SDL: Clarified that testffmpeg will resize the window to the video size

SDL Commits
1 
From efa9a45048e759155bf32ac5780b6ada56c482ef Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Wed, 11 Oct 2023 23:38:08 -0700
Subject: [PATCH] Clarified that testffmpeg will resize the window to the video
 size

---
 test/testffmpeg.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/test/testffmpeg.c b/test/testffmpeg.c
index ddf375996d55..090aca6b3609 100644
--- a/test/testffmpeg.c
+++ b/test/testffmpeg.c
@@ -55,10 +55,6 @@
 
 #include "icon.h"
 
-#define WINDOW_WIDTH  640
-#define WINDOW_HEIGHT 480
-
-
 static SDL_Texture *sprite;
 static SDL_FRect *positions;
 static SDL_FRect *velocities;
@@ -108,7 +104,8 @@ static SDL_bool CreateWindowAndRenderer(Uint32 window_flags, const char *driver)
     SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 6);
     SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 5);
 
-    if (SDL_CreateWindowAndRenderer(WINDOW_WIDTH, WINDOW_HEIGHT, window_flags, &window, &renderer) < 0) {
+    /* The window will be resized to the video size when it's loaded, in OpenVideoStream() */
+    if (SDL_CreateWindowAndRenderer(320, 200, window_flags, &window, &renderer) < 0) {
         return SDL_FALSE;
     }