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• FFMPEG overlay dark frame

  21 septembre 2016, par Pavel Chursin

  I have problem with FFMPEG overlaying. It adds black frame around objects with transparent border.
  For example, take the yellow rectangle 100x100. Then generates video from it :

  ./ffmpeg -loop 1 -i yellow.png -t 5 -vcodec qtrle yellow.mov

  Then take a transparent PNG 100x100, within the green rectangle inside 75x75.

  Overlay it on the first video :

  ./ffmpeg -i yellow.mov -i green.png -filter_complex 'overlay' -vcodec qtrle yg.mov

  In the final video green rectangle has got dark frame.

  Result

  How can I remove this frame ?

  EXAMPLE

• Normalizing with ffmpeg-normalize, slight variations in sound

  20 mai 2022, par Antti Rytsölä

  I have some flacs which I am trying to normalize for Spotify and Distrokid.

  


  I got the guide from this post

  


  ffmpeg-normalize inbound/*.flac -t -14 -lrt 11 -tp -1 -ext flac -c:a flac -of normalized/


  


  Now the problem is ( before submitting to Distrokid ) that when listening to normalized versions there seems to be light deviations, like muffling, to the sound at half a second lenghts.

  


  Small sample, towards the end.

  


  Now I'm asking for help because even though I can try different settings I still want to conform to Spotify normalization guide.

  


  The Spotify guide is as follows :

  


  Target the loudness level of your master at -14dB integrated LUFS 
and keep it below -1dB TP (True Peak) max. This is best for lossy 
formats (Ogg/Vorbis and AAC) and makes sure no extra distortion’s 
introduced in the transcoding process.

If your master’s louder than -14dB integrated LUFS, make sure 
it stays below -2dB TP (True Peak) to avoid extra distortion. This 
is because louder tracks are more susceptible to extra distortion 
in the transcoding process.


  


  and

  


   ffmpeg version N-102727-g580e168a94-tessus
 ffmpeg-normalize v1.22.8


  


  Tracks now on Spotify.

  


• Merging/concatenating video and keeping sound in R using AV package

  30 juin 2022, par Jack Cornwall

  I am trying to merge/concatenate multiple videos with sound sequentially into one video using only R, (I don't want to work with ffmpeg in the command line as the rest of the project doesn't require it and I would rather not bring it in at this stage).

  


  My code looks like the following :

  


  dir<-"C:/Users/Admin/Documents/r_programs/"

videos<-c(
  paste0(dir,"video_1.mp4"),
  paste0(dir,"video_2.mp4"),
  paste0(dir,"video_3.mp4")
)

#encoding
av_encode_video(
  videos,
  output=paste0(dir,"output.mp4"),
  framerate=30,
  vfilter="null",
  codec="libx264rgb",
  audio=videos,
  verbose=TRUE
)


  


  It almost works, the output file is an mp4 containing the 3 videos sequentially one after the other, but the audio present is only from the first of the 3 video and then it cuts off.

  


  It doesn't really matter what the videos are. I have recreated this issue with the videos I was using or even 3 randomly downloaded 1080p 30fps videos from YouTube.

  


  Any help is appreciated & thank you in advance.