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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 ?

  


• pyav / ffmpeg / libav receiving too many keyframe

  26 mai 2021, par user1315621

  I am streaming from an rtsp source. It looks like half of the frames received are key frames. Is there a way to reduce this percentage and have an higher number of P-frames and B-frames ? If possible, I would like to increase the number of P-frames (not the one of B-frames).
I am using pyav which is a Python wrapper for libav (ffmpeg)

  


  Code :

  


  container = av.open(
    url, 'r',
    options={
        'rtsp_transport': 'tcp',
        'stimeout': '5000000',
        'max_delay': '5000000',
    }
)
stream = container.streams.video[0]
codec_context = stream.codec_context
codec_context.export_mvs = True
codec_context.gop_size = 25  

for packet in self.container.demux(video=0):
    for video_frame in packet.decode():
        print(video_frame.is_key_frame)


  


  Output :

  


  True
False
True
False
...


  


  Note 1 : I can't edit the source. I can just edit the code used to stream the video.

  


  Note 2 : same solution should apply to pyav, libavi and ffmpeg.

  


  Edit : it seems that B-frames are disabled : codec_context.has_b_frames is False

  


• 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 ?