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• ffmpeg video freezes some seconds the output video

  7 septembre 2022, par FreddicMatters

  I'm using the program ffmpeg on windows, I just downloaded the binaries setted the path variable of windows to be able of use it.

  


  I'm ran ffmpeg with python and also just running the command in the cmd

  


  #videos.txt

  


  file C:/Users/freddydev/Videos/video1.mp4
file C:/Users/freddydev/Videos/video2.mp4
file C:/Users/freddydev/Videos/video3.mp4
file C:/Users/freddydev/Videos/video4.mp4


  


  #python script :

  


  import subprocess
import shlex

subprocess.run(shlex.split('ffmpeg -f concat -safe 0  -i videos.txt -c:v libx264 -c copy output.mp4'))


  


  #cmd

  


  ffmpeg -f concat -safe 0  -i videos.txt -c:v libx264 -c copy output.mp4


  


  The output video plays fine the half of the video and after some 5 seconds it freezes and the final seconds of the video there is not sound.

  


  I have downloaded multiple ffmpeg binaries from https://ottverse.com/ffmpeg-builds and I'm getting the same result.

  


  My laptop is a core i5 with 12GB of RAM.
The rendering is very fast only takes 2 seconds, I also used moviepy library with python and it takes more than 20sg to render the video but when I concatenate large videos this give me wrong frames in the video at the end.

  


  What could I do to fix this problem with ffmpeg.
Thanks so much.

  


• Overlay a 16/9 video to a 9/16 ratio and shrink the original video [closed]

  6 avril 2024, par thanhbo

  I assume the video has an aspect ratio of 16/9 (size 1920:1080). I want to convert it to 9/16 ratio and shrink the original video. The formula I wrote is as follows but there is an error. I hope someone can help, thank you.

  


  ffmpeg -y -i A1.mp4 -filter_complex "split[crp0][crp1];[crp0]scale=iw:2*trunc(iw*16/18),boxblur=luma_radius=min(h\,w)/20:luma_power=1:chroma_radius=min(cw\,ch)/20:chroma_power=11,setsar=1[bg],[1:v]scale=(iw-100):-1[bg2];[bg][bg2]overlay=(W-w)/2:(H-h)/2[bg3]" -map "[bg3]" bg3.mp4

ffmpeg -y -i A1.mp4 -filter_complex "split[crp0][crp1];[crp0]scale=iw:2*trunc(iw*16/18),boxblur=luma_radius=min(h\,w)/20:luma_power=1:chroma_radius=min(cw\,ch)/20:chroma_power=11,setsar=1[bg],[1:v]scale=(iw-100):-1[bg2];[bg][bg2]overlay=(W-w)/2:(H-h)/2[bg3]" -map "[bg3]" bg3.mp4


  


• Remove video noise from video with ffmpeg without producing blur / scale down effect

  17 avril 2024, par Sucahyo Aji

  My videos are 1920x1080 recorded with high ISO (3200) using smartphone (to get bright view, backlight scene mode). It produce a lot of noise. I try many video filter but all of them produce blur similar to when we reduce the resolution in half then increase it back again.

  


  Is there a good video noise filter that only remove noise without producing blur ?

  


  Because if it produce blur, I would prefer to not do any filtering at all.

  


  I have tried video filter :

  


  


  • nlmeans=s=30:r=3:p=1

    


  


  • vaguedenoiser=threshold=22:percent=100:nsteps=4

    


  


  • owdenoise=8:6:6

    


  


  • hqdn3d=100:0:50:0

    


  


  • bm3d=sigma=30:block=4:bstep=8:group=1:range=8:mstep=64:thmse=0:hdthr=5:estim=basic:planes=1

    


  


  • dctdnoiz=sigma=30:n=4

    


  


  • fftdnoiz=30:1:6:0.8

    


  


  


  All produce blur, some even worse. I have to use strong setting to make the noise moderately removed. I end up halving the resolution and use remove grain then scale it up again. This is much better for me than all the above method (pp filter is used to reduce size without reducing image detail) :

  


  

  • scale=960:540,removegrain=3:0:0:0,pp=dr/fq|8,scale=1920:1080

  


  


  code example

  


  FOR %%G IN (*.jpg) DO "ffmpeg.exe" -y -i "%%G"  -vf "nlmeans=s=30:r=3:p=1" -qmin 1 -qmax 1 -q:v 1   "%%G.jpg"

  


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