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• Accord.Video.FFMPEG.VideoFileWriter writes different data from the input data

  14 novembre 2017, par Rasool Ahmed

  I’m working on project that encrypting video frames using RC4 algorithm and save these frames in playable video file.

  I used a package named Accord.Video.FFMPEG. This package has a classes (VideoFileReader, & VideoFileWriter) that reads and writes video frames.

  The first step is reads the video :

  VideoHandler v = new VideoHandler();
  
  OpenFileDialog newimag = new OpenFileDialog();
  
          if (newimag.ShowDialog() == DialogResult.OK)
  
          {
  
              textfile = newimag.FileName;
  
              picbox.ImageLocation = textfile;
  
              status1.Text = "loaded";
  
              //MessageBox.Show("your video file have been loaded seccufly"); // is an idea for viwing message 
  
  
  
          }
  
      bytedata = v.ReadAllFrameBytes(textfile);

  The second step is encrypting the frames of video :

  byte[] bn = new byte[bytedata.Length];// new array to hold the encryptred file
  
  
  
          bn = Encrypt(bytedata, ba);

  The last step is saving the encrypted frames :

  v.WriteFramesData(newfilepath, bn);

  My encrypting algorithm is encrypting and decrypting the cipher with same algorithm and key.

  These stpes works on Text, and Images files, but when I use it on video I can’t restore the encrypted video. After some testings, I found that VideoFileWriter dosn’t write the same input frames. Whyyyyyyy ?

  Here is my VideoFileHandler I made it :

   using System;
  
   using System.Collections.Generic;
  
   using System.Drawing;
  
   using System.Linq;
  
   using System.Text;
  
   using System.Drawing.Imaging;
  
   using System.IO;
  
   using Accord.Video.FFMPEG;
  
   namespace imgtobyt_1_in_c
  
   {
  
  class VideoHandler
  
  {
  
      public List data;
  
      public byte[] imagedata;
  
      public int Height, Width;
  
      public byte[] ReadAllFrameBytes(string FileName)
  
      {
  
          // create instance of video reader
  
          VideoFileReader reader = new VideoFileReader();
  
          // open video file
  
          reader.Open(FileName);
  
          Height = reader.Height;
  
          Width = reader.Width;
  
  
  
          data = new List();
  
          // read video frames
  
          for (int i = 0; i < 100; i++) //change 100 to reader.FrameCount
  
          {
  
              Bitmap videoFrame = reader.ReadVideoFrame();
  
              byte[] framebytes = GetBytesFromFrame(videoFrame);
  
              data.Add(framebytes);
  
              // dispose the frame when it is no longer required
  
              videoFrame.Dispose();
  
          }
  
          reader.Close();
  
          imagedata = new byte[data.Count * data[0].Length];
  
          int c = 0;
  
          for (int i = 0; i < data.Count; i++)
  
          {
  
              byte[] d = data[i];
  
              for (int x = 0; x < d.Length; x++)
  
              {
  
                  imagedata[c] = d[x];
  
                  c++;
  
              }
  
          }
  
          return imagedata;
  
      }
  
  
  
      public byte[] GetBytesFromFrame(Bitmap Frame)
  
      {
  
          LockBitmap lockBitmap = new LockBitmap(Frame);
  
          lockBitmap.LockBits();
  
  
  
          byte[] framebytes = new byte[Frame.Width * Frame.Height * 3];
  
          int z = 0;
  
          for (int x = 0; x < lockBitmap.Height; x++)
  
              for (int y = 0; y < lockBitmap.Width; y++)
  
              {
  
                  Color Pixel = lockBitmap.GetPixel(y, x);
  
                  framebytes[z] = Pixel.R;
  
                  z++;
  
                  framebytes[z] = Pixel.G;
  
                  z++;
  
                  framebytes[z] = Pixel.B;
  
                  z++;
  
              }
  
  
  
          lockBitmap.UnlockBits();
  
          return framebytes;
  
          //using (var stream = new MemoryStream())
  
