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• MP4 to DASH (bash script)

  18 mars 2019, par Francesco Galgani

  I have a web site in which users can upload video files. I want to stream all of them using DASH to obtain an adaptive bitrate streaming. So I wrote a bash script (to run by cron) that converts all mp4 files to DASH, but it doesn’t work properly : what is wrong ?

  For example, using the following script, I obtained :
  https://www.informatica-libera.net/dash_faq/stream.mpd

  It validates, but it doesn’t play. I tested it on :
  http://dash-mse-test.appspot.com/dash-player.html?url=https%3A%2F%2Fwww.informatica-libera.net%2Fdash_faq%2Fstream.mpd&autoplay=on&adapt=auto&flavor=

  Thank you for any help.
  The code :

  #!/bin/bash
  
  
  
  # THIS SCRIPT CONVERTS EVERY MP4 (IN THE CURRENT FOLDER AND SUBFOLDER)
  
  # TO A MULTI-BITRATE VIDEO IN MP4-DASH
  
  # For each file "videoname.mp4" it creates a folder "dash_videoname" 
  
  # containing a dash manifest file "stream.mpd" and subfolders containing 
  
  # video segments.
  
  
  
  # mp4dash documentation and download: https://www.bento4.com/developers/dash/
  
  
  
  MYDIR=$(dirname $(readlink -f ${BASH_SOURCE[0]}))
  
  SAVEDIR=$(pwd)
  
  
  
  # Check programs
  
  if [ -z "$(which ffmpeg)" ]; then
  
      echo "Error: ffmpeg is not installed"
  
      exit 1
  
  fi
  
  
  
  if [ -z "$(which mp4dash)" ]; then
  
      echo "Error: mp4dash is not installed"
  
      exit 1
  
  fi
  
  
  
  cd "$MYDIR"
  
  
  
  TARGET_FILES=$(find ./ -type f -name "*.mp4")
  
  for f in $TARGET_FILES
  
  do
  
    f=$(basename "$f") # fullname of the file
  
    f="${f%.*}" # name without extension
  
  
  
    if [ ! -d "dash_${f}" ]; then
  
      echo "Converting \"$f\" to multi-bitrate video in MPEG-DASH"
  
  
  
      ffmpeg -y -i "${f}.mp4" -c:a libfdk_aac -ac 2 -ab 128k -c:v libx264 -x264opts 'keyint=24:min-keyint=24:no-scenecut' -b:v 1500k -vf "scale=-2:720" -f mp4 -pass 1 -y /dev/null
  
      ffmpeg -y -i "${f}.mp4" -c:a libfdk_aac -ac 2 -ab 128k -c:v libx264 -x264opts 'keyint=24:min-keyint=24:no-scenecut' -b:v 1500k -vf "scale=-2:720" -f mp4 -pass 2 "${f}_1500.mp4"
  
  
  
      ffmpeg -y -i "${f}.mp4" -c:a libfdk_aac -ac 2 -ab 128k -c:v libx264 -x264opts 'keyint=24:min-keyint=24:no-scenecut' -b:v 800k -vf "scale=-2:540" -f mp4 -pass 1 -y /dev/null
  
      ffmpeg -y -i "${f}.mp4" -c:a libfdk_aac -ac 2 -ab 128k -c:v libx264 -x264opts 'keyint=24:min-keyint=24:no-scenecut' -b:v 800k -vf "scale=-2:540" -f mp4 -pass 2 "${f}_800.mp4"
  
  
  
      ffmpeg -y -i "${f}.mp4" -c:a libfdk_aac -ac 2 -ab 128k -c:v libx264 -x264opts 'keyint=24:min-keyint=24:no-scenecut' -b:v 400k -vf "scale=-2:360" -f mp4 -pass 1 -y /dev/null
  
      ffmpeg -y -i "${f}.mp4" -c:a libfdk_aac -ac 2 -ab 128k -c:v libx264 -x264opts 'keyint=24:min-keyint=24:no-scenecut' -b:v 400k -vf "scale=-2:360" -f mp4 -pass 2 "${f}_400.mp4"
  
