gstreamer/gst/gl/regcomb_yuvrgb.c

// these includes don't do a lot in Linux, they are more needed in Win32 (for the OpenGL function call pointers)
// but they are used at least for checking if the necessary extensions are present
#include "ARB_multitexture.h"
#include "NV_register_combiners.h"
#include "EXT_paletted_texture.h"

/***********************************************************************************************
 INTERESTING PART:                                                                            *
 handles initialization of the Nvidia register combiners for YUV->RGB conversion. 
 This code was created by Jens Schneider <schneider@glhint.de>                      
 ***********************************************************************************************/

GLuint Yhandle;
GLuint Uhandle;
GLuint Vhandle;
unsigned char *YPlane;
unsigned char *UPlane;
unsigned char *VPlane;

// YUV 4:2:2 example
unsigned int Ywidth=512,  Yheight=512;
unsigned int UVwidth=256, UVheight=512;

int tex_xsize, tex_ysize;

void GenerateRGBTables(unsigned char *Ytable, // Y-palette
		       unsigned char *Utable, // U-palette
		       unsigned char *Vtable, // V-palette
		       float *bias,   // bias (fourth vector to be added)
		       float *Uscale, // scaling color for U
		       float *Vscale) // scaling color for V
{
	int i;
	const float mat[9]= { // the modified YUV->RGB matrix
		+1.130469478f,-0.058755723f,+1.596026304f,
		+1.130469478f,-0.450515935f,-0.812967512f,
		+1.130469478f,+1.958477882f, 0.0f
	};
	#define COMPRESS(a)(0.5f*(a)+128.0f) // counter-piece to EXPAND_NORMAL
	#define fCOMPRESS(a) (0.5f*(a)+0.5f);
	#define XCLAMP(a) ((a)<0.0f ? 0.0f : ((a)>255.0f ? 255.0f : (a))) // should not be necessary, but what do you know.
	bias[0]=fCOMPRESS(-0.842580964f);
	bias[1]=fCOMPRESS(+0.563287723f);
	bias[2]=fCOMPRESS(-1.0f);
	bias[3]=0.0f;
	Uscale[0]=8.0f/255.0f;
	Uscale[1]=60.0f/255.0f;
	Uscale[2]=250.0f/255.0f;
	Uscale[3]=0.0f;
	Vscale[0]=204.0f/255.0f;
	Vscale[1]=105.0f/255.0f;
	Vscale[2]=0.5f;
	Vscale[3]=0.0f;
	for (i=0; i<256; i++) {
		// Y-table holds unsigned values
		Ytable[3*i  ]=(unsigned char)XCLAMP(mat[0]*(float)i); // R
		Ytable[3*i+1]=(unsigned char)XCLAMP(mat[3]*(float)i); // G
		Ytable[3*i+2]=(unsigned char)XCLAMP(mat[6]*(float)i); // B
		// U-table holds signed values
		Utable[3*i  ]=(unsigned char)XCLAMP(COMPRESS(255.0f/ 16.0f*mat[1]*(float)i)); // R
		Utable[3*i+1]=(unsigned char)XCLAMP(COMPRESS(255.0f/120.0f*mat[4]*(float)i)); // G
		Utable[3*i+2]=(unsigned char)XCLAMP(COMPRESS(255.0f/500.0f*mat[7]*(float)i)); // B
		// V-table holds signed values
		Vtable[3*i  ]=(unsigned char)XCLAMP(COMPRESS(255.0f/408.0f*mat[2]*(float)i)); // R
		Vtable[3*i+1]=(unsigned char)XCLAMP(COMPRESS(255.0f/210.0f*mat[5]*(float)i)); // G
		Vtable[3*i+2]=(unsigned char)(128.0f-14.0f); // G constant
	}
	#undef fCOMPRESS
	#undef COMPRESS
	#undef XCLAMP
}


// Sets the constants. Call once prior to rendering.
void SetConsts(float *bias, float *Uscale, float *Vscale) {
	glEnable(GL_REGISTER_COMBINERS_NV);
	glColor3fv(bias);
	//printf("%f %f %f\n",bias[0],bias[1],bias[2]);
	glCombinerParameterfvNV(GL_CONSTANT_COLOR0_NV,Uscale);
	glCombinerParameterfvNV(GL_CONSTANT_COLOR1_NV,Vscale);
}

