使用 Accord.net 录制视频 (AForge)

Question

我使用 Accord.net (AForge) 连接网络摄像头并录制视频但是存储的视频是慢动作... 这是我的项目：

    using AForge.Video;
using AForge.Video.DirectShow;
using AForge.Video.FFMPEG;
using System;
using System.Drawing;
using System.IO;
using System.Threading;
using System.Windows.Forms;

namespace CaptureWebcam
{
    public partial class Form1 : Form
    {
        private VideoCaptureDeviceForm captureDevice;
        private string path = Path.GetDirectoryName(Application.ExecutablePath) + @"\Videos\";
        private FilterInfoCollection videoDevice;
        private VideoCaptureDevice videoSource;
        private VideoFileWriter FileWriter = new VideoFileWriter();
        private Bitmap video;
        bool isRecord = false;

        public Form1()
        {
            InitializeComponent();
        }

        private void videoSource_NewFrame(object sender, NewFrameEventArgs eventArgs)
        {
            video = (Bitmap)eventArgs.Frame.Clone();
            pictureBox1.Image = (Bitmap)eventArgs.Frame.Clone();
        }

        private void btnStartCam_Click(object sender, EventArgs e)
        {
            videoDevice = new FilterInfoCollection(FilterCategory.VideoInputDevice);
            captureDevice = new VideoCaptureDeviceForm();
            if (captureDevice.ShowDialog(this) == DialogResult.OK)
            {
                videoSource = captureDevice.VideoDevice;
                videoSource = captureDevice.VideoDevice;
                videoSource.NewFrame += new NewFrameEventHandler(videoSource_NewFrame);
                videoSource.Start();
                timer1.Enabled = true;
            }
            //videoSource.DisplayPropertyPage(IntPtr.Zero);
        }

        private Thread workerThread = null;
        private bool stopProcess = false;

        private void recordLiveCam()
        {
            if (!stopProcess)
            {
                while (isRecord)
                {
                    FileWriter.WriteVideoFrame(video);
                }
                FileWriter.Close();
            }
            else
            {
                workerThread.Abort();
            }            
        }

        private void btnRecord_Click(object sender, EventArgs e)
        {
            //try
            //{
            isRecord = true;
            if (!Directory.Exists(path))
            {
                Directory.CreateDirectory(path);
            }
            int h = captureDevice.VideoDevice.VideoResolution.FrameSize.Height;
            int w = captureDevice.VideoDevice.VideoResolution.FrameSize.Width;
            FileWriter.Open(path + "recorded at " + DateTime.Now.ToString("HH-mm-ss") + ".mp4", w, h, 25, VideoCodec.MPEG4);
            stopProcess = false;
            workerThread = new Thread(new ThreadStart(recordLiveCam));
            workerThread.Start();

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

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void btnStopRecord_Click(object sender, EventArgs e)
        {
            stopProcess = true;
            isRecord = false;
            FileWriter.Close();
            workerThread.Abort();
            video = null;

        }

        private void btnStopCam_Click(object sender, EventArgs e)
        {
            try
            {
                if (videoSource.IsRunning)
                {
                    videoSource.SignalToStop();
                    videoSource.Stop();                  
                    pictureBox1.Image = null;
                    pictureBox1.Invalidate();
                    if (FileWriter.IsOpen)
                    {
                        FileWriter.Close();
                        video = null;
                    }
                }
                else
                    return;
            }
            catch
            {
                videoSource.Stop();
                FileWriter.Close();
                video = null;
            }
        }

        float fts = 0.0f;
        private void timer1_Tick(object sender, EventArgs e)
        {
            fts = videoSource.FramesReceived;
            label1.Text = "Frame Rate : " + fts.ToString("F2") + " fps";
        }
    }
}

点击 btnStopRecord 时出现以下错误：

Additional information: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.

