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• Android video color ajustments

  4 octobre 2012, par Christian

  I'm working on an Android app that among other things will allow the users to make short videos, apply funny effects to them and share them with one another. To begin with, i'm looking for simple color-effects like grayscale, brightness, contrast, sepiatoning, and such.

  All this would be very simple by using the camera-class which can apply the color effects at recording-time - at least most phone's cameras can - i've tested some using Camera.getParameters().getSupportedColorEffects();. But the thing is : i need to do it after the recording has been done : the user would open a video, and choose among a set of effects to apply ; then upload that changed video to a shared server.

  I can't for the love of * find a good way to do this.

  Android doesn't seem to include any videoutilities in the sdk. The android.media.effect package can do some effects, but only backdropper for videos, the rest are for images. Extracting bitmaps from the surfaceview of a videoview during playback doesn't work, it just returns an all-black bitmap. It seems like there's no way to intercept the datastream between the storage and the screen. and apply the effects there. I've started to look into using the FFmpeg library to decode a video file so i can get access to the data, but that requires quite a bit of native coding, and also requires separate compiles for various CPU architectures, so it's very messy. I thought that as the camera can apply these effects (on a Sony LT26i : none, mono, negative, solarize, sepia, posterize), perhaps one could feed the recorder with a videostream not from the camera, but from the memory, and by that way use a stored video file ?

  Do anyone know if there is a good way to apply effects to a video - after it has been recorded ?

• What encoding settings for BlackBerry HTML5 streaming ?

  27 septembre 2012, par user1441859

  For several days I've been desperately trying to get my videos stream on BlackBerry as well as the major desktop and mobile browser.
  The videos are embedded in this way :

  <video preload="auto" controls="controls">
  
  <source src="url.mp4" type="video/mp4"></source>
  
  <source src="url.ogv" type="video/ogv"></source>
  
  //flash fallback
  
  </video>

  When opening the page in the BB browser the black video frame with the controls appears but when I try to play the video the frame stays black and displays an error message : "Video portion is of an unsupported format".
  Sound does play however.

  By now I have tried H.264 and mpeg4 with AAC audio and both of them don't play properly on my BB (OS version 6.0).
  I've been using ffmpeg to encode the files.

• Want to convert my 16:9 size MKV video to 4:3 size AVI video file

  19 septembre 2012, par Bimal Rekhadiya

  I have a video in MKV format and it's size is 720x304 (16:9 ratio) size video.

  I want to convert it to AVi format (using xvid video codec). The output file size should be 480x360 (4:3 ratio) and also want to keep the original (16:9) ratio so it should be cinemascope (black areas at top and bottom).

  I am on Ubuntu linux OS so I can use mencoder, avconv(ffmpeg) or any tool that work on Linux.

  I am trying this command :

  avconv -i sample.mkv -vcodec libxvid -r 25 -b 1200 -aspect 4:3 -q 1 t.avi

  But the problem is that the video is stretched to 4:3 and I want to keep original video's ratio and want to add black boxes at top and bottom so it will look cinemascope.

  Please provide me command to do this.