  
  
      ffmpeg -y -i "${f}.mp4" -c:a libfdk_aac -ac 2 -ab 128k -c:v libx264 -x264opts 'keyint=24:min-keyint=24:no-scenecut' -b:v 200k -vf "scale=-2:180" -f mp4 -pass 1 -y /dev/null
  
      ffmpeg -y -i "${f}.mp4" -c:a libfdk_aac -ac 2 -ab 128k -c:v libx264 -x264opts 'keyint=24:min-keyint=24:no-scenecut' -b:v 200k -vf "scale=-2:180" -f mp4 -pass 2 "${f}_200.mp4"
  
  
  
      rm -f ffmpeg*log*
  
  
  
      mp4fragment "${f}_1500.mp4" "${f}_1500_fragmented.mp4"
  
      mp4fragment "${f}_800.mp4" "${f}_800_fragmented.mp4"
  
      mp4fragment "${f}_400.mp4" "${f}_400_fragmented.mp4"
  
      mp4fragment "${f}_200.mp4" "${f}_200_fragmented.mp4"
  
  
  
      rm -f "${f}_1500.mp4" "${f}_800.mp4" "${f}_400.mp4" "${f}_200.mp4"
  
  
  
      mp4dash -v -o "dash_${f}" "${f}_1500_fragmented.mp4" "${f}_800_fragmented.mp4" "${f}_400_fragmented.mp4" "${f}_200_fragmented.mp4"
  
  
  
      rm -f "${f}_1500_fragmented.mp4" "${f}_800_fragmented.mp4" "${f}_400_fragmented.mp4" "${f}_200_fragmented.mp4"
  
  
  
      fi
  
  
  
  done
  
  
  
  cd "$SAVEDIR"

• Get result of ffmpeg and pass it to a python script

  1er mai 2018, par Rex Low

  Pretty sure this is doable but I am not exactly sure on how to achieve it.

  I have a Raspberry Pi streaming constantly on my local network and I use this ffmpeg script to save the video inside the Pi.

  ffmpeg -i http://0.0.0.0:8080/stream/video.mjpeg -vcodec copy -map 0 -f segment -segment_time 5 -segment_format mp4 capture-%05d.mp4

  The script is rather straightforward, it loads and saves 5 seconds video continuously in a local directory.

  

  Here’s what I am trying to do ultimately

  Upload all saved videos to a Cloud Storage, then delete the local copy

  I tried to pipe the output of ffmpeg to a python script like this but it does not work the way I imagine it would.

  ffmpeg -i http://0.0.0.0:8080/stream/video.mjpeg -vcodec copy -map 0 -f segment -segment_time 5 -segment_format mp4 capture-%05d.mp4 | py test.py -p capture-%05d.mp4

  This is my script, just to get the name/path of video

  import argparse
  
  
  
  if __name__ == "__main__":
  
      parser = argparse.ArgumentParser()
  
      parser.add_argument('-p', '--videoPath', type=str, help="Path to recorded video", required=True)
  
      args = parser.parse_args()
  
  
  
      print(args.videoPath)

• Extract audio from youtube in a client-side script

  5 mai 2018, par Kevin

  There are a lot of node libraries for turning a youtube video into an audio stream, but all of them rely on a C-library called ffmpeg.

  Ffmpeg has been ported to javascript as well, but it has a 30MB size, which seems rather cumbersome (ffmpeg does a lot more than just rip audio from youtube, it has many advanced audio filtering techniques that won’t be needed for this application).

  Lastly, I came across this link,https://hackernoon.com/how-to-build-an-audio-processor-in-your-browser-302cb7aa502a, which claims to be a client-side audio processor but really does all the stuff on the server-side, and then says that stuff can’t be done in the client because of CORS (not sure I understand this, can’t CORS be avoided with a simple flag in the request ?).

  Does anyone know of any way to stream audio within the client-side browser, specifically from youtube, in a manner that’s general and unopposed ?