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• avformat/matroskaenc : Don't override samplerate for CodecDelay

  29 août 2022, par Andreas Rheinhardt

  avformat/matroskaenc : Don't override samplerate for CodecDelay
  Opus can be decoded to multiple samplerates (namely 48kHz, 24KHz,
  
  16Khz, 12 KHz and 8Khz) ; libopus as well as our encoder wrapper
  
  support these sample rates. The OpusHead contains a field for
  
  this original samplerate. Yet the pre-skip (and the granule-position
  
  in the Ogg-Opus mapping in general) are always in the 48KHz clock,
  
  irrespective of the original sample rate.
  Before commit c3c22bee6362737cf290929b7f31df9fb88da983, our libopus
  
  encoder was buggy : It did not account for the fact that the pre-skip
  
  field is always according to a 48kHz clock and wrote a too small
  
  value in case one uses the encoder with a sample rate other than 48kHz ;
  
  this discrepancy between CodecDelay and OpusHead led to Firefox
  
  rejecting such streams.
  In order to account for that, said commit made the muxer always use
  
  48kHz instead of the actual sample rate to convert the initial_padding
  
  (in samples in the stream's sample rate) to ns. This meant that both
  
  fields are now off by the same factor, so Firefox was happy.
  Then commit f4bdeddc3cab807e43e0450744dfe9a45661e1d7 fixed the issue
  
  in libopusenc ; so the OpusHead is correct, but the CodecDelay is
  
  still off*. This commit fixes this by effectively reverting
  
  c3c22bee6362737cf290929b7f31df9fb88da983.
  * : Firefox seems to no longer abort when CodecDelay and OpusHead
  
  are off.
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] libavformat/matroskaenc.c
  • [DH] libavformat/version.h

• CJEU rules US cloud servers don’t comply with GDPR and what this means for web analytics

  17 juillet 2020, par Jake Thornton
  Breaking news : On July 16, 2020, the Court of Justice of the European Union (CJEU) has ruled that any cloud services hosted in the US are incapable of complying with the GDPR and EU privacy laws.

  In August 2016, the EU-US Privacy Shield framework came into effect, which “protects the fundamental rights of anyone in the EU whose personal data is transferred to the United States for commercial purposes. It allows the free transfer of data to companies that are certified in the US under the Privacy Shield.” – European Commission website

  However after today’s CJEU ruling, this Privacy Shield framework became invalidated due to significant differences between EU and US privacy laws.

  European privacy law activist Max Schrems summarises with “The Court clarified for a second time now that there is a clash between EU privacy law and US surveillance law. As the EU will not change its fundamental rights to please the NSA, the only way to overcome this clash is for the US to introduce solid privacy rights for all people – including foreigners. Surveillance reform thereby becomes crucial for the business interests of Silicon Valley.” – noyb website

  Today’s ruling also continues to spark concern into the legitimacy of US privacy laws which doesn’t fully protect people’s personal data when hosted on cloud servers based in the US.

  

  How will this affect you ?

  For any business operating a website in the EU or if you have traffic coming to your website from EU visitors, you need to know what data you’re capturing and where this data is being stored.

  Here’s what Maja Smoltczyk (Berlin’s Commissioner for Data Protection and Freedom of Information) says :

  Controllers who transfer personal data to the USA, especially when using cloud-based services, are now required to switch immediately to service providers based in the European Union or a country that can
  ensure an adequate level of data protection. The CJEU has made it refreshingly clear that data exports are not just financial decisions, as people’s fundamental rights must also be considered as a matter of priority. This ruling will put
  an end to the transfer of personal data to the USA for the sake of convenience or to cut costs.

  The controller is you (not Google) and by transferring data to the US you are at risk of being fined up to €20 million or 4% of your annual worldwide turnover for not being GDPR compliant. 

  It’s you who has to take action, not Google or other US companies. The court’s decision has immediate effect. While we assume there will be a grace period, companies should act now as finding and implementing alternatives solution can take a while. 

  Can no data be exported outside the EU anymore ?

  Data can still be exported outside the EU if an adequate level of data protection is guaranteed. This is the case for some trading partners of the EU such as New Zealand, Japan, Switzerland, and Canada. They have been certified by the EU as having a comparable level of privacy protection and therefore demonstrate adequacy at a country level.

  Necessary data can still flow to countries like the US too. This is for example the case when someone books a hotel in the US or when sending an email to someone in the US. Backups for disaster recovery and most other reasons don’t qualify as necessary.

  In all other cases you can still send data to countries like the US if you get explicit and informed consent from a user. Meaning the user has been informed about all possible risks of sending the data to the US and who can access the data (for example the US government).