/*
 * SOFTWARE PATH
 */ 

inline void map_EXPAND_NORMAL(float *v) {
	v[0]=2.0f*v[0]-1.0f;
	v[1]=2.0f*v[1]-1.0f;
	v[2]=2.0f*v[2]-1.0f;
}

inline void map_UNSIGNED_INVERT(float *v) {
	v[0]=1.0f-v[0];
	v[1]=1.0f-v[1];
	v[2]=1.0f-v[2];
}

inline void map_UNSIGNED_IDENTITY(float *v) {
	v[0]=(v[0]<0.0f ? 0.0f : v[0]);
	v[1]=(v[1]<0.0f ? 0.0f : v[1]);
	v[2]=(v[2]<0.0f ? 0.0f : v[2]);
}

inline void map_SIGNED_IDENTITY(float *v) {
}

inline void omap_SCALE_BY_TWO(float *v) {
	v[0]*=2.0f;
	v[1]*=2.0f;
	v[2]*=2.0f;
}

inline void omap_SCALE_BY_ONE_HALF(float *v) {
	v[0]*=0.5f;
	v[1]*=0.5f;
	v[2]*=0.5f;
}

inline void omap_RANGE(float *v) {
	v[0]=(v[0]<-1.0f ? -1.0f : (v[0]>1.0f ? 1.0f : v[0]));
	v[1]=(v[1]<-1.0f ? -1.0f : (v[1]>1.0f ? 1.0f : v[1]));
	v[2]=(v[2]<-1.0f ? -1.0f : (v[2]>1.0f ? 1.0f : v[2]));
}


inline void omap_CLAMP_01(float *v) {
	v[0]=(v[0]<0.0f ? 0.0f : (v[0]>1.0f ? 1.0f : v[0]));
	v[1]=(v[1]<0.0f ? 0.0f : (v[1]>1.0f ? 1.0f : v[1]));
	v[2]=(v[2]<0.0f ? 0.0f : (v[2]>1.0f ? 1.0f : v[2]));
}

void PerformSWCombiner(unsigned char *Result,
					   unsigned char *tex0,
					   unsigned char *tex1,
					   unsigned char *tex2,
					   float *COLOR0,
					   float *CONST0,
					   float *CONST1
						) 
{
	float SPARE0[3];
	float SPARE1[3];
	float A[3],B[3],C[3],D[3];
	float TEX0[3],TEX1[3],TEX2[3];
	float ZERO[3]={0.0f,0.0f,0.0f};
	
	TEX0[0]=(float)tex0[0]/255.0f;
	TEX0[1]=(float)tex0[1]/255.0f;
	TEX0[2]=(float)tex0[2]/255.0f;

	TEX1[0]=(float)tex1[0]/255.0f;
	TEX1[1]=(float)tex1[1]/255.0f;
	TEX1[2]=(float)tex1[2]/255.0f;

	TEX2[0]=(float)tex2[0]/255.0f;
	TEX2[1]=(float)tex2[1]/255.0f;
	TEX2[2]=(float)tex2[2]/255.0f;

	// Combiner Stage 0:
	memcpy(A,TEX0,3*sizeof(float));		map_UNSIGNED_IDENTITY(A);
	memcpy(B,ZERO,3*sizeof(float));		map_UNSIGNED_INVERT(B);
	memcpy(C,COLOR0,3*sizeof(float));	map_EXPAND_NORMAL(C);
	memcpy(D,ZERO,3*sizeof(float));		map_UNSIGNED_INVERT(D);
	SPARE0[0]=A[0]*B[0]+C[0]*D[0];
	SPARE0[1]=A[1]*B[1]+C[1]*D[1];
	SPARE0[2]=A[2]*B[2]+C[2]*D[2];
	omap_SCALE_BY_ONE_HALF(SPARE0);
	omap_RANGE(SPARE0);

	// Combiner Stage 1:
	memcpy(A,TEX1,3*sizeof(float));		map_EXPAND_NORMAL(A);
	memcpy(B,CONST0,3*sizeof(float));	map_UNSIGNED_IDENTITY(B);
	memcpy(C,TEX2,3*sizeof(float));		map_EXPAND_NORMAL(C);
	memcpy(D,CONST1,3*sizeof(float));	map_UNSIGNED_IDENTITY(D);
	SPARE1[0]=A[0]*B[0]+C[0]*D[0];
	SPARE1[1]=A[1]*B[1]+C[1]*D[1];
	SPARE1[2]=A[2]*B[2]+C[2]*D[2];
	omap_RANGE(SPARE1);

