SDI – Switch Display Input

1. Overview

SDI provides a simple way to switch a display's input source (HDMI / DP / VGA / DVI) using DDC/CI. The main script, switch_display_input.sh, uses a mapping file that contains display names and their I²C bus IDs. A helper script, extract_bus.sh, generates this mapping file automatically.

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2. Requirements

• Installed ddcutil
• Give execution permission to both scripts:

chmod +x switch_display_input.sh
chmod +x extract_bus.sh

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3. Usage – switch_display_input.sh

Syntax:

./switch_display_input.sh <input> [display_name]

Examples:

Switch the first display in the mapping file to HDMI 1:

./switch_display_input.sh hdmi1

Switch a specific display to DisplayPort 1:

./switch_display_input.sh dp1 OMEN_27q

Supported input values:

Argument	Description
1, hdmi1	HDMI 1
2, hdmi2	HDMI 2
dp, dp1	DisplayPort 1
dp2	DisplayPort 2
vga, vga1	VGA 1
dvi, dvi1	DVI 1

• If no display name is provided, the script uses the first entry in the mapping file.
• If a display name is provided but not found, the script returns an error.

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4. Helper Script – extract_bus.sh

You can manually generate or refresh the display bus mapping file using:

./extract_bus.sh

This script scans all connected displays and writes their names and bus IDs into monitors_bus_ids.txt. switch_display_input.sh will automatically attempt to run it if the file is missing.

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