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• how to check the number of duplicated frame for video 1sec ( about 30frames ) from video start and want to apply this for mpdecimate

  20 octobre 2018, par cool jobs

  How to check the number of duplicated frame for video 1sec ( about 30frames ) from video beginning point ? I want to apply this for mpdecimate with audio. Some videos have three duplicated frames, some videos - 15 duplicated frame, some videos have 19 duplicated frames.. so it looks I need a variable or math operator in ffmpeg as expression.

  1. some video have duplicated frames at beginning point , but it is
     not same always the number of duplicated frames.
  2. if get back variable which is for the number of duplicated frames
     from step-1 then split and trim apply mpdecimate with audio as
     much as step-1 variable returned, finally do concatenate each other.

  Is this possible with -filter_complex for one line ffmpeg command ?

• How to extract encoded transport stream frames from a video file ?

  3 mai 2022, par Ivy Growing

  Searching for a method to extract from video stream (.m2t or .ts file) a certain frames as is, encoded. OpenCV also extracts frames easily but decodes them immediately.
Given :

  


  

  • A .ts or .m2t file with H.264/MPEG-4 encoded stream.

  


  • Starting point in time for extraction like h:m:s.f (example : 0:2:1.12).

  


  • Ending point in time in the same format.

  


  


  I need to read from the file all frames in the given interval and provide to another program as buffer frame by frame as they are. The catch here is to keep the frames encoded as they are, do not decode/encode/encapsulate them.

  


  Picking a frame from the H.264 m2t to a pipe :

  


  ffmpeg -ss 0:2:1.12 -i .\my_video.ts -c:v copy -f mpegts -frames:v 1 pipe: -y -hide_banner

  


  Obviously, the time stamp is increasing for every next frame. From the pipe it is not a problem to convert it to a buffer.

  


  Questions :

  


  

  1. Is this method correct to extract a separate frame as it is without
any reference/recalculations with neighbor frames ?

  


  2. Not sure that flag -f mpegts really keeps the frame untouched. Is there better flag ? (Maybe -f null ?)

  


  3. How to know the type of extracted frame (i, P, or B) ?

  


  


  Thank you.

  


• How to identify users in video file when streaming video ? [on hold]

  24 octobre 2017, par blackjak231

  I’m trying to find a solution to "secure" online video courses on a video streaming platform. The goals are the following :

  • Prevent easy download of video - OK
  • Be able to identify which connected user downloaded the video if it happens - NOK

  The server will be a Debian machine running PHP 7 and the "encryption" of the video will be done "on the stream" for each user.

  ---

  My question is for the second point. I’m unable to find a good solution for it. Here is what i thought of so far and the downsides :

  1. Add a watermark with the user’s name/email with "ffmpeg" on the whole video (in a corner)
     • Can be blurred and therefore useless
  2. Add an invisible digital watermark (inside the video file) with a tool (which i have not found yet)
     • Screen can be recorded and the invisible digital watermark lost.
  3. Add a watermark with the user’s name/email on 2 or 3 specific frames of the video while streaming using "ffmpeg"
     • Best solution from my point of view but no technical solution found so far.

  ---

  Do you have any recommendations on how to do this or a completely different approach to the problem ?

  I’m open to any third party video tool such as Vimeo or any other available.

  Thank you in advance for your help ! :)