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• FFMPEG H264 with custom overlay per frame

  4 October 2020, by La bla bla

  We have a stream that is stored in the cloud (Amazon S3) as individual H264 frames. The frames are stored as framexxxxxx.264, the numbering doesn't start from 0 but rather from some larger number, say 1000 (so, frame001000.264)

  


  The goal is to create a mp4 clip which is either timelapse or just faster for inspection and other checking (much faster, compressing around 3 hours of video down to < 20 minutes), this also requires we overlay the frame number (the filename) on the frame itself

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  At first I was creating a timelapse by pulling from S3 only the keyframes (i-frames? still rather new to codecs & stuff) and overlaying the filename on them and saving as png (which probably isn't needed, but that's what I did) using (this command is used inside a python script)

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  ffmpeg -y -i {h264_name} -vf \"scale=1920:-1, 
drawtext=fontfile=/usr/share/fonts/truetype/ubuntu-font-family/Ubuntu-B.ttf:fontsize=34:text={txt}:fontcolor=white:x=50:y=50:bordercolor=black:borderw=2\" 
-c:a copy -pix_fmt yuv420p {basename}.png


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  after this I combined all the frames by using python to convert the lowest numbered frame to 0.png and incrementing (so it would be continuous, because I only used keyframes the numbers originally weren't sequential) and running

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  ffmpeg -y -f image2 -i %d.png -r {self.params.fps} -vcodec libx264 -crf {self.params.crf} -pix_fmt yuv420p {out_file}


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  and this worked great, but the difference between keyframes was too long to allow for proper inspection

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  so now for the question(s)

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  since I know frames that are not keyframes (p-frames?) can't be used alone by ffmpeg, the method of overlaying the file name and converting it to png (or keep as h264, same thing) won't work, or at least, I couldn't find a way for it to work, maybe there's a way to specify a frame's keyframe?, how can one overlay the filename (and not the frame number as shown here for example)

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  Also, is it possible to skip some p-frames between the keyframes? (so if a keyframe is every 30 frames, we would take a keyframe, a frame 15 frames later, and next another keyframe)

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  I thought about using ffmpeg's pipe option to feed it with the files as they're being downloaded, but I'm not sure if I can specify drawtext this way

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  Also, if there's another alternative that can achieve that (at first I was converting to png, using python and OpenCV to add the filename and then merging the pngs to mp4, but then I found drawtext can do that in a single command so I used it)

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• Processing 3.0 get Error=2 No such file or directory

  29 October 2016, by Tuang Pingfavilunda

  I cannot figure it out what happen to my Processing file. I am trying to use VideoExport library and my Macbook Pro cannot play it, but the Mac-mini is able to do so.

  Before the error happened it is another error=13 permission denied thing, so I messed in the terminal for a while with chmod 777 and finding the file with ls. I don’t know if that may be the reason that caused this happen. FYI, I also installed ffmpeg already.

  And this is the full error:

      java.io.IOException: Cannot run program "/Users/Tuang/Desktop/DMA_WORKS/Work1_Facial Muscles/Cam_Rec/sketch_161027a/sketch_161027a.pde": error=2, No such file or directory
  
      at java.lang.ProcessBuilder.start(ProcessBuilder.java:1048)
  
      at com.hamoid.VideoExport.startFfmpeg(Unknown Source)
  
      at com.hamoid.VideoExport.initialize(Unknown Source)
  
      at com.hamoid.VideoExport.saveFrame(Unknown Source)
  
      at Basic.draw(Basic.java:32)
  
      at processing.core.PApplet.handleDraw(PApplet.java:2412)
  
      at processing.awt.PSurfaceAWT$12.callDraw(PSurfaceAWT.java:1540)
  
      at processing.core.PSurfaceNone$AnimationThread.run(PSurfaceNone.java:316)
  
  Caused by: java.io.IOException: error=2, No such file or directory
  
      at java.lang.UNIXProcess.forkAndExec(Native Method)
  
      at java.lang.UNIXProcess.<init>(UNIXProcess.java:247)
  
      at java.lang.ProcessImpl.start(ProcessImpl.java:134)
  
      at java.lang.ProcessBuilder.start(ProcessBuilder.java:1029)
  
      ... 7 more
  
  VideoExport error: Ffmpeg failed. Study /Users/Tuang/Desktop/DMA_WORKS/Work1_Facial_Muscles/Camera_Recorder/Basic/basic.mp4.txt for more details.
  
  Could not run the sketch (Target VM failed to initialize).
  
  For more information, read revisions.txt and Help → Troubleshooting.
  
  </init>

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  1) The java.io.IOException: trying to call "/Work1_Facial Muscles/Cam_Rec/sketch_161027a/sketch_161027a.pde" which doesn’t exist for real. It is gone for a long time but seems like the program stuck here.

  2) "basic" is a file name from the Example of the Library. I just use it to test. Surprisingly, Every files that have been saved and changed the name still get the java.io.IOException’s error of the missing sketch_161027a.pde file.

  ---

  What I have done:
  1 I have already done the Homebrew thing to install ffmpeg.
  2 I deleted everything of Processing and reinstall it again.

  Any suggestion?

• swr: split out DSP functions.

  14 June 2014, by Ronald S. Bultje

  swr: split out DSP functions.
  DSP bits of swri_resample go into their own mini-DSP functions; DSP
  
  init goes from a per-call branch in multiple_resample to a proper
  
  DSP init routine; x86 bits go into x86/; swri_resample() moves out of
  
  resample_template.c into resample.c because it’s independent of DSP
  
  code or sample type; multiple_resample() is simplified.
  Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] libswresample/Makefile
  • [DH] libswresample/resample.c
  • [DH] libswresample/resample.h
  • [DH] libswresample/resample_dsp.c
  • [DH] libswresample/resample_template.c
  • [DH] libswresample/x86/Makefile
  • [DH] libswresample/x86/resample_x86_dsp.c