D3D还是GDI? Windows平台播放RTSP或RTMP渲染模式比较

先说结论,Windows平台播放渲染这块,支持D3D的前提下,优先D3D,如果检测到不支持D3D,数据回调上来,GDI模式绘制。

相比GDI模式,D3D绘制更细腻,绘制效率更高,CPU占用低,只要是系统检测支持,一般建议D3D模式。

无图无真相:

D3D还是GDI? Windows平台播放RTSP或RTMP渲染模式比较

本文以1920*1080分辨率、30帧、固定码率(采集屏幕左侧区域)为例,通过大牛直播SDK ( github) 的Windows平台SmartPublisherDemo.exe工具推送到内网nginx服务器,然后分别以D3D模式和GDI模式拉流(播放端缓冲设置为0)。

可以看到:

D3D模式,CPU占用只有2.7%,延迟:249-156 = 93ms;

GDI模式,CPU占用19.5%,延迟249-73 = 176ms。

无论是从延迟和CPU占用上看,D3D模式都占优。

实现思路:

以C#的demo为例:

1. 先检测系统是否支持D3D模式:

                if (NT.NTBaseCodeDefine.NT_ERC_OK == NTSmartPlayerSDK.NT_SP_IsSupportD3DRender(player_handle_, playWnd.Handle, ref in_support_d3d_render))
                {
                    if (1 == in_support_d3d_render)
                    {
                        is_support_d3d_render = true;
                    }
                }

2. 如不支持D3D,数据回到上层,做绘制:

                if (is_support_d3d_render)
                {
                    is_gdi_render_ = false;

                    // 支持d3d绘制的话,就用D3D绘制
                    NTSmartPlayerSDK.NT_SP_SetRenderWindow(player_handle_, playWnd.Handle);

                    if (btn_check_render_scale_mode.Checked)
                    {
                        NTSmartPlayerSDK.NT_SP_SetRenderScaleMode(player_handle_, 1);
                    }
                    else
                    {
                        NTSmartPlayerSDK.NT_SP_SetRenderScaleMode(player_handle_, 0);
                    }
                    
                }
                else
                {
                    is_gdi_render_ = true;

                    playWnd.Visible = false;

                    // 不支持D3D就让播放器吐出数据来,用GDI绘制

                    //video frame callback (YUV/RGB)
                    //format请参见 NT_SP_E_VIDEO_FRAME_FORMAT,如需回调YUV,请设置为 NT_SP_E_VIDEO_FRAME_FROMAT_I420
                    video_frame_call_back_ = new SP_SDKVideoFrameCallBack(SetVideoFrameCallBack);
                    NTSmartPlayerSDK.NT_SP_SetVideoFrameCallBack(player_handle_, (Int32)NT.NTSmartPlayerDefine.NT_SP_E_VIDEO_FRAME_FORMAT.NT_SP_E_VIDEO_FRAME_FORMAT_RGB32, IntPtr.Zero, video_frame_call_back_);
                }
        public void SetVideoFrameCallBack(IntPtr handle, IntPtr userData, UInt32 status, IntPtr frame)
        {
            if (frame == IntPtr.Zero)
            {
                return;
            }

            //如需直接处理RGB数据,请参考以下流程
            NT_SP_VideoFrame video_frame = (NT_SP_VideoFrame)Marshal.PtrToStructure(frame, typeof(NT_SP_VideoFrame));

            NT_SP_VideoFrame pVideoFrame = new NT_SP_VideoFrame();

            pVideoFrame.format_ = video_frame.format_;
            pVideoFrame.width_ = video_frame.width_;
            pVideoFrame.height_ = video_frame.height_;

            pVideoFrame.timestamp_ = video_frame.timestamp_;
            pVideoFrame.stride0_ = video_frame.stride0_;
            pVideoFrame.stride1_ = video_frame.stride1_;
            pVideoFrame.stride2_ = video_frame.stride2_;
            pVideoFrame.stride3_ = video_frame.stride3_;

            Int32 argb_size = video_frame.stride0_ * video_frame.height_;

            pVideoFrame.plane0_ = Marshal.AllocHGlobal(argb_size);
            CopyMemory(pVideoFrame.plane0_, video_frame.plane0_, (UInt32)argb_size);


            if (playWnd.InvokeRequired)
            {
                BeginInvoke(set_video_frame_call_back_, status, pVideoFrame);
            }
            else
            {
                set_video_frame_call_back_(status, pVideoFrame);
            }
        }

具体绘制代码:

        private void SmartPlayerForm_Paint(object sender, PaintEventArgs e)
        {
            if (player_handle_ == IntPtr.Zero || !is_gdi_render_ || !is_playing_)
            {
                return;
            }

            if (cur_video_frame_.plane0_ == IntPtr.Zero)
            {
                return;
            }

            Bitmap bitmap = new Bitmap(cur_video_frame_.width_, cur_video_frame_.height_, cur_video_frame_.stride0_,
                 System.Drawing.Imaging.PixelFormat.Format32bppRgb, cur_video_frame_.plane0_);

            int image_width = cur_video_frame_.width_;
            int image_height = cur_video_frame_.height_;

            Graphics g = e.Graphics;    //获取窗体画布
            g.SmoothingMode = SmoothingMode.HighSpeed;

            int limit_w = this.Width - 60;
            int limit_h = this.Height - playWnd.Top - 60;

            if (btn_check_render_scale_mode.Checked)
            {
                int d_w = 0, d_h = 0;
                int left_offset = 0;
                int top_offset = 0;

                Brush brush = new SolidBrush(Color.Black);
                g.FillRectangle(brush, playWnd.Left, playWnd.Top, limit_w, limit_h);

                GetRenderRect(limit_w, limit_h, image_width, image_height, ref left_offset, ref top_offset, ref d_w, ref d_h);
                g.DrawImage(bitmap, playWnd.Left + left_offset, playWnd.Top + top_offset, d_w, d_h);   //在窗体的画布中绘画出内存中的图像
            }
            else
            {
                g.DrawImage(bitmap, playWnd.Left, playWnd.Top, limit_w, limit_h);   //在窗体的画布中绘画出内存中的图像
            }
        }

目前来看,不支持D3D的机器少之又少,在环境具备的情况下,优先建议考虑D3D模式绘制。

上一篇:使用ffserver实现本地视频以rtsp视频流访问


下一篇:【疑难解决】如何解决RTSP拉流协议视频平台EasyNVR硬件设备意外断电重启无法进入initramfs界面?