Recherche avancée

Sur d’autres sites (8291)

• avcodec/dvenc : Change quantizer dead zone default to 7

  6 août 2017, par Michael Niedermayer

  avcodec/dvenc : Change quantizer dead zone default to 7
  This improves the quality and reduces the "blocking" in flat areas
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavcodec/dvenc.c
  • [DH] tests/ref/lavf/dv_fmt
  • [DH] tests/ref/vsynth/vsynth1-dv
  • [DH] tests/ref/vsynth/vsynth1-dv-411
  • [DH] tests/ref/vsynth/vsynth1-dv-50
  • [DH] tests/ref/vsynth/vsynth2-dv
  • [DH] tests/ref/vsynth/vsynth2-dv-411
  • [DH] tests/ref/vsynth/vsynth2-dv-50
  • [DH] tests/ref/vsynth/vsynth_lena-dv
  • [DH] tests/ref/vsynth/vsynth_lena-dv-411
  • [DH] tests/ref/vsynth/vsynth_lena-dv-50

• OBS and OBS Portable Recording Into Same File Simultaneously

  26 juin 2020, par aerodavo

  Corrupted video file, FFprobe output text file, and FFmpeg output text files are all available to download here :
https://drive.google.com/drive/folders/1R0Y5plgkhTWWFNNKgSNJ5yitpKQbIKgg?usp=sharing

  


  I'm hoping there is a way to extract good video and audio from this video file, this was for a very important job that is impossible to do again. The video linked is a 1 minute recreation of the exact same problem... the actual video file is confidential (for a legal court case) and is much longer/larger. I used the exact same settings, the only difference was the window OBS was capturing (I used a YouTube video as opposed to the videoconference software window used for the deposition).

  


  Here's what happened :

  


  In OBS and OBS Portable, I had the save location set to the same exact folder (this was not how I intended it to be, but I made a last minute change to accommodate what I suspected was a faulty hard drive). I also had a hotkey to start recording on both apps simultaneously. I left the auto-naming scheme in place for both instances of OBS since they were supposed to be saving to two totally different external hard drives. I have since changed the auto-naming so it won't happen again, but this perfect storm resulted in both recordings being written into a single file (see link above), instead of two files as intended. It is unplayabe in VLC.

  


  I ran an FFprobe (available via link above), and found that there are 8 streams in the file. Each file should have had 4 streams (1 video and 3 audio streams per my setup in OBS), so at first glance it looks like all the data is there in some form/arrangement.

  


  I tried to map the 0:0 stream to a new file and tried the same thing with the 0:4 stream (these are the video streams), but did not have any luck extracting good video. Here are the two things I ran (again see link above for text files with full FFmpeg ouput of each) :

  


  ffmpeg -i C :\Users\David\Videos\2020-06-23_17-39-32_corrupted.mkv -map 0:0 -c copy C :\Users\David\Videos\2020-06-23_17-39-32_corrupted_map0-0.mkv

  


  ffmpeg -i C :\Users\David\Videos\2020-06-23_17-39-32_corrupted.mkv -map 0:4 -c copy C :\Users\David\Videos\2020-06-23_17-39-32_corrupted_map0-4.mkv

  


  It seems the audio is intact, as I was able to map one of the audio streams into a wav file... although there seemed to be extra/repeated audio tacked onto where the video/audio should have ended...

  


  It looks to me like both video streams got written into stream 0:0, while stream 0:4 looks empty (because this map results in a very small file). However the thing that's weird (and maybe promising) is that when I play the corrupted file in VLC, it mostly looks like smeared digital colors, but if I click around to different times in the video, it sometimes shows good video, even though it won't show any good video if you just play it from the beginning.

  


  My life would saved if there is a way to extract good video/audio from this corrupted file. Any help would be greatly appreciated, thanks in advance !

  


• How to keep personally identifiable information safe

  23 janvier 2020, par Joselyn Khor
  The protection of personally identifiable information (PII) is important both for individuals, whose privacy may be compromised, and for businesses that may have their reputation ruined or be liable if PII is wrongly accessed, used, or shared.

  Curious about what PII is ? Here’s your introduction to personally identifiable information.

  Due to hacking, data leaks or data thievery, PII acquired can be combined with other pieces of information to form a more complete picture of you. On an individual level, this puts you at risk of identity theft, credit card theft or other harm caused by the fraudulent use of your personal information.

  On a business level, for companies who breach data privacy laws – like Cambridge Analytica’s harvesting of millions of FB profiles – the action leads to an erosion of trust. It can also impact your financial position as heavy fines can be imposed for the illegal use and processing of personally identifiable information.

  So what can you do to ensure PII compliance ?

  On an individual level :

  1. Don’t give your data away so easily. Although long, it’s worthwhile to read through privacy policies to make sure you know what you’re getting yourself into.
  2. Don’t just click ‘agree’ when faced with consent screens, as consent screens are majorly flawed. Users mostly always opt in without reading and without being properly informed what they opt in to.
  3. Did you know you’re most likely being tracked from website to website ? For example, Google can identify you across visits and websites. One of the things you can do is to disable third party cookies by default. Businesses can also use privacy friendly analytics which halt such tracking. 
  4. Use strong passwords.
  5. Be wary of public wifi – hackers can easily access your PII or sensitive data. Use a VPN (virtual private network), which lets you create a secure connection to a server of your choosing. This allows you to browse the internet in a safe manner.

  A PII compliance checklist for businesses/organisations :

  1. Identify where all PII exists and is stored – review and make sure this is in a safe environment.
  2. Identify laws that apply to you (GDPR, California privacy law, HIPAA) and follow your legal obligations.
  3. Create operational safeguards – policies and procedures for handling PII at an organisation level ; and building awareness to focus on the protection of PII.
  4. Encrypt databases and repositories where such info is kept.
  5. Create privacy-specific safeguards in the way your organisation collects, maintains, uses, and disseminates data so you protect the confidentiality of the data.
  6. Minimise the use, collection, and retention of PII – only collect and keep PII if it’s necessary for you to perform your legal business function.
  7. Conduct privacy impact assessments (PIA) to find and prevent privacy risks (identify what and why it’s to be collected ; how the information will be secured etc.).
  8. De-identify within the scope of your data collection and analytics tools.
  9. Anonymise data.
  10. Keep your privacy policy updated.
  11. Pseudonymisation.
  12. A more comprehensive guide for businesses can be found here : https://iapp.org/media/pdf/knowledge_center/NIST_Protecting_PII.pdf

  Unsure of what information could be considered PII ? Check out this list of examples.

  Additional resources :

  • https://www.umassmed.edu/it/security/compliance/what-is-pii/
  • http://www.osec.doc.gov/opog/privacy/PII_BII.html