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• ffmpeg cut and stitch video

  5 janvier 2023, par user726720

  I have a scenario where i need to cut and stitch parts of the video together using ffmpeg, but this video has multiple audio channels (8 audio channels). The below is working for me but only gives me one audio channel as output

  


  ffmpeg -i c:\process\abc.mxf -filter_complex \
"[0:v]trim=600:2663,setpts=PTS-STARTPTS,format=yuv420p[0v]; \
[0:a]atrim=600:2663,asetpts=PTS-STARTPTS[0a]; \
[0:v]trim=2886:3286,setpts=PTS-STARTPTS,format=yuv420p[1v]; \
[0:a]atrim=2886:3286,asetpts=PTS-STARTPTS[1a]; \
[0v][0a][1v][1a]concat=n=2:v=1:a=1[outv][outa]" -map [outv] -map [outa] out.mxf


  


  How can i get all the 8 audio channels in the output. I have tried the below, as an attempt to get two audio channels, but does work

  


  ffmpeg -i c:\process\abc.mxf -filter_complex \
"[0:v]trim=600:2663,setpts=PTS-STARTPTS,format=yuv420p[0v]; \
[0:a]atrim=600:2663,asetpts=PTS-STARTPTS[0a]; \
[0:b]atrim=600:2663,asetpts=PTS-STARTPTS[2a]; \
[0:v]trim=2886:3286,setpts=PTS-STARTPTS,format=yuv420p[1v]; \ 
[0:a]atrim=2886:3286,asetpts=PTS-STARTPTS[1a];
[0:b]atrim=600:2663,asetpts=PTS-STARTPTS[3a];  \
[0v][0a][2a][1v][1a][3a]concat=n=6:v=1:a=2[outv][outa]" -map [outv] -map [outa] out.mxf


  


  Any hint will be much appreciated.

  


  ANOTHER ATTEMPT

  


  ffmpeg -i c:\process\3010010155-TCRHD.mxf -filter_complex " \
[0:v]trim=600:2663,setpts=PTS-STARTPTS,format=yuv420p[0v]; \
[0:a:0]atrim=600:2663,asetpts=PTS-STARTPTS[0a]; \ 
[0:a:1]atrim=600:2663,asetpts=PTS-STARTPTS[2a]; \
[0:v]trim=2886:3286,setpts=PTS-STARTPTS,format=yuv420p[1v]; \
[0:a:0]atrim=2886:3286,asetpts=PTS-STARTPTS[1a]; \
[0:a:1]atrim=600:2663,asetpts=PTS-STARTPTS[3a]; \
[0v][0a][2a][1v][1a][3a]concat=n=6:v=1:a=2[outv][outa]" -map [outv] -map [outa] out.mxf


  


  This gives me an error Cannot find a matching stream for unlabeled input pad 6 on filter Parsed_concat_14

  


• System.InvalidOperationException thrown when running as part of a WPF application. Xabe.FFmpeg

  16 mars 2021, par S. O. James

  I have the following code which runs on a console application

  


    string filePath = "C:\\Users\\**\\Desktop\\sample-mp4-file.mp4";
  string output1 = "C:\\Users\\**\\Desktop\\1.jpg";
  string output2 = "C:\\Users\\**\\Desktop\\2.jpg";
  var ms = new MultiSnapshotCommand(filePath);
  await ms.Add(TimeSpan.FromSeconds(20), output1);
  await ms.Add(TimeSpan.FromSeconds(20), output2);
  await ms.Invoke();


  


  Which uses the following

  


    public async Task Add(TimeSpan timestamp, string outputPath)
  {
      var conversion = await FFmpeg.Conversions.FromSnippet.Snapshot(filePath, outputPath, timestamp);
      conversionQueue.Enqueue(conversion);
  }


  


  This executes fine and both snapshots are created when calling Invoke().
However, when executing the same code running in an async method in response to a button click in a WPF scenario, the UI freezes, then a few moments later Exception thrown: 'System.InvalidOperationException' in System.Diagnostics.Process.dll is shown from the debugger output with no recovery.

  


  The error seems to be occurring at await FFmpeg.Conversions.FromSnippet.Snapshot(filePath, outputPath, timestamp);

  


  Original - https://github.com/tomaszzmuda/Xabe.FFmpeg/issues/341

  


  Edit

  


  My project files https://github.com/Scharps/MP4ToImageConverter/tree/05beeb1cc359b654fb51a9695b5c20386c4d5fb6.
FFmpeg is required in Path system variable. File locations will need to be changed also

  


• Java 1.7 atomic move does not work correctly ?

  22 février 2018, par Ferguson

  have this scenario :
  On a file system have FFmpeg program which streams a video source from a webcam to youtube server. FFmpeg supports text filter where you can specify from which file it can read some static text to be then "overlayed" over video. The problem is if the file not exists or if someone else is writing in this file then the FFmpeg can crash.

  In Java have done this example with StandardCopyOption.ATOMIC_MOVE option :

  import java.io.PrintWriter;
  
  import java.nio.file.Files;
  
  import java.nio.file.Path;
  
  import java.nio.file.Paths;
  
  import java.nio.file.StandardCopyOption;
  
  import java.util.Date;
  
  import java.util.Random;
  
  import java.util.Timer;
  
  import java.util.TimerTask;
  
  
  
  public class FileMover {
  
  
  
      private void runIt() {
  
          Random r = new Random();
  
          Timer timer = new Timer();
  
          timer.schedule(new TimerTask() {
  
              public void run() {
  
  
  
                  try
  
                  {
  
                    PrintWriter writer = new PrintWriter("c:/video/temppodatki.txt", "UTF-8");
  
                    writer.println("Temp: " + ((int)(Math.random() * (40 - 10)) + 10)+ " °C");
  
                    writer.println("Sla: " +  ((int)(Math.random() * (37 - 30)) + 30)+ " PSU");
  
                    writer.close();    
  
  
  
                    //premaknemo fajl..
  
                    Path sourceFile = Paths.get("c:/video/temppodatki.txt");
  
                    Path destinationFile = Paths.get("c:/video/podatki.txt");
  
                    Files.move(sourceFile, destinationFile, StandardCopyOption.ATOMIC_MOVE);
  
                    System.out.println("move.." + new Date().toString());
  
                  }
  
                  catch(Exception ex)
  
                  {
  
  
  
                  }
  
              }
  
          }, 0, 5 * (1000 * 1));
  
      }
  
  
  
      public static void main(String[] args) {
  
          new FileMover().runIt();
  
      }
  
  
  
  }

  this script writes into tmp file and after that it moves to file from which FFmpeg read.
  But the problem stil remain the same because randomly FFmpeg can crash with :

  

  Is there some other approach to take ?