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• FFmpeg recording h264 to a circular buffer "Packet header not contained in global..."

  25 novembre 2015, par user15941

  I’ve made a class which captures a RTSP h264 stream and stores its Packets in a circular buffer. On demand the content of the buffer is dumped to a file with header and trailer. I based the code mainly on : this question example, but by trial and error I came up with three modifications :

  1. I use wrapping object for AVPacket not to bother with memory deallocation.
  2. I convert the data with a filter : "h264_mp4toannexb", so the result file is in .ts format.
  3. I wait in a loop to get a key-frame before any push_back() to circular buffer.

  However something’s wrong with the framerate. The only player, that opens my videos correctly is mplayer. VLC and other players I tested show all the frames in one second.

  ffmpeg lib also reports a lot of error messages : "Packet header is not contained in global metadata", but I don’t know whether the information is held in that header or in some other place ?

  With this code I assign consecutive pts and dts. Then every packet is stored in the circular buffer.

  packet.pts = idx++;
  
  packet.dts = packet.pts;
  
  if (cbuf_mutex.try_lock()) {
  
      cbuf.push_back(PACKET(&packet));
  
      captured_frames++;
  
      if (captured_frames > CBUF_SIZE)
  
          captured_frames = CBUF_SIZE;
  
      cbuf_mutex.unlock();
  
  }
  
  else {
  
      syslog(LOG_ERR, "Buffer mutex was locked - packet skipped");
  
  }

  PACKET class implements copying of the data.
  Is there something missing, which may cause the errors ?

  PACKET::PACKET(const PACKET& rhs)
  
  {
  
      av_new_packet(&packet, rhs.packet.size);
  
      av_copy_packet(&packet, &rhs.packet);
  
  }
  
  
  
  PACKET& PACKET::operator=(const PACKET& rhs)
  
  {
  
      if (&rhs == this)
  
          return *this;
  
      av_free_packet(&packet);
  
      av_new_packet(&packet, rhs.packet.size);
  
      av_copy_packet(&packet, &rhs.packet);
  
      return *this;
  
  }

• Attempting to Process.Start("ffmpeg.exe") ; unhandled exception [duplicate]

  7 janvier 2016, par hallwayRaptor

  This question already has an answer here :

  • Can Process.Start() take the system PATH into account ?
    
    7 answers
    

  I’m attempting to create a Windows Forms Application that will

  Process.Start("ffmpeg.exe");

  I’ve added the path (C :\Program Files (x86)\ffmpeg\bin) in the environment variables in Windows, and I can launch ffmpeg from anywhere in the CMD prompt with just ffmpeg or ffmpeg.exe.

  When I change the line to open something else that I’ve added to the environment variables manually such as Livestreamer the application launches no problem.

  It’s driving me crazy trying to figure out why this particular executable won’t launch when others that have been added the exact same way launch without problem.

  An unhandled exception of type ’System.ComponentModel.Win32Exception’
  occurred in System.dll

• "Amix" and "adelay" combined leads to "Error while filtering : Cannot allocate memory"

  10 février 2016, par Harald Nordgren

  I was trying to add to audio clips together (using amix) while delaying one of them (with adelay). I used the following command

  ffmpeg -i org/onclassical_demo_luisi_chopin_scherzo_2_31_small-version_ii-ending.wav \
  
  -i org/all_u_had_2_say.wav -filter_complex \
  
  "[1]adelay=1000[del1];[0][del1]amix" out.wav

  and get the following output

  ffmpeg version N-77387-g9d38f06 Copyright (c) 2000-2015 the FFmpeg developers
  
    built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04)
  
    configuration: --enable-libmp3lame --enable-gpl --enable-libx264 --enable-libx265
  
    libavutil      55. 11.100 / 55. 11.100
  
    libavcodec     57. 18.100 / 57. 18.100
  
    libavformat    57. 20.100 / 57. 20.100
  
    libavdevice    57.  0.100 / 57.  0.100
  
    libavfilter     6. 21.100 /  6. 21.100
  
    libswscale      4.  0.100 /  4.  0.100
  
    libswresample   2.  0.101 /  2.  0.101
  
    libpostproc    54.  0.100 / 54.  0.100
  
  Guessed Channel Layout for  Input Stream #0.0 : stereo
  
  Input #0, wav, from 'org/onclassical_demo_luisi_chopin_scherzo_2_31_small-version_ii-ending.wav':
  
    Duration: 00:02:18.26, bitrate: 1411 kb/s
  
      Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, 2 channels, s16, 1411 kb/s
  
  Guessed Channel Layout for  Input Stream #1.0 : mono
  
  Input #1, wav, from 'org/all_u_had_2_say.wav':
  
    Duration: 00:00:03.85, bitrate: 88 kb/s
  
      Stream #1:0: Audio: pcm_u8 ([1][0][0][0] / 0x0001), 11025 Hz, 1 channels, u8, 88 kb/s
  
  Output #0, wav, to 'out.wav':
  
    Metadata:
  
      ISFT            : Lavf57.20.100
  
      Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 11025 Hz, mono, s16, 176 kb/s (default)
  
      Metadata:
  
        encoder         : Lavc57.18.100 pcm_s16le
  
  Stream mapping:
  
    Stream #0:0 (pcm_s16le) -> amix:input0
  
    Stream #1:0 (pcm_u8) -> adelay
  
    amix -> Stream #0:0 (pcm_s16le)
  
  Press [q] to stop, [?] for help
  
  Error while filtering: Cannot allocate memory
  
  size=      83kB time=00:00:03.85 bitrate= 176.6kbits/s speed= 213x    
  
  video:0kB audio:83kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.091808%

  Maybe there is some incompatibility between the streams (pcm_s16le, 44100 Hz, 2 channels vs. pcm_u8, 11025 Hz, 1 channel) that need to be handled first, but running only amix works so that doesn’t actually seem to be the case.