Answer 1

您可以尝试放置一些计时器以了解哪个操作正在减慢进程。（秒表 class 将是完美的）
我不知道你的框架的格式，但通常转换为位图是瓶颈，AForge 非常快。此外，您可以将时间戳传递给 WriteVideoFrame 方法，然后 Open 中指示的帧速率仅用于重播视频。 Aforge会在正确的时间以正确的顺序排列帧。
这是根据我的经验。希望对你有帮助。

Answer 2

"Slow motion" 可能有多种原因。首先，您需要知道生成 NewFrames 的实际帧率是否太慢（那么多少 HZ？）或者 CPU 是否太忙。或者是显卡。

对于与 DirectShow 相关的所有内容，我强烈建议使用 GraphEdit 和 AMCap 来查看设备的实际功能。 AForge 容易过采样，我不会怀疑它在 Accord 中是否类似。

此外，您始终可以依靠良好的旧 processexplorer 来查看负载（如果有）是由 SYSTEM 或 INTERRUPRS 引起的，还是实际上是由您的可执行文件产生的。

发生在我身上的另一件事是 PictureBox。 VideoSourcePlayer 好得多，最后我自己做了 blitting。

值得一提的是这三个优化：

不要使用 Bitmap.GetPixel!
使用videoSource.DisplayPinPropertyPage(IntPtr.Zero)
检查视频流的颜色space

Bitmap.GetPixel

GetPixel 的问题在于，它真的很慢，因为它必须 unmanage/manage 对每个像素进行大量处理。这很好，因为您只需要少量调用并在加载的位图上使用它。如果您想每隔几毫秒在所有 pixelx 上使用它，那肯定是错误的方法。这种现象的 CPU 负载与您的应用程序相关联，并将在进程资源管理器中显示。最后，我从这里开始编写了自己的像素例程：Work with bitmap faster with Csharp 如果你只是想要一个内核或比我需要的更普通的东西，实现一个自定义 Filter.

VideoSource.DisplayPinPropertyPage

如果您使用 AForge 内置机制来选择分辨率和启动视频流，则无法设置帧率（我不认为这是 AForge 中的错误）。所以 AForge 总是选择最高的帧率。如果绕过 videoSource.VideoCapabilities 并直接显示本机设备配置对话框（正式名称为 "Video Capture Pin Properties Dialog"）。您可以在那里手动设置所有参数，对话框将填写适当的帧率。这样，您将在回调中获得 "real"（硬件）刷新率。此过采样的 CPU 负载发生在 SYSTEM 进程中。

颜色space转换

在我的例子中，相机支持三种输出格式：YUY2、MJPG 和 RGB24。根据您使用的格式，图像由 AForge 转换为 RGB（我认为实际上是 ARGB32）。所有三种格式的渲染 DirectShow 图形都不同，并且 RGB 显然比其他格式使用的 CPU 少得多，因为颜色转换非常简单。此转换的负载也显示在 SYSTEM 进程中，而不是在您的应用程序 exe 中。

Answer 3

您可以使用emguCV录制视频。

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;


using Emgu;
using Emgu.CV;
using Emgu.CV.Structure;



namespace Load_Images
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }

        double TotalFrame;
        double Fps;
        int captureFrameNo;

        VideoCapture capture;
        VideoWriter writer;



        bool isCapturing = false;



        private void button1_Click(object sender, EventArgs e)
        {
            if (isCapturing == false)
            {

                capture = new VideoCapture(0);

                TotalFrame = capture.GetCaptureProperty(Emgu.CV.CvEnum.CapProp.FrameCount);
                Fps = capture.GetCaptureProperty(Emgu.CV.CvEnum.CapProp.Fps);


                isCapturing = true;

                int fourcc = fourcc = VideoWriter.Fourcc('H', '2', '6', '4');
                capture.SetCaptureProperty(Emgu.CV.CvEnum.CapProp.FrameWidth, 2048);
                capture.SetCaptureProperty(Emgu.CV.CvEnum.CapProp.FrameHeight, 1024);

