Emgucv视频操作--进阶1

2020-08-19 11:04:59 浏览数 (1)

实现功能：

  1. 播放视频
  2. 提取每一帧图片并保存
  3. 显示视频播放的时间 videowrite 视频保存的方法还未调试成功，等待后续再继续研究!
代码语言：javascript复制
//----------------------------------------------------------------------------
//  Copyright (C) 2004-2019 by EMGU Corporation. All rights reserved.       
//----------------------------------------------------------------------------

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using Emgu.CV;
using Emgu.CV.CvEnum;
using Emgu.CV.Structure;
using Emgu.Util;

using System.Threading;

namespace CameraCapture
{
public partial class CameraCapture : Form
   {
private VideoCapture _capture = null;
private bool _captureInProgress;
private Mat _frame, _frame1;
private Mat _grayFrame;
private Mat _smallGrayFrame;
private Mat _smoothedGrayFrame;
private Mat _cannyFrame;
private double FrameRate;
private int cam,count;
      Bitmap bmp;
//VideoWriter _Wvideo;
    
//private Image<Bgr, byte> frame = new Image<Bgr, byte>("你好.jpg");
//参考链接 https://blog.csdn.net/cuoban/article/details/50555953
public CameraCapture()
      {
         InitializeComponent();
        Control.CheckForIllegalCrossThreadCalls = false;//加入这句话，不过治标不治本 
//使用显卡处理图像数据效率会很多,如果你的设备支持,最好打开,使用CvInvoke.HaveOpenCLCompatibleGpuDevice能返回是否支持.
// 配置CvInvoke.UseOpenCL能让OpenCV 启用或者停用 GPU运算
//CvInvoke.UseOpenCL = CvInvoke.HaveOpenCLCompatibleGpuDevice;
            CvInvoke.UseOpenCL = false;
            count = 0;
try
         {
//构造一个摄像头实例,如果调用本地摄像机则括号里面为空
           _capture = new VideoCapture(@"C:UsersAdministratorDesktopvideovtest.avi");
           _capture.ImageGrabbed  = ProcessFrame;//图像捕捉事件
double TotalFrames = _capture.GetCaptureProperty(Emgu.CV.CvEnum.CapProp.FrameCount);
           _capture.SetCaptureProperty(Emgu.CV.CvEnum.CapProp.FrameHeight, 96);
           _capture.SetCaptureProperty(Emgu.CV.CvEnum.CapProp.FrameWidth, 128);//FrameWidth=3视频流的帧宽度（只对摄像头有效）
// FrameRate = _capture.GetCaptureProperty(Emgu.CV.CvEnum.CAP_PROP.CV_CAP_PROP_FPS);
            FrameRate = _capture.GetCaptureProperty(Emgu.CV.CvEnum.CapProp.Fps);//帧率
// MessageBox.Show(FrameRate.ToString());
           cam = 0;
            }
catch (NullReferenceException excpt)
         {
            MessageBox.Show(excpt.Message);
         }
         _frame = new Mat();
            _frame1 = new Mat();
            _grayFrame = new Mat();
         _smallGrayFrame = new Mat();
         _smoothedGrayFrame = new Mat();
         _cannyFrame = new Mat();



        }

private void ProcessFrame(object sender, EventArgs arg)
      {

/* if (_capture != null && _capture.Ptr != IntPtr.Zero)
                // if (_capture != null)
                 {
                   _capture.Retrieve(_frame, 0);  //_capture.RetrieveBgrFrame(); 老版本写法 得到捕捉到的帧数据。
                   //  _frame1 = _capture.QueryFrame();
                    // pictureBox1.Image = _frame1.ToBitmap();

                     CvInvoke.CvtColor(_frame, _grayFrame, ColorConversion.Bgr2Gray);

             CvInvoke.PyrDown(_grayFrame, _smallGrayFrame);
                 //进行高斯向下采样,执行高斯金字塔分解步骤向下采样。固定原图像，
                 //删除指定行和列（可以全为奇数行和列，或者偶数行和列...），从而减小图像的宽度和高度。

             CvInvoke.PyrUp(_smallGrayFrame, _smoothedGrayFrame);
           //执行高斯金字塔分解向上采样，首先透过注入固定行和列0像素值，在通过插值算法，对插入行列进行插值，这样用于放大原图像的四倍。
           //参数解析：IInputArraysrc：输入图像，即原图像。IOutputArraydst：输出图像，采样后得到的图像。

             CvInvoke.Canny(_smoothedGrayFrame, _cannyFrame, 100, 60);
             //多级边缘检测算法

              captureImageBox.Image = _frame;
             grayscaleImageBox.Image = _grayFrame;
             smoothedGrayscaleImageBox.Image = _smoothedGrayFrame;
             cannyImageBox.Image = _cannyFrame;*/
try
            {
                Double Framesno = _capture.GetCaptureProperty(Emgu.CV.CvEnum.CapProp.PosFrames);
                _capture.Retrieve(_frame, 0);
if (_frame != null)
                {
//pictureBox1.Image = _frame.Bitmap;
                    captureImageBox.Image = _frame;
                    Thread.Sleep((int)(1000.0 / FrameRate));

