Windows平台设计RTSP播放器/RTMP播放器需要考虑的几个方面

Posted daniulivesdk

tags:

篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了Windows平台设计RTSP播放器/RTMP播放器需要考虑的几个方面相关的知识,希望对你有一定的参考价值。

我们在实现Windows平台RTSP播放器或RTMP播放器的时候,需要考虑的点很多,比如多实例设计、多绘制模式兼容、软硬解码支持、快照、RTSP下TCP-UDP自动切换等,以下就其中几个方面,做个大概的探讨:

1. 视频绘制模式

我们在实现Windows平台播放的时候,一般首选D3D,D3D不支持的情况下,考虑数据回上来,采用GDI模式,一般实现如下,先做D3D检测,以大牛直播SDK播放端为例(Github),调用NT_SP_IsSupportD3DRender(),检测是否支持D3D模式,如果支持的话,调用NT_SP_SetRenderWindow(), 然后,设置是否等比例缩放(调用NT_SP_SetRenderScaleMode())。

                bool is_support_d3d_render = false;
                Int32 in_support_d3d_render = 0;

                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;
                    }
                }

                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_);
                }
技术图片

如果不支持D3D,设置RGB数据回调:

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_);
 
技术图片

数据处理如下:

        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);
            }
        }
技术图片

在OnPaint()绘制即可:

        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


            }
        }
技术图片

2. 特定机型硬解码

Windows平台硬解码,主要适用于性能偏弱的PC端,或者有多路播放诉求的场景,一般建议在软解性能没问题的情况下,尽量软解,具体处理如下,先检测系统是否支持硬解,如果支持,再做硬解设置,这样的好处在于如果系统不支持硬解,可以继续软解播放,具体设置如下,在调用NT_SP_Open()之前,做检测,因为NT_SP_Open()每个句柄对应一个player实例,多个实例只需要做一次判断即可:


            is_support_h264_hardware_decoder_ = NT.NTBaseCodeDefine.NT_ERC_OK == NT.NTSmartPlayerSDK.NT_SP_IsSupportH264HardwareDecoder();
            is_support_h265_hardware_decoder_ = NT.NTBaseCodeDefine.NT_ERC_OK == NT.NTSmartPlayerSDK.NT_SP_IsSupportH265HardwareDecoder();

            if (player_handle_ == IntPtr.Zero)
            {
                player_handle_ = new IntPtr();

                UInt32 ret_open = NTSmartPlayerSDK.NT_SP_Open(out player_handle_, IntPtr.Zero, 0, IntPtr.Zero);

                if (ret_open != 0)
                {
                    player_handle_ = IntPtr.Zero;
                    MessageBox.Show("调用NT_SP_Open失败..");
                    return;
                }
            }
技术图片

播放之前,设置硬解码:

            if (checkBox_hardware_decoder.Checked)
            {
                NTSmartPlayerSDK.NT_SP_SetH264HardwareDecoder(player_handle_, is_support_h264_hardware_decoder_ ? 1 : 0, 0);
                NTSmartPlayerSDK.NT_SP_SetH265HardwareDecoder(player_handle_, is_support_h265_hardware_decoder_ ? 1 : 0, 0);
            }
            else
            {
                NTSmartPlayerSDK.NT_SP_SetH264HardwareDecoder(player_handle_, 0, 0);
                NTSmartPlayerSDK.NT_SP_SetH265HardwareDecoder(player_handle_, 0, 0);
            }
技术图片

3. 只解码关键帧

只解关键帧的场景,也是用于多路播放诉求,比如一般的监控场景,考虑到多路的场景,一般关键帧间隔不大(如1-2秒一个),平台可对现场场景有个宏观了解,如需重点关注某几路画面的时候,再实时取消这个选项,实现全帧播放,所以,只解关键帧一定要做成实时调用的接口才更有设计意义。

            // 设置是否只解码关键帧
            if (btn_check_only_decode_video_key_frame.Checked)
            {
                NTSmartPlayerSDK.NT_SP_SetOnlyDecodeVideoKeyFrame(player_handle_, 1);
            }
            else
            {
                NTSmartPlayerSDK.NT_SP_SetOnlyDecodeVideoKeyFrame(player_handle_, 0);
            }
技术图片

4. 视频view旋转

好多现场的开发人员有这样的困惑,有些设备,在安装时,可能没调整好角度,导致拍出来的角度倒立等,看着很不方便,这时候,如果现场设备比较多的话,不可能每台设备都到现场重新安装,实时view旋转,就体现了价值,具体如下:

