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• 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

• Learn Multimedia Programming By Writing A JPEG Decoder

  6 janvier 2011, par Multimedia Mike — Programming

  For those of you who hack on multimedia tech, how did you get started ? Did you begin by studying the mathematical underpinnings of multimedia codec algorithms ? Or did you find a practical problem and jump right in by writing code ? (Personally, I was always more of a nuts & bolts hacker than a math guy.) I ask because I occasionally get emails from aspiring multimedia hackers who want to know where to begin. Invariably, they want to go the math-first route. I heavily discourage this approach.

  I have a crazy idea for anyone who wants a crash course on multimedia hacking : write a JPEG decoder. In doing so, you will be exposed to a lot of key domain concepts such as bitstream parsing, Huffman decoding, dequantization, zigzagging, the dreaded (inverse) discrete cosine transform, YUV vs. RGB colorspaces, macroblock organization, delta coding, and run length coding.

  Sure, JPEG decoding is a solved problem. But that’s hardly the point. Why would you enter an unfamiliar field and hope to come up to speed on the basics by leaping straight into the domain’s unsolved problems ? If you are successful in this exercise, no one will ever use the fruits of your labor, but that doesn’t really matter.

  So, do you want to learn multimedia hacking quickly ? Then grab a JPEG file (maybe create a few contrived ones that are small, have friendly dimensions, and feature predictable patterns), grab a good JPEG reference, and implement the decoding algorithm in the language and platform of your choice.

  On the matter of the reference, my personal favorite reference has always been A note about the JPEG decoding algorithm by Cristi Cuturicu. The English grammar is a bit dodgy but overall, it might be the best reference you’ll find on the matter— as simple as it needs to be, but no simpler.

  Good luck !