//保存图片
                    bmp = new Bitmap(_frame.Bitmap);
                    bmp.Save(@"D:image" count ".jpg", System.Drawing.Imaging.ImageFormat.Jpeg);
                    bmp.Dispose();
                    count  ;

// _Wvideo = new VideoWriter(@"D:image1.avi", -1,10,new Size(_frame.Cols, _frame.Rows),true);
if (cam == 0)
                    {
int  Video_seek = (int)(Framesno);
double time_index = _capture.GetCaptureProperty(Emgu.CV.CvEnum.CapProp.PosMsec);
                       label5.Text = "Time: "   TimeSpan.FromMilliseconds(time_index).ToString().Substring(0, 8);
// double framenumber = _capture.GetCaptureProperty(Emgu.CV.CvEnum.CAP_PROP.CV_CAP_PROP_POS_FRAMES);
// Frame_lbl.Text = "Frame: "   framenumber.ToString();
                       
                    }
if (cam == 1)
                    {
//Frame_lbl.Text = "Frame: "   (webcam_frm_cnt  ).ToString();
                    }
                }
            }
catch (Exception ex)
            {
                MessageBox.Show(ex.Message.ToString());
            }
        
           
        }

private void captureButtonClick(object sender, EventArgs e)
      {
if (_capture != null)
         {
if (_captureInProgress)
            {  //stop the capture
               captureButton.Text = "Start Capture";
               _capture.Pause();
            }
else
            {
//start the capture
               captureButton.Text = "Stop";
               _capture.Start();
            }

            _captureInProgress = !_captureInProgress;
         }
      }
//Dispose意为释放，释放组件所占用的内存。
//C#特性，为提高运行效率，自动会释放已使用过且不再需要使用的组件来减少程序的CPU使用率。
//默认会在程序运行一段时间后自动加载该Dispose方法，或者可以显式的自行调用此方法。
private void ReleaseData()
      {
if (_capture != null)
            
                _capture.Dispose();

      }

private void FlipHorizontalButtonClick(object sender, EventArgs e)
      {
// 得到和设置Capture类是否进行水平翻转。

if (_capture != null) _capture.FlipHorizontal = !_capture.FlipHorizontal;
      }

private void FlipVerticalButtonClick(object sender, EventArgs e)
      {
if (_capture != null) _capture.FlipVertical = !_capture.FlipVertical;
      }
   }
}

要显示视频播放的时间可以以下两种方式：

  1. 初始化代码中加： Control.CheckForIllegalCrossThreadCalls = false;//加入这句话，不过治标不治本 视频播放还可以用
  2. 使用委托：SetText("Time: " TimeSpan.FromMilliseconds(time_index).ToString().Substring(0, 8));
  3. private delegate void SetTextDelegate(string value); private void SetText(string value) { if (this.InvokeRequired) { SetTextDelegate d = new SetTextDelegate(SetText); object arg = (object)value;//要传入的参数值 this.Invoke(d, arg);//这里参数不对。 } else { this.label5.Text = value; } }
代码语言：javascript复制
QueryFrame() 去实现
代码语言：javascript复制
//----------------------------------------------------------------------------
//  Copyright (C) 2004-2019 by EMGU Corporation. All rights reserved.       
//----------------------------------------------------------------------------

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using Emgu.CV;
using Emgu.CV.CvEnum;
using Emgu.CV.Structure;
using Emgu.Util;

using System.Threading;

namespace WindowsFormsApplication40
{
public partial class Form1 : Form
    {
private VideoCapture _capture = null;
private Mat _frame;
private double FrameRate;

//private Image<Bgr, byte> frame = new Image<Bgr, byte>("你好.jpg");
//参考链接 https://blog.csdn.net/cuoban/article/details/50555953
public Form1()
        {
            InitializeComponent();
//使用显卡处理图像数据效率会很多,如果你的设备支持,最好打开,使用CvInvoke.HaveOpenCLCompatibleGpuDevice能返回是否支持.
// 配置CvInvoke.UseOpenCL能让OpenCV 启用或者停用 GPU运算
//CvInvoke.UseOpenCL = CvInvoke.HaveOpenCLCompatibleGpuDevice;
            CvInvoke.UseOpenCL = false;
try
            {
                Application.Idle  = Application_Idle;
//构造一个摄像头实例,如果调用本地摄像机则括号里面为空
  //Application.Idle  = new EventHandler(Application_Idle);//也可以
                _capture = new VideoCapture(@"C:UsersAdministratorDesktopvideovtest.avi");              
double TotalFrames = _capture.GetCaptureProperty(Emgu.CV.CvEnum.CapProp.FrameCount);
                FrameRate = _capture.GetCaptureProperty(Emgu.CV.CvEnum.CapProp.Fps);//帧率


