ResetVideo

ResetVideo总其三大部分：

• 获取基本的视频配置参数
• obs_reset_video
• 增加主窗口渲染回调

bool OBSBasic::ResetVideo()
{
    struct obs_video_info ovi;

    GetConfigFPS(ovi.fps_num, ovi.fps_den);
    ovi.graphics_module = App()->GetRenderModule();
    ovi.base_width     = (uint32_t)config_get_uint(basicConfig,    "Video", "BaseCX");
    ovi.base_height    = (uint32_t)config_get_uint(basicConfig,    "Video", "BaseCY");
    ovi.output_width   = (uint32_t)config_get_uint(basicConfig,    "Video", "OutputCX");
    ovi.output_height  = (uint32_t)config_get_uint(basicConfig,    "Video", "OutputCY");
    ovi.output_format  = VIDEO_FORMAT_NV12;
    ovi.adapter        = 0;
    ovi.gpu_conversion = true;
    QTToGSWindow(ui->preview->winId(), ovi.window);//获取窗口句柄

    //required to make opengl display stuff on osx(?)
    ResizePreview(ovi.base_width, ovi.base_height);

    QSize size = GetPixelSize(ui->preview);
    ovi.window_width  = size.width();
    ovi.window_height = size.height();

    if (!obs_reset_video(&ovi))
        return false;

    obs_add_draw_callback(OBSBasic::RenderMain, this);
    return true;
}