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• latency when streaming x264

  18 novembre 2013, par tobsen

  I would like to produce a zerolatency live video stream and play it in VLC player with as little latency as possible.

  This are the settings I currently use :

  x264_param_default_preset( &m_Params, "veryfast", "zerolatency" );
  
  
  
  m_Params.i_threads              =   2;
  
  m_Params.b_sliced_threads       =   true;
  
  m_Params.i_width                =   m_SourceWidth;
  
  m_Params.i_height               =   m_SourceHeight;
  
  
  
  m_Params.b_intra_refresh        =   1;
  
  
  
  m_Params.b_vfr_input            =   true;
  
  m_Params.i_timebase_num         =   1;
  
  m_Params.i_timebase_den         =   1000;
  
  
  
  m_Params.i_fps_num              =   1;
  
  m_Params.i_fps_den              =   60;
  
  
  
  m_Params.rc.i_vbv_max_bitrate   =   512;
  
  m_Params.rc.i_vbv_buffer_size   =   256;
  
  m_Params.rc.f_vbv_buffer_init   =   1.1f;
  
  
  
  m_Params.rc.i_rc_method         =   X264_RC_CRF;
  
  m_Params.rc.f_rf_constant       =   24;
  
  m_Params.rc.f_rf_constant_max   =   35;
  
  
  
  m_Params.b_annexb               =   0;
  
  m_Params.b_repeat_headers       =   0;
  
  m_Params.b_aud                  =   0;
  
  
  
  x264_param_apply_profile( &m_Params, "high" );

  Using those settings, I have the following issues :

  • VLC shows lots of missing frames (see screenshot, "verloren"). I am not sure if this is an issue.
  • If I set a value <200ms for the network stream delay in VLC, VLC renders a few frames and than stops to decode/render frames.
  • If I set a value >= 200ms for the network stream delay in VLC, everything looks good so far but the latency is, obviously, 200ms, which is too high.

  Question :
  Which settings (x264lib and VLC) should I use in order to encode and stream with as little latency as possible ?

  

• latency when streaming x264

  18 novembre 2013, par tobsen

  I would like to produce a zerolatency live video stream and play it in VLC player with as little latency as possible.

  This are the settings I currently use :

  x264_param_default_preset( &m_Params, "veryfast", "zerolatency" );
  
  
  
  m_Params.i_threads              =   2;
  
  m_Params.b_sliced_threads       =   true;
  
  m_Params.i_width                =   m_SourceWidth;
  
  m_Params.i_height               =   m_SourceHeight;
  
  
  
  m_Params.b_intra_refresh        =   1;
  
  
  
  m_Params.b_vfr_input            =   true;
  
  m_Params.i_timebase_num         =   1;
  
  m_Params.i_timebase_den         =   1000;
  
  
  
  m_Params.i_fps_num              =   1;
  
  m_Params.i_fps_den              =   60;
  
  
  
  m_Params.rc.i_vbv_max_bitrate   =   512;
  
  m_Params.rc.i_vbv_buffer_size   =   256;
  
  m_Params.rc.f_vbv_buffer_init   =   1.1f;
  
  
  
  m_Params.rc.i_rc_method         =   X264_RC_CRF;
  
  m_Params.rc.f_rf_constant       =   24;
  
  m_Params.rc.f_rf_constant_max   =   35;
  
  
  
  m_Params.b_annexb               =   0;
  
  m_Params.b_repeat_headers       =   0;
  
  m_Params.b_aud                  =   0;
  
  
  
  x264_param_apply_profile( &m_Params, "high" );

  Using those settings, I have the following issues :

  • VLC shows lots of missing frames (see screenshot, "verloren"). I am not sure if this is an issue.
  • If I set a value <200ms for the network stream delay in VLC, VLC renders a few frames and than stops to decode/render frames.
  • If I set a value >= 200ms for the network stream delay in VLC, everything looks good so far but the latency is, obviously, 200ms, which is too high.

  Question :
  Which settings (x264lib and VLC) should I use in order to encode and stream with as little latency as possible ?

  

• ffmpeg on android : playing MPEG2 TS udp multicast stream

  27 août 2013, par user1513822

  I want to make android media player using ffmpeg.
  (catch MPEG2 TS multicast stream via WIFI network and decode it)
  I checked followings :

  • My iptime AP supports WIFI multicast protocol.
    (send multicast stream in wired PC, and wifi connected PC can receive it)
  • My Android phone can receive multicast stream via WIFI.
    I coded NDK socket programming which is join udp multicast group and receive packets
    (I added multicast access grant to AndroidManifest.xml)
  • FFMPEG library is ported to android and it can play local media file.

  But when I try to open network stream using FFMPEG library, avformat_open_input() function returns fail.

  gFormatCtx = avformat_alloc_context();
  
  av_register_all(); 
  
  avcodec_register_all(); 
  
  avformat_network_init(); 
  
  if(avformat_open_input(&gFormatCtx,"udp://@239.100.100.100:4000",NULL,NULL) != 0)
  
      return -2;

  this code always return "-2".
  If I use "av_dict_set()" api, which option should I use ?

  av_dict_set(&options, "udp_multicast", "mpegtsraw", 0);

  please let me know what should I check for avformat_open_input error ?

  thanks.