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• Buffering while converting stream to frames with ffmpeg

  7 mars 2016, par Pavel K.

  I am trying to convert udp stream into frames using ffmpeg. I run following command :

  ffmpeg -loglevel debug -strict 2 -re -i "udp://192.168.15.50:3200?fifo_size=1000000&overrun_nonfatal=1" -r 8 -vf scale=432:243 -f image2pipe -vcodec ppm pipe:1

  It happens with different stream types, mpeg2video and h264. Cpu load for core processing this specific stream is under 30%, its low quality sd stream with resolution of 640x576.

  It works well for the most time, however sometimes, once in a while, latency occurs and frames arrive later. So i want exactly 8 fps but sometime i get less, sometimes more.

  Why does this latency occur and how can i reduce it ?

  update : i tried changing it to :

  ffmpeg -loglevel debug -i "udp://192.168.15.50:3200?fifo_size=1000000&overrun_nonfatal=1" -r 8 -preset ultrafast -fflags nobuffer -vf scale=432:243 -f image2pipe -vcodec ppm pipe:1

  But i still get the issue. For example, in ffmpeg log i get :

  [2016/02/11 13:32:30] frame= 7477 fps=8.0 q=-0.0 size= 2299638kB time=00:15:34.62 bitrate=20156.4kbits/s dup=7 drop=15867 ^M*** dropping frame 7477 from stream 0 at ts 7475
  
  [2016/02/11 13:32:30] ***dropping frame 7477 from stream 0 at ts 7476
  
  [2016/02/11 13:32:30] ***dropping frame 7478 from stream 0 at ts 7476
  
  [2016/02/11 13:32:32] Last message repeated 1 times
  
  [2016/02/11 13:32:32] frame= 7479 fps=8.0 q=-0.0 size= 2300253kB time=00:15:34.87 bitrate=20156.4kbits/s dup=7 drop=15871 ^M*** dropping frame 7479 from stream 0 at ts 7477

  As you can see, during second 31, no frames are output... and ffmpeg reported time between two frames is 0.25s

• Senior Software Engineer for Enterprise Analytics Platform

  28 janvier 2016, par Matthieu Aubry — Jobs

  We’re looking for a lead developer to work on Piwik Analytics core platform software. We have some exciting challenges to solve and need you !

  You’ll be working with both fellow employees and our open-source community. Piwik PRO staff lives in New Zealand, Europe (Poland, Germany) and in the U.S. We do the vast majority of our collaboration online.

  We are a small, flexible team, so when you come aboard, you will play an integral part in engineering. As a leader you’ll help us to prioritise work and grow our community. You’ll help to create a welcoming environment for new contributors and set an example with your development practices and communications skills. You will be working closely with our CTO to build a future for Piwik.

  Key Responsibilities

  • Strong competency coding in PHP and JavaScript.
  • Scaling existing backend system to handle ever increasing amounts of traffic and new product requirements.
  • Outstanding communication and collaboration skills.
  • Drive development and documentation of internal and external APIs (Piwik is an open platform).
  • Help make our development practices better and reduce friction from idea to deployment.
  • Mentor junior engineers and set the stage for personal growth.

  Minimum qualifications

  • 5+ years of experience in product development, security, usable interface design.
  • 5+ years experience building successful production software systems.
  • Strong competency in PHP5 and JavaScript application development.
  • Skill at writing tests and reviewing code.
  • Strong analytical skills.

  Location

  • Remote work position !
  • or you can join us in our office based in Wellington, New Zealand or in Wrocław, Poland.

  Benefits

  • Competitive salary.
  • Equity in Piwik PRO.
  • Remote work is possible.
  • Yearly meetup with the whole team abroad.
  • Be part of a successful open source company and community.
  • In our Wellington (NZ) and Wroclaw (PL) offices : snacks, coffee, nap room, Table football, Ping pong…
  • Regular events.
  • Great team of people.
  • Exciting projects.

  Learn more

  Learn more what it’s like to work on Piwik in our blog post

  About Piwik

  At Piwik and Piwik PRO we develop the leading open source web analytics platform, used by more than one million websites worldwide. Our vision is to help the world liberate their analytics data by building the best open alternative to Google Analytics.

  The Piwik platform collects, stores and processes a lot of information : hundreds of millions of data points each month. We create intuitive, simple and beautiful reports that delight our users.

  About Piwik PRO company

  At Piwik PRO we’re solving hard problems with simple solutions that make our users and customers happy. We practise agile methodology, test driven development and fast release cycles. Our backend is mostly built in modern PHP with a bit of Python. We use MySQL/MariaDB and Redis as data stores. Our frontends is built in JavaScript using AngularJS and jQuery. Our tools include Github, Travis CI, PhpStorm and Slack.

  As a Lead Software Developer for Piwik PRO, you will be writing open source code that will run on more than 200,000 servers and be used in 200+ countries and 50 languages !

  Apply online

  To apply for this position, please Apply online here. We look forward to receiving your applications !

• How to ffmpeg resize 2.7k DJI Phantom Standard video to 1080p good quality ?

  23 mai 2016, par augre

  ffmpeg -i :

  Duration: 00:01:59.99, start: 0.000000, bitrate: 39988 kb/s
  
  Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 2704x1520 [SAR 1:1 DAR 169:95], 39984 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
  
  Metadata:
  
    creation_time   : 2016-05-22 11:04:26
  
    handler_name    : DJI.AVC
  
    encoder         : Dji AVC encoder

  I used :

  ffmpeg -i DJI_0002.MOV -vf scale=1920:1080 DJI_0002FullHD.MOV

  But the output quality is much worse than it should be.

  How to improve the quality ?