FBIOPAN_DISPLAY

Applicable Products

Product

Supported

Ascend 950PR / Ascend 950DT

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Atlas A3 training products / Atlas A3 inference products

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Atlas A2 training products / Atlas A2 inference products

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Atlas 200I/500 A2 inference products

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Atlas inference products

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Atlas training products

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Function

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.

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

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 virtual resolution range. Otherwise, the setting fails.
  • This API does not support multiple processes or multiple threads.