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• Is there a document or page describing the output of ffprobe -show_frames ?

  4 novembre 2017, par yang

  I am trying to use scene detection filter and extract key frames.

  ffprobe -v quiet -show_frames -of compact=p=0 -f lavfi "movie=sample.mp4,select='gt(scene,.5)'"

  However, the output is really hard to read for me.

  media_type=video|stream_index=0|key_frame=1|pkt_pts=4879872|pkt_pts_time=317.700000|pkt_dts=4879872|pkt_dts_time=317.700000|best_effort_timestamp=4879872|best_effort_timestamp_time=317.700000|pkt_duration=N/A|pkt_duration_time=N/A|pkt_pos=16582154|pkt_size=691200|width=640|height=360|pix_fmt=rgb24|sample_aspect_ratio=1:1|pict_type=I|coded_picture_number=0|display_picture_number=0|interlaced_frame=0|top_field_first=0|repeat_pict=0|tag:lavfi.scene_score=0.548330

  I searched google and here, couldn’t find a document that explain each result. Like what is pkt_pts ? what does best_effort_timestamp mean ? Is there a place to learn all these outputs ?

• Packet Corruption : Why sometimes ffmpeg .bat batch video editing makes my computer unstable unable to restart ?

  13 juin 2022, par principal-ideal-domain

  I'm doing very time consuming ffmpeg video editing. That's why I put my commands into a .bat batch file and run them over night. Usually that works fine, but from time to time when I look the next moring I see an error message of this kind :

  


  

  


  From that state on, I didn't find any good way to close the console. When I press the [x] button in the top right corner, it freezes. When I try to kill the application using the task manager nothing happens. Even explorer.exe cannot be closed using the task manager. A shutdown won't do anything. During the last month I had this problem about three times and the only way I could close it was to long press the power button of the computer until it was turned off "the bad way".

  


  Any ideas what to in such situations ?
  
Or even better : How to prevent those situations ?
What can the reason(s) be for the error ?
Do you understand the message ?

  


  When the computer is started again the next morining and I run the same .bat file again everything works fine. So the same error does not repeat and the video is edited nicely !

  


  Edit : Now, about one week after posting this question the problem occurred many more times ! It is very annoying. I guess it has to do with the external hard drive connected by USB. Sometimes it randomly interrupts the connection ! That might be the reason for the behavior. Whatever its causing the error, I want to learn a solution how to deal with this in future. I don't want to always push the reset button of my computer. I want a proper way to be able to shut it down.

  


• play encrypted movies in vlc by decrypting them by ffmpeg "on the fly"

  21 mai 2024, par doctor

  I would like to play encrypted movies in vlc by decrypting them by ffmpeg like below on macOS.
The size of my movie is, say, 200-1000MB. (hundreds of files)

  


  My problem is that it is too slow to decrypt ; it takes 5mins for 300MB movie before it starts to play.
My guess is that ffmpeg first decrypts the whole content of 300MB and then VLC plays it.
My question : Is it possible to play the movie "on the fly" while decrypting it ?
(play the decrypted chunk once it is decrypted, Not wait until the whole movie is decrypted before it plays, so that it starts to play in, say, 10 secs delay.)

  


  ffmpeg -decryption_key 0 -i "movie.locked.mp4" -f matroska | /Applications/VLC.app/Contents/MacOS/VLC - --fullscreen --quiet --play-and-exit