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• NodeJS - FFmpeg : Extract Frame from Video stdin stream (EPIPE write Error)

  3 avril 2022, par ManiB

  I want to pipe an input steam (video) (should later be an http stream) to ffmpeg child process to extract an thumbnail :

  


  require("stream").pipeline(
  require("fs").createReadStream("files/myVideo.mp4"),
  require("child_process").spawn("ffmpeg", ["-i", "-", "-ss", "00:00:01", "-frames:v", "1", "-y", "files/myImage.jpeg"]).stdin,
  (err) => console.log("Done", err)
);


  


  So far so good, I get an extracted Image, but also an Error :

  


  Error: write EPIPE
    at WriteWrap.onWriteComplete [as oncomplete] (node:internal/stream_base_commons:94:16) {
  errno: -32,
  code: 'EPIPE',
  syscall: 'write'
}


  


  Converting full videos (e.g. mp4 -> mkv) works without errors.

  


  My suggestion is, FFmpeg will close stdin too early (because image is already found on first second) and readable-stream is not able to write to stdin anymore.

  


  How can I manage, to fix the error and gracefully close all streams ?

  


  System :

  


  

  • Linux Centos 7 (also tried Windows Server 1809)

  


  • NodeJS v16.14.1 (Windows v16.13.0)

  


  • FFmpeg v4.4.1-static (Windows v4.4-full_build-www.gyan.dev)

  


  


• Remapping multiple Mp4 videos into a single one with ffmpeg

  21 septembre 2016, par Josep Bosch

  I’m interested in remapping multiple (6) MP4 videos into a high resolution final video according to lookup tables I calculated. The idea is convert 6 independent videos in a 360º video according to an equirectangular projection.

  
  Example of equirectangular video here

  Is there a way to do this remapping with ffmpeg or any other linux program ?
  Right now I’m extracting all the frames from the videos, creating the equirectangular individual images and joining them again into a video. There must be a better way for this...

  UPDATE :

  Following Mulyva’s suggestion I first remap each individual video using the remap filter. Those parts of the panoramic video not covered are interpreted like chromakey pixels using :

  ffmpeg -i videos/camera1.MP4 -i camera0_map_x_radius5.pgm -i camera0_map_y_radius5.pgm -lavfi remap -qscale 1 out0.MP4

  

  

  Then I try to overlay them using the chomakey filter :

   ffmpeg -i out0.MP4 -i out1.MP4 -filter_complex "[1:v]chromakey=0x12da11:0.2:0.2[chromakey_res];[0:v][chromakey_res]overlay=eof_action=pass[out]" -map "[out]" out.mp4

  As you can see, the final result has an undesirable green shadow. Any idea of how to remove it ?

  

• Noobs approach to automate x264 cmd

  16 novembre 2012, par nightcrawler

  so here is my script to loop through specific video extensions » add a manual profile » generate necessary *.bat & finally a final 'loader' batch file to execute previous *.bat files sequentially & necessary logging (this gives quiet a deal of freedom if you so want)

  ::==
  
  :: gets lines into vars c1 v2 v...
  
  @echo off
  
  :: user input required
  
  cd /d "d:\Trainers\out\"
  
  setLocal EnableDelayedExpansion
  
  dir /B /O:N | findstr ".wmv$ " >filename.txt
  
  echo. >log.txt
  
  :: user input required
  
  for /f "tokens=* delims= " %%a in ('type filename.txt ^|findstr ".wmv$"') do (
  
  set /a n+=1
  
  echo. >file!n!.bat
  
  set in=%in%%%a
  
  :: user input required
  
  set out=!in:.wmv=.mp4!
  
  :: user input required
  
  set v=x264 --crf 23  --level 3.1 --tune film -o "d:\Trainers\out\!in!" "d:\Trainers\out\!out!"
  
  echo. !v!>file!n!.bat
  
  )
  
  dir /B /O:N | findstr ".bat$ " >x264_home.txt
  
  for /f "tokens=* delims= " %%a in (x264_home.txt) do (
  
  set /a n+=1
  
  :: mtee is an external library Google it
  
  set "z=call %%a | mtee /d/c/t/+ log.txt"
  
  echo. !z! >> x264_home.bat
  
  )
  
  echo. @echo off > newFile.bat
  
  type x264_home.bat >> newFile.bat
  
  type newFile.bat > x264_home.bat
  
  del newFile.bat,x264_home.txt,filename.txt
  
  echo. pause >> x264_home.bat
  
  echo. @echo All Operation done... >> x264_home.bat
  
  :: user input required
  
  move "d:\Trainers\out\*.bat" "d:\Program Files\x264_auto\test\"
  
  :: user input required
  
  move "d:\Trainers\out\log.txt" "d:\Program Files\x264_auto\test\"
  
  ::==

  Now the above code which is fairly easy to understand (bcz its written by a noob) run perfectly & create necessary files. For instance one of the file1.bat looks like this :

  x264 --crf 23  --level 3.1 --tune film --preset veryslow --deblock -2:-1 --zones 24233,25324,q=20 --acodec aac --abitrate 80 -o "d:\Trainers\out\1.wmv" "d:\Trainers\out\1.mp4"

  ...& the loader .bat file looks like

   @echo off 
  
   call file1.bat | mtee /d/c/t/+ log.txt 
  
   call file2.bat | mtee /d/c/t/+ log.txt
  
   call file3.bat | mtee /d/c/t/+ log.txt
  
   @echo All Operation done... 

  You see this is a quiet flexible approach in that you can use special filestr » set another loop » set another profile. Furthermore every batch file can be latter edited especiialy when you heavily use --zone x264 feature
  I am successful because there is no error in any output ...but its the x264.exe (provider/compiler x264GUI) throws error which it otherwise don't ?

  d:\Program Files\x264_auto\test>x264 --crf 23  --level 3.1 --tune film --preset
  
  veryslow --deblock -2:-1 --zones 24233,25324,q=20 --acodec aac --abitrate 80 -o
  
  "d:\Trainers\out\1.wmv" "d:\Trainers\out\1.mp4"
  
  ffms [error]: could not create index
  
  lavf [error]: could not open input file
  
  raw [error]: raw input requires a resolution.
  
  x264 [error]: could not open input file `d:\Trainers\out\1.mp4' via any method!

  its the x264 thats the culprit perhaps a senior guide is required here