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• How to detect a common section in a set of videos with ffmpeg [on hold]

  7 août 2019, par Hans J

  I have a set of videos that are assumed to contain common (or very similar) sections. I want to be able to detect (with FFmpeg) how long each common section is, and where the sections are in each individual video.

  An individual section can have multiple scene changes, and is continuous. A common section would also be assumed to be longer than 10 seconds (This is an arbitrary choice, it can be changed).

  The final output of the command would include the various time-codes of the instance of each section in each video. Assuming a timebase 1/1, with 1 common section that is 60 seconds long, an output would along the lines of :

  Video1.mp4 0 60
  
  Video2.mp4 120 180
  
  Video3.mp4 50 110
  
  Video4.mp4 null

  where video1, video2, video3, and video4 are the input videos. In this case, video4 does not contain a common section.

  For example, I could have three episodes of a TV show. They all contain the same commercial. Without knowing what that commercial is, I want to be able to find where that commercial shows up in each of the episodes. Ideally the function would detect additional common commercials as well.

  Edit : Another example would be removing the intro sequence in all three episodes.

  Note : For the purpose of a good solution, the common sections do not have to exactly match. Because there could be artifacts or embedded subtitles in one episode and not the other.

• How to detect a common scene in a set of videos with ffmpeg

  6 août 2019, par Hans J

  I have a set of videos that are assumed to contain a common (or very similar) scene. I want to be able to detect (with FFmpeg) what that common scene is, how long the scene is, and where the scene is in each individual video.

  The scene would be assumed to be longer than 10 seconds (This is an arbitrary choice, it can be changed).

  The final output of the command would include the various time-codes of the instance of the scene in each video. Assuming a timebase 1/1, with a common scene that is 60 seconds long, an output would along the lines of :

  Video1.mp4 0 60
  
  Video2.mp4 120 180
  
  Video3.mp4 50 110
  
  Video4.mp4 null

  where video4 does not contain any common scene.

  For example, I could have three episodes of a TV show. They all contain the same commercial. Without knowing what that commercial is, I want to be able to find where that commercial shows up in each of the episodes.

  Note : For the purpose of a good solution, the common scenes do not have to exactly match. Because there could be artifacts or embedded subtitles in one episode and not the other.

• Adding watermark bitmap over video in android : 4.3's MediaMuxer or ffmpeg

  24 novembre 2018, par Alin

  Here is my scenario :

  • Download an avi movie from the web
  • Open a bitmap resource
  • Overlay this bitmap at the bottom of the movie on all frames in the background
  • Save the video on extarnal storage
  • The video length is 15 seconds usually

  Is this possible to achieve using MediaMuxer ? Any info on the matter is gladly received

  I’ve been looking to http://bigflake.com/mediacodec/#DecodeEditEncodeTest (Thanks @fadden) and it says there :

  "Decoding the frame and copying it into a ByteBuffer with
  glReadPixels() takes about 8ms on the Nexus 5, easily fast enough to
  keep pace with 30fps input, but the additional steps required to save
  it to disk as a PNG are expensive (about half a second)"

  So having almost 1 sec/frame is not acceptable. From what I am thinking one way would be to save each frame as PNG, open it, add the bitmap overlay on it and then save it. However this would take an enormous time to accomplish.

  I wonder if there is a way to do things like this :

  1. Open video file from external storage
  2. Start decoding it
  3. Each decoded frame will be altered with the bitmap overlay in memory
  4. The frame is sent to an encoder.

  On iOS I saw that there a way to take the original audio + original video + an image and add them in a container and then just encode the whole thing...

  Should I switch to ffmpeg ? How stable and compatible is ffmpeg ? Am I risking compatibility issues with android 4.0+ devices ? Is there a way to use ffmpeg to acomplish this ? I am new to this domain and still doing research.

  ---

  Years later edit :
  Years have passed since the question and ffmpeg isn’t really easy to add to a commercial software in terms of license. How did this evolved ? Newer versions of android are more capable on this with the default sdk ?

  ---

  Some more time later edit

  I got some negative votes for posting info as an answer so I’ll edit the original question. Here is a great library which, from my testing does apply watermark to video and does it with progress callback making it a lot easier to show progress to the user and also uses the default android sdks. https://github.com/MasayukiSuda/Mp4Composer-android

  This library generate an Mp4 movie using Android MediaCodec API and apply filter, scale, and rotate Mp4.

  Sample code, could look like :

  new mp4Composer(sourcePath, destinationPath)
  
          .filter(new GlWatermarkFilter(watermarkBitmap)
  
          .listener(){
  
                @Override 
  
                private void onProgress(double value){}
  
  
  
                @Override 
  
                private void onCompleted(double value){
  
                    runOnUiThread( () ->{
  
                       showSneakbar
  
                    }
  
                }
  
  
  
                @Override 
  
                private void onCancelled(double value){}
  
  
  
                @Override 
  
                private void onFailed(Exception e){}
  
  
  
          }).start();

  Testing on emulator, seems to work fine on android 8+ while on older generates a black video file.However, when testing on real device seems to work.