yuv-to-rgb.c is not correct though it is faster

yuv_rgb.h

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+// Copyright 2016 Adrien Descamps
+// Distributed under BSD 3-Clause License
+
+// Provide optimized functions to convert images from 8bits yuv420 to rgb24 format
+
+// There are a few slightly different variations of the YCbCr color space with different parameters that 
+// change the conversion matrix.
+// The three most common YCbCr color space, defined by BT.601, BT.709 and JPEG standard are implemented here.
+// See the respective standards for details
+// The matrix values used are derived from http://www.equasys.de/colorconversion.html
+
+// YUV420 is stored as three separate channels, with U and V (Cb and Cr) subsampled by a 2 factor
+// For conversion from yuv to rgb, no interpolation is done, and the same UV value are used for 4 rgb pixels. This 
+// is suboptimal for image quality, but by far the fastest method.
+
+// For all methods, width and height should be even, if not, the last row/column of the result image won't be affected.
+// For sse methods, if the width if not divisable by 32, the last (width%32) pixels of each line won't be affected.
+
+#include <stdint.h>
+
+typedef enum
+{
+	YCBCR_JPEG,
+	YCBCR_601,
+	YCBCR_709
+} YCbCrType;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// yuv to rgb, standard c implementation
+void yuv420_rgb24_std(
+	uint32_t width, uint32_t height, 
+	const uint8_t *y, const uint8_t *u, const uint8_t *v, uint32_t y_stride, uint32_t uv_stride, 
+	uint8_t *rgb, uint32_t rgb_stride, 
+	YCbCrType yuv_type);
+
+// yuv to rgb, yuv in nv12 semi planar format
+void nv12_rgb24_std(
+	uint32_t width, uint32_t height,
+	const uint8_t *y, const uint8_t *uv, uint32_t y_stride, uint32_t uv_stride,
+	uint8_t *rgb, uint32_t rgb_stride,
+	YCbCrType yuv_type);
+
+// yuv to rgb, yuv in nv12 semi planar format
+void nv21_rgb24_std(
+	uint32_t width, uint32_t height,
+	const uint8_t *y, const uint8_t *uv, uint32_t y_stride, uint32_t uv_stride,
+	uint8_t *rgb, uint32_t rgb_stride,
+	YCbCrType yuv_type);
+
+// yuv to rgb, sse implementation
+// pointers must be 16 byte aligned, and strides must be divisable by 16
+void yuv420_rgb24_sse(
+	uint32_t width, uint32_t height, 
+	const uint8_t *y, const uint8_t *u, const uint8_t *v, uint32_t y_stride, uint32_t uv_stride, 
+	uint8_t *rgb, uint32_t rgb_stride, 
+	YCbCrType yuv_type);
+
+// yuv to rgb, sse implementation
+// pointers do not need to be 16 byte aligned
+void yuv420_rgb24_sseu(
+	uint32_t width, uint32_t height, 
+	const uint8_t *y, const uint8_t *u, const uint8_t *v, uint32_t y_stride, uint32_t uv_stride, 
+	uint8_t *rgb, uint32_t rgb_stride, 
+	YCbCrType yuv_type);
+
+// yuv nv12 to rgb, sse implementation
+// pointers must be 16 byte aligned, and strides must be divisable by 16
+void nv12_rgb24_sse(
+	uint32_t width, uint32_t height, 
+	const uint8_t *y, const uint8_t *uv, uint32_t y_stride, uint32_t uv_stride, 
+	uint8_t *rgb, uint32_t rgb_stride, 
+	YCbCrType yuv_type);
+
+// yuv nv12 to rgb, sse implementation
+// pointers do not need to be 16 byte aligned
+void nv12_rgb24_sseu(
+	uint32_t width, uint32_t height, 
+	const uint8_t *y, const uint8_t *uv, uint32_t y_stride, uint32_t uv_stride, 
+	uint8_t *rgb, uint32_t rgb_stride, 
+	YCbCrType yuv_type);
+
+// yuv nv21 to rgb, sse implementation
+// pointers must be 16 byte aligned, and strides must be divisable by 16
+void nv21_rgb24_sse(
+	uint32_t width, uint32_t height, 
+	const uint8_t *y, const uint8_t *uv, uint32_t y_stride, uint32_t uv_stride, 
+	uint8_t *rgb, uint32_t rgb_stride, 
+	YCbCrType yuv_type);
+
+// yuv nv21 to rgb, sse implementation
+// pointers do not need to be 16 byte aligned
+void nv21_rgb24_sseu(
+	uint32_t width, uint32_t height, 
+	const uint8_t *y, const uint8_t *uv, uint32_t y_stride, uint32_t uv_stride, 
+	uint8_t *rgb, uint32_t rgb_stride, 
+	YCbCrType yuv_type);
+
+
+
+
+// rgb to yuv, standard c implementation
+void rgb24_yuv420_std(
+	uint32_t width, uint32_t height, 
+	const uint8_t *rgb, uint32_t rgb_stride, 
+	uint8_t *y, uint8_t *u, uint8_t *v, uint32_t y_stride, uint32_t uv_stride, 
+	YCbCrType yuv_type);
+
+// rgb to yuv, sse implementation
+// pointers must be 16 byte aligned, and strides must be divisible by 16
+void rgb24_yuv420_sse(
+	uint32_t width, uint32_t height, 
+	const uint8_t *rgb, uint32_t rgb_stride, 
+	uint8_t *y, uint8_t *u, uint8_t *v, uint32_t y_stride, uint32_t uv_stride, 
+	YCbCrType yuv_type);
+
+// rgb to yuv, sse implementation
+// pointers do not need to be 16 byte aligned
+void rgb24_yuv420_sseu(
+	uint32_t width, uint32_t height, 
+	const uint8_t *rgb, uint32_t rgb_stride, 
+	uint8_t *y, uint8_t *u, uint8_t *v, uint32_t y_stride, uint32_t uv_stride, 
+	YCbCrType yuv_type);
+
+// rgba to yuv, standard c implementation
+// alpha channel is ignored
+void rgb32_yuv420_std(
+	uint32_t width, uint32_t height, 
+	const uint8_t *rgba, uint32_t rgba_stride, 
+	uint8_t *y, uint8_t *u, uint8_t *v, uint32_t y_stride, uint32_t uv_stride, 
+	YCbCrType yuv_type);
+
+// rgba to yuv, sse implementation
+// pointers must be 16 byte aligned, and strides must be divisible by 16
+// alpha channel is ignored
+void rgb32_yuv420_sse(
+	uint32_t width, uint32_t height, 
+	const uint8_t *rgba, uint32_t rgba_stride, 
+	uint8_t *y, uint8_t *u, uint8_t *v, uint32_t y_stride, uint32_t uv_stride, 
+	YCbCrType yuv_type);
+
+// rgba to yuv, sse implementation
+// pointers do not need to be 16 byte aligned
+// alpha channel is ignored
+void rgb32_yuv420_sseu(
+	uint32_t width, uint32_t height, 
+	const uint8_t *rgba, uint32_t rgba_stride, 
+	uint8_t *y, uint8_t *u, uint8_t *v, uint32_t y_stride, uint32_t uv_stride, 
+	YCbCrType yuv_type);
+
+#ifdef __cplusplus
+}
+#endif