# Reference examples

Source: [https://docs.qualcomm.com/doc/80-88500-4/topic/137_Reference_examples.html](https://docs.qualcomm.com/doc/80-88500-4/topic/137_Reference_examples.html)

The display use cases apply the qtioverlay element, which is a hardware accelerated
    in-place image draw and blit plugin for drawing overlays on top of YUV images.

- Apply the user text overlay on 1080p live video preview, which highlights the use of the
        qti-overlay plugin: `export WAYLAND_DISPLAY=wayland-1
          `

        export XDG_RUNTIME_DIR=/run/user/root && gst-launch-1.0 -e qmmfsrc name=qmmf ! "video/x-raw(memory:GBM),format=NV12,camera=0,width=1920,height=1080,framerate=30/1" ! qtioverlay overlay-text="Qualcomm Intelligence" ! waylandsink sync=false fullscreen=trueCopy to clipboard

Note: This command `export WAYLAND_DISPLAY=wayland-1` is
          applicable for the Linux Embedded systems only.
- The qmmfsrc element is used to generate one 1080p resolution YUV stream. This stream is
        received by the qtioverlay plugin, which applies the user text given as overlay-text
        property value on to the stream, and then passes it to the waylandsink element for rendering
        on display: `export
          WAYLAND_DISPLAY=wayland-1`

        export XDG_RUNTIME_DIR=/run/user/root && gst-launch-1.0 -e qmmfsrc name=qmmf ! "video/x-raw(memory:GBM),format=NV12,camera=0,width=1920,height=1080,framerate=30/1" ! qtioverlay overlay-date=true ! waylandsink sync=false fullscreen=trueCopy to clipboard

Note: This command `export WAYLAND_DISPLAY=wayland-1` is
          applicable for the Linux Embedded systems only.

**Parent Topic:** [Display](https://docs.qualcomm.com/doc/80-88500-4/topic/136_Display.html)

Last Published: Aug 18, 2023

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