WebSVN – Kolibri OS – Blame – /contrib/sdk/sources/Mesa/mesa-10.6.0/docs/specs/MESA_ycbcr_texture.spec

Rev	Author	Line No.	Line
5564	serge	1	Name
		2
		3	MESA_ycbcr_texture
		4
		5	Name Strings
		6
		7	GL_MESA_ycbcr_texture
		8
		9	Contact
		10
		11	Brian Paul, Tungsten Graphics, Inc. (brian.paul 'at' tungstengraphics.com)
		12	Keith Whitwell, Tungsten Graphics, Inc. (keith 'at' tungstengraphics.com)
		13
		14	Status
		15
		16	Shipping (Mesa 4.0.4 and later)
		17
		18	Version
		19
		20	1.0
		21
		22	Number
		23
		24	TBD
		25
		26	Dependencies
		27
		28	OpenGL 1.0 or later is required
		29	This extension is written against the OpenGL 1.4 Specification.
		30	NV_texture_rectangle effects the definition of this extension.
		31
		32	Overview
		33
		34	This extension supports texture images stored in the YCbCr format.
		35	There is no support for converting YCbCr images to RGB or vice versa
		36	during pixel transfer. The texture's YCbCr colors are converted to
		37	RGB during texture sampling, after-which, all the usual per-fragment
		38	operations take place. Only 2D texture images are supported (not
		39	glDrawPixels, glReadPixels, etc).
		40
		41	A YCbCr pixel (texel) is a 16-bit unsigned short with two components.
		42	The first component is luminance (Y). For pixels in even-numbered
		43	image columns, the second component is Cb. For pixels in odd-numbered
		44	image columns, the second component is Cr. If one were to convert the
		45	data to RGB one would need to examine two pixels from columns N and N+1
		46	(where N is even) to deduce the RGB color.
		47
		48	IP Status
		49
		50	None
		51
		52	Issues
		53
		54	None
		55
		56	New Procedures and Functions
		57
		58	None
		59
		60	New Tokens
		61
		62	Accepted by the and parameters of
		63	TexImage2D and TexSubImage2D:
		64
		65	YCBCR_MESA 0x8757
		66
		67	Accepted by the parameter of TexImage2D and TexSubImage2D:
		68
		69	UNSIGNED_SHORT_8_8_MESA 0x85BA /* same as Apple's */
		70	UNSIGNED_SHORT_8_8_REV_MESA 0x85BB /* same as Apple's */
		71
		72	Additions to Chapter 2 of the OpenGL 1.4 Specification (OpenGL Operation)
		73
		74	None
		75
		76	Additions to Chapter 3 of the OpenGL 1.4 Specification (Rasterization)
		77
		78	In section 3.6.4, Rasterization of Pixel Rectangles, on page 101,
		79	add the following to Table 3.8 (Packed pixel formats):
		80
		81	type Parameter GL Data Number of Matching
		82	Token Name Type Components Pixel Formats
		83	-------------- ------- ---------- -------------
		84	UNSIGNED_SHORT_8_8_MESA ushort 2 YCBCR_MESA
		85	UNSIGNED_SHORT_8_8_REV_MESA ushort 2 YCBCR_MESA
		86
		87
		88	In section 3.6.4, Rasterization of Pixel Rectangles, on page 102,
		89	add the following to Table 3.10 (UNSIGNED_SHORT formats):
		90
		91	UNSIGNED_SHORT_8_8_MESA:
		92
		93	15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
		94	+-------------------------------+-------------------------------+
		95	\| 1st \| 2nd \|
		96	+-------------------------------+-------------------------------+
		97
		98	UNSIGNED_SHORT_8_8_REV_MESA:
		99
		100	15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
		101	+-------------------------------+-------------------------------+
		102	\| 2nd \| 1st \|
		103	+-------------------------------+-------------------------------+
		104
		105
		106	In section 3.6.4, Rasterization of Pixel Rectangles, on page 104,
		107	add the following to Table 3.12 (Packed pixel field assignments):
		108
		109	First Second Third Fourth
