used, orders that might be made non-default}.
std::pair<uint32_t, uint32_t> ComputeUsedOrders(
    SpeedTier speed, const AcStrategyImage& ac_strategy, const Rect& rect);

// Modify zig-zag order, so that DCT bands with more zeros go later.
// Order of DCT bands with same number of zeros is untouched, so
// permutation will be cheaper to encode.
Status ComputeCoeffOrder(SpeedTier speed, const ACImage& acs,
                         const AcStrategyImage& ac_strategy,
                         const FrameDimensions& frame_dim,
                         uint32_t& all_used_orders, uint32_t prev_used_acs,
                         uint32_t current_used_acs,
                         uint32_t current_used_orders,
                         coeff_order_t* JXL_RESTRICT order);

Status EncodeCoeffOrders(uint16_t used_orders,
                         const coeff_order_t* JXL_RESTRICT order,
                         BitWriter* writer, LayerType layer,
                         AuxOut* JXL_RESTRICT aux_out);

// Encoding/decoding of a single permutation. `size`: number of elements in the
// permutation. `skip`: number of elements to skip from the *beginning* of the
// permutation.
Status EncodePermutation(const coeff_order_t* JXL_RESTRICT order, size_t skip,
                         size_t size, BitWriter* writer, LayerType layer,
                         AuxOut* aux_out);

}  // namespace jxl

#endif  // LIB_JXL_ENC_COEFF_ORDER_H_