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• Native function in Vitamio

  1er août 2014, par hclee

  I am now looking the code beind the Vitamio (media framework) cause I want to know what API does it use to retrieve the buffer percentage/download rate and how it interect with the android OS to retrieve other information about the streaming video.

  But I realized that it does use some native functions which enable it use some code written in C/C++ language.

  I try to investigate on the C++ code but I don’t know where are they.
  I guessed they are stored inside the res/raw/librarm.so.
  I unzipped the file but all I can find is some machine code but what I want is the implementation of the native function.

  For example, I want to know the implementation of the following function :

  public native int getVideoTrack() ; // What is this function for ? What does it mean by the track
  // number of a straming video ?

  or

  private static native boolean loadFFmpeg_native(String ffmpegPath) ;

  and when will this function be called :

  private static void postEventFromNative(Object mediaplayer_ref, int what, int arg1, int arg2, Object obj)

  Do anyone know where can I investigate the implementation of such native function.
  It should be some C++ code but I don’t want machine code...

  I went to
  https://www.vitamio.org/en/2013/Tutorial_0509/13.html

  but they didn’t have the thing that I want

  Thanks in advance !!!

• broadcast HLS/TS Stream from FFMPEG

  2 août 2014, par Dylan Lundy

  I’m still wrapping my head around most of this, so sorry if my issue is an obvious one !

  I’m trying to broadcast a FFMPEG ’stream’ to a HLS stream i can load into a webpage.

  My understanding is that i need a media server to broadcast it from FFMPEG to a HLS stream ? with FFMPEG feeding the data to the server. I’m probably wrong though.

  I previously semi achieved what i want to do with stream-m, however it was too slow (less than 1 FPS) and wasn’t broadcasting in HLS.

  Previously, the steps i went through were to launch the stream-m server. then launce FFMPEG with the following command :

  ffmpeg.exe -f dshow -i video="screen-capture-recorder" -r 1 -g 2 -vcodec libvpx -vb 1024 -f matroska http://localhost:8080/publish/first?password=secret

  I could connect to the stream with Chrome using the following HTML :

  <video src="http://localhost/consume" autoplay="autoplay">
  
  </video>

  The issue is that this was slow, unusable in fact, and it’s not in HLS/H264.

  I need the feed in the specific codec as i intend to send it to a WiiU browser, which only supports "M3U8+TS(HTTPLiveStreaming)"
  http://www.nintendo.com/wiiu/built-in-software/browser-specs/

  Cheers

• How to decode a H.264 frame on iOS by hardware decoding ?

  23 septembre 2015, par ChihHao

  I have been used ffmpeg to decode every single frame that I received from my ip cam. The brief code looks like this :

  -(void) decodeFrame:(unsigned char *)frameData frameSize:(int)frameSize{
  
     AVFrame frame;
  
     AVPicture picture;
  
     AVPacket pkt;
  
     AVCodecContext *context;
  
     pkt.data = frameData;
  
     pat.size = frameSize;
  
     avcodec_get_frame_defaults(&frame);
  
     avpicture_alloc(&picture, PIX_FMT_RGB24, targetWidth, targetHeight);
  
     avcodec_decode_video2(&context, &frame, &got_picture, &pkt);
  
  }

  The code woks fine, but it’s software decoding. I want to enhance the decoding performance by hardware decoding. After lots of research, I know it may be achieved by AVFoundation framework.
  The AVAssetReader class may help, but I can’t figure out what’s the next.Could anyone points out the following steps for me ? Any help would be appreciated.