Sur d’autres sites (7652)

• Java Runtime exec() get stuck after a while

  20 décembre 2013, par codareee

  I'm building a simple UI for ffmpeg launching ffmpeg.exe with parameters using exec(). it works on Os X but on Windows 7-8 after few seconds the ffmpeg process suspends itself and resumes only when I kill the father process. (also ddlhost.exe is created)
  Ffmpeg.exe converts successfully the same video from cmd.

  Searching on the internet I've found this answer but I have the same problem running a simple test program which is not using the Input and Error streams.

  Here is the test program code which has the same problem of the main one :

  public class Main {
  
  
  
  static String param_ffmpeg_1 = "./data/ffmpeg.exe";
  
  static String param_ffmpeg_2 = "-i";
  
  
  
  static String in = "./data/source.mov";
  
  static String out = "./data/out.flv";
  
  
  
  static Process p;
  
  
  
  public static void main(String[] args) {
  
  
  
      /*File f = new File(out);
  
  
  
      if (f.exists()){
  
          f.delete();
  
      }*/
  
  
  
  
  
      Runtime rt = Runtime.getRuntime() ;
  
      //String cmd1 =  param_ffmpeg_1 + param_ffmpeg_2 +  in_path +  param_ffmpeg_3 + out_path ;
  
      System.out.println(in);
  
      System.out.println(out);
  
      String[] cmd1 = new String[] { param_ffmpeg_1, param_ffmpeg_2, in, "-ar", "44100", "-vb", "2500k", "-s", "882x496", "-f", "flv", out};
  
  
  
      try {
  
          p = rt.exec(cmd1);
  
      } catch (IOException e) {
  
          // TODO Auto-generated catch block
  
          e.printStackTrace();
  
      }
  
      int r = 123456;
  
      try {
  
          r = p.waitFor();
  
      } catch (InterruptedException e) {
  
          // TODO Auto-generated catch block
  
          e.printStackTrace();
  
      }
  
  
  
      System.out.println(r);
  
  
  
  
  
  }

  }

• Inputting files in different folders as arguments to ffmpeg in Python

  20 janvier 2016, par John Stanford

  I’m working on a program using ffmpeg in Python and I’m trying to stack a bunch of PNG images into a video. I want to keep the code on my Dropbox but use the local hard drive to do the work, so I when I input the files as arguments, I want to include the directory. The code below makes the raw input file just fine, but when I try to begin a pipe with ffmpeg, it tells me it can’t find the input file. Is there some special way to format this if the input file is in a different directory ? I’ve had similar code work fine with the files all located in the same folder. Thanks !

  import subprocess as sp
  
  
  
  import numpy as np
  
  import matplotlib.pyplot as plt
  
  
  
  import os
  
  import shutil
  
  
  
  import tkinter.filedialog as tkFileDialog
  
  
  
  FFMPEG_BIN = 'ffmpeg.exe'
  
  
  
  def readImages(pathToImages):
  
      filenames = os.listdir(path=pathToImages)
  
      f = open("C:\\Users\johnwstanford\Desktop\outputfile.raw", "wb")
  
  
  
      for file in filenames:
  
          print(file)
  
          image = plt.imread(pathToImages + '/' + file)
  
          image = np.delete(image, 3, 2)*255
  
  
  
          f.write(image.tobytes())
  
      f.close()
  
  
  
  readImages(tkFileDialog.askdirectory())
  
  
  
  command2 = [FFMPEG_BIN,
  
             '-y',
  
             '-f', 'rawvideo',
  
             '-vcodec', 'rawvideo',
  
             '-s', '1600x1200',
  
             '-pix_fmt', 'rgb24',
  
             '-r', '25',
  
             '-i', "C:\\Users\johnwstanford\Desktop\outputfile.raw",
  
             "C:\\Users\johnwstanford\Desktop\output.mp4"]
  
  
  
  pipe2 = sp.Popen(command2, stdin = sp.PIPE, stderr=sp.PIPE)
  
  print(pipe2.communicate()[1])
  
  pipe2.kill()
  
  os.remove("C:\\Users\johnwstanford\Desktop\outputfile.raw")

• On-demand and seamless transcoding of individual HLS segments

  5 janvier 2024, par Omid Ariyan

  Background

  


  I've been meaning to implement on-demand transcoding of certain video formats such as ".mkv", ".wmv", ".mov", etc. in order to serve them on a media management server using ASP.NET Core 6.0, C# and ffmpeg.

  


  My Approach

  


  The approach I've decided to use is to serve a dynamically generated .m3u8 file which is simply generated using a segment duration of choice e.g. 10s and the known video duration. Here's how I've done it. Note that the resolution is currently not implemented and discarded :

  


  public string GenerateVideoOnDemandPlaylist(double duration, int segment)
{
   double interval = (double)segment;
   var content = new StringBuilder();

   content.AppendLine("#EXTM3U");
   content.AppendLine("#EXT-X-VERSION:6");
   content.AppendLine(String.Format("#EXT-X-TARGETDURATION:{0}", segment));
   content.AppendLine("#EXT-X-MEDIA-SEQUENCE:0");
   content.AppendLine("#EXT-X-PLAYLIST-TYPE:VOD");
   content.AppendLine("#EXT-X-INDEPENDENT-SEGMENTS");

   for (double index = 0; (index * interval) < duration; index++)
   {
      content.AppendLine(String.Format("#EXTINF:{0:#.000000},", ((duration - (index * interval)) > interval) ? interval : ((duration - (index * interval)))));
      content.AppendLine(String.Format("{0:00000}.ts", index));
   }

   content.AppendLine("#EXT-X-ENDLIST");

   return content.ToString();
}

[HttpGet]
[Route("stream/{id}/{resolution}.m3u8")]
public IActionResult Stream(string id, string resolution)
{
   double duration = RetrieveVideoLengthInSeconds();
   return Content(GenerateVideoOnDemandPlaylist(duration, 10), "application/x-mpegURL", Encoding.UTF8);
}


