testyuv_cvt.c
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/*
Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org>
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely.
*/
#include "SDL.h"
#include "testyuv_cvt.h"
static float clip3(float x, float y, float z)
{
return ((z < x) ? x : ((z > y) ? y : z));
}
static void RGBtoYUV(Uint8 * rgb, int *yuv, SDL_YUV_CONVERSION_MODE mode, int monochrome, int luminance)
{
if (mode == SDL_YUV_CONVERSION_JPEG) {
/* Full range YUV */
yuv[0] = (int)(0.299 * rgb[0] + 0.587 * rgb[1] + 0.114 * rgb[2]);
yuv[1] = (int)((rgb[2] - yuv[0]) * 0.565 + 128);
yuv[2] = (int)((rgb[0] - yuv[0]) * 0.713 + 128);
} else {
// This formula is from Microsoft's documentation:
// https://msdn.microsoft.com/en-us/library/windows/desktop/dd206750(v=vs.85).aspx
// L = Kr * R + Kb * B + (1 - Kr - Kb) * G
// Y = floor(2^(M-8) * (219*(L-Z)/S + 16) + 0.5);
// U = clip3(0, (2^M)-1, floor(2^(M-8) * (112*(B-L) / ((1-Kb)*S) + 128) + 0.5));
// V = clip3(0, (2^M)-1, floor(2^(M-8) * (112*(R-L) / ((1-Kr)*S) + 128) + 0.5));
float S, Z, R, G, B, L, Kr, Kb, Y, U, V;
if (mode == SDL_YUV_CONVERSION_BT709) {
/* BT.709 */
Kr = 0.2126f;
Kb = 0.0722f;
} else {
/* BT.601 */
Kr = 0.299f;
Kb = 0.114f;
}
S = 255.0f;
Z = 0.0f;
R = rgb[0];
G = rgb[1];
B = rgb[2];
L = Kr * R + Kb * B + (1 - Kr - Kb) * G;
Y = (Uint8)SDL_floorf((219*(L-Z)/S + 16) + 0.5f);
U = (Uint8)clip3(0, 255, SDL_floorf((112.0f*(B-L) / ((1.0f-Kb)*S) + 128) + 0.5f));
V = (Uint8)clip3(0, 255, SDL_floorf((112.0f*(R-L) / ((1.0f-Kr)*S) + 128) + 0.5f));
yuv[0] = (Uint8)Y;
yuv[1] = (Uint8)U;
yuv[2] = (Uint8)V;
}
if (monochrome) {
yuv[1] = 128;
yuv[2] = 128;
}
if (luminance != 100) {
yuv[0] = yuv[0] * luminance / 100;
if (yuv[0] > 255)
yuv[0] = 255;
}
}
static void ConvertRGBtoPlanar2x2(Uint32 format, Uint8 *src, int pitch, Uint8 *out, int w, int h, SDL_YUV_CONVERSION_MODE mode, int monochrome, int luminance)
{
int x, y;
int yuv[4][3];
Uint8 *Y1, *Y2, *U, *V;
Uint8 *rgb1, *rgb2;
int rgb_row_advance = (pitch - w*3) + pitch;
int UV_advance;
rgb1 = src;
rgb2 = src + pitch;
Y1 = out;
Y2 = Y1 + w;
switch (format) {
case SDL_PIXELFORMAT_YV12:
V = (Y1 + h * w);
U = V + ((h + 1)/2)*((w + 1)/2);
UV_advance = 1;
break;
case SDL_PIXELFORMAT_IYUV:
U = (Y1 + h * w);
V = U + ((h + 1)/2)*((w + 1)/2);
UV_advance = 1;
break;
case SDL_PIXELFORMAT_NV12:
U = (Y1 + h * w);
V = U + 1;
UV_advance = 2;
break;
case SDL_PIXELFORMAT_NV21:
V = (Y1 + h * w);
U = V + 1;
UV_advance = 2;
break;
default:
SDL_assert(!"Unsupported planar YUV format");
return;
}
for (y = 0; y < (h - 1); y += 2) {
for (x = 0; x < (w - 1); x += 2) {
RGBtoYUV(rgb1, yuv[0], mode, monochrome, luminance);
rgb1 += 3;
*Y1++ = (Uint8)yuv[0][0];
RGBtoYUV(rgb1, yuv[1], mode, monochrome, luminance);
rgb1 += 3;
*Y1++ = (Uint8)yuv[1][0];
RGBtoYUV(rgb2, yuv[2], mode, monochrome, luminance);
rgb2 += 3;
*Y2++ = (Uint8)yuv[2][0];
RGBtoYUV(rgb2, yuv[3], mode, monochrome, luminance);
rgb2 += 3;
*Y2++ = (Uint8)yuv[3][0];
*U = (Uint8)SDL_floorf((yuv[0][1] + yuv[1][1] + yuv[2][1] + yuv[3][1])/4.0f + 0.5f);