	// Combiner Stage 2:
	memcpy(A,SPARE0,3*sizeof(float));	map_SIGNED_IDENTITY(A);
	memcpy(B,ZERO,3*sizeof(float));		map_UNSIGNED_INVERT(B);
	memcpy(C,SPARE1,3*sizeof(float));	map_SIGNED_IDENTITY(C);
	memcpy(D,ZERO,3*sizeof(float));		map_UNSIGNED_INVERT(D);
	SPARE0[0]=A[0]*B[0]+C[0]*D[0];
	SPARE0[1]=A[1]*B[1]+C[1]*D[1];
	SPARE0[2]=A[2]*B[2]+C[2]*D[2];
	omap_SCALE_BY_TWO(SPARE0);
	omap_RANGE(SPARE0);

	// Final Combiner Stage:
	memcpy(A,ZERO,3*sizeof(float));		map_UNSIGNED_INVERT(A);
	memcpy(B,SPARE0,3*sizeof(float));	map_UNSIGNED_IDENTITY(B);
	memcpy(C,ZERO,3*sizeof(float));		map_UNSIGNED_IDENTITY(C);
	memcpy(D,ZERO,3*sizeof(float));		map_UNSIGNED_IDENTITY(D);
	SPARE0[0]=A[0]*B[0]+(1.0f-A[0])*C[0]+D[0];
	SPARE0[1]=A[1]*B[1]+(1.0f-A[1])*C[1]+D[1];
	SPARE0[2]=A[2]*B[2]+(1.0f-A[2])*C[2]+D[2];
	omap_CLAMP_01(SPARE0);
	Result[0]=(unsigned char)(SPARE0[0]*255.0f);
	Result[1]=(unsigned char)(SPARE0[1]*255.0f);
	Result[2]=(unsigned char)(SPARE0[2]*255.0f);
}

// Sets up the register combiners. Call once prior to rendering
void SetupCombiners(void) 
{
	glCombinerParameteriNV(GL_NUM_GENERAL_COMBINERS_NV,3);
	// Combiner Stage 0: th. OK
	glCombinerInputNV (GL_COMBINER0_NV,GL_RGB,GL_VARIABLE_A_NV,GL_TEXTURE0_ARB,    GL_UNSIGNED_IDENTITY_NV,GL_RGB);
	glCombinerInputNV (GL_COMBINER0_NV,GL_RGB,GL_VARIABLE_B_NV,GL_ZERO,            GL_UNSIGNED_INVERT_NV,  GL_RGB);
	glCombinerInputNV (GL_COMBINER0_NV,GL_RGB,GL_VARIABLE_C_NV,GL_PRIMARY_COLOR_NV,GL_EXPAND_NORMAL_NV,    GL_RGB);
	glCombinerInputNV (GL_COMBINER0_NV,GL_RGB,GL_VARIABLE_D_NV,GL_ZERO,            GL_UNSIGNED_INVERT_NV,  GL_RGB);
	glCombinerOutputNV(GL_COMBINER0_NV,GL_RGB,GL_DISCARD_NV,GL_DISCARD_NV,GL_SPARE0_NV,GL_SCALE_BY_ONE_HALF_NV,GL_NONE,GL_FALSE,GL_FALSE,GL_FALSE);
	// Combiner Stage 1: th. OK
	glCombinerInputNV (GL_COMBINER1_NV,GL_RGB,GL_VARIABLE_A_NV,GL_TEXTURE1_ARB,      GL_EXPAND_NORMAL_NV,    GL_RGB);
	glCombinerInputNV (GL_COMBINER1_NV,GL_RGB,GL_VARIABLE_B_NV,GL_CONSTANT_COLOR0_NV,GL_UNSIGNED_IDENTITY_NV,GL_RGB);
	glCombinerInputNV (GL_COMBINER1_NV,GL_RGB,GL_VARIABLE_C_NV,GL_TEXTURE2_ARB,      GL_EXPAND_NORMAL_NV,    GL_RGB);
	glCombinerInputNV (GL_COMBINER1_NV,GL_RGB,GL_VARIABLE_D_NV,GL_CONSTANT_COLOR1_NV,GL_UNSIGNED_IDENTITY_NV,GL_RGB);
	glCombinerOutputNV(GL_COMBINER1_NV,GL_RGB,GL_DISCARD_NV,GL_DISCARD_NV,GL_SPARE1_NV,GL_NONE,GL_NONE,GL_FALSE,GL_FALSE,GL_FALSE);
	// Combiner Stage 2: th. OK
	glCombinerInputNV (GL_COMBINER2_NV,GL_RGB,GL_VARIABLE_A_NV,GL_SPARE0_NV,       GL_SIGNED_IDENTITY_NV,  GL_RGB);
	glCombinerInputNV (GL_COMBINER2_NV,GL_RGB,GL_VARIABLE_B_NV,GL_ZERO,            GL_UNSIGNED_INVERT_NV,  GL_RGB);
	glCombinerInputNV (GL_COMBINER2_NV,GL_RGB,GL_VARIABLE_C_NV,GL_SPARE1_NV,       GL_SIGNED_IDENTITY_NV,  GL_RGB);
	glCombinerInputNV (GL_COMBINER2_NV,GL_RGB,GL_VARIABLE_D_NV,GL_ZERO,            GL_UNSIGNED_INVERT_NV,  GL_RGB);
	glCombinerOutputNV(GL_COMBINER2_NV,GL_RGB,GL_DISCARD_NV,GL_DISCARD_NV,GL_SPARE0_NV,GL_SCALE_BY_TWO_NV,GL_NONE,GL_FALSE,GL_FALSE,GL_FALSE);
	// Final Sage: th. OK
	glFinalCombinerInputNV(GL_VARIABLE_A_NV,GL_ZERO,     GL_UNSIGNED_INVERT_NV,  GL_RGB);
	glFinalCombinerInputNV(GL_VARIABLE_B_NV,GL_SPARE0_NV,GL_UNSIGNED_IDENTITY_NV,GL_RGB);
	glFinalCombinerInputNV(GL_VARIABLE_C_NV,GL_ZERO,     GL_UNSIGNED_IDENTITY_NV,GL_RGB);
	glFinalCombinerInputNV(GL_VARIABLE_D_NV,GL_ZERO,     GL_UNSIGNED_IDENTITY_NV,GL_RGB);
	glFinalCombinerInputNV(GL_VARIABLE_G_NV,GL_ZERO,     GL_UNSIGNED_INVERT_NV,  GL_ALPHA);
}


