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• Speeding up videocomposing in pymovie

  10 février 2024, par rawlung

  I'm trying to resize videos similarly to what this api provides
https://creatomate.com/docs/json/quick-start/blur-video-background
I accomplished the result more or less but the problem is it takes ages to render out.
I'm a total beginner when it comes to video processing and for the life of me i can't figure out how to speed it up. When the rendering is running python only uses CPU at about 20% utilization.

  


  from moviepy.editor import VideoFileClip, concatenate_videoclips,CompositeVideoClipimport datetimefrom skimage.filters import gaussian

def _blur(image):
  return gaussian(image.astype(float), sigma=25,preserve_range=True,channel_axis=-1)

def blurVideos(filenames):
  clips = [VideoFileClip(c) for c in filenames]
  overlay_clips = [VideoFileClip((c), has_mask=True) for c in filenames]
  overlay = concatenate_videoclips(overlay_clips,"chain")
  output = concatenate_videoclips(clips, method="chain")
  print("Bluring video")
  blured_output = output.fl_image( _blur )
  print("Done")
  print("Resizing video")
  resized_output = blured_output.resize((1920,1080))
  print("Done")
  composited_output = CompositeVideoClip([resized_output.without_audio(),overlay.set_position("center","center")])
  composited_output.write_videofile(f"output/out_{datetime.datetime.today().strftime('%Y-%m-%d')}.mp4",fps=20,threads=16,codec="h264_nvenc",preset="fast")


  


  I've tried to use GPU accelerated codecs like h264_nvenc, I've tried to modify ffmpeg arguments under the hood of moviepy to use cuda also no succses
What can i do to speed this up ?

  


• How can I parse ffprobe output and run ffmpeg depending on the result ?

  14 septembre 2019, par Eli Greenberg

  I have had incredible trouble building a binary of ffmpeg for Mac that works correctly for all of my needs. I have an older build that works great remuxing h264 video without problems but lacks a library I need, namely libspeex. I built a newer build based on ffmpeg’s git that includes libspeex but crashes when trying to remux h264 from .flv files with bad timecodes (live dumps from rtmpdump). So I have two ffmpeg binaries that each do half of what I need. This is what I have as my current .command file :

  for f in ~/Desktop/Uploads/*.flv
  
  do
  
  /usr/local/bin/ffmpeg -i "$f" -vcodec copy -acodec libfaac -ab 128k -ar 48000 -async 1 "${f%.*}".mp4 && rmtrash "$f" || rmtrash "${f%.*}".mp4
  
  done

  This ffmpeg binary has libspeex included so it can decode speex audio in the .flv input files. What I’m looking to do is something like this pseudocode :

  for f in ~/Desktop/Uploads/*.flv
  
  do
  
  ffprobe input.flv
  
      if Stream #0:1 contains speex
  
          ffmpeg-speex -i input.flv -acodec copy -async 1 output.m4a
  
      fi
  
  ffmpeg-h264 -i input.flv -vcodec copy output.mp4
  
  MP4Box -add output.mp4 -add output.m4a finaloutput.mp4
  
  done

  Is something like this possible ? Are there any alternatives ?

• ffmpeg randomly hangs and takes huge cpu usage when recording audio streams

  7 décembre 2017, par Maximax40

  I am trying to record 54 radio station using ffmpeg for Windows. I get those audio from different URL and separate instances of ffmpeg record and encode them to .wav format. It works great, it does it’s job with a very low cpu and memory usage and I get the results I want. However, sometimes a random ffmpeg process seems to hang and start using 25% cpu usage on it’s own and stop recording.

  It happens several times a day, and everytime I need to restart the process. If I’m not paying attention to the processes when one is stall, others will start to hang as well. If 4 of them hangs, I get 100% cpu usage and more than half of the recordings stops working, probably because of overload or something.

  When a process stall, I don’t get any error in the cmd window, it just freezes. It really seems to be random, because 2 computers are doing the same thing and record the exact same streams, but when a process stall on a computer, the same process works fine on the other, so I don’t think it’s related to the stream input.

  Here is an example of the command I use to launch a ffmpeg process :

  ffmpeg -y -i "http://icecast-cftx.rncm.ca/cftx.mp3" -ab 3200 -ar 16000 -ac 1 -f segment -segment_time 600 -strftime 1 "audios/CBFFMTR %%Y-%%m-%%d %%H-%%M-%%S.wav"

  Can anyone help me on this issue ? It’s really sad that I can’t rely on this software because of this.

  Thank you

  EDIT : After another check, I realise that when a recording crash on one of the computers, the same one crash on the other.