U += UV_advance;
*V = (Uint8)SDL_floorf((yuv[0][2] + yuv[1][2] + yuv[2][2] + yuv[3][2])/4.0f + 0.5f);
V += UV_advance;
}
/* Last column */
if (x == (w - 1)) {
RGBtoYUV(rgb1, yuv[0], mode, monochrome, luminance);
rgb1 += 3;
*Y1++ = (Uint8)yuv[0][0];
RGBtoYUV(rgb2, yuv[2], mode, monochrome, luminance);
rgb2 += 3;
*Y2++ = (Uint8)yuv[2][0];
*U = (Uint8)SDL_floorf((yuv[0][1] + yuv[2][1])/2.0f + 0.5f);
U += UV_advance;
*V = (Uint8)SDL_floorf((yuv[0][2] + yuv[2][2])/2.0f + 0.5f);
V += UV_advance;
}
Y1 += w;
Y2 += w;
rgb1 += rgb_row_advance;
rgb2 += rgb_row_advance;
}
/* Last row */
if (y == (h - 1)) {
for (x = 0; x < (w - 1); x += 2) {
RGBtoYUV(rgb1, yuv[0], mode, monochrome, luminance);
rgb1 += 3;
*Y1++ = (Uint8)yuv[0][0];
RGBtoYUV(rgb1, yuv[1], mode, monochrome, luminance);
rgb1 += 3;
*Y1++ = (Uint8)yuv[1][0];
*U = (Uint8)SDL_floorf((yuv[0][1] + yuv[1][1])/2.0f + 0.5f);
U += UV_advance;
*V = (Uint8)SDL_floorf((yuv[0][2] + yuv[1][2])/2.0f + 0.5f);
V += UV_advance;
}
/* Last column */
if (x == (w - 1)) {
RGBtoYUV(rgb1, yuv[0], mode, monochrome, luminance);
*Y1++ = (Uint8)yuv[0][0];
*U = (Uint8)yuv[0][1];
U += UV_advance;
*V = (Uint8)yuv[0][2];
V += UV_advance;
}
}
}
static void ConvertRGBtoPacked4(Uint32 format, Uint8 *src, int pitch, Uint8 *out, int w, int h, SDL_YUV_CONVERSION_MODE mode, int monochrome, int luminance)
{
int x, y;
int yuv[2][3];
Uint8 *Y1, *Y2, *U, *V;
Uint8 *rgb;
int rgb_row_advance = (pitch - w*3);
rgb = src;
switch (format) {
case SDL_PIXELFORMAT_YUY2:
Y1 = out;
U = out+1;
Y2 = out+2;
V = out+3;
break;
case SDL_PIXELFORMAT_UYVY:
U = out;
Y1 = out+1;
V = out+2;
Y2 = out+3;
break;
case SDL_PIXELFORMAT_YVYU:
Y1 = out;
V = out+1;
Y2 = out+2;
U = out+3;
break;
default:
SDL_assert(!"Unsupported packed YUV format");
return;
}
for (y = 0; y < h; ++y) {
for (x = 0; x < (w - 1); x += 2) {
RGBtoYUV(rgb, yuv[0], mode, monochrome, luminance);
rgb += 3;
*Y1 = (Uint8)yuv[0][0];
Y1 += 4;
RGBtoYUV(rgb, yuv[1], mode, monochrome, luminance);
rgb += 3;
*Y2 = (Uint8)yuv[1][0];
Y2 += 4;
*U = (Uint8)SDL_floorf((yuv[0][1] + yuv[1][1])/2.0f + 0.5f);
U += 4;
*V = (Uint8)SDL_floorf((yuv[0][2] + yuv[1][2])/2.0f + 0.5f);
V += 4;
}
/* Last column */
if (x == (w - 1)) {
RGBtoYUV(rgb, yuv[0], mode, monochrome, luminance);
rgb += 3;
*Y2 = *Y1 = (Uint8)yuv[0][0];
Y1 += 4;
Y2 += 4;
*U = (Uint8)yuv[0][1];
U += 4;
*V = (Uint8)yuv[0][2];
V += 4;
}
rgb += rgb_row_advance;
}
}
SDL_bool ConvertRGBtoYUV(Uint32 format, Uint8 *src, int pitch, Uint8 *out, int w, int h, SDL_YUV_CONVERSION_MODE mode, int monochrome, int luminance)
{
switch (format)
{
case SDL_PIXELFORMAT_YV12:
case SDL_PIXELFORMAT_IYUV:
case SDL_PIXELFORMAT_NV12:
case SDL_PIXELFORMAT_NV21:
ConvertRGBtoPlanar2x2(format, src, pitch, out, w, h, mode, monochrome, luminance);
return SDL_TRUE;
case SDL_PIXELFORMAT_YUY2:
case SDL_PIXELFORMAT_UYVY:
case SDL_PIXELFORMAT_YVYU:
ConvertRGBtoPacked4(format, src, pitch, out, w, h, mode, monochrome, luminance);
return SDL_TRUE;
default:
return SDL_FALSE;
