jpayne@69: // Copyright 2022 Google Inc. All Rights Reserved.
jpayne@69: //
jpayne@69: // Use of this source code is governed by a BSD-style license
jpayne@69: // that can be found in the COPYING file in the root of the source
jpayne@69: // tree. An additional intellectual property rights grant can be found
jpayne@69: // in the file PATENTS. All contributing project authors may
jpayne@69: // be found in the AUTHORS file in the root of the source tree.
jpayne@69: // -----------------------------------------------------------------------------
jpayne@69: //
jpayne@69: // Colorspace utilities.
jpayne@69: 
jpayne@69: #ifndef WEBP_SHARPYUV_SHARPYUV_CSP_H_
jpayne@69: #define WEBP_SHARPYUV_SHARPYUV_CSP_H_
jpayne@69: 
jpayne@69: #include "sharpyuv/sharpyuv.h"
jpayne@69: 
jpayne@69: #ifdef __cplusplus
jpayne@69: extern "C" {
jpayne@69: #endif
jpayne@69: 
jpayne@69: // Range of YUV values.
jpayne@69: typedef enum {
jpayne@69:   kSharpYuvRangeFull,     // YUV values between [0;255] (for 8 bit)
jpayne@69:   kSharpYuvRangeLimited   // Y in [16;235], YUV in [16;240] (for 8 bit)
jpayne@69: } SharpYuvRange;
jpayne@69: 
jpayne@69: // Constants that define a YUV color space.
jpayne@69: typedef struct {
jpayne@69:   // Kr and Kb are defined such that:
jpayne@69:   // Y = Kr * r + Kg * g + Kb * b where Kg = 1 - Kr - Kb.
jpayne@69:   float kr;
jpayne@69:   float kb;
jpayne@69:   int bit_depth;  // 8, 10 or 12
jpayne@69:   SharpYuvRange range;
jpayne@69: } SharpYuvColorSpace;
jpayne@69: 
jpayne@69: // Fills in 'matrix' for the given YUVColorSpace.
jpayne@69: SHARPYUV_EXTERN void SharpYuvComputeConversionMatrix(
jpayne@69:     const SharpYuvColorSpace* yuv_color_space,
jpayne@69:     SharpYuvConversionMatrix* matrix);
jpayne@69: 
jpayne@69: // Enums for precomputed conversion matrices.
jpayne@69: typedef enum {
jpayne@69:   // WebP's matrix, similar but not identical to kSharpYuvMatrixRec601Limited
jpayne@69:   kSharpYuvMatrixWebp = 0,
jpayne@69:   // Kr=0.2990f Kb=0.1140f bit_depth=8 range=kSharpYuvRangeLimited
jpayne@69:   kSharpYuvMatrixRec601Limited,
jpayne@69:   // Kr=0.2990f Kb=0.1140f bit_depth=8 range=kSharpYuvRangeFull
jpayne@69:   kSharpYuvMatrixRec601Full,
jpayne@69:   // Kr=0.2126f Kb=0.0722f bit_depth=8 range=kSharpYuvRangeLimited
jpayne@69:   kSharpYuvMatrixRec709Limited,
jpayne@69:   // Kr=0.2126f Kb=0.0722f bit_depth=8 range=kSharpYuvRangeFull
jpayne@69:   kSharpYuvMatrixRec709Full,
jpayne@69:   kSharpYuvMatrixNum
jpayne@69: } SharpYuvMatrixType;
jpayne@69: 
jpayne@69: // Returns a pointer to a matrix for one of the predefined colorspaces.
jpayne@69: SHARPYUV_EXTERN const SharpYuvConversionMatrix* SharpYuvGetConversionMatrix(
jpayne@69:     SharpYuvMatrixType matrix_type);
jpayne@69: 
jpayne@69: #ifdef __cplusplus
jpayne@69: }  // extern "C"
jpayne@69: #endif
jpayne@69: 
jpayne@69: #endif  // WEBP_SHARPYUV_SHARPYUV_CSP_H_