Recherche avancée

Sur d’autres sites (6610)

• ffmpeg generated video with silent audio has different stream lengths

  18 septembre 2015, par JennHarper

  I am trying to generate a video clip of a single image and add a silent audio track for concatenating with other video files.
  I can successfully create the mp4 video with the desired image and audio track BUT, according to mediaInfo, the length of the video stream and the length of the audio stream are different. They are off by up to 60 ms. As I plan to concatenate several of these image clips and other video clips, I don’t want the error to accumulate. Any thoughts or suggestions for maintaining perfect video/audio sync ?

  Here are the ffmpeg commands that I am using :

  C :\FFmpeg\bin\ffmpeg.exe -loop 1 -i myImage.jpg -codec:v libx264 -t 7 -profile:v high -preset slow -r 25 -b:v 500k -maxrate 500k -vf scale=1280:720 -y videoStreamOnly.mp4

  C :\FFmpeg\bin\ffmpeg.exe -f lavfi -i anullsrc=r=48000 -i videoStreamOnly.mp4 -shortest -c:v copy -c:a aac -strict experimental -y videoWithSilentAudioStream.mp4

• FFMPEG command works on terminal but not with Java/Kotlin

  11 septembre 2019, par Antony

  I’m trying to use an FFMPEG command for concatenating different videos. The command is

  ffmpeg -i video.mp4 -i video-2.mp4 -filter_complex "[0:v:0] [0:a:0] [1:v:0] [1:a:0] concat=n=2:v=1:a=1 [v] [a]" -map "[v]" -map "[a]" output.mp4

  This command works good when I run on Windows PowerShell. But when I try to run with Kotlin code it doesn’t work.

  val firstVideo = "D:\\Videos\\ffmpeg\\video.mp4"
  
  val secondVideo = "D:\\Videos\\ffmpeg\\video-2.mp4"
  
  val resultPath = "D:\\Videos\\ffmpeg\\result-2.mp4"
  
  
  
  val cmd = "ffmpeg -i $firstVideo -i $secondVideo -filter_complex \"[0:v:0] [0:a:0] [1:v:0] [1:a:0] concat=n=2:v=1:a=1 [v] [a]\" -map \"[v]\" -map \"[a]\" $resultPath"
  
  .split(" ").toTypedArray()
  
  
  
  Runtime.getRuntime().exec(cmd)

  I’m not taking any error messages since I’m using FFMPEG cli.

  Also, this piece of Kotlin works perfect when I’m trying to run other FFMPEG operations.

• FFMPEG add/remove input on the fly

  10 août 2022, par Thomas Halvick

  I'm trying to merge audio on the fly for my bot with discord JS.
I found a way to do it, but it's not perfect.

  


  My solution

  


  

  • Create a FFmpeg process with each input into stream and process them at same speed while playing

  


  • And merge each stream in one with another FFmpeg process

  


  • When adding a new audio, I create a new process for this one and destroy the merge process and recreate one

  


  


  Issues

  


  

  1. It's take seconds before playing

  


  2. When adding a new song, my bot stop playing while the merge process start

  


  


  There is a way to do it with one FFmpeg process to add and remove input stream ? FFmpeg is the best way to do that ?