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• How to convert H264 RTP stream from PCAP to a playable video file

  21 août 2014, par yoosha

  I have captured stream of H264 in PCAP files and trying to create media files from the data. The container is not important (avi,mp4,mkv,…).
  When I’m using videosnarf or rtpbreak (combined with python code that adds 00 00 00 01 before each packet) and then ffmpeg, the result is OK only if the input frame rate is constant (or near constant). However, when the input is vfr, the result plays too fast (and on same rare cases too slow).
  For example :

  videosnarf -i captured.pcap –c
  ffmpeg -i H264-media-1.264 output.avi

  After doing some investigation of the issue I believe now that since the videosnarf (and rtpbreak) are removing the RTP header from the packets, the timestamp is lost and ffmpeg is referring to the input data as cbr.

  1. I would like to know if there is a way to pass (on a separate file ?)
     the timestamps vector or any other information to ffmpeg so the
     result will be created correctly ?
  2. Is there any other way I can take the data out of the PCAP file and play it or convert it and then play it ?
  3. Since all work is done in Python, any suggestion of libraries/modules that can help with the work (even if requires some codding) is welcome as well.

  Note : All work is done offline, no limitations on the output. It can be cbr/vbr, any playable container and transcoding. The only "limitation" I have : it should all run on linux…

  Thanks
  Y

  Some additional information :
  Since the nothing provides the FFMPEG with the timestamp data, i decided to try a different approach : skip videosnarf and use Python code to pipe the packets directly to ffmpeg (using the "-f -i -" options) but then it refuses to accept it unless I provide an SDP file...
  How do I provide the SDP file ? is it an additional input file ? ("-i config.sdp")

  The following code is an unsuccessful try doing the above :

  import time  
  
  import sys  
  
  import shutil  
  
  import subprocess  
  
  import os  
  
  import dpkt  
  
  
  
  if len(sys.argv) < 2:  
  
      print "argument required!"  
  
      print "txpcap <pcap file="file">"  
  
      sys.exit(2)  
  
  pcap_full_path = sys.argv[1]  
  
  
  
  ffmp_cmd = ['ffmpeg','-loglevel','debug','-y','-i','109c.sdp','-f','rtp','-i','-','-na','-vcodec','copy','p.mp4']  
  
  
  
  ffmpeg_proc = subprocess.Popen(ffmp_cmd,stdout = subprocess.PIPE,stdin = subprocess.PIPE)  
  
  
  
  with open(pcap_full_path, "rb") as pcap_file:  
  
      pcapReader = dpkt.pcap.Reader(pcap_file)  
  
      for ts, data in pcapReader:  
  
          if len(data) &lt; 49:  
  
              continue  
  
          ffmpeg_proc.stdin.write(data[42:])
  
  
  
  sout, err = ffmpeg_proc.communicate()  
  
  print "stdout ---------------------------------------"  
  
  print sout  
  
  print "stderr ---------------------------------------"  
  
  print err  
  
  </pcap>

  In general this will pipe the packets from the PCAP file to the following command :

  ffmpeg -loglevel debug -y -i 109c.sdp -f rtp -i - -na -vcodec copy p.mp4

  SDP file : [RTP includes dynamic payload type # 109, H264]

  v=0
  o=- 0 0 IN IP4 ::1
  s=No Name
  c=IN IP4 ::1
  t=0 0
  a=tool:libavformat 53.32.100
  m=video 0 RTP/AVP 109
  a=rtpmap:109 H264/90000
  a=fmtp:109
  packetization-mode=1 ;profile-level-id=64000c ;sprop-parameter-sets=Z2QADKwkpAeCP6wEQAAAAwBAAAAFI8UKkg==,aMvMsiw= ;
  b=AS:200

  Results :

  ffmpeg version 0.10.2 Copyright (c) 2000-2012 the FFmpeg developers
  built on Mar 20 2012 04:34:50 with gcc 4.4.6 20110731 (Red Hat
  4.4.6-3) configuration : —prefix=/usr —libdir=/usr/lib64 —shlibdir=/usr/lib64 —mandir=/usr/share/man —enable-shared —enable-runtime-cpudetect —enable-gpl —enable-version3 —enable-postproc —enable-avfilter —enable-pthreads —enable-x11grab —enable-vdpau —disable-avisynth —enable-frei0r —enable-libopencv —enable-libdc1394 —enable-libdirac —enable-libgsm —enable-libmp3lame —enable-libnut —enable-libopencore-amrnb —enable-libopencore-amrwb —enable-libopenjpeg —enable-librtmp —enable-libschroedinger —enable-libspeex —enable-libtheora —enable-libvorbis —enable-libvpx —enable-libx264 —enable-libxavs —enable-libxvid —extra-cflags=’-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector —param=ssp-buffer-size=4 -m64 -mtune=generic -fPIC’ —disable-stripping libavutil 51. 35.100 / 51. 35.100 libavcodec 53. 61.100 / 53. 61.100 libavformat 53. 32.100
  / 53. 32.100 libavdevice 53. 4.100 / 53. 4.100
  libavfilter 2. 61.100 / 2. 61.100 libswscale 2. 1.100
  / 2. 1.100 libswresample 0. 6.100 / 0. 6.100
  libpostproc 52. 0.100 / 52. 0.100 [sdp @ 0x15c0c00] Format sdp
  probed with size=2048 and score=50 [sdp @ 0x15c0c00] video codec set
  to : h264 [NULL @ 0x15c7240] RTP Packetization Mode : 1 [NULL @
  0x15c7240] RTP Profile IDC : 64 Profile IOP : 0 Level : c [NULL @
  0x15c7240] Extradata set to 0x15c78e0 (size : 36) !error,_recognition
  separate : 1 ; 1 [h264 @ 0x15c7240] error,_recognition combined : 1 ;
  10001 [sdp @ 0x15c0c00] decoding for stream 0 failed [sdp @
  0x15c0c00] Could not find codec parameters (Video : h264) [sdp @
  0x15c0c00] Estimating duration from bitrate, this may be inaccurate
  109c.sdp : could not find codec parameters Traceback (most recent
  call last) : File "./ffpipe.py", line 26, in
  ffmpeg_proc.stdin.write(data[42 :]) IOError : [Errno 32] Broken pipe

