【ffmpeg 视频播放】深入探索：ffmpeg视频播放优化策略与设计模式的实践应用（三）

// 组件接口
class OptimizationStrategy {
public:
    virtual void optimize() = 0;
};
// 具体组件：双缓冲优化
class DoubleBufferingStrategy : public OptimizationStrategy {
public:
    void optimize() override {
        // 实现双缓冲优化
    }
};
// 装饰器基类：继承自组件接口
class StrategyDecorator : public OptimizationStrategy {
protected:
    OptimizationStrategy* strategy;  // 持有一个组件对象的引用
public:
    StrategyDecorator(OptimizationStrategy* strategy) : strategy(strategy) {}
    virtual void optimize() override {
        strategy->optimize();
    }
};
// 具体装饰器：添加日志功能
class LoggingDecorator : public StrategyDecorator {
public:
    LoggingDecorator(OptimizationStrategy* strategy) : StrategyDecorator(strategy) {}
    void optimize() override {
        // 在优化前后添加日志
        std::cout << "Optimization started." << std::endl;
        StrategyDecorator::optimize();
        std::cout << "Optimization finished." << std::endl;
    }
};

// 单例类：优化管理器
class OptimizationManager {
private:
    static OptimizationManager* instance;  // 单例对象
    OptimizationManager() {}  // 私有构造函数
public:
    // 获取单例对象
    static OptimizationManager* getInstance() {
        if (instance == nullptr) {
            instance = new OptimizationManager();
        }
        return instance;
    }
    // 其他方法...
};
// 初始化单例对象
OptimizationManager* OptimizationManager::instance = nullptr;

class OptimizationStrategy {
public:
    virtual void optimize(Parameters* params) = 0;
};
class PreloadingStrategy : public OptimizationStrategy {
public:
    void optimize(Parameters* params) override {
        // 获取预加载所需的参数
        int preloadSize = params->get("preloadSize");
        // ...
    }
};

class OptimizationContext {
public:
    int getPreloadSize() {
        // 获取预加载大小
    }
    // 其他可能需要的数据和操作...
};
class OptimizationStrategy {
public:
    virtual void optimize(OptimizationContext* context) = 0;
};
class PreloadingStrategy : public OptimizationStrategy {
public:
    void optimize(OptimizationContext* context) override {
        // 从上下文对象中获取预加载大小
        int preloadSize = context->getPreloadSize();
        // ...
    }
};

class OptimizationStrategy {
public:
    virtual void setParameters(Parameters* params) = 0;
    virtual void optimize() = 0;
};
class PreloadingStrategy : public OptimizationStrategy {
private:
    int preloadSize;
public:
    void setParameters(Parameters* params) override {
        // 从参数对象中获取预加载大小
        preloadSize = params->get("preloadSize");
    }
    void optimize() override {
        // 使用预加载大小进行优化
        // ...
    }
};

class DoubleBufferingStrategy {
public:
    void play(VideoData* data) {
        // 将数据加载到后台缓冲区
        loadToBackBuffer(data);
        
        // 当前台缓冲区的数据播放完毕后，交换前后台缓冲区
        if (isFrontBufferEmpty()) {
            swapBuffers();
        }
        
        // 从前台缓冲区中获取数据并播放
        playFromFrontBuffer();
    }
    
private:
    void loadToBackBuffer(VideoData* data);
    bool isFrontBufferEmpty();
    void swapBuffers();
    void playFromFrontBuffer();
};

class CompositeOptimizationStrategy {
public:
    void play(VideoData* data) {
        // 使用双缓冲策略来减少卡顿和延迟
        doubleBufferingStrategy.play(data);
        
        // 使用自适应流策略来动态调整视频的质量和分辨率
        adaptiveStreamingStrategy.play(data);
    }
    
private:
    DoubleBufferingStrategy doubleBufferingStrategy;
    AdaptiveStreamingStrategy adaptiveStreamingStrategy;
};