Newest 'ffmpeg' Questions - Stack Overflow

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• How to timestamp video with seconds and milliseconds with ffmpeg ? [closed]

  10 février, par JulianJ

  I am trying to timestamp an .mp4 video with seconds and milliseconds using ffmpeg. I can timestamp with hours, minutes, seconds and milliseconds using the code below but just can't figure out how to print seconds and milliseconds.

  ffmpeg -i input.mp4 -vf "drawtext=:text='%{pts\:s}':rate=25:start_number=0:x=(w-tw)/2:y=h-(3*lh):fontcolor=white:fontsize=50,drawtext=:text='%{pts\:hms}':rate=25:start_number=0:x=(w-tw)/2:y=h-(2*lh):fontcolor=white:fontsize=50" output.mp4
  

• How to hide the output of yt-dl in CMD ? python

  10 février, par Qais Albeaiz

  I'm coding program that download mp3 audio from youtube videos but I have an issue that yt-dl show some output in console

  my code:

  with open('Links.txt') as f:
      content = f.readlines()
      for links in content:
  
          ydl_opts = {
              'format': 'bestaudio/best',
              'postprocessors': [{
                  'key': 'FFmpegExtractAudio',
                  'preferredcodec': 'mp3',
                  'preferredquality': '192',
              }],
          }
          with youtube_dl.YoutubeDL(ydl_opts) as ydl:
              ydl.download([links])
  

  photo of output:

  and i need the option or some way to hide the output.

• How to make multiple ffmpeg commands run in parallel [duplicate]

  9 février, par Kim Mỹ

  I'm using the following ffmpeg command to compress video:

  `nice -n 10 ${ffmpegPath} -i "${chunkPath}" -c:v libx264 -preset fast -crf 28 "${compressedPath}"`
  

  However, when I run two instances of ffmpeg of this command to achieve parallelism:

  Either in two child processes within a single Node.js application or in two separate Node.js applications running at the same time, it seems only one command is processed, and the other is skipped.

  I've noticed that 2 FFmpeg instances are loaded into RAM and both create a starting file for the final compressed video, they finish compression around the same time. However, the total processing time is effectively doubled compared to compressing a single video file alone, which only takes half the time.

  I also try to pass the -threads argument but it produces same result.

• Thread count option in FFmpeg for FASTEST conversion to h264 ?

  9 février, par S B

  I need to maximize speed while converting videos using FFmpeg to h264

  • Any input format of source videos
  • User's machine can have any number of cores
  • Power and memory consumption are non-issues

  Of course, there are a whole bunch of options that can be tweaked but this question is particularly about choosing the best -thread option. I am trying to find an ideal thread count as a function of

  • no. of cores
  • input video format
  • h264-friendly values maybe?
  • anything else missed above?

  I am aware the default -thread 0 follows one-thread-per-core approach which is supposed to be optimal. But I am not sure if this is time or space-optimized. Also, on certain testcases, I've seen more threads (say 4 threads on my dual core test machine) finishes quicker than the default.

  Any other direction, say configure options w.r.t. threads, worth pursuing?

• How to remove a specific segment from an audio file using timestamps ? [closed]

  9 février, par Hilal Khan

  I am working on a C# project where I need to remove a specific segment from an audio file (e.g., WAV, MP3) based on start and end timestamps, while keeping the rest of the audio intact.

  For example, given a 20-minute audio file, I want to remove the section from 17:00 to 19:00 and be left with a new audio file containing only 0:00-17:00 and 19:00-20:00 (i.e., keeping the parts before and after the cut).

  I have used NAudio and FFmpeg to trim a file by cutting from the start or end, but I only get my desired snippet as a separate file which is not what I am looking for as I want it to be removed from the audio itself

  Heres what I have so far:

  static void RemoveSegment(string inputPath, string outputPath, double startTime, double endTime)
  {
      using (var reader = new Mp3FileReader(inputPath))
      {
          var writer = new FileStream(outputPath, FileMode.Create, FileAccess.Write);
  
          int bytesPerMillisecond = reader.WaveFormat.AverageBytesPerSecond / 1000;
          long startPosition = (long)(startTime * 1000) * bytesPerMillisecond;
          long endPosition = (long)(endTime * 1000) * bytesPerMillisecond;
  
          byte[] buffer = new byte[4096];
          int bytesRead;
  
          while ((bytesRead = reader.Read(buffer, 0, buffer.Length)) > 0)
          {
              if (reader.Position < startPosition || reader.Position > endPosition)
              {
                  writer.Write(buffer, 0, bytesRead);
              }
          }
  
          writer.Close();
      }
  
      Console.WriteLine("Segment removed successfully!");
  }