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• Live Streaming RTMP to RTSP

  19 septembre 2013, par user2794054

  i need to test a restream work like this.
  now i m using crtmpserver. i want to restream rtmp live source to iis smooth streaming format & rtsp format. Please guide me
  rtmp live to rtsp live
  &
  rtmp to live http streaming (target IIS server)

  Thanks

• Streaming Audio with OpenAL and FFMPEG

  28 janvier 2013, par Michael Barth

  Alright, basically I'm working on a simple video player and I'll probably be asking another question about lagging video\syncing to audio later, but for now I'm having a problem with audio. What I've managed to do to is go through all of the audio frames of a video and add them to a vector buffer then play the audio from that buffer using OpenAL.

  This is inefficient and memory hogging and so I need to be able stream it using what I guess is called a rotating buffer. I've ran into problems, one being that there's not a lot of information on streaming with OpenAL let alone the proper way to decode audio with FFMPEG and pipe it to OpenAL. I'm even less comfortable using a vector for my buffer because I honestly have no idea how vectors work in C++, but I some how managed to pull something out of my head to make it work.

  Currently I have a Video class that looks like this :

  class Video
  
  {
  
      public:
  
          Video(string MOV);
  
          ~Video();
  
          bool HasError();
  
          string GetError();
  
          void UpdateVideo();
  
          void RenderToQuad(float Width, float Height);
  
          void CleanTexture();
  
      private:
  
          string FileName;
  
          bool Error;
  
          int videoStream, audioStream, FrameFinished, ErrorLevel;
  
          AVPacket packet;
  
          AVFormatContext *pFormatCtx;
  
          AVCodecContext *pCodecCtx, *aCodecCtx;
  
          AVCodec *pCodec, *aCodec;
  
          AVFrame *pFrame, *pFrameRGB, *aFrame;
  
  
  
          GLuint VideoTexture;
  
          struct SwsContext* swsContext;
  
  
  
          ALint state;
  
          ALuint bufferID, sourceID;
  
          ALenum format;
  
          ALsizei freq;
  
  
  
          vector  bufferData;
  
  };

  The bottom private variables are the relevant ones. Currently I'm decoding audio in the class constructor to an AVFrame and adding the data to bufferData like so :

      av_init_packet(&packet);
  
  
  
      alGenBuffers(1, &bufferID);
  
      alGenSources(1, &sourceID);
  
  
  
      alListener3f(AL_POSITION, 0.0f, 0.0f, 0.0f);
  
  
  
      int GotFrame = 0;
  
  
  
      freq = aCodecCtx->sample_rate;
  
      if (aCodecCtx->channels == 1)
  
          format = AL_FORMAT_MONO16;
  
      else
  
          format = AL_FORMAT_STEREO16;
  
  
  
      while (av_read_frame(pFormatCtx, &packet) >= 0)
  
      {
  
          if (packet.stream_index == audioStream)
  
          {
  
              avcodec_decode_audio4(aCodecCtx, aFrame, &GotFrame, &packet);
  
              bufferData.insert(bufferData.end(), aFrame->data[0], aFrame->data[0] + aFrame->linesize[0]);
  
              av_free_packet(&packet);
  
          }
  
      }
  
      av_seek_frame(pFormatCtx, audioStream, 0, AVSEEK_FLAG_BACKWARD);
  
  
  
      alBufferData(bufferID, format, &amp;bufferData[0], static_cast<alsizei>(bufferData.size()), freq);
  
  
  
      alSourcei(sourceID, AL_BUFFER, bufferID);
  
  </alsizei>

  In my UpdateVideo() is where I'm decoding video to an OpenGL texture through the video stream, so it would make sense for me to decode my audio there and stream it :

  void Video::UpdateVideo()
  
  {
  
      alGetSourcei(sourceID, AL_SOURCE_STATE, &state);
  
      if (state != AL_PLAYING)
  
          alSourcePlay(sourceID);
  
      if (av_read_frame(pFormatCtx, &packet) >= 0)
  
      {
  
          if (packet.stream_index == videoStream)
  
          {
  
              avcodec_decode_video2(pCodecCtx, pFrame, &FrameFinished, &packet);
  
              if (FrameFinished)
  
              {
  
                  sws_scale(swsContext, pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameRGB->data, pFrameRGB->linesize);
  
                  av_free_packet(&packet);
  
              }
  
          }
  
          else if (packet.stream_index == audioStream)
  
          {
  
              /*
  
              avcodec_decode_audio4(aCodecCtx, aFrame, &FrameFinishd, &packet);
  
              if (FrameFinished)
  
              {
  
                  //Update Audio and rotate buffers here!
  
              }
  
              */
  
          }
  
          glGenTextures(1, &VideoTexture);
  
          glBindTexture(GL_TEXTURE_2D, VideoTexture);
  
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
  
          glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  
          glTexImage2D(GL_TEXTURE_2D, 0, 3, pCodecCtx->width, pCodecCtx->height, 0, GL_RGB, GL_UNSIGNED_BYTE, pFrameRGB->data[0]);
  
      }
  
      else
  
      {
  
          av_seek_frame(pFormatCtx, videoStream, 0, AVSEEK_FLAG_BACKWARD);
  
      }
  
  }

  So I guess the big question is how do I do it ? I've got no clue. Any help is appreciated, thank you !

• FFMPEG multi bitrate wowza live streaming keyframe alignment

  27 septembre 2013, par Michael Dietriech

  I tried live streaming with ffmpeg to wowza but even though i use -r 25 -g 50 -keyint_min 50 -sc_threshold 0, the keyframes don't seem to be aligned at the same place of the stream for all the outputs so when Wowza makes chunks for HLS out of it, the keyframes don't get alligned at the beginning of each chunk.

  Any suggestions ?