ffmpeg播放器11

1背景

上一篇找了window下的依赖库和头文件，这一篇分析渲染。

2步骤

2.1 单个视频渲染

class HVideoWidget : public QFrame
{

public:
    int     playerid;
    int     status;
    QString title;
    int     fps;
    aspect_ratio_t  aspect_ratio;
    renderer_type_e renderer_type;

    HVideoWnd       *videownd;
    HVideoTitlebar  *titlebar;
    HVideoToolbar   *toolbar;
    QPushButton     *btnMedia;

之前初始化了HVideoWidget，只关注了open和start方法，没关注界面渲染。这里先关注HVideoWnd，另外的控制可以后面再关注。

2.2 HVideoWnd声明

先看声明文件(src/ui/HVideoWnd.h)

class HVideoWnd {
public:
    HVideoWnd(QWidget* parent = nullptr);
    virtual ~HVideoWnd() {}

    virtual void setGeometry(const QRect& rc) = 0;
    virtual void update() = 0;

protected:
    void calcFPS();

public:
    HFrame      last_frame;
    int         fps;
    bool        draw_time;
    bool        draw_fps;
    bool        draw_resolution;
protected:
    // for calFPS
    uint64_t    tick;
    int         framecnt;
};

再看cpp文件，除了构造器和calcFPS方法，其他的都没处理。

2.3 HVideoWnd 初始化

在HVideoWidget的cpp中可以找到如下代码

void HVideoWidget::initUI() {
    setFocusPolicy(Qt::ClickFocus);

    videownd = HVideoWndFactory::create(renderer_type, this);

从这里可以看到videownd是通过工厂方法创建的实例 查看参数

HVideoWidget::HVideoWidget(QWidget *parent) : QFrame(parent)
{
    str = g_confile->GetValue("renderer", "video");
    if (str.empty()) {
        renderer_type = RENDERER_TYPE_OPENGL;
    }
    else {
        renderer_type = renderer_type_enum(str.c_str());
    }

上面默认使用了RENDERER_TYPE_OPENGL

从bin的config文件来看(bin/xxx/config)，也是默认配置的OpenGL

[video] 
frame_cache = 5 
# fps = 25 

# aspect_ratio = [x%, w:h, x:y, wxh] 
# aspect_ratio = 100% # FULL 
# aspect_ratio = 50% # PERCENT 
# aspect_ratio = w:h # ORIGINAL_RATIO 
# aspect_ratio = 4:3 # CUSTOM_RATIO 
# aspect_ratio = wxh # ORIGINAL_SIZE 
# aspect_ratio = 800x600 # CUSTOM_SIZE 

# renderer = [opengl, sdl, ...] 
renderer = opengl 

继续看工厂方法实现

enum renderer_type_e {
    RENDERER_TYPE_OPENGL,
    RENDERER_TYPE_SDL2,
    // Windows only
    // RENDERER_TYPE_D3D,
    // RENDERER_TYPE_DDRAW,
    // RENDERER_TYPE_GDI,
};
#define DEFAULT_RENDERER_TYPE RENDERER_TYPE_OPENGL

class HVideoWndFactory {
public:
    static HVideoWnd* create(renderer_type_e type = DEFAULT_RENDERER_TYPE, QWidget* parent = NULL) {
        switch(type) {
        case RENDERER_TYPE_OPENGL:
            return new GLWnd(parent);
        case RENDERER_TYPE_SDL2:
            return new SDL2Wnd(parent);
        default:
            return NULL;
        }
    }
};

未完待续