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• Announcement : Piwik to focus on Reliability, Performance and Security

  7 octobre 2014, par Matthieu Aubry — About, Community

  To our valued team and community,

  Well, we have moved fast and achieved so much during the past few months. Relentlessly releasing major version after major version… We got a lot done including several major new features !

  The speed of adding new features was a great showcase of how agile our small teams and the larger community are. And I’m so proud to see automated testing becoming common practice among everyone hacking on Piwik !

  For the next few months until the new year we will focus on making what we have better. We will fix those rare but longstanding critical bugs, and aim to solve all Major issues and other must-have performance and general improvements. The core team and Piwik PRO will have the vision of making the existing Piwik and all plugins very stable and risk free. This includes edge cases, general bugs but also specific performance issues for high traffic or issues with edge case data payloads.

  We’ll be more pro-active and take Piwik platform to the next level of Performance, Security, Privacy & Reliability ! We will prove to the world that Free/Libre Web software can be of the highest standard of quality. By focusing on quality we will make Piwik even easier to maintain and improve in the future. We are building the best open platform that will let every user liberate their data and keep full control of it.

  If you have any feedback or questions get in touch or let’s continue the discussion in the forum.

  Thank you for your trust and for liberating your data with Piwik,

  Matthieu Aubry
  Piwik founder

  More information

  • How long is each release of Piwik maintained for ? (FAQ)
  • When is the next release of Piwik ? What is the release schedule ? (FAQ)
  • Pulse of Piwik : our monthly pulse report shows 27 different people contributed to Piwik core in the last month !

  

  This is an amazing testament of the power of free/libre software and yet we think this is just the beginning. We hope more developers will join and contribute to the Piwik project !

• swresample/resample : speed up build_filter by 50%

  4 novembre 2015, par Ganesh Ajjanagadde

  swresample/resample : speed up build_filter by 50%
  This speeds up build_filter by 50%. This gain should be pretty
  
  consistent across all architectures and platforms.
  Essentially, this relies on a observation that the filters have some
  
  even/odd symmetry that may be exploited during the construction of the
  
  polyphase filter bank. In particular, phases (scaled to [0, 1]) in [0.5, 1] are
  
  easily derived from [0, 0.5] and expensive reevaluation of function
  
  points are unnecessary. This requires some rather annoying even/odd
  
  bookkeeping as can be seen from the patch.
  I vaguely recall from signal processing theory more general symmetries allowing even greater
  
  optimization of the construction. At a high level, "even functions"
  
  correspond to 2, and one can imagine variations. Nevertheless, for the sake
  
  of some generality and because of existing filters, this is all that is
  
  being exploited.
  Currently, this patch relies on phase_count being even or (trivially) 1,
  
  though this is not an inherent limitation to the approach. This
  
  assumption is safe as phase_count is 1 << phase_bits, and is hence a
  
  power of two. There is no way for user API to set it to a nontrivial odd
  
  number. This assumption has been placed as an assert in the code.
  To repeat, this assumes even symmetry of the filters, which is the most common
  
  way to get generalized linear phase anyway and is true of all currently
  
  supported filters.
  As a side note, accuracy should be identical or perhaps slightly better
  
  due to this "forcing" filter symmetries leading to a better phase
  
  characteristic. As before, I can’t test this claim easily, though it may
  
  be of interest.
  Patch tested with FATE.
  Sample benchmark (x86-64, Haswell, GNU/Linux) :
  test : swr-resample-dblp-44100-2626
  new :
  
  527376779 decicycles in build_filter(loop 1000),     256 runs,      0 skips
  
  524361765 decicycles in build_filter(loop 1000),     512 runs,      0 skips
  
  516552574 decicycles in build_filter(loop 1000),    1024 runs,      0 skips
  old :
  
  974178658 decicycles in build_filter(loop 1000),     256 runs,      0 skips
  
  972794408 decicycles in build_filter(loop 1000),     512 runs,      0 skips
  
  954350046 decicycles in build_filter(loop 1000),    1024 runs,      0 skips
  Note that lower level optimizations are entirely possible, I focussed on
  
  getting the high level semantics correct. In any case, this should
  
  provide a good foundation.
  Reviewed-by : Michael Niedermayer <michael@niedermayer.cc>
  
