Cutscenes are still 4:3 (black bars on sides). Fix: These are pre-rendered FMVs (Full Motion Videos). You cannot fix them without replacing the video files (which breaks audio sync). Just accept that cutscenes will pillarbox.
The Definitive Guide to Resident Evil 4 (GameCube) Widescreen on Dolphin: Beyond Simple Stretching resident evil 4 dolphin widescreen
QTE prompts (L+R, A+B) appear off-center. Fix: Disable the “Widescreen HUD Fix” Gecko code. You’ll get stretched QTEs, but at least you’ll see them. Better yet, memorize the QTEs – they’re consistent. Final Verdict Do this. Playing Resident Evil 4 on Dolphin in true widescreen at 1440p with 16x AF is arguably the best way to experience the GameCube original. It retains the original lighting effects (which were neutered in the later "Ultimate HD" PC port) while filling your modern display. Cutscenes are still 4:3 (black bars on sides)
The GameCube version of RE4 was built for 4:3 CRT TVs. However, with the right codes and settings, we can achieve widescreen that rivals the later PC ports. Here’s how. Method 1: The Simple Built-in Hack (Gecko Code) This is the gold standard. Dolphin has native support for AR (Action Replay) / Gecko widescreen codes that adjust the camera projection matrix—not just the UI. Just accept that cutscenes will pillarbox
Dolphin Emulator (GameCube version) Game: Resident Evil 4 (G8ME01 / G8MP01) Introduction: The Problem with "Widescreen" Let’s get one thing straight right away: if you just set the Dolphin graphics to “Force 16:9” or stretch the window, you’re playing a horrible, squat version of a masterpiece. Leon looks like a fridge, and enemies appear wider than they are tall.