| 1 | // Copyright 2022 Google Inc. All Rights Reserved. |
|---|
| 2 | // |
|---|
| 3 | // Use of this source code is governed by a BSD-style license |
|---|
| 4 | // that can be found in the COPYING file in the root of the source |
|---|
| 5 | // tree. An additional intellectual property rights grant can be found |
|---|
| 6 | // in the file PATENTS. All contributing project authors may |
|---|
| 7 | // be found in the AUTHORS file in the root of the source tree. |
|---|
| 8 | // ----------------------------------------------------------------------------- |
|---|
| 9 | // |
|---|
| 10 | // Colorspace utilities. |
|---|
| 11 | |
|---|
| 12 | #ifndef WEBP_SHARPYUV_SHARPYUV_CSP_H_ |
|---|
| 13 | #define WEBP_SHARPYUV_SHARPYUV_CSP_H_ |
|---|
| 14 | |
|---|
| 15 | #include "sharpyuv/sharpyuv.h" |
|---|
| 16 | |
|---|
| 17 | #ifdef __cplusplus |
|---|
| 18 | extern "C" { |
|---|
| 19 | #endif |
|---|
| 20 | |
|---|
| 21 | // Range of YUV values. |
|---|
| 22 | typedef enum { |
|---|
| 23 | kSharpYuvRangeFull, // YUV values between [0;255] (for 8 bit) |
|---|
| 24 | kSharpYuvRangeLimited // Y in [16;235], YUV in [16;240] (for 8 bit) |
|---|
| 25 | } SharpYuvRange; |
|---|
| 26 | |
|---|
| 27 | // Constants that define a YUV color space. |
|---|
| 28 | typedef struct { |
|---|
| 29 | // Kr and Kb are defined such that: |
|---|
| 30 | // Y = Kr * r + Kg * g + Kb * b where Kg = 1 - Kr - Kb. |
|---|
| 31 | float kr; |
|---|
| 32 | float kb; |
|---|
| 33 | int bit_depth; // 8, 10 or 12 |
|---|
| 34 | SharpYuvRange range; |
|---|
| 35 | } SharpYuvColorSpace; |
|---|
| 36 | |
|---|
| 37 | // Fills in 'matrix' for the given YUVColorSpace. |
|---|
| 38 | SHARPYUV_EXTERN void SharpYuvComputeConversionMatrix( |
|---|
| 39 | const SharpYuvColorSpace* yuv_color_space, |
|---|
| 40 | SharpYuvConversionMatrix* matrix); |
|---|
| 41 | |
|---|
| 42 | // Enums for precomputed conversion matrices. |
|---|
| 43 | typedef enum { |
|---|
| 44 | kSharpYuvMatrixWebp = 0, |
|---|
| 45 | kSharpYuvMatrixRec601Limited, |
|---|
| 46 | kSharpYuvMatrixRec601Full, |
|---|
| 47 | kSharpYuvMatrixRec709Limited, |
|---|
| 48 | kSharpYuvMatrixRec709Full, |
|---|
| 49 | kSharpYuvMatrixNum |
|---|
| 50 | } SharpYuvMatrixType; |
|---|
| 51 | |
|---|
| 52 | // Returns a pointer to a matrix for one of the predefined colorspaces. |
|---|
| 53 | SHARPYUV_EXTERN const SharpYuvConversionMatrix* SharpYuvGetConversionMatrix( |
|---|
| 54 | SharpYuvMatrixType matrix_type); |
|---|
| 55 | |
|---|
| 56 | #ifdef __cplusplus |
|---|
| 57 | } // extern "C" |
|---|
| 58 | #endif |
|---|
| 59 | |
|---|
| 60 | #endif // WEBP_SHARPYUV_SHARPYUV_CSP_H_ |
|---|
| 61 | |
|---|