		/*
         * 设置旋转,顺时针旋转
         * degress: 设置0, 90, 180, 270度有效,其他值无效
         * 注意:除了0度,其他角度播放会耗费更多CPU
         * 接口调用成功返回NT_ERC_OK
		 */
        [DllImport(@"SmartPlayerSDK.dll")]
        public static extern UInt32 NT_SP_SetRotation(IntPtr handle, Int32 degress);
技术图片

视频view选择,会消耗一定的CPU。

5. 实时快照

实时快照功能不表,是一个好的RTSP播放器和RTMP播放器必备的功能,实时快照是把解码后的yuv数据重新编码成png,所以有一定的CPU消耗,不建议过于频繁操作,具体实现如下:

            if ( String.IsNullOrEmpty(capture_image_path_) )
	        {
		        MessageBox.Show("请先设置保存截图文件的目录! 点击截图左边的按钮设置!");
		        return;
	        }

	        if ( player_handle_ == IntPtr.Zero )
	        {
		        return;
	        }

	        if ( !is_playing_)
	        {
                MessageBox.Show("请在播放状态下截图!");
		        return;
	        }

            String name = capture_image_path_ + "\" +  DateTime.Now.ToString("hh-mm-ss") + ".png";

            byte[] buffer1 = Encoding.Default.GetBytes(name);
            byte[] buffer2 = Encoding.Convert(Encoding.Default, Encoding.UTF8, buffer1, 0, buffer1.Length);

            byte[] buffer3 = new byte[buffer2.Length + 1];
            buffer3[buffer2.Length] = 0;

            Array.Copy(buffer2, buffer3, buffer2.Length);

            IntPtr file_name_ptr = Marshal.AllocHGlobal(buffer3.Length);
            Marshal.Copy(buffer3, 0, file_name_ptr, buffer3.Length);

            capture_image_call_back_ = new SP_SDKCaptureImageCallBack(SDKCaptureImageCallBack);

            UInt32 ret = NTSmartPlayerSDK.NT_SP_CaptureImage(player_handle_, file_name_ptr, IntPtr.Zero, capture_image_call_back_);

            Marshal.FreeHGlobal(file_name_ptr);

            if (NT.NTBaseCodeDefine.NT_ERC_OK == ret)
	        {
		        // 发送截图请求成功
	        }
            else if ((UInt32)NT.NTSmartPlayerDefine.SP_E_ERROR_CODE.NT_ERC_SP_TOO_MANY_CAPTURE_IMAGE_REQUESTS == ret)
	        {
		        // 通知用户延时
		        MessageBox.Show("Too many capture image requests!");
	        }
	        else
	        {
		        // 其他失败
	        }
技术图片
        public void SDKCaptureImageCallBack(IntPtr handle, IntPtr userData, UInt32 result, IntPtr file_name)
        {
            if (file_name == IntPtr.Zero)
                return;

            int index = 0;

            while (true)
            {
                if (0 == Marshal.ReadByte(file_name, index))
                    break;

                index++;
            }

            byte[] file_name_buffer = new byte[index];

            Marshal.Copy(file_name, file_name_buffer, 0, index);

            byte[] dst_buffer = Encoding.Convert(Encoding.UTF8, Encoding.Default, file_name_buffer, 0, file_name_buffer.Length);
            String image_name = Encoding.Default.GetString(dst_buffer, 0, dst_buffer.Length);

            if (playWnd.InvokeRequired)
            {
                BeginInvoke(set_capture_image_call_back_, result, image_name);
            }
            else
            {
                set_capture_image_call_back_(result, image_name);
            }
        }
技术图片

后续,我们将针对RTSP和RTMP播放器设计过程中的其他点,做更进一步的探讨。

以上是关于Windows平台设计RTSP播放器/RTMP播放器需要考虑的几个方面的主要内容,如果未能解决你的问题,请参考以下文章

庖丁解牛之Android平台RTSP|RTMP播放器设计

Windows平台如何集成RTSP/RTMP直播播放功能

Windows平台如何集成RTSP/RTMP直播播放功能

如何设计一款跨平台低延迟的RTMP/RTSP直播播放器

能用D3D要啥自行车?Windows平台播放RTSP或RTMP渲染模式比较

EasyPlayer播放器全线开放:EasyPlayer RTSP版RTMP版Pro版Windows平台Android平台iOS平台H5版本