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Emgu CV receives all frames from a video file

I would like to ask you to help me with getting all the frames from a video file using Emgu CV. I know that I can use the Capture class and its QueryFrame() method, but this returns only one frame. What is the easiest way to get all frames? (and save it, for example, until Image<Bgr, Byte>[] ). I need all the frames to do the extra processing (more specifically: extracting a keyframe to add video).

Many thanks for your help.

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c # video emgucv
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See my answer here for help. Emgu Capture plays video super fast

But this should do when you ask, I used a list to store images that you can use in an array, but you need to know how big your avi file is.

 Timer My_Time = new Timer(); int FPS = 30; List<Image<Bgr,Byte>> image_array = new List<Image<Bgr,Byte>>(); Capture _capture; public Form1() { InitializeComponent(); //Frame Rate My_Timer.Interval = 1000 / FPS; My_Timer.Tick += new EventHandler(My_Timer_Tick); My_Timer.Start() _capture = new Capture("test.avi"); } private void My_Timer_Tick(object sender, EventArgs e) { Image<Bgr, Byte> frame = _capture.QueryFrame(); if (frame != null) { imageBox.Image = _capture.QueryFrame(); image_array.Add(_capture.QueryFrame().Copy()); } else { My_Timer.Stop(); { }

It was intended to play a video file with a responsible course, but since you are just converting, you could use the Application.Idle method as easily as this ...

 List<Image<Bgr,Byte>> image_array = new List<Image<Bgr,Byte>>(); Capture _capture; public Form1() { InitializeComponent(); //Frame Rate _capture = new Capture("test.avi"); Application.Idle += ProcessFrame; } private void ProcessFrame(object sender, EventArgs arg) { Image<Bgr, Byte> frame = _capture.QueryFrame(); if (frame != null) { image_array.Add(frame.Copy()); } else { Application.Idle -= ProcessFrame;// treat as end of file } }

You need to be careful that you get an error message at the end of the file error. You can always use the try catch statement to catch the specific error it will give instead of simply completing the conversion.

If you use an array of images to use, you will have to iterate over the file, increasing the variable and counting frames, and then create an array of images before converting the video file into an array.

[EDIT]

As requested, this is a version of the method for extracting all frames from a video file, which I did not test in a large video file, since I expect the program to crash, as this will require a lot of memory.

  private List<Image<Bgr, Byte>> GetVideoFrames(String Filename) { List<Image<Bgr,Byte>> image_array = new List<Image<Bgr,Byte>>(); Capture _capture = new Capture(Filename); bool Reading = true; while (Reading) { Image<Bgr, Byte> frame = _capture.QueryFrame(); if (frame != null) { image_array.Add(frame.Copy()); } else { Reading = false; } } return image_array; }

Alternatively, I understand that you might want to record 10 seconds of video from a webcam so that this method does this, I used a stopwatch, since the while loop forbids using a timer, unless your application is multithreading

  private List<Image<Bgr, Byte>> GetVideoFrames(int Time_millisecounds) { List<Image<Bgr,Byte>> image_array = new List<Image<Bgr,Byte>>(); System.Diagnostics.Stopwatch SW = new System.Diagnostics.Stopwatch(); bool Reading = true; Capture _capture = new Capture(); SW.Start(); while (Reading) { Image<Bgr, Byte> frame = _capture.QueryFrame(); if (frame != null) { image_array.Add(frame.Copy()); if (SW.ElapsedMilliseconds >= Time_millisecounds) Reading = false; } else { Reading = false; } } return image_array; }

and it will look like this:

 List<Image<Bgr, Byte>> Image_Array = GetVideoFrames(10000); //10 Secounds

Hope this helps,

Greetings

Chris

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Even I ran into the same problem. So, I initialized another timer and provided the video saving code there. And this timer is enabled only when the record button is pressed [the button on the form that records the video on the click]. Now I can record video, but no sound is recorded.

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