Documentation/fb/api.rst

13 buffer core are not described.
24 Device and driver capabilities are reported in the fixed screen information
39 When supported, formats are configured using a FOURCC instead of manually
46 Pixels are stored in memory in hardware-dependent formats. Applications need
50 Formats are described by frame buffer types and visuals. Some visuals require
51 additional information, which are stored in the variable screen information
55 macropixels. Types describe how macropixels are stored in memory. The following
56 types and visuals are supported.
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
69 Macropixels are split across multiple planes. The number of planes is equal to
73 Planes are located contiguously in memory.
77 Macropixels are split across multiple planes. The number of planes is equal to
81 Planes are interleaved in memory. The interleave factor, defined as the
88 Macropixels are stored in memory as described by the format FOURCC identifier
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
98 are packed together in a byte.
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
109 are packed together in a byte.
115 Pixels are broken into red, green and blue components, and each component
117 are device-dependent, and provide linear or non-linear ramps.
124 Pixel values are encoded as indices into a colormap that stores red, green and
133 Pixels are broken into red, green and blue components, and each component
141 Pixels are encoded and  interpreted as described by the format FOURCC
148 Screen information are queried by applications using the FBIOGET_FSCREENINFO
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
271   length fields. Offset are computed from the right.
273   Pixels are always stored in an integer number of bytes. If the number of
274   bits per pixel is not a multiple of 8, pixel values are padded to the next
282 (FOURCC). FOURCCs are abstract identifiers that uniquely define a format
284 formats. Drivers are also encouraged to implement the FOURCC-based API for RGB
290 FOURCC definitions are located in the linux/videodev2.h header. However, and
291 despite starting with the V4L2_PIX_FMT_prefix, they are not restricted to V4L2
300 The red, green, blue and transp fields are not used with the FOURCC-based API.
307 and visual fields are set to FB_TYPE_FOURCC and FB_VISUAL_FOURCC respectively.