Recherche avancée

Sur d’autres sites (9776)

• Extract alpha from video ffmpeg

  23 octobre 2018, par Yarik Denisyk

  I want to overlay transparent video on the background image. I have a video where the top half is RGB object and bottom half is an alpha mask.

  Now, for making this I do next steps :

  1) I am extracting all frames from video and save to the folder

  2) Each frame splitting to top and bottom half bitmap

  3) Top bitmap composite with bottom mask for extract alpha and get a frame with transparent background

  3) I am drawing each frame on the background and save to a folder

  4) Create a video using FFmpeg

  The problem is step 2, 3 and 4, they very slow. Maybe has another way to overlay transparent video on the background image ?

• Is anyone willing to join a GTK+3 project started in 2009 and still active ?

  15 mars 2020, par GiuTor

  first of all if my question is not relevant to stackoverflow website please delete it, I apologize in advance.

  I started Imagination, a DVD slideshow maker developed with GTK+2 in 2009. Along the years users have contributed with few patches. The software was ported to GTK+3 last year. Imagination works by using Cairo to paint the transition on a GTK drawing area and ffmpeg run in the background to encode the video. I’m currently getting rid of ffmpeg and using libav to encode the video.

  Does anybody want to help with libav coding ? The software is available through SVN :

  svn co https://svn.code.sf.net/p/imagination/code/trunk imagination

  The web site is hosted at sourceforge : http://imagination.sourceforge.net/

  Thanks :)

• Why when using ffmpeg to create video file in real time the ffmpeg.exe take over 1GB of memory ?

  3 juillet 2015, par Brubaker Haim

  This is my class where i’m using the ffmpeg.exe.

  using System;
  
  using System.Windows.Forms;
  
  using System.Collections.Generic;
  
  using System.Linq;
  
  using System.Text;
  
  using System.Threading.Tasks;
  
  using System.Drawing;
  
  using System.IO.Pipes;
  
  using System.Runtime.InteropServices;
  
  using System.Diagnostics;
  
  using System.IO;
  
  using DannyGeneral;
  
  
  
  namespace Manager
  
  {
  
      public class Ffmpeg
  
      {
  
          NamedPipeServerStream p;
  
          String pipename = "mytestpipe";
  
          System.Diagnostics.Process process;
  
          string ffmpegFileName = "ffmpeg.exe";
  
          string workingDirectory;
  
  
  
          public Ffmpeg()
  
          {
  
              workingDirectory = Path.GetDirectoryName(Application.ExecutablePath);
  
              Logger.Write("workingDirectory: " + workingDirectory);
  
              if (!Directory.Exists(workingDirectory))
  
              {
  
                  Directory.CreateDirectory(workingDirectory);
  
              }
  
              ffmpegFileName = Path.Combine(workingDirectory, ffmpegFileName);
  
              Logger.Write("FfmpegFilename: " + ffmpegFileName);
  
          }
  
  
  
          public void Start(string pathFileName, int BitmapRate)
  
          {
  
              try
  
              {
  
  
  
                  string outPath = pathFileName;
  
                  p = new NamedPipeServerStream(pipename, PipeDirection.Out, 1, PipeTransmissionMode.Byte);
  
  
  
                  ProcessStartInfo psi = new ProcessStartInfo();
  
                  psi.WindowStyle = ProcessWindowStyle.Hidden;
  
                  psi.UseShellExecute = false;
  
                  psi.CreateNoWindow = false;
  
                  psi.FileName = ffmpegFileName;
  
                  psi.WorkingDirectory = workingDirectory;
  
                  psi.Arguments = @"-f rawvideo -pix_fmt bgra -video_size 1920x1080 -i \\.\pipe\mytestpipe -c:v libx264 -crf 20 -r " + BitmapRate + " " + outPath;
  
                  process = Process.Start(psi);
  
                  process.EnableRaisingEvents = false;
  
                  psi.RedirectStandardError = true;
  
                  p.WaitForConnection();
  
              }
  
              catch (Exception err)
  
              {
  
                  Logger.Write("Exception Error: " + err.ToString());
  
              }
  
          }
  
  
  
          public void PushFrame(Bitmap bmp)
  
          {
  
              try
  
              {
  
                  int length;
  
                  // Lock the bitmap's bits.
  