            }
catch (NullReferenceException excpt)
            {
                MessageBox.Show(excpt.Message);
            }
          


        }

private void Application_Idle(object sender, EventArgs e)
        {
try
            {

                _frame = _capture.QueryFrame();
if (_frame != null)
                {
                    System.Threading.Thread.Sleep((int)(1000.0 / FrameRate - 5));
                    pictureBox1.Image = _frame.Bitmap;

                    GC.Collect();
                }
            }
catch (Exception ex)
            {
                MessageBox.Show(ex.Message.ToString());
            }


        }

       
//Dispose意为释放，释放组件所占用的内存。
//C#特性，为提高运行效率，自动会释放已使用过且不再需要使用的组件来减少程序的CPU使用率。
//默认会在程序运行一段时间后自动加载该Dispose方法，或者可以显式的自行调用此方法。
private void ReleaseData()
        {
if (_capture != null)

                _capture.Dispose();

        }

      
    }
}

项目拓展：

点击按钮选择需要播放的视频进行播放

代码语言：javascript复制
//----------------------------------------------------------------------------
//  Copyright (C) 2004-2019 by EMGU Corporation. All rights reserved.       
//----------------------------------------------------------------------------

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using Emgu.CV;
using Emgu.CV.CvEnum;
using Emgu.CV.Structure;
using Emgu.Util;

using System.Threading;

namespace WindowsFormsApplication40
{
public partial class Form1 : Form
    {
private VideoCapture _capture = null;
private Mat _frame;
private double FrameRate;

//private Image<Bgr, byte> frame = new Image<Bgr, byte>("你好.jpg");
//参考链接 https://blog.csdn.net/cuoban/article/details/50555953
public Form1()
        {
            InitializeComponent();
//使用显卡处理图像数据效率会很多,如果你的设备支持,最好打开,使用CvInvoke.HaveOpenCLCompatibleGpuDevice能返回是否支持.
// 配置CvInvoke.UseOpenCL能让OpenCV 启用或者停用 GPU运算
//CvInvoke.UseOpenCL = CvInvoke.HaveOpenCLCompatibleGpuDevice;
            CvInvoke.UseOpenCL = false;
try
            {
// Application.Idle  = Application_Idle;
//Application.Idle  = new EventHandler(Application_Idle);
//构造一个摄像头实例,如果调用本地摄像机则括号里面为空
// _capture = new VideoCapture(@"C:UsersAdministratorDesktopvideovtest.avi");              
// double TotalFrames = _capture.GetCaptureProperty(Emgu.CV.CvEnum.CapProp.FrameCount);
//FrameRate = _capture.GetCaptureProperty(Emgu.CV.CvEnum.CapProp.Fps);//帧率
               

            }
catch (NullReferenceException excpt)
            {
                MessageBox.Show(excpt.Message);
            }
          
 

        }

private void Application_Idle(object sender, EventArgs e)
        {
try
            {

                _frame = _capture.QueryFrame();
if (_frame != null)
                {
                    System.Threading.Thread.Sleep((int)(1000.0 / FrameRate - 5));
                    pictureBox1.Image = _frame.Bitmap;

double time_index = _capture.GetCaptureProperty(Emgu.CV.CvEnum.CapProp.PosMsec);
                    label1.Text = "Time: "   TimeSpan.FromMilliseconds(time_index).ToString().Substring(0, 8);
                    GC.Collect();
                }
            }
catch (Exception ex)
            {
                MessageBox.Show(ex.Message.ToString());
            }


        }

       
//Dispose意为释放，释放组件所占用的内存。
//C#特性，为提高运行效率，自动会释放已使用过且不再需要使用的组件来减少程序的CPU使用率。
//默认会在程序运行一段时间后自动加载该Dispose方法，或者可以显式的自行调用此方法。
private void ReleaseData()
        {
if (_capture != null)

                _capture.Dispose();

        }

private void button1_Click(object sender, EventArgs e)
        {
            OpenFileDialog op = new OpenFileDialog();
if(op.ShowDialog() == DialogResult.OK)
            {
try
                {
                    
                     _capture = new VideoCapture(op.FileName);
double TotalFrames = _capture.GetCaptureProperty(Emgu.CV.CvEnum.CapProp.FrameCount);
                    FrameRate = _capture.GetCaptureProperty(Emgu.CV.CvEnum.CapProp.Fps);//帧率
                    Application.Idle  = new EventHandler(Application_Idle);

                }                
catch (Exception ex)
                {
                    MessageBox.Show(ex.Message.ToString());
                }


            }
        }
    }
}
云点播 编程算法

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