  How this affects Google Analytics and Google Tag Manager users

  If your website is using Google Analytics, the safest bet is to deactivate it immediately. Otherwise, you must ask for consent from everyone who visits your website and inform them that the data will be processed in the United States under less strict privacy laws and all associated risks. If you don’t, you could be liable to privacy law infringements and face being fined for not complying with the GDPR. This also applies to Google Tag Manager as it transfers the IP address to the US which is considered personal data under the GDPR.

  Consent needs to be :

  • Freely given (the user must have a choice to not give consent and be able to opt out at any time) 
  • Informed (you need to disclose who is processing the data, what data is processed, where the data will be stored and how to opt out) 
  • Specific (consent is only valid for the specific informed purpose) 
  • Unambiguous (for example pre-ticked boxes or similar aren’t allowed)

  

  If users don’t give you consent, you are not allowed to track them using Google Analytics or any other US based cloud solution.

  Update August 19, 2020

  A month after this ruling, over 100 complaints have been filed against websites for continuing to send data to the US via Google Analytics or Facebook, by the European privacy campaign group noyb. It’s clear Google and Facebook fall under US surveillance laws such as FISA 702 and the court clearly ruled these companies cannot rely on SCCs to transfer data to the US. Anyone still using Google Analytics is now at risk of facing fines and compensation damages. 

  How this affects Matomo users

  Our cloud servers are based in Germany.

  Matomo On-Premise users choose the location of their data themselves. If the servers are located in the EU nothing changes. If the servers are located outside the EU and the website targets EU users and tracks personal data, then you need to assess whether you are required to ask for tracking consent.

  If the data is stored inside the EU you can use Matomo without asking for any consent and you can continue tracking users even if they reject a consent screen which greatly increases the quality of your data.

  Want to avoid informing users about transferring their data to the US and all associated risks ?

  Try Matomo now for free ! No credit card required.

  Download Matomo

• Converting raw video to mp4 on beaglebone with ffmpeg

  15 juin 2018, par Engineer999

  I’d really appreciate help with this one.
  I am recording video via a webcam with my beaglebone black.
  The formats supported by the camera are shown below.

      v4l2-ctl --list-formats
  
  ioctl: VIDIOC_ENUM_FMT
  
      Index       : 0
  
      Type        : Video Capture
  
      Pixel Format: 'YUYV'
  
      Name        : YUV 4:2:2 (YUYV)
  
  
  
      Index       : 1
  
      Type        : Video Capture
  
      Pixel Format: 'MJPG' (compressed)
  
      Name        : MJPEG

  When I record a raw 4:2:2 YUV video clip, there is no way to play it back to view, so I am trying to convert it to mp4 with ffmpeg.

  It states that yuyv422 is an incompatible pixel format, so I try to first convert the video to 420p with the below command, output_422.yuv being the video that I recorded from the camera.

  ffmpeg -y -pix_fmt yuyv422 -s 640x480 -r 30 -i output_422.yuv -f rawvideo -pix_fmt yuv420p -s 640x480 -r 30 output_420.yuv

  The result is :

      Input #0, rawvideo, from 'output_422.yuv':
  
    Duration: N/A, start: 0.000000, bitrate: N/A
  
      Stream #0.0: Video: rawvideo, yuyv422, 640x480, 30 tbr, 30 tbn, 30 tbc
  
  [buffer @ 0x41520] w:640 h:480 pixfmt:yuyv422
  
  [avsink @ 0x412c0] auto-inserting filter 'auto-inserted scaler 0' between the 
  
  filter 'src' and the filter 'out'
  
  [scale @ 0x44700] w:640 h:480 fmt:yuyv422 -> w:640 h:480 fmt:yuv420p 
  
  flags:0x4
  
  Output #0, rawvideo, to 'output_420.yuv':
  
    Metadata:
  
      encoder         : Lavf53.21.1
  
      Stream #0.0: Video: rawvideo, yuv420p, 640x480, q=2-31, 200 kb/s, 90k 
  
  tbn, 30 tbc
  
  Stream mapping:
  
    Stream #0.0 -> #0.0
  
  Press ctrl-c to stop encoding
  
  Error while decoding stream #0.0
  
  frame=   11 fps=  0 q=0.0 Lsize=    4950kB time=0.37 bitrate=110592.0kbits/s
  
  video:4950kB audio:0kB global headers:0kB muxing overhead 0.000000%

  I then try to convert this to mp4 like this :

  ffmpeg -f rawvideo -pix_fmt yuv420p -s 640x480 -r 30 -i output_420.yuv -vcodec libx264 output.mp4

  It looks like the conversion is successful, however when I try to play this back via vlc player, I have no video, just flickering for a few seconds. I have tried changing resolutions, frame rates etc. but no joy. Something is wrong somewhere but not sure where.

  Would anyone have some idea as to what could be wrong ? Thanks