Recherche avancée

Sur d’autres sites (8155)

• Use ffmpeg to create a music video with the cover on a black background

  21 septembre 2020, par user6329530

  I am trying to use this tutorial to create youtube videos with ffmpeg
https://trac.ffmpeg.org/wiki/Encode/YouTube

  


  When using this example, I get a video that works however the background is white

  


  ffmpeg -loop 1 -framerate 2 -i albumcover.png -i audio.wav -c:v libx264 -preset medium -tune stillimage -crf 18 -c:a copy -shortest -pix_fmt yuv420p output.mkv


  


  I tried to add a color filter but that makes the whole video output black :

  


  ffmpeg -loop 1 -framerate 2 -i albumcover.png -filter_complex "color=s=1920x1080:c=black" -i audio.wav -c:v libx264 -preset medium -tune stillimage -crf 18 -c:a copy -shortest -pix_fmt yuv420p output.mkv


  


  I find it very difficult to find something about this on the internet as most ask for just a black video or a transparent background for a gif ect.

  


  So how do I get the albumcover.png on a black background ?

  


  EDIT : I just realized that the video format is of course the image format (square) and therefore it's white on youtube. The question therefore is now how do I create a black background 16:9 and put the albumcover centered on it...

  


• How to modify this Windows script to do a match ?

  21 janvier 2016, par Andrei Clear

  ffmpeg can resize a video/image file .. first is input_file .. parameters .. output_file ..

  ffmpeg -i input.avi -vf scale=320:240 output.avi

  or

  ffmpeg -i 20140724_071746.mp4 -vf scale=640:-1 20140724_071746_LOW_640.mp4

  more info here : https://trac.ffmpeg.org/wiki/Scaling%20%28resizing%29%20with%20ffmpeg

  I want it to downscale all the videos on my microSD card to create space (I have originals backed-up)

  So I want it to go throw all the files in all the sub-directories overnight and resize all the files. Chances are that the script might stop or crash and I would need to run it again, or if I add new files I would want to run it again.

  So I would want it to skip processing all the files that have been processed AND their resized versions.

  In my case if a FILE_NAME.mp4 also has FILE_NAME_LOW_640.mp4 SKIP it
  AND
  if a FILE_NAME_LOW_640.mp4 has *640 SKIP it

  Here is my Windows batch script so far

  REM @echo off
  
  REM just save as "DOS"
  
  REM cd /d C:\s
  
  
  
  setlocal enabledelayedexpansion
  
  for %%j in (*.mp4) do (
  
  set filename=%%~nj
  
  echo %%j
  
  
  
  ffmpeg -i %%j -vf scale=640:-1 %%j_LOW_640.mp4
  
  
  
  REM but now I want to add the two checks to skip files that have been resized .. or if they are the resized version 
  
  
  
  REM if not "!filename!"=="%%j_LOW_640.mp4" AND IF FILE !COINTAIN *640* THEN ffmpeg -i %%j -vf scale=640:-1 %%j_LOW_640.mp4
  
  
  
  )
  
  
  
  pause
  
  REM AND I would also want it to process all the sub-directories  

  In other words my questions for help are :

  1. How can I do a check for a string if it contains a string match ?

  2. How can I have my script also process all the subdirectories ?

• Skipping incompatible libmp3lame.a while searching mp3lame (FFMPEG)

  19 octobre 2014, par trololo

  I want to compile ffmpeg with libmp3lame for my Android app. I’m using Virtual Machine with OS Debian.
  While compiling I recieve with message in Console.log file :

  skipping incompatible /home/sla/ffmpeg_build/lib/libmp3lame.a while searching mp3lame
  ...

  That’s why compilations doesn’t work properly.

  I’ve installed lame for debian using this code install.sh :
  (https://trac.ffmpeg.org/wiki/CompilationGuide/Ubuntu)

  sudo apt-get install libmp3lame-dev
  
  mkdir /home/sla/ffmpeg_build
  
  mkdir /home/sla/ffmpeg_sources
  
  sudo apt-get install nasm
  
  cd /home/sla/ffmpeg_sources
  
  wget http://downloads.sourceforge.net/project/lame/lame/3.99/lame-3.99.5.tar.gz
  
  tar xzvf lame-3.99.5.tar.gz
  
  cd lame-3.99.5
  
  ./configure --prefix="/home/sla/ffmpeg_build" --enable-nasm --disable-shared
  
  make
  
  make install
  
  make distclean

  But it doesn’t work (lame compiles but ffmpeg - doesn’t).
  ffmpeg compiler says something strange.

  For ffmpeg I wrote flags :

  --export-cflags
  
  -I/home/sla/ffmpeg_build/include
  
  
  
  --export-ldflags
  
  -L/home/sla/ffmpeg_build/lib

  How to fix it ?