Documentation/fb/api.rst

9 ---------------
12 with frame buffer devices. In-kernel APIs between device drivers and the frame
22 ---------------
36 - FB_CAP_FOURCC
44 --------------------
46 Pixels are stored in memory in hardware-dependent formats. Applications need
47 to be aware of the pixel storage format in order to write image data to the
58 - FB_TYPE_PACKED_PIXELS
60 Macropixels are stored contiguously in a single plane. If the number of bits
61 per macropixel is not a multiple of 8, whether macropixels are padded to the
62 next multiple of 8 bits or packed together into bytes depends on the visual.
67 - FB_TYPE_PLANES
70 the number of bits per macropixel, with plane i'th storing i'th bit from all
75 - FB_TYPE_INTERLEAVED_PLANES
78 the number of bits per macropixel, with plane i'th storing i'th bit from all
86 - FB_TYPE_FOURCC
91 - FB_VISUAL_MONO01
93 Pixels are black or white and stored on a number of bits (typically one)
96 Black pixels are represented by all bits set to 1 and white pixels by all bits
97 set to 0. When the number of bits per pixel is smaller than 8, several pixels
102 - FB_VISUAL_MONO10
104 Pixels are black or white and stored on a number of bits (typically one)
107 Black pixels are represented by all bits set to 0 and white pixels by all bits
108 set to 1. When the number of bits per pixel is smaller than 8, several pixels
113 - FB_VISUAL_TRUECOLOR
116 indexes a read-only lookup table for the corresponding value. Lookup tables
117 are device-dependent, and provide linear or non-linear ramps.
122 - FB_VISUAL_PSEUDOCOLOR and FB_VISUAL_STATIC_PSEUDOCOLOR
124 Pixel values are encoded as indices into a colormap that stores red, green and
125 blue components. The colormap is read-only for FB_VISUAL_STATIC_PSEUDOCOLOR
126 and read-write for FB_VISUAL_PSEUDOCOLOR.
128 Each pixel value is stored in the number of bits reported by the variable
131 - FB_VISUAL_DIRECTCOLOR
139 - FB_VISUAL_FOURCC
146 ---------------------
198 	__u32 nonstd;			/* != 0 Non standard pixel format */
208 	__u32 pixclock;			/* pixel clock in ps (pico seconds) */
218 	__u32 colorspace;		/* colorspace for FOURCC-based modes */
232 -----------------------
235 legacy API and the FOURCC-based API.
241 non-standard formats.
247 - For grayscale formats, applications set the grayscale field to one. The red,
252 - For pseudocolor formats, applications set the grayscale field to zero. The
257 - For truecolor and directcolor formats, applications set the grayscale field
268   Pixel values are bits_per_pixel wide and are split in non-overlapping red,
270   component in the pixel value are described by the fb_bitfield offset and
274   bits per pixel is not a multiple of 8, pixel values are padded to the next
275   multiple of 8 bits.
281 The FOURCC-based API replaces format descriptions by four character codes
284 formats. Drivers are also encouraged to implement the FOURCC-based API for RGB
287 Drivers that support the FOURCC-based API report this capability by setting
293 available in Documentation/userspace-api/media/v4l/pixfmt.rst.
298 documented in Documentation/userspace-api/media/v4l/colorspaces.rst.
300 The red, green, blue and transp fields are not used with the FOURCC-based API.