Recherche avancée

Sur d’autres sites (7461)

• Join us for the Piwik Community Meetup 2015 !

  25 juin 2015, par Piwik Core Team — Community, Meta

  

  We’re excited to announce that our third Piwik Community Meetup will be held in Berlin on Tuesday, the 4th of August, 2015. Don’t miss this great opportunity to connect with other users and meet the core team behind Piwik. It’s free, so REGISTER TODAY ! And maybe you would like to share your Piwik use case ? We’re also waiting for your presentation ideas.

  We will cover some of the upcoming features, discuss the future of Piwik, share tricks and hacks to help you get the most out of your Piwik platform, and socialise. If you use Piwik to improve your websites and apps, or are just generally curious about digital analytics and marketing – this event is not to be missed. As our core team is scattered all over the world, this will be a rare opportunity for you to meet and talk to us all at once – especially for those of you interested in the platform, integrating your app with Piwik, and building plugins.

  After the official part, we would like to enjoy drinks with all the participants in the nearby bars. We hope you will be able to join us !

  All Piwik community members are warmly invited to take part in the meetup !

  Piwik Community Meetup 2015

  When ?

  Tuesday, the 4th of August, from 5-9pm

  Where ?

  Kulturbrauerei
  Schönhauser Allee
  Prenzlauer Berg area
  Berlin, Germany
  exact directions tbc.

  Languages :

  English and German

  Book tickets :

  BOOK YOUR FREE INVITATION HERE

  Open call for YOUR presentation ideas

  We would also like to hear how you use Piwik – we’ll be delighted if you’d share your interesting use case during the Meetup. Please send your presentation ideas (speaking time : 5 to 7 minutes) to : meetup@piwik.pro ! Deadline : 20th of July 2015.

  Contact the organisers :

  meetup@piwik.pro

• Piwik 3 Development Update #1 – New UI design, API changes & release date

  1er septembre 2016, par Thomas Steur — Community, Development

  Over the last months, we have been actively working on the Piwik 3 release and we want to introduce you to the changes that we have done so far. They include a new and modern UI redesign, new widgets for your dashboard, and technical improvements under the hood.

  New Piwik 3 UI

  Based on Material Design we have revamped the user interface which is now more responsive, more usable and faster. While the UI is not yet finished, we invite you to check it out already and to let us know what you think.

  

  This new Piwik material design is a visual language that synthesizes classic principles of good design with the innovation and possibility of technology and science.

  More responsive

  Piwik 3 will look and feel much better on your mobile phone and tablet. Many elements have been improved : the menus, the segment editor and dashboard selector, the widgets, the settings pages and most other pages so you can fully experience and enjoy Piwik on any device !

  

  Improved usability

  We have updated the menu structure, the dashboard selector as well as the footer in reports to make your life easier when using Piwik. We love to keep these complicated things simple. There are also many other tiny improvements that you will appreciate.

  

  The Zen Mode lets you view in full screen your analytics reports and dashboards. Users love this feature and it can now be accessed by pressing “z” key.

  

  Faster

  To make the Piwik interface faster, we have refactored most of our CSS, HTML and JavaScript and moved more and more of our code into the client. As a result, Piwik now needs to reload the page much less often ! For example when you change the date or change the segment, Piwik will now load the reports instantly. To improve performance even further, Piwik will now load multiple reports on a single page in parallel.

  Native fonts

  Over the last months more and more web services have started using system fonts, and so will Piwik 3. System fonts look better, improve language support and give you a more native, familiar feeling.

  For more details and screenshots have a look at the pull request for the Piwik 3 UI update.

  New widgets

  With the “Latest Piwik Plugin Updates” widget you won’t miss any newly added or updated plugin anymore. This will help you learn about and discover the useful plugins and themes available on the Marketplace.

  

  Super users can now see at a glance the current state of the Piwik system, thanks to the new “System Check” and “System Summary” widgets.

  

  API Changes

  Piwik is the leading open analytics platform, highly customisable and extensible thanks to a flexible plugins architecture and a design based on APIs. In this new major Piwik 3 release, we significantly improve the foundation of our open platform and several of its core APIs.

  The new Widgets and Reporting API makes it possible to add reports and widgets to any existing reporting page. In the past, reporting pages had to be created manually which was time consuming and it was hard to maintain a consistent look across different reporting pages. Now reporting pages are generated automatically by the Piwik platform.

  The Plugin Settings API was changed to improve performance and to let plugin developers customize the Websites Manager. This is one step towards our goal to let users not only manage websites but also mobile apps, cars, coffee machines or any other thing.

  To see a full list of changes in the Piwik 3 analytics platform, have a look at the developer changelog.