  Signed-off-by : Ganesh Ajjanagadde <gajjanagadde@gmail.com>
  

  • [DH] libswresample/resample.c

• Error recording an RTSP stream without transcoding

  23 août 2017, par Matt

  I’m trying to use FFmpeg to record RTSP streams from several security cameras. I have been successfully transcoding each stream for months now, but since this requires considerable CPU power, I’d like to simply copy each stream to disk in it’s original H.264 format.

  Whenever I try this, I receive and error similar to this (the "current" value varies) :

  Non-monotonous DTS in output stream 0:0 ; previous : 0, current : -62743 ;

  I’ve stripped most of the options I was using, although I really do want to keep -xerror so that FFmpeg quits when it encounters an error :

  ffmpeg.exe -xerror -i rtsp://admin:admin@192.168.1.135 -an -vcodec copy test.mp4

  And I still get this :

      ffmpeg version 3.3.3 Copyright (c) 2000-2017 the FFmpeg developers  
      built with gcc 7.1.0 (GCC)   
      configuration : —enable-gpl
      —enable-version3 —enable-cuda —enable-cuvid —enable-d3d11va —enable-dxva2 —enable-libmfx —enable-nvenc —enable-avisynth —enable-bzlib —enable-fontconfig —enable-frei0r —enable-gnutls —enable-iconv —enable-libass —enable-libbluray —enable-libbs2b —enable-libcaca —enable-libfreetype —enable-libgme —enable-libgsm —enable-libilbc —enable-libmodplug —enable-libmp3lame —enable-libopencore-amrnb —enable-libopencore-amrwb —enable-libopenh264 —enable-libopenjpeg —enable-libopus —enable-librtmp —enable-libsnappy —enable-libsoxr —enable-libspeex —enable-libtheora —enable-libtwolame —enable-libvidstab —enable-libvo-amrwbenc —enable-libvorbis —enable-libvpx —enable-libwavpack —enable-libwebp —enable-libx264 —enable-libx265 —enable-libxavs —enable-libxvid —enable-libzimg —enable-lzma —enable-zlib   
      libavutil      55. 58.100 / 55. 58.100   
      libavcodec     57. 89.100 / 57. 89.100   
      libavformat    57. 71.100 / 57. 71.100   
      libavdevice    57.  6.100 / 57.  6.100   
      libavfilter     6. 82.100 / 6. 82.100   
      libswscale      4.  6.100 / 4.  6.100  
      libswresample   2.  7.100 / 2.  7.100   
      libpostproc    54.  5.100 / 54.  5.100
      [udp @ 0000000002533b60] ’circular_buffer_size’ option was set but it is not supported on this build (pthread support is required) 
      [udp @ 0000000000ec97a0] ’circular_buffer_size’ option was set but it is not supported on this build (pthread support is required) 
      Input #0, rtsp, from ’rtsp ://admin:admin@192.168.1.135’ :   Metadata :
          title : RTSP Session/2.0   Duration : N/A, start : 0.837144, bitrate : N/A
          Stream #0:0 : Video : h264 (High), yuvj420p(pc, bt709, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 7 fps, 25 tbr, 90k tbn, 14 tbc Output
      #0, mp4, to ’test.mp4’ :   Metadata :
          title : RTSP Session/2.0
      y    encoder : Lavf57.71.100
          Stream #0:0 : Video : h264 (High) ([33][0][0][0] / 0x0021), yuvj420p(pc, bt709, progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 7 fps, 25 tbr, 90k tbn, 90k tbc 
      Stream mapping :   Stream #0:0 -> #0:0 (copy) 
      Press [q] to stop, [?] for help
      [mp4 @ 00000000036b8340] Non-monotonous DTS in output stream 0:0 ; previous : 0, current : -62743 ; aborting.
      Conversion failed !
  

  Can anyone explain what the problem is and/or suggest the appropriate flags to handle this ?