From 7adbef59143af49fb153812d1d0368522e70dcaf Mon Sep 17 00:00:00 2001 From: Jyri Sarha Date: Tue, 9 May 2017 17:37:15 +0300 Subject: Add different YCbCr encodings. --- kms++util/src/color.cpp | 74 +++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 59 insertions(+), 15 deletions(-) (limited to 'kms++util/src/color.cpp') diff --git a/kms++util/src/color.cpp b/kms++util/src/color.cpp index ae8a4b4..2e6f217 100644 --- a/kms++util/src/color.cpp +++ b/kms++util/src/color.cpp @@ -59,11 +59,40 @@ uint16_t RGB::bgr565() const return ((b >> 3) << 11) | ((g >> 2) << 5) | ((r >> 3) << 0); } -YUV RGB::yuv() const -{ - return YUV(*this); -} - +YUV RGB::yuv(YUVType type) const +{ + return YUV(*this, type); +} + +#define CF_ONE (256) +#define CF(a, b, c) { ((int) ((a) * CF_ONE)), ((int) ((b) * CF_ONE)), ((int) ((c) * CF_ONE)) } +#define CLAMP(a) ((a) > (CF_ONE-1) ? (CF_ONE-1) : (a) < 0 ? 0 : (a)) + +const int YUVcoef[static_cast(YUVType::MAX)][3][3] = { + [static_cast(YUVType::BT601_Lim)] = { + CF( 0.257, 0.504, 0.098), + CF(-0.148, -0.291, 0.439), + CF( 0.439, -0.368, -0.071) }, + [static_cast(YUVType::BT601_Full)] = { + CF( 0.299, 0.587, 0.114), + CF(-0.169, -0.331, 0.500), + CF( 0.500, -0.419, -0.081) }, + [static_cast(YUVType::BT709_Lim)] = { + CF( 0.1826, 0.6142, 0.0620), + CF(-0.1006, -0.3386, 0.4392), + CF( 0.4392, -0.3989, -0.0403) }, + [static_cast(YUVType::BT709_Full)] = { + CF( 0.2126, 0.7152, 0.0722), + CF(-0.1146, -0.3854, 0.5000), + CF( 0.5000, -0.4542, -0.0468) }, +}; + +const int YUVoffset[static_cast(YUVType::MAX)][3] = { + [static_cast(YUVType::BT601_Lim)] = CF(0.0625, 0.5, 0.5), + [static_cast(YUVType::BT601_Full)] = CF( 0, 0.5, 0.5), + [static_cast(YUVType::BT709_Lim)] = CF(0.0625, 0.5, 0.5), + [static_cast(YUVType::BT709_Full)] = CF( 0, 0.5, 0.5), +}; YUV::YUV() { @@ -78,26 +107,41 @@ YUV::YUV(uint8_t y, uint8_t u, uint8_t v) this->a = 0; } -static inline uint8_t MAKE_YUV_601_Y(uint8_t r, uint8_t g, uint8_t b) +static inline +uint8_t MAKE_YUV_Y(uint8_t r, uint8_t g, uint8_t b, YUVType type) { - return (((66 * r + 129 * g + 25 * b + 128) >> 8) + 16); + unsigned tidx = static_cast(type); + + return CLAMP(((YUVcoef[tidx][0][0] * r + YUVcoef[tidx][0][1] * g + + YUVcoef[tidx][0][2] * b + CF_ONE/2) / CF_ONE) + + YUVoffset[tidx][0]); } -static inline uint8_t MAKE_YUV_601_U(uint8_t r, uint8_t g, uint8_t b) +static inline +uint8_t MAKE_YUV_U(uint8_t r, uint8_t g, uint8_t b, YUVType type) { - return (((-38 * r - 74 * g + 112 * b + 128) >> 8) + 128); + unsigned tidx = static_cast(type); + + return CLAMP(((YUVcoef[tidx][1][0] * r + YUVcoef[tidx][1][1] * g + + YUVcoef[tidx][1][2] * b + CF_ONE/2) / CF_ONE) + + YUVoffset[tidx][1]); } -static inline uint8_t MAKE_YUV_601_V(uint8_t r, uint8_t g, uint8_t b) +static inline +uint8_t MAKE_YUV_V(uint8_t r, uint8_t g, uint8_t b, YUVType type) { - return (((112 * r - 94 * g - 18 * b + 128) >> 8) + 128); + unsigned tidx = static_cast(type); + + return CLAMP(((YUVcoef[tidx][2][0] * r + YUVcoef[tidx][2][1] * g + + YUVcoef[tidx][2][2] * b + CF_ONE/2) / CF_ONE) + + YUVoffset[tidx][2]); } -YUV::YUV(const RGB& rgb) +YUV::YUV(const RGB& rgb, YUVType type) { - this->y = MAKE_YUV_601_Y(rgb.r, rgb.g, rgb.b); - this->u = MAKE_YUV_601_U(rgb.r, rgb.g, rgb.b); - this->v = MAKE_YUV_601_V(rgb.r, rgb.g, rgb.b); + this->y = MAKE_YUV_Y(rgb.r, rgb.g, rgb.b, type); + this->u = MAKE_YUV_U(rgb.r, rgb.g, rgb.b, type); + this->v = MAKE_YUV_V(rgb.r, rgb.g, rgb.b, type); this->a = rgb.a; } } -- cgit v1.2.3