Splashscreen (VLC) Fails to Display Video on GPi Case 2 (CM4) – Video Output Forced to HDMI

Description:
After the omxplayer → VLC upgrade for splashscreens, the video output no longer appears on the GPi Case 2’s LCD (though audio now works). Testing suggests VLC defaults to HDMI output, ignoring the GPi Case’s custom display configuration.

Steps to Reproduce (GPi Case 2 + CM4, undocked):

1. Fresh install RetroPie 4.8 via Raspberry Pi Imager.
2. Run the RetroFlag GPi Case 2 script (switches between config_hdmi.txt/config_lcd.txt dynamically).
   • RetroFlag | GPiCase2-Script
3. Boot RetroPie, configure Wi-Fi, install the safe shutdown script (restores audio).

wget -O - "https://raw.githubusercontent.com/RetroFlag/GPiCase2-Script/main/retropie_install_gpi2.sh" | sudo bash

4. Enable a video splashscreen (e.g., .mp4 with audio). - Observe (Pre-Upgrade): Video plays on LCD, no audio. 5. Run retropie_setup.sh to upgrade packages (triggers VLC transition). Reboot.
   • Observe (Post-Upgrade): No video on LCD, but audio works (likely via HDMI).

Expected Behavior:

Splashscreen video and audio should play on the GPi Case 2’s LCD.

Critical Context:

• Hardware: Retro Flag GPi Case 2 (Raspberry Pi CM4), used undocked (LCD only).
• Display Management:
  • The RetroFlag script dynamically swaps config.txt with either config_hdmi.txt (docked) or config_lcd.txt (undocked).
  • Issue Hypothesis: VLC ignores the active config_lcd.txt and defaults to HDMI for video output, while audio routes correctly.
• Prior State:
  • omxplayer: Video worked on LCD (no audio).
  • VLC: Audio works, but video fails (LCD unused).

User Note:

Not tested in docked mode. Issue likely stems from VLC’s output detection bypassing the GPi Case’s dynamic display switching.

Start by reproducing the undocked GPi Case 2 behavior, then inspect retropie_setup.sh, retropie_install_gpi2.sh, and the config_hdmi.txt/config_lcd.txt switching described in the report. Compare the splashscreen setup before and after the omxplayer-to-VLC transition. Done means video and audio both play on the GPi LCD after the upgrade.