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Diffstat (limited to '')
-rw-r--r-- | third_party/jpeg-xl/lib/jxl/coeff_order_fwd.h | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/third_party/jpeg-xl/lib/jxl/coeff_order_fwd.h b/third_party/jpeg-xl/lib/jxl/coeff_order_fwd.h new file mode 100644 index 0000000000..26306575c1 --- /dev/null +++ b/third_party/jpeg-xl/lib/jxl/coeff_order_fwd.h @@ -0,0 +1,47 @@ +// 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_COEFF_ORDER_FWD_H_ +#define LIB_JXL_COEFF_ORDER_FWD_H_ + +// Breaks circular dependency between ac_strategy and coeff_order. + +#include <stddef.h> +#include <stdint.h> + +#include "lib/jxl/base/compiler_specific.h" + +namespace jxl { + +// Needs at least 16 bits. A 32-bit type speeds up DecodeAC by 2% at the cost of +// more memory. +using coeff_order_t = uint32_t; + +// Maximum number of orders to be used. Note that this needs to be multiplied by +// the number of channels. One per "size class" (plus one extra for DCT8), +// shared between transforms of size XxY and of size YxX. +constexpr uint8_t kNumOrders = 13; + +// DCT coefficients are laid out in such a way that the number of rows of +// coefficients is always the smaller coordinate. +JXL_INLINE constexpr size_t CoefficientRows(size_t rows, size_t columns) { + return rows < columns ? rows : columns; +} + +JXL_INLINE constexpr size_t CoefficientColumns(size_t rows, size_t columns) { + return rows < columns ? columns : rows; +} + +JXL_INLINE void CoefficientLayout(size_t* JXL_RESTRICT rows, + size_t* JXL_RESTRICT columns) { + size_t r = *rows; + size_t c = *columns; + *rows = CoefficientRows(r, c); + *columns = CoefficientColumns(r, c); +} + +} // namespace jxl + +#endif // LIB_JXL_COEFF_ORDER_FWD_H_ |