  Developer docs

  The Piwik Developer Zone is full of guides and API references to help developers understand, integrate and extend Piwik. As some APIs have changed in the Piwik 3 release it is now possible to select the Piwik version in the top right corner of the developer zone.

  

  We are updating guides for Piwik 3 and added a Piwik 2 -> Piwik 3 Migration Guide for plugin developers. Many other guides were updated such as Menus, Custom Report and Widgets.

  Release date

  The first Piwik 3 beta release will be available in the next four weeks. Beta testers automatically receive the update if they are subscribed to the “Latest Beta” release channel. The final Piwik 3 release will be ready before the end of the year. If you want to give it a try, you can either use Piwik from Git and check out the “3.x-dev” branch, or download Piwik 3 from GitHub.

  Closing thoughts

  With faster & more beautiful reports, better APIs and more stability, Piwik 3 is a big step forward for all Piwik users. As our mission is to create, as a community, the leading international open source web analytics platform that gives every user full control of their data, we are very excited to introduce you to this upcoming release.

  We now offer Custom Development services if you like to sponsor a new feature or bug fix, or if you have any custom requirements. And if you use Piwik Analytics to grow your business and need quality help, contact the Piwik analytics experts to get started.

  Until our next Piwik 3 dev update, Happy analysis !

• Writing opencv frames to avi container using libavformat Custom IO

  16 juillet 2017, par Aryan

  I have to write OpenCV cv::Mat frames to an AVI container. I cannot use OpenCV’s VideoWriter because I do not intend to write the AVI file to disk directly, instead I want to send it to a custom stream, so I have to use ffmpeg/libav. As I have never used ffmpeg before I have taken help from solutions provided here and here, alongwith the ffmpeg documentation.

  I am able to send AVI container packets to my custom output stream as required but the performance is very bad. Specifically, the call to avcodec_encode_video2 is taking too long.

  First, I suspect that due to my inexperience I have misconfigured or wrongly coded something. I am currently working wit 640*480 grayscale frames. On my i.MX6 platform the call to avcodec_encode_video2 is taking about 130ms on average per frame, which is unacceptably slow. Any pointers to an obvious performance killer ??? (i know sws_scale looks useless but it takes negligible time, and might be useful for me later).

  Second, I am using PNG encoder, but that is not required, I would be happy to write uncompressed data if I know how to : If the slowdown is not due to my bad programming, can we just get rid of the encoder and generate uncompressed packets for the avi container ? Or use some encoder that accepts grayscale images and is not that slow ?

  For Initialization and writing of header I am using :

  void MyWriter::WriteHeader()  
  
  {
  
      av_register_all();
  
  
  
      // allocate output format context
  
      if (avformat_alloc_output_context2(&avFmtCtx, NULL, "avi", NULL) < 0) { printf("DATAREC: avformat_alloc_output_context2 failed"); exit(1); }
  
  
  
      // buffer for avio context    
  
      bufSize = 640 * 480 * 4; // Don't know how to derive, but this should be big enough for now
  
      buffer = (unsigned char*)av_malloc(bufSize);
  
      if (!buffer) { printf("DATAREC: Buffer alloc failed"); exit(1); }
  
  
  
      // allocate avio context
  
      avIoCtx = avio_alloc_context(buffer, bufSize, 1, this, NULL, WriteCallbackWrapper, NULL);
  
      if (!avIoCtx) { printf("DATAREC: avio_alloc_context failed"); exit(1); }
  
  
  
      // connect avio context to format context
  
      avFmtCtx->pb = avIoCtx;
  
  
  
      // set custom IO flag
  
      avFmtCtx->flags |= AVFMT_FLAG_CUSTOM_IO;
  
  
  
      // get encoder
  
      encoder = avcodec_find_encoder(AV_CODEC_ID_PNG);
  
      if (!encoder) { printf("DATAREC: avcodec_find_encoder failed"); exit(1); }
  
  
  
      // create new stream
  
      avStream = avformat_new_stream(avFmtCtx, encoder);
  
      if (!avStream) { printf("DATAREC: avformat_new_stream failed"); exit(1); }
  
  
  
      // set stream codec defaults
  
      if (avcodec_get_context_defaults3(avStream->codec, encoder) < 0)  { printf("DATAREC: avcodec_get_context_defaults3 failed"); exit(1); }
  
  
  
     // hardcode settings for now
  
      avStream->codec->pix_fmt = AV_PIX_FMT_GRAY8;
  
      avStream->codec->width = 640;
  
      avStream->codec->height = 480;
  
      avStream->codec->time_base.den = 15;
  
      avStream->codec->time_base.num = 1;
  
      avStream->time_base.den = avStream->codec->time_base.den;
  
      avStream->time_base.num = avStream->codec->time_base.num;
  
      avStream->r_frame_rate.num = avStream->codec->time_base.den;
  
      avStream->r_frame_rate.den = avStream->codec->time_base.num;
  