unsigned int PowerOfTwo(unsigned int i) {
	unsigned int bitsum=0;
	unsigned int shifts=0;
	unsigned int j=(unsigned int)i;
	// Check wether i is a power of two - may contain at most one set bit
	do {
		bitsum+=j&1;
		j=j>>1;
		++shifts;
	} while (j>0);
	if (bitsum==1) return i;
	else return (1<<shifts);
}


// Initializes textures. Call once prior to rendering
void InitYUVPlanes(GLuint *Yhandle, GLuint *Uhandle, GLuint *Vhandle, 
		   unsigned int Ywidth,  unsigned int Yheight,
		   unsigned int UVwidth, unsigned int UVheight,
		   GLenum filter, // filter should be either GL_NEAREST or GL_LINEAR. Test this! 
		   unsigned char* Ypal, unsigned char *Upal, unsigned char *Vpal)
{
  glGenTextures(1,Yhandle);
  glGenTextures(1,Uhandle);
  glGenTextures(1,Vhandle);
  glBindTexture(GL_TEXTURE_2D,(*Yhandle));
#ifdef _WIN32
  glColorTableEXT(GL_TEXTURE_2D,GL_RGB8,256,GL_RGB,GL_UNSIGNED_BYTE,Ypal);
#else // Hopefully Linux
  glColorTable(GL_TEXTURE_2D,GL_RGB8,256,GL_RGB,GL_UNSIGNED_BYTE,Ypal);
#endif
  glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,filter);
  glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,filter);
  glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_CLAMP);
  glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_CLAMP);	
  tex_xsize = PowerOfTwo(Ywidth);
  tex_ysize = PowerOfTwo(Yheight);
  glTexImage2D(GL_TEXTURE_2D,0,GL_COLOR_INDEX8_EXT,PowerOfTwo(Ywidth),PowerOfTwo(Yheight),0,GL_COLOR_INDEX,GL_UNSIGNED_BYTE,NULL);
  
