SDL_mixer: docs: Note that SDL 3.4.0 or later is required.

From a39b14702b013ae5b41e85ca6acd1139c3fe48a3 Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Mon, 18 May 2026 16:00:52 -0400
Subject: [PATCH] docs: Note that SDL 3.4.0 or later is required.

Fixes #848.
---
 INSTALL.md | 3 +++
 README.md  | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/INSTALL.md b/INSTALL.md
index 8194592e..1ccf9c18 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -1,5 +1,8 @@
 # To build and use SDL_mixer:
 
+Please make sure you have at least SDL 3.4.0. SDL 3.2.x does not have API
+functions that SDL3_mixer requires!
+
 SDL_mixer supports a number of development environments:
 - [CMake](docs/INTRO-cmake.md)
 - [Visual Studio on Windows](docs/INTRO-visualstudio.md)
diff --git a/README.md b/README.md
index be790418..e61010a9 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,8 @@ opinion, a significant improvement in power and ease of use. Please refer to
 docs/README-migration.md for details on how to migrate your program to the new
 API.
 
+SDL3_mixer requires SDL 3.4.0 or later.
+
 The latest version of this library is available from GitHub:
 https://github.com/libsdl-org/SDL_mixer/releases