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• AS3 NetStream AppendBytes Seek issue

  18 novembre 2015, par AntBirch

  I’m having trouble with NetStream in AS3. The project I am working on allows users to browse a video (locally) and play it back. The issue I am having is that netStream.seek(0); from what I can tell it doesn’t do anything, although I get inside a NetStatusEvent function and NetStream.Seek.Notify is triggered. I’m using NativeProcess and the following function is this makes any difference.

  public function ProgressEventOutputHandler(e:ProgressEvent):void {
  
      videoByteArray = new ByteArray();
  
      nativeProcess.standardOutput.readBytes(videoByteArray, 0, nativeProcess.standardOutput.bytesAvailable);
  
      netStream.appendBytes(videoByteArray);
  
  }

  Am I missing something here ? I am pausing netStream before using netStream.seek(0);.

  EDIT :

  In an attempt to fix this issue I followed the instructions by VC.One I’ve done the following :

  • Moved videoByteArray = new ByteArray(); to my init function and also created tempVideoByteArray = new ByteArray(); in this function.

  • Update my ProgressEventOutputHandler function so that it no longer created a new ByteArray for videoByteArray and changed this line - nativeProcess.standardOutput.readBytes(videoByteArray, videoByteArray.length, nativeProcess.standardOutput.bytesAvailable);

  I have changed nothing else and now the video will not load. If I allow a new ByteArray to be created inside the ProgressEventOutputHandler function the video does load again.

• ppc : reduce overreads when loading 8 pixels in altivec dsp functions

  13 février 2014, par Janne Grunau

  ppc : reduce overreads when loading 8 pixels in altivec dsp functions
  Altivec can only load naturally aligned vectors. To handle possibly
  
  unaligned data a second vector is loaded from an offset of the original
  
  location and the data is recovered through a vector permutation.
  
  Overreads are minimal if the offset for second load points to the last
  
  element of data. This is 7 for loading eight 8-bit pixels and overreads
  
  are reduced from 16 bytes to 8 bytes if the pixels are 64-bit aligned.
  
  For unaligned pixels the overread is reduced from 23 bytes to 15 bytes
  
  in the worst case.
  

  • [DBH] libavcodec/ppc/dsputil_altivec.c

• Rotate Android video for display on web

  16 juin 2017, par Kim

  I’m building a website. I’m trying to load my first video onto it. This mp4 video is in portrait orientation and was recorded on an Android device.

  When I load this mp4 onto my website, it plays perfectly (in portrait orientation) on Chrome ; however, it plays in landscape orientation on Firefox & IE. I realise that this is because Chrome is using the rotation metadata that is stored within the mp4 to play the video in the correct orientation, while FF & IE don’t use this metadata.

  I’ve tried to correct this issue using FFMPEG, and various combinations of the Transpose, Metadata & Rotate commands. I am using MediaInfo to view the metadata associated with the files that I produce using FFMPEG.

  My problem is :
  1) If I use Transpose=1, then on FF & IE & Windows Media Player, the resulting video is actually rotated through 180 degrees, and the metadata shows the file width and depth to be the same as the original file.
  2) If I use -metadata:s:v rotate=0 (I’ve also tried rotate=90), then MediaInfo tells me that the resulting files width & depth are now portrait, but FF & IE & WMP will not play the resulting file. WMP plays the sound but no image, and FF gives an error message "Error Loading This Resource".

  What ffmpeg command do I need to use to convert a portrait MP4 recorded an android device into an mp4 that will play in the correct orientation on Firefox ?

  Thanks in advance