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FBIOPAN_DISPLAY

The Atlas 200/300/500 Inference Product does not support this API.

The Atlas Training Series Product does not support this API.

Description

The display starts from different offsets of the virtual resolution. The actual resolution remains unchanged. As shown in the following figure, (xres_virtual, yres_virtual) indicates the virtual resolution, (xres, yres) indicates the actual display resolution, and (xoffset, yoffset) indicates the display offset.

Restrictions

  • Before using the HiFB API, you need to call hi_mpi_vo_enable to enable the VO device.
  • Ensure that the sum of the actual resolution and offset is within the range of the virtual resolution. Otherwise, the setting fails.
  • This API does not support multiple processes or multiple threads.

Prototype

int ioctl (int fd, FBIOPAN_DISPLAY, fb_var_screeninfo *var)

Parameters

Parameter

Input/Output

Description

fd

Input

File descriptor of an FB device.

When open("/dev/fbx") is called in the application, the file descriptor of the FB device corresponding to the current VO device is returned.

FBIOPAN_DISPLAY

Input

ioctl number.

var

Input

Pointer to the variable information structure.

Returns

  • 0: success
  • Other values: failure