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• How you show the GOP structure of a video ?

  1er mai 2016, par medic911

  I use ffmpeg and h.265 codec. I want to evaluate the structure of the GOP. I found how to do with ffprobe :https://forums.creativecow.net/thread/291/71

  ./ffprobe -show_frames -pretty two_pass.mp4 | grep size|pict_type|coded_picture_number’

  I tried it but it did not work. Are there some similar solution ?

• libavfilter/vf_hwdownload : show error when ff_formats_ref fails

  22 mai 2016, par dsmudhar

  libavfilter/vf_hwdownload : show error when ff_formats_ref fails
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavfilter/vf_hwdownload.c

• When using ffmpeg.exe to create video from sequence of images the result is avi file that show green color why ?

  9 janvier 2014, par user3163653

  In Form1 im taking screenshots of my screen I checked they are ok i save them to the hard disk and see they are ok.

  private void timer1_Tick(object sender, EventArgs e)
  
          {
  
  
  
              using (bitmap = (Bitmap)ScreenCapture.CaptureScreen(true))
  
              {
  
  
  
              Image mScreenImage = new Bitmap(Screen.PrimaryScreen.Bounds.Width,
  
                                       Screen.PrimaryScreen.Bounds.Height);
  
              Graphics g = Graphics.FromImage(bitmap);
  
              g.CopyFromScreen(0, 0, 0, 0, new Size(bitmap.Width, bitmap.Height));
  
              g.Dispose();
  
                  bitmap.Save(@"D:\Testbmp\" + counter.ToString("D6") + ".jpg", ImageFormat.Jpeg);
  
                  counter++;
  
              ffmp.PushFrame((Bitmap)mScreenImage);
  
  
  
              }
  
  
  
          }

  Then in the new class ffmp im using pipe to get the screenshots and build the avi file in real time :

  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;
  
  
  
  namespace ScreenVideoRecorder
  
  {
  
      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 yuv420p -video_size 1920x1080 -i \\.\pipe\mytestpipe -map 0 -c:v mpeg4 -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();
  
          }
  
      }
  
  }

  This is the arguments im using now :

  psi.Arguments = @"-f rawvideo -pix_fmt yuv420p -video_size 1920x1080 -i \\.\pipe\mytestpipe -map 0 -c:v mpeg4 -r " + BitmapRate + " " + outPath;

  Before that I tried to use libx264 instead the mpeg4 but it didn't create the avi file good.
  The problem is that the avi file on the hard disk when I play it show just green color.
  I can play any other avi files on my hard disk but when playing this avi file I see green.

  

  And this is what I see when im playing the avi file :

  

  I tried to use Gspot to find if I need any codec to install and this is what I see :

  

  And I have ffdshow installed already so what should I do now ?