Recherche avancée

Sur d’autres sites (5446)

• How to make cropping when doing motion-tracking look super smooth ? (using cv2 and yolo v8)

  4 décembre 2024, par Thomas Lancer

  I'm using yolo to track a face in a video on a frame by frame basis, and then I'm using cv2 to crop the video (with some padding) around the speakers face so it creates a motion tracking type effect. (short example here : https://www.instagram.com/reel/DCIFkFEObkE/?hl=en)

  


  The problem I'm running into is my final crop looks "shaky". Like it's flickering a bit. I think this is because every frame yolo is updating the coordinates, and so there's a slight change in x, y and because of that it creates this shakiness/flickering effect. Here's what mine looks like compared to the example : https://drive.google.com/file/d/1MKHWK-5EH5abSq6i32r71GWld76tN1GP/view?usp=sharing

  


  You can see there's this "shakiness" type look to it. it's especially apparent when the speaker is relatively still.

  


  I've tried doing an exponential moving average and a few other averaging techniques but none have fixed it.

  


  Is my fundamental approach of doing a frame by frame crop wrong ? or is there just some smoothing algorithm or some dumb mistake that you think I may be making ? Any advice is mega appreciated !

  


• Can VideoView be detach and reattached without stopping the stream ?

  17 septembre 2018, par Thierry-Dimitri Roy

  I’m building an app where the user clicks on a button to show a video full screen. Initially the video is attached to a view inside a ViewPager. To be able to show it fullscreen I detach it from its parent and reattach it to the root view. This works fine, except when the video is switched to fullscreen while playing. When I detach a playing VideoView it just stop and I need to restart it. This is not acceptable since the video starts buffering before resume. Here the part of the code where the detach is done :

      final ViewGroup parent = (ViewGroup) findViewById(R.id.parent);
  
  
  
      final ViewGroup root = (ViewGroup) findViewById(R.id.root);
  
  
  
      Button b = (Button) findViewById(R.id.button);
  
      b.setOnClickListener(new OnClickListener() {
  
  
  
          @Override
  
          public void onClick(View v) {
  
              parent.removeView(mVideoView);
  
  
  
              LayoutParams lp = new FrameLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
  
              root.addView(mVideoView, lp);
  
          }
  
      });

  Depending of the device, I have a different log error. Probably because the actual video player is provided by the manufacturer and not the Android SDK. Here are the error logs for a Nexus 7 :

  10-30 20:26:18.618: D/NvOsDebugPrintf(124): NvMMDecTVMRDestroyParser Begin 
  
  10-30 20:26:18.618: D/NvOsDebugPrintf(124): --------- Closing TVMR Frame Delivery Thread -------------
  
  10-30 20:26:18.678: D/NvOsDebugPrintf(124): ------- NvAvpClose -------
  
  10-30 20:26:18.678: D/NvOsDebugPrintf(124): NvMMDecTVMRDestroyParser Done 
  
  10-30 20:26:18.678: D/NvOsDebugPrintf(124): NvMMLiteTVMRDecPrivateClose Done 

  I haven’t been able to detach the video without stopping it. I tried using SurfaceView or TextureView without success.

  I also tried finding a third party video player. I found a commercial one (http://www.vitamio.org/) that I can’t really use for business reason. I found an open source one, that hasn’t been updated in the last year (https://code.google.com/p/dolphin-player/).

  I’m currently targeting Android 4.2 or better on tablet only.

  ---

  Note that the ViewPager is not fullscreen. So I can’t use LayoutParams to make the video fullscreen. I need to remove the VideoView from the parent in the ViewPager and add it to the root view to be able to show it fullscreen.

  The URL I’m testing with : http://bellvps1.cpl.delvenetworks.com/media/e1b3e24ecb944abd8f4ed823a0b76ddc/68f78d35296243bfb46d2418f03f2fd0/bande-annonce---the-secret-life-of-walter-mitty-1-9efcc5c6e52ac07a3edf84a1b21967995b7796a2.m3u8

• Can VideoView be detach and reattached without stopping the stream ?

  1er juin 2015, par Thierry-Dimitri Roy

  I’m building an app where the user clicks on a button to show a video full screen. Initially the video is attached to a view inside a ViewPager. To be able to show it fullscreen I detach it from its parent and reattach it to the root view. This works fine, except when the video is switched to fullscreen while playing. When I detach a playing VideoView it just stop and I need to restart it. This is not acceptable since the video starts buffering before resume. Here the part of the code where the detach is done :

      final ViewGroup parent = (ViewGroup) findViewById(R.id.parent);
  
  
  
      final ViewGroup root = (ViewGroup) findViewById(R.id.root);
  
  
  
      Button b = (Button) findViewById(R.id.button);
  
      b.setOnClickListener(new OnClickListener() {
  
  
  
          @Override
  
          public void onClick(View v) {
  
              parent.removeView(mVideoView);
  
  
  
              LayoutParams lp = new FrameLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
  
              root.addView(mVideoView, lp);
  
          }
  
      });

  Depending of the device, I have a different log error. Probably because the actual video player is provided by the manufacturer and not the Android SDK. Here are the error logs for a Nexus 7 :

  10-30 20:26:18.618: D/NvOsDebugPrintf(124): NvMMDecTVMRDestroyParser Begin 
  
  10-30 20:26:18.618: D/NvOsDebugPrintf(124): --------- Closing TVMR Frame Delivery Thread -------------
  
  10-30 20:26:18.678: D/NvOsDebugPrintf(124): ------- NvAvpClose -------
  
  10-30 20:26:18.678: D/NvOsDebugPrintf(124): NvMMDecTVMRDestroyParser Done 
  
  10-30 20:26:18.678: D/NvOsDebugPrintf(124): NvMMLiteTVMRDecPrivateClose Done 

  I haven’t been able to detach the video without stopping it. I tried using SurfaceView or TextureView without success.

  I also tried finding a third party video player. I found a commercial one (http://www.vitamio.org/) that I can’t really use for business reason. I found an open source one, that hasn’t been updated in the last year (https://code.google.com/p/dolphin-player/).

  I’m currently targeting Android 4.2 or better on tablet only.

  ---

  Note that the ViewPager is not fullscreen. So I can’t use LayoutParams to make the video fullscreen. I need to remove the VideoView from the parent in the ViewPager and add it to the root view to be able to show it fullscreen.

  The URL I’m testing with : http://bellvps1.cpl.delvenetworks.com/media/e1b3e24ecb944abd8f4ed823a0b76ddc/68f78d35296243bfb46d2418f03f2fd0/bande-annonce---the-secret-life-of-walter-mitty-1-9efcc5c6e52ac07a3edf84a1b21967995b7796a2.m3u8