  glBindTexture(GL_TEXTURE_2D,(*Uhandle));
#ifdef _WIN32
  glColorTableEXT(GL_TEXTURE_2D,GL_RGB8,256,GL_RGB,GL_UNSIGNED_BYTE,Upal);
#else // Hopefully Linux
  glColorTable(GL_TEXTURE_2D,GL_RGB8,256,GL_RGB,GL_UNSIGNED_BYTE,Upal);
#endif
  glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,filter);
  glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,filter);
  glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_CLAMP);
  glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_CLAMP);
  glTexImage2D(GL_TEXTURE_2D,0,GL_COLOR_INDEX8_EXT,PowerOfTwo(UVwidth),PowerOfTwo(UVheight),0,GL_COLOR_INDEX,GL_UNSIGNED_BYTE,NULL);
  
  glBindTexture(GL_TEXTURE_2D,(*Vhandle));
#ifdef _WIN32
  glColorTableEXT(GL_TEXTURE_2D,GL_RGB8,256,GL_RGB,GL_UNSIGNED_BYTE,Vpal);
#else // Hopefully Linux
  glColorTable(GL_TEXTURE_2D,GL_RGB8,256,GL_RGB,GL_UNSIGNED_BYTE,Vpal);
#endif
  glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,filter);
  glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,filter);
  glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_CLAMP);
  glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_CLAMP);
  glTexImage2D(GL_TEXTURE_2D,0,GL_COLOR_INDEX8_EXT,PowerOfTwo(UVwidth),PowerOfTwo(UVheight),0,GL_COLOR_INDEX,GL_UNSIGNED_BYTE,NULL);
}

void LoadYUVPlanes(GLuint Yhandle, GLuint Uhandle, GLuint Vhandle,
		   unsigned int Ywidth,  unsigned int Yheight,
		   unsigned int UVwidth, unsigned int UVheight,
		   unsigned char *Ydata,
		   unsigned char *Udata,
		   unsigned char *Vdata) 
{
  glActiveTextureARB(GL_TEXTURE0_ARB);
  glBindTexture(GL_TEXTURE_2D,Yhandle);
  glTexSubImage2D(GL_TEXTURE_2D,0,0,0,Ywidth,Yheight,GL_COLOR_INDEX,GL_UNSIGNED_BYTE,Ydata);
  glEnable(GL_TEXTURE_2D);
  
  glActiveTextureARB(GL_TEXTURE1_ARB);
  glBindTexture(GL_TEXTURE_2D,Uhandle);
  glTexSubImage2D(GL_TEXTURE_2D,0,0,0,UVwidth,UVheight,GL_COLOR_INDEX,GL_UNSIGNED_BYTE,Udata);
  glEnable(GL_TEXTURE_2D);
  
  glActiveTextureARB(GL_TEXTURE2_ARB);
  glBindTexture(GL_TEXTURE_2D,Vhandle);
  glTexSubImage2D(GL_TEXTURE_2D,0,0,0,UVwidth,UVheight,GL_COLOR_INDEX,GL_UNSIGNED_BYTE,Vdata);
  glEnable(GL_TEXTURE_2D);
}


void Initialize_Backend(unsigned int Ywidth, unsigned int Yheight, unsigned int UVwidth, unsigned int UVheight, GLenum filter) 
{
  printf("Reinitializing register combiner backend with res %d x %d!\n", Ywidth, Yheight);
  if (!GL_ARB_multitexture_Init()) exit(0);
  if (!GL_EXT_paletted_texture_Init()) exit(0);
  if (!GL_NV_register_combiners_Init()) exit(0);
  unsigned char Ypal[768];
  unsigned char Upal[768];
  unsigned char Vpal[768];
  float bias[4];
  float Uscale[4];
  float Vscale[4];
  GenerateRGBTables(Ypal,Upal,Vpal,bias,Uscale,Vscale);
  InitYUVPlanes(&Yhandle,&Uhandle,&Vhandle,Ywidth,Yheight,UVwidth,UVheight,filter,Ypal,Upal,Vpal);
  SetupCombiners();
  SetConsts(bias,Uscale,Vscale);
}


void initialize(GLenum filter) {
	glShadeModel(GL_SMOOTH);
	glHint(GL_PERSPECTIVE_CORRECTION_HINT,GL_NICEST);
	glClearColor(0.0f,0.0f,0.2f,1.0f);
	Initialize_Backend(Ywidth,Yheight,UVwidth,UVheight,filter);
}