Recherche avancée

Sur d’autres sites (8566)

• ffmpeg - using bash variable for multiple inputs. Problem with spaces in filenames [duplicate]

  30 août 2019, par drake7

  This question already has an answer here :

  • Why does shell ignore quotes in arguments passed to it through variables ? [duplicate]
    
    3 answers
    

  I want to concatenate files with different codecs. My code only works for filenames without spaces.

  I have a fair amount of experience with using ffmpeg with bash.
  However everything I’ve tried to solve the problem did’t work :

  Let’s say my videos are "01 video.mov" and "02 video.mp4".

  not quoting $i : (This is the current status quo of my script.)

  ffmpegInput="$ffmpegInput -i ${i}"

  results in :

  01: No such file or directory

  quoting $i :

  ffmpegInput="$ffmpegInput -i \"${i}\""

  results in :

  "01: No such file or directory

  This code only works for filenames without spaces :

  ffmpegInput=""
  
  
  
  for i in *
  
  do
  
  
  
  ffmpegInput="$ffmpegInput -i ${i}"
  
  
  
  ffmpeg ${ffmpegInput} -filter_complex "[0:v:0][0:a:0][1:v:0][1:a:0]concat=n=2:v=1:a=1[outv][outa]" -map "[outv]" -map "[outa]" ../output.mkv
  
  
  
  done

  I did’t expect to encounter problems with quoting.

  But the fact that I store all inputs in a variable or an array makes it difficult.

  Althought the variable stores the string :

  -i "01 video.mov" -i "02 video.mp4"

  ffmpeg doesn’t seem to see the first " as a valid quote.
  Since ffmpeg throws the error

  "01: No such file or directory

  it seems as if the " is actually there.

• Question with complex ffmpeg compositing, overlays, visualizations etc [closed]

  14 novembre 2023, par Michael Ciesielczyk

  I'm trying to make a video that will consist of an underlying video that will need to repeat until the end of the video. The video's length as well as to video elements will come from a wav audio file. There will also be one static image overlay and 3 to 5 more images that will be overlayed at set intervals.

  


  I was able to get a little ways with a few of the elements but when I have tried to put them all together in one go I can't figure it out. And I'm trying to get it in one got to get the best possible image quality I can so I don't end up re encoding the video multiple times. I'm also using this as a template for multiple videos so when I get it figured out I can just change the images to generate the new videos.

  


  so I have these elements :

  


  background video: bg.mp4
audio file: test.wav
static image: logo.png
rotating images: 1.png, 2.png, 3.png


  


  so I have :

  


  ffmpeg -i test.wav -filter_complex " 
[0:a]avectorscope=s=1320x1240:zoom=1.5,pad=3840:2160[vs]; 
[0:a]showwaves=s=1280x202:colors=White:mode=line[sw];[vs][sw]overlay=x=(main_w- 
overlay_w)/2:y=(main_h-400)[bg]" -map "[bg]" -map 0:a  -y -acodec aac video.mp4


  


  This gets me my 4k video file and my two visualizations and my audio in my video file placed about where I want them.

  


  I can get the rotating images to appear at the right times overlayed on the bg.mp4 file with this.

  


  ffmpeg -i bg.mp4 -i 1.png -i 2.png -i 3.png -filter_complex "[0] 
[1]overlay=x=0:y=0:enable='between(t,0,4)'[out];[out] 
[2]overlay=x=0:y=0:enable='between(t,4,8)'[out];[out] 
[3]overlay=x=0:y=0:enable='between(t,8,12)'[out]" -map "[out]" video.mp4


  


  But I can't figure out how to do it all together. I have ended up with bg.mp4 file playing inside the avectorscope visual. like the rest of that box was cropping it. And I know I can loop an overlay video with -stream_loop -1 and shortest=1 but I'm not sure what to do in order to have the bg video loop until the end of the audio.

  


  I think some of my trouble is I am terrible dyslexic and a missing comma or missing close quote and it's a no go.

  


  Anyone able to help me put this together ?

  


  Oh and one last thing. I'm also wanting to put some simple text overlayed. like with

  


  overlay=0:0,drawtext=fontfile=/usr/share/fonts/TTF/Vera.ttf:fontcolor=
white:x=200:y=200:text='"text'[out]"`


  


  thank you to anyone who can help me !

  


• How to detect noisy R channel in ffmpeg ? [closed]

  17 novembre 2024, par davidvankemenade

  Does anyone know how ffmpeg can identify that the R channel in the example below is noisy ?

  


  waveform : noisy R channel
flac file with noisy R channel

  


  For reference, the following file's R channel is not noisy (except from the first few seconds) :

  


  waveform : normal R channel
flac file with normal R channel

  


  How could ffmpeg be used to classify the first file as "poor" and the second file as "OK" ?

  


  I've not yet been able to find an example to solve this problem.