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• movenc : Add a flag for using default-base-is-moof in tfhd atoms

  29 octobre 2014, par Martin Storsjö

  movenc : Add a flag for using default-base-is-moof in tfhd atoms
  Similarly to the omit_tfhd_offset flag added in e7bf085b, this
  
  avoids writing absolute byte positions to the file, making them
  
  more easily streamable.
  This is a new feature from 14496-12:2012, so application support
  
  isn’t necessarily too widespread yet (support for it in libav was
  
  added in 20f95f21f in July 2014).
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DBH] doc/muxers.texi
  • [DBH] libavformat/movenc.c
  • [DBH] libavformat/movenc.h
  • [DBH] libavformat/version.h

• FFmpeg audio channel rematrix (5.1 to stereo)

  29 octobre 2014, par Flock Dawson

  I’ve got a (very large !) Apple ProRes 422 file with 16ch audio. To be able to use it on a less powerful computer, I’d like to convert it to a standard MP4 file (h264 video codec, stereo audio). The original file has 16 channels of audio, however, and FFmpeg gives an error when I try to convert it (’Rematrix is needed’). How do I do rematrixing of audio channels ? Are there additional steps needed ?

  This is the FFmpeg command I used :

  ffmpeg -y -i Capture0000.mov -vcodec libx264 -vb 2000k -pix_fmt yuv420p -coder 0 -profile:v baseline -acodec libfaac -ab 128k /tmp/out.mp4

  This is the FFmpeg output :

  ffmpeg version 2.2.git Copyright (c) 2000-2014 the FFmpeg developers
  
        built on May  8 2014 14:17:45 with gcc 4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5)
  
        configuration: --prefix=/usr/local/ffmpeg_build --extra-cflags=-I/usr/local/ffmpeg_build/include --extra-ldflags=-L/usr/local/ffmpeg_build/lib --bindir=/usr/local/bin --extra-libs=-ldl --enable-gpl --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-nonfree --enable-x11grab --enable-libxvid --enable-libfaac
  
        libavutil      52. 81.100 / 52. 81.100
  
        libavcodec     55. 60.103 / 55. 60.103
  
        libavformat    55. 37.102 / 55. 37.102
  
        libavdevice    55. 13.101 / 55. 13.101
  
        libavfilter     4.  5.100 /  4.  5.100
  
        libswscale      2.  6.100 /  2.  6.100
  
        libswresample   0. 18.100 /  0. 18.100
  
        libpostproc    52.  3.100 / 52.  3.100
  
      Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Capture0000.mov':
  
        Metadata:
  
          creation_time   : 2014-08-17 18:30:31
  
        Duration: 01:01:22.52, start: 0.000000, bitrate: 202001 kb/s
  
          Stream #0:0(eng): Video: prores (apch / 0x68637061), yuv422p10le, 1920x1080, 183513 kb/s, SAR 1:1 DAR 16:9, 25 fps, 25 tbr, 2500 tbn, 2500 tbc (default)
  
          Metadata:
  
            creation_time   : 2014-08-17 18:30:31
  
            handler_name    : Apple Alias Data Handler
  
            encoder         : Apple ProRes 422 (HQ)
  
          Stream #0:1(eng): Audio: pcm_s24le (lpcm / 0x6D63706C), 48000 Hz, 16 channels, s32, 18432 kb/s (default)
  
          Metadata:
  
            creation_time   : 2014-08-17 18:30:31
  
            handler_name    : Apple Alias Data Handler
  
      [auto-inserted resampler 0 @ 0x3943da0] [SWR @ 0x39441a0] Rematrix is needed between 16 channels and 5.1 but there is not enough information to do it
  
      [auto-inserted resampler 0 @ 0x3943da0] Failed to configure output pad on auto-inserted resampler 0
  
      Error opening filters!

  This is the FFprobe output :

  ffprobe version 2.2.git Copyright (c) 2007-2014 the FFmpeg developers
  
    built on May  8 2014 14:17:45 with gcc 4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5)
  
    configuration: --prefix=/usr/local/ffmpeg_build --extra-cflags=-I/usr/local/ffmpeg_build/include --extra-ldflags=-L/usr/local/ffmpeg_build/lib --bindir=/usr/local/bin --extra-libs=-ldl --enable-gpl --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-nonfree --enable-x11grab --enable-libxvid --enable-libfaac
  
    libavutil      52. 81.100 / 52. 81.100
  
    libavcodec     55. 60.103 / 55. 60.103
  
    libavformat    55. 37.102 / 55. 37.102
  
    libavdevice    55. 13.101 / 55. 13.101
  
    libavfilter     4.  5.100 /  4.  5.100
  
    libswscale      2.  6.100 /  2.  6.100
  
    libswresample   0. 18.100 /  0. 18.100
  
    libpostproc    52.  3.100 / 52.  3.100
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Capture0000.mov':
  