}
}
int CalculateYUVPitch(Uint32 format, int width)
{
switch (format)
{
case SDL_PIXELFORMAT_YV12:
case SDL_PIXELFORMAT_IYUV:
case SDL_PIXELFORMAT_NV12:
case SDL_PIXELFORMAT_NV21:
return width;
case SDL_PIXELFORMAT_YUY2:
case SDL_PIXELFORMAT_UYVY:
case SDL_PIXELFORMAT_YVYU:
return 4*((width + 1)/2);
default:
return 0;
}
}
/* vi: set ts=4 sw=4 expandtab: */
SDL_YUV_CONVERSION_JPEG
Definition: SDL_surface.h:105
ConvertRGBtoPacked4
static void ConvertRGBtoPacked4(Uint32 format, Uint8 *src, int pitch, Uint8 *out, int w, int h, SDL_YUV_CONVERSION_MODE mode, int monochrome, int luminance)
Definition: testyuv_cvt.c:192
z
GLdouble GLdouble z
Definition: SDL_opengl_glext.h:404
SDL_TRUE
Definition: SDL_stdinc.h:142
SDL_YUV_CONVERSION_MODE
SDL_YUV_CONVERSION_MODE
The formula used for converting between YUV and RGB.
Definition: SDL_surface.h:103
x
GLint GLint GLint GLint GLint x
Definition: SDL_opengl.h:1574
SDL_FALSE
Definition: SDL_stdinc.h:141
h
GLfloat GLfloat GLfloat GLfloat h
Definition: SDL_opengl_glext.h:1946
f
GLfloat f
Definition: SDL_opengl_glext.h:1870
SDL_PIXELFORMAT_NV21
Definition: SDL_pixels.h:289
RGBtoYUV
static void RGBtoYUV(Uint8 *rgb, int *yuv, SDL_YUV_CONVERSION_MODE mode, int monochrome, int luminance)
Definition: testyuv_cvt.c:23
Uint32
uint32_t Uint32
Definition: SDL_stdinc.h:181
src
GLenum src
Definition: SDL_opengl_glext.h:1737
ConvertRGBtoPlanar2x2
static void ConvertRGBtoPlanar2x2(Uint32 format, Uint8 *src, int pitch, Uint8 *out, int w, int h, SDL_YUV_CONVERSION_MODE mode, int monochrome, int luminance)
Definition: testyuv_cvt.c:76
width
GLint GLint GLsizei width
Definition: SDL_opengl.h:1572
SDL_PIXELFORMAT_YVYU
Definition: SDL_pixels.h:285
format
GLint GLint GLsizei GLsizei GLsizei GLint GLenum format
Definition: SDL_opengl.h:1572
SDL_PIXELFORMAT_NV12
Definition: SDL_pixels.h:287
Uint8
uint8_t Uint8
Definition: SDL_stdinc.h:157
mode
GLenum mode
Definition: SDL_opengl_glext.h:1122
w
GLubyte GLubyte GLubyte GLubyte w
Definition: SDL_opengl_glext.h:731
y
GLint GLint GLint GLint GLint GLint y
Definition: SDL_opengl.h:1574
CalculateYUVPitch
int CalculateYUVPitch(Uint32 format, int width)
Definition: testyuv_cvt.c:282
SDL_assert
#define SDL_assert(condition)
Definition: SDL_assert.h:169
clip3
static float clip3(float x, float y, float z)
Definition: testyuv_cvt.c:18
SDL_bool
SDL_bool
Definition: SDL_stdinc.h:139
SDL_PIXELFORMAT_YV12
Definition: SDL_pixels.h:277
SDL_YUV_CONVERSION_BT709
Definition: SDL_surface.h:107
SDL_PIXELFORMAT_IYUV
Definition: SDL_pixels.h:279
G
#define G(x, y, z)
Definition: SDL_test_md5.c:74
SDL_PIXELFORMAT_UYVY
Definition: SDL_pixels.h:283
SDL_PIXELFORMAT_YUY2
Definition: SDL_pixels.h:281
SDL_floorf
#define SDL_floorf
Definition: SDL_dynapi_overrides.h:657
V
#define V(value)
Definition: yuv_rgb.c:35
SDL.h
testyuv_cvt.h
ConvertRGBtoYUV
SDL_bool ConvertRGBtoYUV(Uint32 format, Uint8 *src, int pitch, Uint8 *out, int w, int h, SDL_YUV_CONVERSION_MODE mode, int monochrome, int luminance)
Definition: testyuv_cvt.c:262