  


  Here's an example of how the .m3u8 file looks like :

  


  #EXTM3U
#EXT-X-VERSION:6
#EXT-X-TARGETDURATION:10
#EXT-X-MEDIA-SEQUENCE:0
#EXT-X-PLAYLIST-TYPE:VOD
#EXT-X-INDEPENDENT-SEGMENTS
#EXTINF:10.000000,
00000.ts
#EXTINF:3.386667,
00001.ts
#EXT-X-ENDLIST


  


  So the player would ask for 00000.ts, 00001.ts, etc. and the next step is to have them generated on demand :

  


  public byte[] GenerateVideoOnDemandSegment(int index, int duration, string path)&#xA;{&#xA;   int timeout = 30000;&#xA;   int totalWaitTime = 0;&#xA;   int waitInterval = 100;&#xA;   byte[] output = Array.Empty<byte>();&#xA;   string executable = "/opt/homebrew/bin/ffmpeg";&#xA;   DirectoryInfo temp = Directory.CreateDirectory(System.IO.Path.Combine(System.IO.Path.GetTempPath(), System.IO.Path.GetRandomFileName()));&#xA;   string format = System.IO.Path.Combine(temp.FullName, "output-%05d.ts");&#xA;&#xA;   using (Process ffmpeg = new())&#xA;   {&#xA;      ffmpeg.StartInfo.FileName = executable;&#xA;&#xA;      ffmpeg.StartInfo.Arguments = String.Format("-ss {0} ", index * duration);&#xA;      ffmpeg.StartInfo.Arguments &#x2B;= String.Format("-y -t {0} ", duration);&#xA;      ffmpeg.StartInfo.Arguments &#x2B;= String.Format("-i \"{0}\" ", path);&#xA;      ffmpeg.StartInfo.Arguments &#x2B;= String.Format("-c:v libx264 -c:a aac ");&#xA;      ffmpeg.StartInfo.Arguments &#x2B;= String.Format("-segment_time {0} -reset_timestamps 1 -break_non_keyframes 1 -map 0 ", duration);&#xA;      ffmpeg.StartInfo.Arguments &#x2B;= String.Format("-initial_offset {0} ", index * duration);&#xA;      ffmpeg.StartInfo.Arguments &#x2B;= String.Format("-f segment -segment_format mpegts {0}", format);&#xA;&#xA;      ffmpeg.StartInfo.CreateNoWindow = true;&#xA;      ffmpeg.StartInfo.UseShellExecute = false;&#xA;      ffmpeg.StartInfo.RedirectStandardError = false;&#xA;      ffmpeg.StartInfo.RedirectStandardOutput = false;&#xA;&#xA;      ffmpeg.Start();&#xA;&#xA;      do&#xA;      {&#xA;         Thread.Sleep(waitInterval);&#xA;         totalWaitTime &#x2B;= waitInterval;&#xA;      }&#xA;      while ((!ffmpeg.HasExited) &amp;&amp; (totalWaitTime &lt; timeout));&#xA;&#xA;      if (ffmpeg.HasExited)&#xA;      {&#xA;         string filename = System.IO.Path.Combine(temp.FullName, "output-00000.ts");&#xA;&#xA;         if (!File.Exists(filename))&#xA;         {&#xA;            throw new FileNotFoundException("Unable to find the generated segment: " &#x2B; filename);&#xA;         }&#xA;&#xA;         output = File.ReadAllBytes(filename);&#xA;      }&#xA;      else&#xA;      {&#xA;         // It&#x27;s been too long. Kill it!&#xA;         ffmpeg.Kill();&#xA;      }&#xA;   }&#xA;&#xA;   // Remove the temporary directory and all its contents.&#xA;   temp.Delete(true);&#xA;&#xA;   return output;&#xA;}&#xA;&#xA;[HttpGet]&#xA;[Route("stream/{id}/{index}.ts")]&#xA;public IActionResult Segment(string id, int index)&#xA;{&#xA;   string path = RetrieveVideoPath(id);&#xA;   return File(GenerateVideoOnDemandSegment(index, 10, path), "application/x-mpegURL", true);&#xA;}&#xA;</byte>

  


  So as you can see, here's the command I use to generate each segment incrementing -ss and -initial_offset by 10 for each segment :

  


  ffmpeg -ss 0 -y -t 10 -i "video.mov" -c:v libx264 -c:a aac -segment_time 10 -reset_timestamps 1 -break_non_keyframes 1 -map 0 -initial_offset 0 -f segment -segment_format mpegts /var/folders/8h/3xdhhky96b5bk2w2br6bt8n00000gn/T/4ynrwu0q.z24/output-%05d.ts


  


  The Problem

  


  Things work on a functional level, however the transition between segments is slightly glitchy and especially the audio has very short interruptions at each 10 second mark. How can I ensure the segments are seamless ? What can I improve in this process ?