    Metadata:
  
      creation_time   : 2014-08-17 18:30:31
  
    Duration: 01:01:22.52, start: 0.000000, bitrate: 202001 kb/s
  
      Stream #0:0(eng): Video: prores (apch / 0x68637061), yuv422p10le, 1920x1080, 183513 kb/s, SAR 1:1 DAR 16:9, 25 fps, 25 tbr, 2500 tbn, 2500 tbc (default)
  
      Metadata:
  
        creation_time   : 2014-08-17 18:30:31
  
        handler_name    : Apple Alias Data Handler
  
        encoder         : Apple ProRes 422 (HQ)
  
      Stream #0:1(eng): Audio: pcm_s24le (lpcm / 0x6D63706C), 48000 Hz, 16 channels, s32, 18432 kb/s (default)
  
      Metadata:
  
        creation_time   : 2014-08-17 18:30:31
  
        handler_name    : Apple Alias Data Handler

• French CNIL recommends Piwik : the only analytics tool that does not require Cookie Consent

  29 octobre 2014, par Matthieu Aubry — Press Releases

  There has been recent and important changes in France regarding data privacy and the use of cookies. This blog post will introduce you to these changes and explain how you make your website compliant.

  Cookie Consent in the data freedom law

  Since the adoption of the EU Directive 2009/136/EC “Telecom Package”, Internet users must be informed and provide their prior consent to the storage of cookies on their computer. The use of cookies for advertising, analytics and social share buttons require the user’s consent :

  It is necessary to inform users of the presence, purpose and duration of the cookies placed in their browsers, and the means at their disposal to oppose it.

  What is a cookie ?

  Cookies are tracers placed on Internet users’ hard drives by the web hosts of the visited website. They allow the website to identify a single user across multiple visits with a unique identifier. Cookies may be used for various purposes : building up a shopping cart, storing a website’s language settings, or targeting advertising by monitoring the user’s web-browsing.

  Which cookies are exempt from the Cookie Consent rule ?

  France has exempted certain cookies from the cookie consent rule : for those cookies that are strictly necessary to offer the service sought after by the user you do not need to ask consent to user. Examples of such cookies are :

  • the shopping cart cookie,
  • authentication cookies,
  • short lived session cookies,
  • load balancer cookies,
  • certain first party analytics (such as Piwik cookies),
  • persistent cookies for interface personalisation.

  Asking users for consent for Analytics (tracking) Cookies

  For all cookies that are not exempted from the Cookie Consent then you will need to :

  • obtain consent from web users before placing or reading cookies and similar technologies,
  • clearly inform web users of the different purposes for which the cookies and similar technologies will be used,
  • propose a real choice to web users between accepting or refusing cookies and similar technologies.

  You don’t need Cookie Consent with Piwik

  The excellent news is that there is a way to bypass the Cookie Consent banner on your website :

  If you are using another analytics solution other than Piwik then you will need to ask users for consent. If you do not want to ask for consent then download and install Piwik or signup to Piwik Cloud to get started.

  If you are already using Piwik you need to do two simple things : (1) anonymise visitor IP addresses (at least two bytes) and (2) include the opt-out iframe solution in your website (learn more).

  Note that these recommendations currently only apply in France, but because the law is European we can expect similar findings in other European countries.

  CNIL recommends Piwik

  We are proud that the CNIL has identified Piwik as the only tool that respects all privacy requirements set by the European Telecom law.

  

  About the CNIL

  The CNIL is an independent administrative body that operates in accordance with the French data protection legislation. The CNIL has been entrusted with the general duty to inform people of the rights that the data protection legislation allows them.

  The role and responsabilities of the CNIL are :

  • to protect citizens and their data
  • to regulate and control processing of personal data
  • to inspect the security of data processing systems and applications, and impose penalties

  Piwik and Privacy

  At Piwik we love Privacy – our open analytics platform comes with built-in Privacy.

  Future of Privacy at Piwik

  Piwik is already the leader when it comes to respecting user privacy but we plan to continue improving privacy within the open analytics platform. For more information and specific ideas see Privacy enhancing issues in our issue tracker.

  References

  Learn more in these articles in French [fr] or English :

  • [fr] Sites web, cookies et autres traceurs
  • [fr] Comment me mettre en conformité avec la recommandation “Cookies” de la CNIL ?
  • [fr] Recommandation sur les cookies : obligations pour les responsables de sites ?
  • CNIL Starts Controlling Cookie Settings in October 2014
  • CNIL recommends Piwik for compliance with data protection laws

  Contact

  To learn more about Piwik, please visit piwik.org,

  Get in touch with the Piwik team : Contact information,

  For professional support contact Piwik PRO.