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• How to transcode a video to custom resolution using Xamarin.MP4Transcoder.Transcoder

  7 juillet 2017, par Prashant

  I need to transcode a video to 640*480 resolution using Xamarin.MP4Transcoder.Transcoder. Currently there are 2 available resolutions 720pFormat and 960x540Format. There is a method called Transcoder For (IMediaFormatStrategy strategy) available in Transcoder class.

  I can create MediaFormat object with MIME Type, Width and Height
  by below mentioned code snippet :

  MediaFormat obj = MediaFormat.CreateVideoFormat("video/mp4", 480, 640);


  but the problem is how can assign it to IMediaFormatStrategy or is there any other way to achieve this.

  Piece of code for Transcoding a video:
  
  
  
  Xamarin.MP4Transcoder.Transcoder.For960x540Format().ConvertAsync(inputFile, outputFile, f =>
                                {
                                  onProgress?.Invoke((int)(f * (double)100), 100);

                                  
                                } );
  
  
  
  inputFile: Video file which needs to be transcoded.
  
  outputFile: Resultant file generated after transcoding.

  For more info you can refer https://github.com/neurospeech/xamarin-android-ffmpeg

  Any help is appreciated. Thanks in advance !!

• Resolution switcher for HLS streaming

  19 septembre 2017, par Awais fiaz

  i am trying to add up a quality picker for users to select desired quality on which they want to play the video using video.js.I have tried using 2 or 3 open source plugins all of which were deprecated or having old code which is not supported now and the worst thing is many of the of the files are missing in them.is there any solution to add up quality picker for HLS streaming on video.js ?
  Any help would be much appreciated
  here is my sample code to play HLS streaming USING video.js

  the current plugin i am using is :
  https://github.com/streamroot/videojs-quality-picker

  <video class="video-js" controls="controls" preload="auto" width="640" height="264" data-setup="{}" autoplay="autoplay">
  
    <source src="legend_hls/legend_playlist.m3u8">
  
  
  
    <p class="vjs-no-js">
  
      To view this video please enable JavaScript, and consider upgrading to a web browser that
  
      <a href="http://videojs.com/html5-video-support/" target="_blank">supports HTML5 video</a>
  
    </p>
  
  </source></video>
  
  <code class="echappe-js">&lt;script&gt;<br />
  
    videojs('my-video').qualityPickerPlugin();<br />
  
  &lt;/script&gt;
  
  

• How can I capture low resolution video on Android reliably across a range of devices ?

  8 décembre 2017, par MisterMat

  Hello Android video experts :)

  I am developing an Android application which allows the user to capture video and upload it to a remote server (it’s more involved than that but the rest of the app is not important). Because of the upload requirement, it is important that the video is of a reasonable size, so not super high resolution. Let’s say a max of 680x480 or 10Mb/minute. This is no problem on Apple devices.

  I have had what can only be described as a complete nightmare trying to capture video at a reasonably low bitrate reliably across a range of Android devices.

  As I understand it there are two ways of capturing video on Android :

  1) Using the Media Recorder/Camera API

  2) Using an Intent to open the cameras video capture application

  Option 1) gives the most flexibility and allows us to easily change the capture resolution. However the Android Camera API is NOT reliable across a range of devices, and I have very good information (including from someone who liaised with Google on this issue) that if you capture video using this API then it will crash on a good 50% of the devices out there. There is a reason that Zoom Camera FX uses an Intent for video capture. Zoom Camera (different app) seems to use Media Recorder, but has lots of bad reviews for video crashing or not working.

  Option 2) works well across a range of devices, as it uses the in built application on the device. The trouble is you have no control whatsoever on the resolution, there is a quality hint on the Intent but the camera app will normally ignore this. My Samsung Galaxy S3 records video by default at about 2Mb/s. This is way too high resolution. The built in application can of course change the resolution, but this relies on action by the user which is difficult to control.

  I understand that I could use a library such as ffmpeg to change the resolution of the video after capture. However this requires me to compile the library for Android, and also I have been informed that in order to legally use the decode/encode codecs on the device you have to pay license fees that amount to about $1 per copy of the app. Since this app will be free to use, this is not an option.

  So that’s where I’m at. I’ve searched long and high for answers, but I can’t figure out how to capture low resolution video reliably using Android.

  Any help very much appreciated !

  Matthew