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• Direct Show Video capture performance

  23 mai 2019, par Barry Andrews

  I originally started out looking for an example of how I can use FFMPEG in c++ builder to create an application to record from usb capture device and playback video because of apparrent poor performance

  I tried Mitov components, Datastead, FFMPEGVCL and winsoft camera which use directshow but their capture performance seemed poor.

  I need to capture 1920x1080 at up to 60fps into a compressed format and play this back later at both normal speed and slow speed.

  What I found was that DirectShow itself has a number of limitations which can be improved by adding things like FFMPEG, but ultimately PC hardware, in particular the HDD and processor limit capture capability.

  1920x1080 60fps is basically the upper end for DirectShow so you need to have best performing hardware in order to achieve this sort of performance @Spektre kindly gave me examples of DirectShow using the API direct which were good for comparison with the purchased components.

  Using this and comparing to the components I found that MITOV has a major issue with regards the larger video sizes and frame rates. Using this 1920x108 30fps and 60fps can be previewed but they have a massive delay between video feed and preview (5 or 6 seconds). The other components performed similar to the API direct method with only minor variations in performance. None were able to capture and record 1920x108 60fps with any sort of compression filter without large frame drops and very jerky preview.

• Checking for files in a directory with bash script ? what is wrong with this code ?

  14 mars 2018, par A Sahra

  I have written this code to check for video files in a directory and convert them with ffmpeg.
  while running this script i get out put as "[ERROR] File Not Found" which i have it in else block.what is wrong with the script that i don’t get the files.

  #!/bin/bash
  
  # set PATH to check existance of video file in this directory
  
  checkfiles='/home/webuser/public_html/shareportal/convertedUp_videos/'
  
  #format of output video file
  
  webm='webm'
  
  for f in checkfiles
  
  do
  
  fullfilename="$f"
  
  filenamewithpath=$(basename "$fullfilename")
  
  filewithoutext="${filename%.*}"
  
  fileextention="${filename##*.}"
  
  changeextension=mv --"$f" "${f%.$fileextention}.$webm"
  
  outputfilename="/home/webuser/public_html/shareportal/converted_videos/$changeextension"
  
  echo "File FUll NAME : $fullfilename"
  
  echo "File name with full path : $filenamewithpath"
  
  echo "File name without extention : $filewithoutext"
  
  echo "File extention : $fileextention"
  
  echo '1 File Converted'
  
  if (ffmpeg -i "$f" "$outputfilename")
  
  then
  
  confullfilename="$outputfilename"
  
  confilenamewithpath=$(basename "$confullfilename")
  
  confilewithoutext="${filename%.*}"
  
  confileextention="${filename##*.}"
  
  echo "File FUll NAME : $confullfilename"
  
  echo "File name with full path : $confilenamewithpath"
  
  echo "File name without extention : $confilewithoutext"
  
  echo "File extention : $confileextention"
  
  echo '1 File Converted'
  
  else
  
  echo "Could Not Convert File"
  
  fi
  
  #get Image of video file on provided time stamp
  
  image_path='/home/webuser/public_html/shareportal/video_images/$filewithoutext.png'
  
  if (ffmpeg -ss 00:00:03 -i "$f" -vframes:v 1 "$image_path")
  
  then
  
  echo "Image Extracted"
  
  else
  
  echo "Could not Extract Image"
  
  fi
  
  done
  
  rm -r f

• Checking for files in a directory with bash script ? what is wrong with this code ?

  4 décembre 2016, par A Sahra

  I have written this code to check for video files in a directory and convert them with ffmpeg.
  while running this script i get out put as "[ERROR] File Not Found" which i have it in else block.what is wrong with the script that i don’t get the files.

  #!/bin/bash
  
  # set PATH to check existance of video file in this directory
  
  checkfiles='/home/webuser/public_html/shareportal/convertedUp_videos/'
  
  #format of output video file
  
  webm='webm'
  
  for f in checkfiles
  
  do
  
  fullfilename="$f"
  
  filenamewithpath=$(basename "$fullfilename")
  
  filewithoutext="${filename%.*}"
  
  fileextention="${filename##*.}"
  
  changeextension=mv --"$f" "${f%.$fileextention}.$webm"
  
  outputfilename="/home/webuser/public_html/shareportal/converted_videos/$changeextension"
  
  echo "File FUll NAME : $fullfilename"
  
  echo "File name with full path : $filenamewithpath"
  
  echo "File name without extention : $filewithoutext"
  
  echo "File extention : $fileextention"
  
  echo '1 File Converted'
  
  if (ffmpeg -i "$f" "$outputfilename")
  
  then
  
  confullfilename="$outputfilename"
  
  confilenamewithpath=$(basename "$confullfilename")
  
  confilewithoutext="${filename%.*}"
  
  confileextention="${filename##*.}"
  
  echo "File FUll NAME : $confullfilename"
  
  echo "File name with full path : $confilenamewithpath"
  
  echo "File name without extention : $confilewithoutext"
  
  echo "File extention : $confileextention"
  
  echo '1 File Converted'
  
  else
  
  echo "Could Not Convert File"
  
  fi
  
  #get Image of video file on provided time stamp
  
  image_path='/home/webuser/public_html/shareportal/video_images/$filewithoutext.png'
  
  if (ffmpeg -ss 00:00:03 -i "$f" -vframes:v 1 "$image_path")
  
  then
  
  echo "Image Extracted"
  
  else
  
  echo "Could not Extract Image"
  
  fi
  
  done
  
  rm -r f