                //int fourcc = Convert.ToInt32(capture.GetCaptureProperty(Emgu.CV.CvEnum.CapProp.FourCC));
                int width = Convert.ToInt32(capture.GetCaptureProperty(Emgu.CV.CvEnum.CapProp.FrameWidth));
                int height = Convert.ToInt32(capture.GetCaptureProperty(Emgu.CV.CvEnum.CapProp.FrameHeight));

                string destin_path = "D:\out.mp4";
                writer = new VideoWriter(destin_path, fourcc, Fps, new Size(width, height), true);


                capture.ImageGrabbed += Capture_ImageGrabbed;
                capture.Start();
            }

        }



        private void Capture_ImageGrabbed(object sender, EventArgs e)
        {
            try
            {
                if (isCapturing == true)
                {

                    if (capture == null)
                    {

                        return;

                    }


                    Mat m = new Mat();
                    capture.Retrieve(m);
                    writer.Write(m);
                    pictureBox1.Image = m.ToImage<Bgr, byte>().Bitmap;
                }

            }
            catch (Exception)
            {

                throw;
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            if (isCapturing == true) {

                capture.Stop();
                isCapturing = false;

            }
        }

        private void button3_Click(object sender, EventArgs e)
        {
            if (capture != null) {

                capture.Pause();

            }
        }

        private void button4_Click(object sender, EventArgs e)
        {


            if (writer.IsOpened)
            {

                isCapturing = false;
                writer.Dispose();

            }
            MessageBox.Show("Completed");
        }

        private void Form2_Load(object sender, EventArgs e)
        {

        }
    }
}

Answer 4

试试这个

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

using AForge;
using AForge.Video.DirectShow;
using Accord.Video.FFMPEG;
using System.IO;
using AForge.Video;
using System.Threading;

namespace New_Project_2
{
    public partial class Form1 : Form
    {
        private VideoCaptureDeviceForm captureDevice;
        private FilterInfoCollection videoDevice;

        private VideoCaptureDevice videoSource;

        private VideoFileWriter FileWriter = new VideoFileWriter();

        bool isRecord = false;

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void videoSource_NewFrame(object sender, NewFrameEventArgs eventArgs)
        {
            try
            {
                if (isRecord == true)
                {
                    pictureBox1.Image = (Bitmap)eventArgs.Frame.Clone();
                    FileWriter.WriteVideoFrame((Bitmap)eventArgs.Frame.Clone());
                }

            }
            catch (Exception)
            {

                throw;
            }

        }

        private void button1_Click(object sender, EventArgs e)
        {
            videoDevice = new FilterInfoCollection(FilterCategory.VideoInputDevice);
            captureDevice = new VideoCaptureDeviceForm();

            if (captureDevice.ShowDialog(this) == DialogResult.OK)
            {
                isRecord = true;

                int h = captureDevice.VideoDevice.VideoResolution.FrameSize.Height;
                int w = captureDevice.VideoDevice.VideoResolution.FrameSize.Width;
                FileWriter.Open("d:\" + "recorded at " + DateTime.Now.ToString("HH-mm-ss") + ".mp4", w, h, 25, VideoCodec.MPEG4);

                videoSource = captureDevice.VideoDevice;
                videoSource.NewFrame += new NewFrameEventHandler(videoSource_NewFrame);
                videoSource.Start();


            }
            //videoSource.DisplayPropertyPage(IntPtr.Zero)
        }




        private void button2_Click(object sender, EventArgs e)
        {

        }

        private void button3_Click(object sender, EventArgs e)
        {
            isRecord = false;
            FileWriter.Close();


        }

        private void button4_Click(object sender, EventArgs e)
        {


        }

    }
}

Answer 5

如果您在 newFrame 处理程序 Func 上写入文件，将导致 fastplaqy/slow 在某些编解码器 VP8-VP9 等上进行记录（mpeg4 无效），但如果您在某个时间启动不同的计时器来写入，您就可以解决问题

使用 Accord.net 录制视频 (AForge)

Record video with Accord.net (AForge)

c#

video

ffmpeg

video-capture

aforge

Bitmap.GetPixel

VideoSource.DisplayPinPropertyPage

颜色space转换