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• Python moviepy, CompositeVideoClip is Slow and Wierd

  4 mars 2023, par Dan

  I want to add a .mov transparent overlay on top of a .mp4 video, and for that I am using movipy and CompositeVideoClip, but it's too slow.

  


  The speed is 40 it/s when only the video is rendering but when it comes to the overlay it is only 5 it/s. To speed it up I have used use_bgclip=True and now I get 90 it/s but when the overlay comes I still get 5 it/s, and when I use use_bgclip=True there are 2 'bugs' that appears :

  


  

  1. The video freezes after the overlay is done playing.

  


  2. The audio of the video is lost and the overlay sound is the only one left

  


  


  For the two 'bugs', I found a good enough solution, but I want to speed up the process when the overlay comes, because 5 it/s it's way too slow. I have tried to use codec="h264_nvenc" or higher crf but the speed is the same.

  


  Is there a way to speed this up ? (I don't care if I need to use other libraries)

  


  import moviepy.editor as mp
video = mp.VideoFileClip("video.mp4")

overlay = mp.VideoFileClip("overlay.mov", has_mask=True)
overlay = overlay.set_start(5) # start the overlay 5 seconds after the video starts

compose = mp.CompositeVideoClip([video, overlay], use_bgclip=True, size=video.size)
compose = compose.set_duration(video.duration) # fix bug 1
compose = compose.set_audio(video.audio) # fix bug 2 (but I lost the audio from the overlay)

compose.write_videofile("cf15.mp4", codec="libx264", preset="veryfast", ffmpeg_params=["-crf", "15"])

compose.close()
video.close()


  


• Java, serve HLS live video streams

  12 février 2016, par momo

  I know the topic is not an easy one, but I am looking for a Java class to send an HLS stream from the server to the client.

  I have files being generated greater and greater :

  out.m3u8
  
  out0.ts
  
  out1.ts
  
  out2.ts
  
  out3.ts
  
  out4.ts
  
  out5.ts
  
  out6.ts

  This is generated using ffmpeg from an original source :

  ffmpeg -i http://sourceurl.com:9981/stream/channel/1232131 out.m3u8

  I can play it using VLC.

  Somehow, I need to stream this live to the clients.

  At this point, I do not really care about different bit rates, i just want live streaming to work, in mobile browsers and on desktop browsers.

  I found this class :

  https://github.com/Red5/red5-hls-plugin/blob/master/plugin/src/main/java/org/red5/stream/http/servlet/PlayList.java

  Which might be doing something like that.

  I have pulled in hls.js into my application in hopes of using it for desktops.

  HLS should however work IOS devices without hls.js right now.

  How should one serve HLS content from the server ? It’s very difficult to find any good and simple example to do that.

  Anyone knows of the steps needed to do that ?

  I’ve looked into Wowza and Red5 just a little bit, but unsure what they can provide for me at this stage and seems to be overly complicated to setup just to serve some files. But please explain to me why that’s not the case.

• How to use temporary files and replace the input when using ffmpeg in batch ?

  18 juin 2020, par Fabio Freitas

  What I did so far :

  



  I learned with this answer that I can use negative mapping to remove unwanted streams (extra audio, subtitles) from my video files.

  



  I them proceeded to apply it to a few dozen files in a folder using a simple for /r loop on Windows' cmd. Since I thought this process as some kind of trim, I didn't care about my original files and wanted ffmpeg to replace them, which of course it cannot.

  



  I tried to search a bit further and find ways to work around this issue without simply using a new destination an manually replacing files afterwards, but had no luck.

  



  However a lot of my findings seemed to indicate that ffmpeg has capabilities to use external temporary files for some of it's functions, even though I couldn't really find more onto it.

  



  What I want to do :

  



  So is there any way that I can make ffmpeg remove those extra streams and them replace the original file somehow. I'll also be needing to use this to multiple file, by I don't think this would be a big issue...

  



  I really need this to be done with ffmpeg, as learning the tool to it's full extent is a long-therm goal of mine and I want to keep working on that curve, but as for batch/cmd, I prefer it because I haven't properly learned a programming language yet (even if I often meddle with a few), but I would be happy to use suggestions of any kind for handling ffmpeg !

  



  Thank you !