  (forgive the mass above, the editor keep on complaining about code that is not indented OK ??)

  I’m working on this issue for days... any help/suggestion/hint will be appreciated.

• I need to build web service that receive video files, and encode these files using ffmpeg API [on hold]

  19 août 2015, par jobin

  I need to build web service that receive video files, and encode these files using ffmpeg API.

  from where I should start ?

  Note : I need to host this service on windows server.

• A *hot* Piwik Community Meetup 2015 !

  10 août 2015 — Community

  Last weekend I arrived in Germany to attend the Piwik Community Meetup 2015 and now I am in Poland. I joined Piwik PRO back in May as enterprise support project coordinator in North America. I am now writing this from the Piwik PRO main office in Wrocław, where I’ll be working from for the next two weeks.

  The meetup was HOT in every sense ! Berlin temperatures reached 35 degrees (celsius), as I finally meet in person several long-time, dedicated Piwik community contributors.

  

  Meetup preparation in Berlin, photo by M. Zawadziński, licensed under CC-BY-SA 4.0

  Pictures from the meetup preparation sessions
  

  In the first leg of my trip I was in Berlin to meet Piwik community members and Piwik PRO staff to prepare for the 2015 annual Piwik community meetup. These are my notes taken during the meeting at the request of one of my colleagues. I also relayed live on Framasphère, Twitter and IRC.

  

  Community discussion at the meetup, photo by D.Czajka, licensed under CC-BY-SA 4.0

  More pictures from the Piwik meetup
  

  This was harder than I expected, as I took notes with my laptop, pictures with my phone, wrote live to social media (using the Android Diaspora Native Web App), and used my laptop to relay on IRC. Going forward this requires better preparation, I was glad I had a few links and pictures ready before hand but it really requires intense focus to achieve this. I am glad presenters were patient when I requested repeating some of the ideas they shared. I am also a bit disappointed not much happened in IRC.

  Two day preparation sessions

  The discussions and session we had during the two days prior to the meetup are available here.

  We gathered in rented apartments in Berlin, this reminded me very much of similar community gatherings and perhaps of BarCamp and, at a much smaller scale, UDS sessions.

  

  Piwik Pizza !, photo by F. Rodríguez, licensed under CC-BY-SA 4.0

  A list of ideas of topics was initially submitted, we then proceeded to have scheduled sessions for open discussion. Several people shared their concern there was no possible remote participation which led to making public the Trello boards used/linked here.

  Note : The Trello links below still have action items and notes that are pending bug report / feature requests filing which should happen over the coming weeks. Most importantly, many action items will need identifying leads for different community team including Translations and Documentation, and better coordination of coming community engagement.

  Monday sessions consisted of the following subjects :

  • What are Piwik values & how to communicate them ? (see below for details)
  • How to encourage and recognize new external contributors ?
  • How could we double the Piwik userbase ?
  • How Community can organise help resources

  On Tuesday we met again to discuss the following subjects :

  • Piwik Long Term support (LTS)
  • How do Piwik.org (project) and Piwik PRO (company) sit together / are organized ? – An important part of this session was about having better communication channels and improving the new team page (bug #8520 and bug #8519, respectively)
  • Improving usability of Piwik e.g. for new users – this last session was not held has we ran out of time and prepared to go to the meetup venue.

  Some more details about individual preparation sessions

  What are Piwik values & how to communicate them ?

  The main subjects in this session were important changes proposed in the project mission and values. This was edited directly on on the wiki page on GitHub, some of the changes can be seen by comparing revisions.

  Piwik mission statement (bug #7376)

  “To create the leading Free and open source analytics platform, and to support global organisations and communities to keep full control over their data.”

  Our values

  • Openness
  • Freedom
  • Transparency
  • Data ownership
  • Privacy
  • Kaizen (改善) : continuous improvement

  This was also presented by Matthieu Aubry at the meetup and is published in the Roadmap page. Bringing more visibility and perhaps having a top page for Mission and Values was also brought up.

  Meetup agenda and notes

  The official agenda is available here.

  Many Piwik PRO employees stayed in Berlin for the meetup, and we had good participation although less than last year in Munich as my colleagues told me. Some were consultants, others staff from public organizations, universities, etc. In retrospect considering the very hot weather and summer holidays the attendance was good. I was very happy to arrive at the beautiful Kulturbrauerei and enter the air-conditioned Soda Club. T-Shirts were waiting for all attendees and free drinks (non-alcohol !) were welcome