  
  
      // open encoder    
  
      if (avcodec_open2(avStream->codec, encoder, NULL) < 0) {
  
          printf("DATAREC: Cannot open codec\n");
  
          exit(1);
  
      }
  
  
  
      // write header
  
      if(avformat_write_header(avFmtCtx, NULL) < 0) { printf("DATAREC: avformat_write_header failed\n"); exit(1);}
  
  
  
      // prepare for first frame
  
      framePts = 0;
  
      firstFrame = true; 
  
  }

  After writing the header, the following function is called in a loop for each cv::Mat frame :

  void MyWriter::WriteFrame(cv::Mat& item)
  
  {
  
      if (firstFrame) // do only once, before writing the first frame
  
      {
  
          // allocate frame
  
          frame = av_frame_alloc();
  
          if (!frame) { printf("DATAREC: av_frame_alloc failed"); exit(1); }
  
  
  
          // get size for framebuffer
  
          int picsz = av_image_get_buffer_size(avStream->codec->pix_fmt, avStream->codec->width, avStream->codec->height, 1);
  
  
  
          // allocate frame buffer
  
          framebuf = (unsigned char*)av_malloc(picsz);
  
          if (!framebuf) { printf("DATAREC: fail to alloc framebuf"); exit(1); }
  
  
  
          // set frame width, height, format
  
          frame->width = avStream->codec->width;
  
          frame->height = avStream->codec->height;
  
          frame->format = static_cast<int>(avStream->codec->pix_fmt);
  
  
  
          // set up data pointers and linesizes
  
          if (av_image_fill_arrays(frame->data, frame->linesize, framebuf, avStream->codec->pix_fmt, avStream->codec->width, avStream->codec->height, 1) &lt; 0) { printf("DATAREC: av_image_fill_arrays failed\n"); exit(1);}
  
  
  
          // get sws context
  
          swsctx = sws_getCachedContext(nullptr, avStream->codec->width, avStream->codec->height, avStream->codec->pix_fmt, avStream->codec->width, avStream->codec->height, avStream->codec->pix_fmt, SWS_BICUBIC, nullptr, nullptr, nullptr);
  
          if (!swsctx) { printf("DATAREC: fail to sws_getCachedContext"); exit(1); }
  
  
  
          // done initializing
  
          firstFrame = false; // don't repeat this for the following frames
  
      }
  
  
  
      // call sws scale
  
      const int stride[] = { static_cast<int>(item.step[0]) };
  
      sws_scale(swsctx, &amp;item.data, stride, 0, item.rows, frame->data, frame->linesize);
  
  
  
      // set presentation timestamp
  
      frame->pts = framePts++;
  
  
  
      // initialize packet
  
      av_init_packet(&amp;pkt);
  
      pkt.data = NULL;
  
      pkt.size = 0;
  
  
  
      // THIS TAKES VERY LONG TO EXECUTE
  
      // call encoder, convert frame to packet
  
      if (avcodec_encode_video2(avStream->codec, &amp;pkt, frame, &amp;got_pkt) &lt; 0) { printf("DATAREC: fail to avcodec_encode_video2");  exit(1); }
  
  
  
      write packet if available
  
      if (got_pkt)
  
      {
  
          pkt.duration = 1;
  
          av_write_frame(avFmtCtx, &amp;pkt);
  
      }
  
  
  
      // wipe packet
  
      av_packet_unref(&amp;pkt);
  
  }
  
  </int></int>

  After writing required frames, trailer is written :

  void MyWriter::WriteTrailer()
  
  {
  
      // prepare packet for trailer
  
      av_init_packet(&pkt);
  
      pkt.data = NULL;
  
      pkt.size = 0;
  
  
  
      // encode trailer packet
  
      if (avcodec_encode_video2(avStream->codec, &pkt, nullptr, &got_pkt) < 0) { printf("DATAREC: fail to avcodec_encode_video2");    exit(1); }
  
  
  
      // write trailer packet
  
      if (got_pkt)
  
      {
  
          pkt.duration = 1;
  
          av_write_frame(avFmtCtx, &pkt);
  
      }
  
  
  
      // free everything
  
      av_packet_unref(&pkt);
  
      av_write_trailer(avFmtCtx);
  
      av_frame_free(&frame);
  
      avcodec_close(avStream->codec);
  
      av_free(avIoCtx);
  
      sws_freeContext(swsctx);
  
      avformat_free_context(avFmtCtx);
  
      av_free(framebuf);
  
      av_free(buffer);
  
      firstFrame = true; // for the next file
  
  }

  Many many thanks to everyone who made it down to this line !