Recherche avancée

Sur d’autres sites (4956)

• FFMPEG Concatenate X video at time from a list.txt

  25 octobre 2019, par Lorenzo Castagnone

  I’m trying to concatenate 3 videos at time from a list.txt, i can concatenate all the videos in the list in a single long video, but i wish to concatenate x videos from the list in a single output, then concatenate the next x videos from the same list in another single output and so on.

  The script i’m developing it’s written in python, it fetches some videos from a server and save them locally in a folder and write my concat.txt, then ffmpeg read the concat.txt and create a single output.mp4

  #this merge all video in concat file in a single output
  
  os.system("ffmpeg -f concat -i downloaded/concat.txt -safe 1 -r 30 -fflags +genpts -c:a copy downloaded/output.mp4")

  I’m looking for a way to make ffmpeg read the first x row from the concat.txt , concatenate them in output1.mp4, then read the next x row from cancat.txt , concatenate them in output2.mp4 and so on.

  Thank you for your time to help me, i really appreciate that !

  ---EDIT
  Thank to @Tejas for the reply, i solved how to split the concat.txt file, now i’m trying to apply a filter to every clip

  import os
  
  x = 3 #Number of files you want to concatenate
  
  
  
  #Making directories so that the working directory stays organized
  
  txtFileName = "./splits/output{}.txt"
  
  outputFile = "./clip/output{}.mp4"
  
  postFile = "./media/post{}.mp4"
  
  os.makedirs(os.path.dirname(txtFileName), exist_ok=True)
  
  os.makedirs(os.path.dirname(outputFile), exist_ok=True)
  
  os.makedirs(os.path.dirname(postFile), exist_ok=True)
  
  
  
  
  
  #While splitting the files store their path to a list
  
  listofSplitFiles = []
  
  with open('./downloaded/concat.txt','r') as concat:
  
      lines = concat.readlines()
  
      for i in range(0,lines.__len__()//x):
  
          with open(txtFileName.format(i+1),'w') as split:
  
              listofSplitFiles.append(txtFileName.format(i+1))
  
              for j in range(0,x):
  
                  if( (i*x)+j < lines.__len__() ):
  
                      split.write(lines[(i*x)+j])
  
  
  
  #Call ffmpeg on the list
  
  for i in listofSplitFiles:
  
      outputBaseName = os.path.basename(i)
  
      outputFileName = os.path.splitext(outputBaseName)[0]
  
      postFileName = os.path.splitext(outputBaseName)[0]
  
      os.system("ffmpeg -f concat -i {} -safe 1 -r 30 -fflags +genpts -c:a copy ./clip/{}.mp4".format(i,outputFileName))
  
      os.system('''ffmpeg -loglevel error -r 30 -i sfondo/bkg.png -i ./clip/output{}.mp4 -b:v 1M -filter_complex ''' + '''"[1:v]scale=''' + "750" + ''':''' + "1080" + ''' [ovrl], [0:v][ovrl]overlay=(main_w-overlay_w)/2:((main_h-overlay_h)/2)"''' + ''' ./media/{}.mp4''' .format(outputFileName,postFileName)) 

  Unfortunately i have this error ./clip/{}.mp4: No such file or directory

• ffmpeg - color-grading video material AND display original source as picture-in-picture, using -filter_complex

  5 octobre 2019, par raven

  this is my first post on this forum, so please be gentle in case I accidentally do trip over any forum rules that I would not know of yet :).

  I would like to apply some color-grading to underwater GoPro footage. To quicker gauge the effect of my color settings (trial-and-error, as of yet), would like to see the original input video stream as a PIP (e.g., scaled down to 50% or even 30%), in the bottom-right corner of the converted output movie.

  I have one input movie that is going to be color graded. The PIP should use the original as an input, just a scaled-down version of it.

  I would like to use ffmpeg’s "-filter_complex" option to do the PIP, but all examples I can find on "-filter_complex" would use two already existing movies. Instead, I would like to make the color-corrected stream an on-the-fly input to "-filter_complex", which then renders the PIP.

  Is that doable, all in one go ?

  Both the individual snippets below work fine, I now would like to combine these and skip the creation of an intermediate color-graded TMP output which then gets combined, with the original, in a final PIP creation process.
  Your help combining these two separate steps into one single "-filter_complex" action is greatly appreciated !

  Thanks in advance,
  raven.

  [existing code snippets (M$ batch files)]
  
  
  
  ::declarations/defines::
  
  set "INPUT="
  
  set "TMP="
  
  set "OUTPUT="
  
  set "FFMPG="
  
  set "QU=9" :: quality settings
  
  
  
  set "CONV='"0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 
  
  0 -1 0:0 -1 0 -1 5 -1 0 -1 0'"" :: sharpening convolution filter
  
  
  
  ::color-grading part::
  
  %FFMPG% -i %INPUT% -vf convolution=%CONV%,colorbalance=rs=%rs%:gs=%gs%:bs=%bs%:rm=%rm%:gm=%gm%:bm=%bm%:rh=%rh%:gh=%gh%:bh=%bh% -q:v %QU% -codec:v mpeg4 %TMP%
  
  
  
  ::PIP part::
  
  %FFMPG% -i %TMP% -i %INPUT% -filter_complex "[1]scale=iw/3:ih/3 
  
  [pip]; [0][pip] overlay=main_w-overlay_w-10:main_h-overlay_h-10" -q:v 
  
  %QU% -codec:v mpeg4 %OUTPUT%
  
  
  
  [/existing code]

• Encoding video for real time streaming

  15 septembre 2019, par lilroo

  Miguel Grinberg’s article video streaming with flask, covers sending multiple JPG formatted images to a client through a multipart response to stream video to the browser.

  After doing some reading, I quickly realized that MJPEG is not a real video format, JPEGs are not optimized for video streaming and MJPEG cannot be streamed to a HTML5 video element.

  for my application (a screen sharing application written in python), I need to be able to encode and stream relatively smooth video (smoother than MJPEG anyway) in semi-realtime to the browser.

  I think what I need to do is encode a video stream using a tool like FFmpeg and then send chunks of that output to a browser using a multipart response - however it doesn’t look like there is a way to get FFmpeg (using python bindings) to write to an in-memory buffer.

  Is ffmpeg up to this task ?

  I appreciate that this question may sound nieve, but I would be thankful for being pointed in the right direction.