Added intro video

src/video/VideoPlayer.h

@@ -0,0 +1,59 @@
+// Minimal FFmpeg-based video player (video) that decodes into an SDL texture.
+// Audio for the intro is currently handled outside this class.
+#pragma once
+
+#include <string>
+#include <SDL3/SDL.h>
+
+struct AVFormatContext;
+struct AVCodecContext;
+struct SwsContext;
+struct AVFrame;
+
+class VideoPlayer {
+public:
+    VideoPlayer();
+    ~VideoPlayer();
+
+    // Open video file and attach to SDL_Renderer for texture creation
+    bool open(const std::string& path, SDL_Renderer* renderer);
+    // Decode the first frame immediately so it can be used for fade-in.
+    bool decodeFirstFrame();
+
+    // Start time-based playback.
+    void start();
+
+    // Update playback using elapsed time in milliseconds.
+    // Returns false if finished or error.
+    bool update(double deltaMs);
+
+    // Compatibility: advance by one decoded frame.
+    bool update();
+
+    // Render video frame fullscreen to the given renderer using provided output size.
+    void render(SDL_Renderer* renderer, int winW, int winH);
+    bool isFinished() const { return m_finished; }
+    bool isTextureReady() const { return m_textureReady; }
+
+    double getFrameIntervalMs() const { return m_frameIntervalMs; }
+    bool isStarted() const { return m_started; }
+
+private:
+    bool decodeOneFrame();
+
+    AVFormatContext* m_fmt = nullptr;
+    AVCodecContext* m_dec = nullptr;
+    SwsContext* m_sws = nullptr;
+    AVFrame* m_frame = nullptr;
+    int m_videoStream = -1;
+    double m_frameIntervalMs = 33.333;
+    double m_frameAccumulatorMs = 0.0;
+    bool m_started = false;
+    int m_width = 0, m_height = 0;
+    SDL_Texture* m_texture = nullptr;
+    uint8_t* m_rgbBuffer = nullptr;
+    int m_rgbBufferSize = 0;
+    bool m_textureReady = false;
+    bool m_finished = true;
+    std::string m_path;
+};