		110	Format Element Element Element Element
		111	------ ------- ------- ------- -------
		112	YCBCR_MESA luminance chroma
		113
		114
		115	In section 3.8.1, Texture Image Specification, on page 125, add
		116	another item to the list of TexImage2D and TexImage3D equivalence
		117	exceptions:
		118
		119	* The value of internalformat and format may be YCBCR_MESA to
		120	indicate that the image data is in YCbCr format. type must
		121	be either UNSIGNED_SHORT_8_8_MESA or UNSIGNED_SHORT_8_8_REV_MESA
		122	as seen in tables 3.8 and 3.10. Table 3.12 describes the mapping
		123	between Y and Cb/Cr to the components.
		124	If NV_texture_rectangle is supported target may also be
		125	TEXTURE_RECTANGLE_NV or PROXY_TEXTURE_RECTANGLE_NV.
		126	All pixel transfer operations are bypassed. The texture is stored as
		127	YCbCr, not RGB. Queries of the texture's red, green and blue component
		128	sizes will return zero. The YCbCr colors are converted to RGB during
		129	texture sampling using an implementation dependent conversion.
		130
		131
		132	In section 3.8.1, Texture Image Specification, on page 126, add
		133	another item to the list of TexImage1D and TexImage2D equivalence
		134	exceptions:
		135
		136	* The value of internalformat and format can not be YCBCR_MESA.
		137
		138
		139	In section 3.8.2, Alternate Texture Image Specification Commands, on
		140	page 129, insert this paragraph after the first full paragraph on the
		141	page:
		142
		143	"If the internal storage format of the image being updated by
		144	TexSubImage2D is YCBCR_MESA then format must be YCBCR_MESA.
		145	The error INVALID_OPERATION will be generated otherwise."
		146
		147
		148	Additions to Chapter 4 of the OpenGL 1.4 Specification (Per-Fragment
		149	Operations and the Frame Buffer)
		150
		151	None
		152
		153	Additions to Chapter 5 of the OpenGL 1.4 Specification (Special Functions)
		154
		155	None
		156
		157	Additions to Chapter 6 of the OpenGL 1.4 Specification (State and
		158	State Requests)
		159
		160	None
		161
		162	Additions to Appendix A of the OpenGL 1.4 Specification (Invariance)
		163
		164	None
		165
		166	Additions to the AGL/GLX/WGL Specifications
		167
		168	None
		169
		170	GLX Protocol
		171
		172	None
		173
		174	Errors
		175
		176	INVALID_ENUM is generated by TexImage2D if is
		177	MESA_YCBCR but is not MESA_YCBCR.
		178
		179	INVALID_ENUM is generated by TexImage2D if is MESA_YCBCR but
		180	is not MESA_YCBCR.
		181
		182	INVALID_VALUE is generated by TexImage2D if is MESA_YCBCR and
		183	is MESA_YCBCR and is not zero.
		184
		185	INVALID_OPERATION is generated by TexSubImage2D if the internal image
		186	format is YCBCR_MESA and is not YCBCR_MESA.
		187
		188	INVALID_OPERATION is generated by CopyTexSubImage2D if the internal
		189	image is YCBCR_MESA.
		190
		191	New State
		192
		193	Edit table 6.16 on page 231: change the type of TEXTURE_INTERNAL_FORMAT
		194	from n x Z42 to n x Z43 to indicate that internal format may also be
		195	YCBCR_MESA.
		196
		197	Revision History
		198
		199	20 September 2002 - Initial draft
		200	29 April 2003 - minor updates
		201	3 September 2003 - further clarify when YCbCr->RGB conversion takes place
		202	19 September 2003 - a few more updates prior to submitting to extension
		203	registry.
		204	3 April 2004 - fix assorted inaccuracies

Subversion Repositories Kolibri OS

(root)/contrib/sdk/sources/Mesa/mesa-10.6.0/docs/specs/MESA_ycbcr_texture.spec – Rev 5564