                  //bmp = new Bitmap(1920, 1080);
  
                  Rectangle rect = new Rectangle(0, 0, bmp.Width, bmp.Height);
  
                  //Rectangle rect = new Rectangle(0, 0, 1280, 720);
  
                  System.Drawing.Imaging.BitmapData bmpData =
  
                      bmp.LockBits(rect, System.Drawing.Imaging.ImageLockMode.ReadOnly,
  
                      bmp.PixelFormat);
  
  
  
                  int absStride = Math.Abs(bmpData.Stride);
  
                  // Get the address of the first line.
  
                  IntPtr ptr = bmpData.Scan0;
  
  
  
                  // Declare an array to hold the bytes of the bitmap.
  
                  //length = 3 * bmp.Width * bmp.Height;
  
                  length = absStride * bmpData.Height;
  
                  byte[] rgbValues = new byte[length];
  
  
  
                  //Marshal.Copy(ptr, rgbValues, 0, length);
  
                  int j = bmp.Height - 1;
  
                  for (int i = 0; i < bmp.Height; i++)
  
                  {
  
                      IntPtr pointer = new IntPtr(bmpData.Scan0.ToInt32() + (bmpData.Stride * j));
  
                      System.Runtime.InteropServices.Marshal.Copy(pointer, rgbValues, absStride * (bmp.Height - i - 1), absStride);
  
                      j--;
  
                  }
  
                  p.Write(rgbValues, 0, length);
  
                  bmp.UnlockBits(bmpData);
  
              }
  
              catch(Exception err)
  
              {
  
                  Logger.Write("Error: " + err.ToString());
  
              }
  
  
  
          }
  
  
  
          public void Close()
  
          {
  
              p.Close();
  
          }
  
      }
  
  }

  ffmpegFileName contain the ffmpeg.exe

  Then i have a timer tick event in another form :

  ScreenShot shot = new ScreenShot();
  
      public static int counter = 0;
  
      private void timer1_Tick(object sender, EventArgs e)
  
      {
  
          counter++;
  
          shot.GetScreenShot(@"e:\screenshots\", "screenshot");
  
          if (counter == 1200)
  
          {
  
              timer1.Stop();
  
              ScreenShot.fmpeg.Close();
  
              this.Close();
  
              ScreenShotsPlayer ssp = new ScreenShotsPlayer();
  
              ssp.Show();
  
          }
  
      }

  This timer interval set to 100ms.
  So it’s taking a screenshot every 100ms.

  In the class ScreenShot i’m using the Ffmpeg class :
  In the top :

  public static Ffmpeg fmpeg;

  In the constructor :

  fmpeg = new Ffmpeg();
  
  fmpeg.Start(@"e:\screenshots\test.mp4", 25);

  Then in the GetScreenShot method i’m calling the Ffmpeg PushFrame method :

  public Bitmap GetScreenShot(string folder, string name)
  
      {
  
          _screenShot = new Bitmap(GetScreen());
  
          System.GC.Collect();
  
          System.GC.WaitForPendingFinalizers();
  
          string ingName = folder + name + Elgato_Video_Capture.counter.ToString("D6") + ".bmp";
  
          _screenShot.Save(ingName,System.Drawing.Imaging.ImageFormat.Bmp);
  
          fmpeg.PushFrame(_screenShot);
  
          _screenShot.Dispose();
  
          return _screenShot;
  
      }

  I can’t figure out why once i start the timer to take the screenshots the ffmpeg.exe eat so much memory also the hard disk is working about 53MB/s and the memory is over 90% and over 1GB.

  I’m doing the memory leak somehow ?

  

  In the ScreenShot class when i’m making an instance once for the Ffmpeg class the ffmpeg.exe is on very low memory usage and the hard disk usage is low.

  The ffmpeg.exe is about only 0.1MB of memory usage.

  fmpeg.Start(@"e:\screenshots\test.mp4", 25);

  But then when i’m clicking the button start the timer and taking screenshots every 100ms and calling PushFrame method the ffmpeg.exe very fast after few seconds getting to over 1GB of memory usage.

  EDIT

  I tried this arguments :

  psi.Arguments = @"-f rawvideo -pix_fmt bgra -video_size 1920x1080 -i \\.\pipe\mytestpipe -c:v libx264 -crf 20 -r 750k e:\screenshots\test.mp4";

  The memory usage was about 1gb of ffmpeg.exe and cpu usage 99-100%
  The hard disk was on 0 but now the cpu usage got to 100% and the memory over 1gb.

  And it didn’t create the video file I got this warnings/errors :