testyuv_cvt.c File Reference

#include "SDL.h"
#include "testyuv_cvt.h"

Include dependency graph for testyuv_cvt.c:

Go to the source code of this file.

Functions
static float	clip3 (float x, float y, float z)
static void	RGBtoYUV (Uint8 *rgb, int *yuv, SDL_YUV_CONVERSION_MODE mode, int monochrome, int luminance)
static void	ConvertRGBtoPlanar2x2 (Uint32 format, Uint8 *src, int pitch, Uint8 *out, int w, int h, SDL_YUV_CONVERSION_MODE mode, int monochrome, int luminance)
static void	ConvertRGBtoPacked4 (Uint32 format, Uint8 *src, int pitch, Uint8 *out, int w, int h, SDL_YUV_CONVERSION_MODE mode, int monochrome, int luminance)
SDL_bool	ConvertRGBtoYUV (Uint32 format, Uint8 *src, int pitch, Uint8 *out, int w, int h, SDL_YUV_CONVERSION_MODE mode, int monochrome, int luminance)
int	CalculateYUVPitch (Uint32 format, int width)

Function Documentation

int CalculateYUVPitch	(	Uint32	format,
		int	width
	)

Definition at line 282 of file testyuv_cvt.c.

References SDL_PIXELFORMAT_IYUV, SDL_PIXELFORMAT_NV12, SDL_PIXELFORMAT_NV21, SDL_PIXELFORMAT_UYVY, SDL_PIXELFORMAT_YUY2, SDL_PIXELFORMAT_YV12, and SDL_PIXELFORMAT_YVYU.

Referenced by main(), and run_automated_tests().

{
    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;
    }
}

static float clip3 ( float  x, float  y, float  z  )

static

Definition at line 18 of file testyuv_cvt.c.

Referenced by RGBtoYUV().

{
    return ((z < x) ? x : ((z > y) ? y : z));
}

static void ConvertRGBtoPacked4 ( Uint32  format, Uint8 *  src, int  pitch, Uint8 *  out, int  w, int  h, SDL_YUV_CONVERSION_MODE  mode, int  monochrome, int  luminance  )

static

Definition at line 192 of file testyuv_cvt.c.

References RGBtoYUV(), SDL_assert, SDL_floorf, SDL_PIXELFORMAT_UYVY, SDL_PIXELFORMAT_YUY2, SDL_PIXELFORMAT_YVYU, and V.

Referenced by ConvertRGBtoYUV().

{
    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;
    }
}

static void ConvertRGBtoPlanar2x2 ( Uint32  format, Uint8 *  src, int  pitch, Uint8 *  out, int  w, int  h, SDL_YUV_CONVERSION_MODE  mode, int  monochrome, int  luminance  )

static

Definition at line 76 of file testyuv_cvt.c.

References RGBtoYUV(), SDL_assert, SDL_floorf, SDL_PIXELFORMAT_IYUV, SDL_PIXELFORMAT_NV12, SDL_PIXELFORMAT_NV21, SDL_PIXELFORMAT_YV12, and V.

Referenced by ConvertRGBtoYUV().

{
    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;
        }
    }
}

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 at line 262 of file testyuv_cvt.c.

References ConvertRGBtoPacked4(), ConvertRGBtoPlanar2x2(), SDL_FALSE, SDL_PIXELFORMAT_IYUV, SDL_PIXELFORMAT_NV12, SDL_PIXELFORMAT_NV21, SDL_PIXELFORMAT_UYVY, SDL_PIXELFORMAT_YUY2, SDL_PIXELFORMAT_YV12, SDL_PIXELFORMAT_YVYU, and SDL_TRUE.

Referenced by main(), and run_automated_tests().

{
    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;
    }
}

static void RGBtoYUV ( Uint8 *  rgb, int *  yuv, SDL_YUV_CONVERSION_MODE  mode, int  monochrome, int  luminance  )

static

Definition at line 23 of file testyuv_cvt.c.

References clip3(), G, SDL_floorf, SDL_YUV_CONVERSION_BT709, SDL_YUV_CONVERSION_JPEG, and V.

Referenced by ConvertRGBtoPacked4(), and ConvertRGBtoPlanar2x2().

{
    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;
    }
}