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• Videos written with moviepy on amazon aws S3 are empty

  10 avril 2019, par cellistigs

  I am working on processing a dataset of large videos ( 100 GB) for a collaborative project. To make it easier to share data and results, I am keeping all videos remotely on an amazon S3 bucket, and processing it by mounting the bucket on an EC2 instance.

  One of the processing steps I am trying to do involves cropping the videos, and rewriting them into smaller segments. I am doing this with moviepy, splitting the video with the subclip method and calling :

  subclip.write_videofile("PathtoS3Bucket"+VideoName.split('.')[0]+'part' +str(segment)+ '.mp4',codec = 'mpeg4',bitrate = "1500k",threads = 2)

  I found that when the videos are too large (parameters set as above) calls to this function will sometimes generate empty files in my S3 bucket ( 10% of the time). Does anyone have insight into features of moviepy/ffmpeg/S3 that would lead to this ?

• Join videos without interruption with removing extra scenes automatically

  19 janvier 2014, par RarLines

  I've tens of splitted videos from a video.

  My english is poor so I will try explain with a simple example :

  The original video scenes like so: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14

  But I had never the original video. I've these videos :

  Video_1.part scenes: 1, 2, 3, 4, 5
  
  Video_2.part scenes: 5, 6, 7, 8, 9 (5 is extra !)
  
  Video_3.part scenes: 9, 10, 11, 12, 13, 14 (9 is extra !)

  When I try to concatenate (or join, merge, combine...etc) these videos with using ffmpeg, the scenes the output file are liked that :

  The output video scenes: 1, 2, 3, 4, 5, 5, 6, 7, 8, 9, 9, 10, 11, 12, 13, 14

  As you can see, when I watch the output video there are interruptions between videos.

  Is there any technical way to join videos without interruption (or nonstop, continuous...etc) ?

  Please note that, my example is so simple. I'm not sure that the splitted videos have regularly extra scenes. If I was sure, I could crop equally. Maybe the length of extra scenes are equal. But I couldn't check.

  Hope you will show an intelligent method. Thanks

• Some transcoded videos get frozen in the middle

  20 juin 2018, par corolok

  OS : ubuntu 16.04
  ffmpeg : 3.4.2-1

  Here are ffmpeg parameters :

  ffmpeg -y -i raw.mp4 -threads 2 -r 25 -profile:v baseline -preset veryfast -s 1280x720 -aspect 1.7777777777777777 test.mp4

  Most of the videos are good but sometimes we get videos which stop playing somewhere in the middle (audio is ok, but video doesn’t play anymore)

  Can it be related to performance ? There are 8 cpu cores and 2-4 ffmpeg processes can be run at once, metrics show that CPU load is always below 60% so it shouldn’t be the case I think.