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Implement more transfer functions in libsharpyuv

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This is inspired by https://github.com/AOMediaCodec/libavif/pull/444/files

Change-Id: I98fae61696b3b8bbc1b5941e7950810d3ac3d588
This commit is contained in:
Vincent Rabaud
2023-06-22 23:09:44 +02:00
parent 2153a6797c
commit 25d94f473b
4 changed files with 409 additions and 35 deletions
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44
sharpyuv/sharpyuv.h
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@ -36,7 +36,7 @@ extern "C" {
// SharpYUV API version following the convention from semver.org
#define SHARPYUV_VERSION_MAJOR 0
#define SHARPYUV_VERSION_MINOR 2
#define SHARPYUV_VERSION_MINOR 3
#define SHARPYUV_VERSION_PATCH 0
// Version as a uint32_t. The major number is the high 8 bits.
// The minor number is the middle 8 bits. The patch number is the low 16 bits.
@ -61,6 +61,33 @@ typedef struct {
int rgb_to_v[4];
} SharpYuvConversionMatrix;
typedef struct SharpYuvOptions SharpYuvOptions;
// Enums for transfer functions, as defined in H.273,
// https://www.itu.int/rec/T-REC-H.273-202107-I/en
typedef enum SharpYuvTransferFunctionType {
// 0 is reserved
kSharpYuvTransferFunctionBt709 = 1,
// 2 is unspecified
// 3 is reserved
kSharpYuvTransferFunctionBt470M = 4,
kSharpYuvTransferFunctionBt470Bg = 5,
kSharpYuvTransferFunctionBt601 = 6,
kSharpYuvTransferFunctionSmpte240 = 7,
kSharpYuvTransferFunctionLinear = 8,
kSharpYuvTransferFunctionLog100 = 9,
kSharpYuvTransferFunctionLog100_Sqrt10 = 10,
kSharpYuvTransferFunctionIec61966 = 11,
kSharpYuvTransferFunctionBt1361 = 12,
kSharpYuvTransferFunctionSrgb = 13,
kSharpYuvTransferFunctionBt2020_10Bit = 14,
kSharpYuvTransferFunctionBt2020_12Bit = 15,
kSharpYuvTransferFunctionSmpte2084 = 16, // PQ
kSharpYuvTransferFunctionSmpte428 = 17,
kSharpYuvTransferFunctionHlg = 18,
kSharpYuvTransferFunctionNum
} SharpYuvTransferFunctionType;
// Converts RGB to YUV420 using a downsampling algorithm that minimizes
// artefacts caused by chroma subsampling.
// This is slower than standard downsampling (averaging of 4 UV values).
@ -85,6 +112,8 @@ typedef struct {
// adjacent pixels on the y, u and v channels. If yuv_bit_depth > 8, they
// should be multiples of 2.
// width, height: width and height of the image in pixels
// This function calls SharpYuvConvertWithOptions with a default transfer
// function of kSharpYuvTransferFunctionSRGB.
SHARPYUV_EXTERN int SharpYuvConvert(const void* r_ptr, const void* g_ptr,
const void* b_ptr, int rgb_step,
int rgb_stride, int rgb_bit_depth,
@ -93,6 +122,19 @@ SHARPYUV_EXTERN int SharpYuvConvert(const void* r_ptr, const void* g_ptr,
int yuv_bit_depth, int width, int height,
const SharpYuvConversionMatrix* yuv_matrix);
struct SharpYuvOptions {
// This matrix cannot be NULL and can be initialized by
// SharpYuvComputeConversionMatrix.
const SharpYuvConversionMatrix* yuv_matrix;
SharpYuvTransferFunctionType transfer_type;
};
SHARPYUV_EXTERN int SharpYuvConvertWithOptions(
const void* r_ptr, const void* g_ptr, const void* b_ptr, int rgb_step,
int rgb_stride, int rgb_bit_depth, void* y_ptr, int y_stride, void* u_ptr,
int u_stride, void* v_ptr, int v_stride, int yuv_bit_depth, int width,
int height, const SharpYuvOptions* options);
// TODO(b/194336375): Add YUV444 to YUV420 conversion. Maybe also add 422
// support (it's rarely used in practice, especially for images).