          //{
  
          //    Frame.Save(stream, System.Drawing.Imaging.ImageFormat.Png);
  
          //    return stream.ToArray();
  
          //}
  
      }
  
  
  
      public Bitmap GetFrameFromBytes(byte[] Framebytes, ref int offset, int Width, int Height)
  
      {
  
          Bitmap Frame = new Bitmap(Width, Height, PixelFormat.Format24bppRgb);
  
          LockBitmap lockBitmap = new LockBitmap(Frame);
  
          lockBitmap.LockBits();
  
          for (int x = 0; x < Height; x++)
  
              for (int y = 0; y < Width; y++)
  
              {
  
                  Color Pixel = Color.FromArgb(Framebytes[offset], Framebytes[offset + 1], Framebytes[offset + 2]); offset += 3;
  
                  lockBitmap.SetPixel(y, x, Pixel);
  
              }
  
  
  
          lockBitmap.UnlockBits();
  
  
  
          return Frame;
  
          //Bitmap bmp;
  
          //using (var ms = new MemoryStream(Framebytes))
  
          //{
  
          //    bmp = new Bitmap(ms);
  
          //}
  
          //return bmp;
  
      }
  
  
  
      public void WriteFramesData(string FileName, byte[] data)
  
      {
  
          // create instance of video writer
  
          VideoFileWriter writer = new VideoFileWriter();
  
          // create new video file
  
          writer.Open(FileName, Width, Height);
  
  
  
          int offset = 0;
  
          // write video frames
  
          for (int i = 0; i < 100; i++)
  
          {
  
              // create a bitmap to save into the video file
  
              Bitmap Frame = GetFrameFromBytes(data, ref offset, Width, Height);
  
              writer.WriteVideoFrame(Frame);
  
          }
  
          writer.Close();
  
      }
  
  }
  
   }

  Please, I need to make this works.

• Save video to disk from WebRTC MediaStream in Node

  27 novembre 2020, par SAGBO Aimé

  I'm building an app where the user can connect to the server through a WebRTC (I'm using simple-peer library both server-side and client-side to set the peer-to-peer connection).
Once the client and the server are connected, the client app stream the user camera and micro to the server.

  


  Now, I want to save the streamed data to the filesystem server-side as an MP4 video file.

  


  I hear about ffmpeg and fluent-ffmpeg to achieve this but i don't know how to use them.

  


  

  • Server side code to set up the peer connection

  


  


  const Peer = require("simple-peer");
const wrtc = require("wrtc");

const peer = new Peer({ initiator: false, wrtc: wrtc, trickle: false });

peer.on("error", (err: any) => console.log("error", err));

  peer.on("signal", (data: any) => {
    if (data.type === "offer" || data.type === "answer")
      dispatchMessage(JSON.stringify(data));
    // if (data.renegotiate || data.transceiverRequest) return;
  });

  peer.on("connect", () => {
    console.log("CONNECTED");
    peer.send(JSON.stringify("HELLO DEER PEER FROM SERVER"));
  });

  peer.on("data", (data: any) => {
    console.log("data: ", data);
  });

  peer.on("stream", (stream: MediaStream) => {
    console.log("-------Stream received", stream);
  });

  peer.on("track", (track: MediaStreamTrack) => {
    console.log("-------trackEvent:", track);
  });


  


  

  • Client-side code

  


  


  const stream = await window.navigator.mediaDevices.getUserMedia({
    video: { width: { ideal: 4096 }, height: { ideal: 2160 }},
    audio: true,
});

const p = new SimplePeer({
    initiator: isInitiator,  
    trickle: false  
});

stream.getTracks().forEach(track => p.addTrack(
    track,  
    stream  
));

// Here I set up the listeners for the peer connection


  


• How to save the whole transportstream(meaning incl. PAT and PMT,etc.) using ffmpeg

  15 mars 2018, par Harris Tailor

  I have been searching the whole Internet for a long time and seems it can only save video/audio using ffmpeg,any help or advice will be appreciate !thanks !