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• Elacarte Presto Tablets

  14 mars 2013, par Multimedia Mike — General

  I visited an Applebee’s restaurant this past weekend. The first thing I spied was a family at a table with what looked like a 7-inch tablet. It’s not an uncommon sight. However, as I moved through the restaurant, I noticed that every single table was equipped with such a tablet. It looked like this :

  
  
  

  For a computer nerd like me, you could probably guess that I was be far more interested in this gadget than the cuisine. The thing said “Presto” on the front and “Elacarte” on the back. Putting this together, we get the website of Elacarte, the purveyors of this restaurant tablet technology. Months after the iPad was released on 2010, I remember stories about high-end restaurants showing their wine list via iPads. This tablet goes well beyond that.

  How was it ? Well, confusing, mostly. The hostess told us we could order through the tablet or through her. Since we already knew what we wanted, she just manually took our order and presumably entered it into the system. So, right away, the question is : Do we order through a human or through a computer ? Or a combination ? Do we have to use the tablet if we don’t want to ?

  Hardware
  When picking up the tablet, it’s hard not to notice that it is very heavy. At first, I suspected that it was deliberately weighted down as some minor attempt at an anti-theft measure. But then I remembered what I know about power budgets of phones and tablets– powering the screen accounts for much of the battery usage. I realized that this device needs to drive the screen for about 14 continuous hours each day. I.e., the weight must come from a massive battery.

  The screen is good. It’s a capacitive touchscreen, so nice and responsive. When I first spied the device, I felt certain it would be a resistive touchscreen (which is more accurately called a touch-and-press-down screen). There is an AC adapter on the side of the tablet. This is the only interface to the device :

  
  
  

  That looks to me like an internal SATA connector (different from an eSATA connector). Foolishly, I didn’t have a SATA cable on me so I couldn’t verify.

  User Interface
  The interface options are : Order, Games, Neighborhood, and Pay. One big benefit of accessing the menu through the Order option is that each menu item can have a picture. For people who order more by picture than text description, this is useful. Rather, it would be, if more items had pictures. I’m not sure there were more pictures than seen in the print menu.
  
  For Games, there were a variety of party games. The interface clearly stated that we got to play 2 free games. This implied to me that further games cost money. We tried one game briefly and the food came.

  2 more options : Neighborhood– I know I dug into this option, but I forget what it was. Maybe it discussed local attractions. Finally, Pay. This thing has an integrated credit card reader. There is no integrated printer, though, so if you want one, you will have to request one from a human.

  Experience
  So we ordered through a human since we didn’t feel like being thrust into this new paradigm when we just wanted lunch. The staff was obviously amenable to that. However, I got a chance to ask them a lot of questions about the particulars. Apparently, they have had this system for about 5 months. It was confirmed that the tablets do, in fact, have gargantuan batteries that have to last through the restaurant’s entire business hours. Do they need to be charged every night ? Yes, they do. But how ? The staff described this several large charging blocks with many cables sprouting out. Reportedly, some units still don’t make it through the entire day.

  When it was time to pay, I pressed the Pay button on the interface. The bill I saw had nothing in common with what we ordered (actually, it was cheaper, so perhaps I should have just accepted it). But I pointed it out to a human and they said that this happens sometimes. So they manually printed my bill. There was a dollar charge for the game that was supposed to be free. I pointed this out and they removed it. It’s minor, I know, but it’s still worth trying to work out these bugs.

  One of the staff also described how a restaurant doesn’t need to employ as many people thanks to the tablet. She gave a nervous, awkward, self-conscious laugh when she said this. All I could think of was this Dilbert comic strip in which the boss realizes that his smartphone could perform certain key functions previously handled by his assistant.

  Not A New Idea
  Some people might think this is a totally new concept. It’s not. I was immediately reminded of my university days in Boulder, Colorado, USA, circa 1997. The local Taco Bell and Arby’s restaurants both had touchscreen ordering kiosks. Step up, interact with the (probably resistive) touchscreen, get a number, and step to the counter to change money, get your food, and probably clarify your order because there is only so much that can be handled through a touchscreen.

  What I also remember is when they tore out those ordering kiosks, also circa 1997. I don’t know the exact reason. Maybe people didn’t like them. Maybe there were maintenance costs that made them not worth the hassle.

  Then there are the widespread self-checkout lanes in grocery stores. Personally, I like those, though I know many don’t. However, this restaurant tablet thing hasn’t won me over yet. What’s the difference ? Perhaps that automated lanes at grocery stores require zero external assistance– at least, if you do everything correctly. Personally, I work well with these lanes because I can pretty much guess the constraints of the system and I am careful not to confuse the computer in any way. Until they deploy serving droids, or at least food conveyors, there still needs to be some human interaction and I think the division between the human and computer roles is unintuitive in the restaurant case.

  I don’t really care to return to the same restaurant. I’ll likely avoid any other restaurant that has these tablets. For some reason, I think I’m probably supposed to be the ideal consumer of this concept. But the idea will probably perform all right anyway. Elacarte’s website has plenty of graphs demonstrating that deploying these tablets is extremely profitable.

• 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

• FFMPEG : How to avoid audio/video desync in output of crossfaded clips when input is variable frame rate video

  25 décembre 2018, par Anders Lunde

  I’m doing screen recordings of gameplay (Dota2) using my NVIDIA graphics card GeForce experience hardware recording (NVEC Encoder). This creates a variable frame rate output video. My NVIDIA settings are 60 fps 15000 kbps. I have paid a guy to make a program that generates scripts that given start/stop timepoints can extract clips from the video and merge them with crossfade. See example code below. The script works for many input recordings but fails often : The audio and video are desynchronized (usually audio delay) in many of the clips, ca 0.5 seconds. I think it fails more when frame rate dropped more during recording. He does not know how to fix the problem, and I wonder if anyone could point out if anything could be fixed in the script (example below) ?

  Processing speed is quite important (now making a 10 min ’highlight’ video takes ca 7-10 min). Solutions increasing that amount very much more is not of too big interest, unfortunately. His approach has been to work separately with audio and video and merge in the end. He already has a program to make ffmpeg code for working with different scenarios (also adding overlays, adding music, intro/outro) so it would be preferable with some easy fixes to his code and not dramatic redesigning of the logic. But if nothing else can fix the problem, a redesign in logic is ok. Using other tools than ffmpeg is also ok, but should be automatable (scripts/cli) and not increase processing times too much.

  Running the program "mediainfo" on the input video shows that framerate dropped quite low for this input video :

  Frame rate mode : Variable

  Frame rate : 60.000 FPS

  Minimum frame rate : 3.059 FPS

  Maximum frame rate : 63.739 FPS

  Full report here : https://pastebin.com/TX061Wih

  The input video can be downloaded from dropbox here (6 GB) :
  https://www.dropbox.com/s/ftwdgapazbi62pr/fullgame.mp4?dl=0

  Here the example of a script when asked to extract two clips from input video at 9:57 (41 sec length) and 15:45 (28 sec length) and crossfade merge them with a 0.5 crossfade time. There might be some code-remnants from options that are not used in this example (overlays, music, intro/outro). Using the input video above, this creates audio/video desync.

  6 commands excecuted in sequence :

  ffmpeg.exe -loglevel warning -ss 00:09:57 -i fullgame.mp4 -t 00:00:41 -filter_complex "[0:a]afade=t=out:st=40.5:d=0.5[a1]" -map "[a1]" -y out_temp_00.mp4.wav
  
  
  
  ffmpeg.exe -loglevel warning -i fullgame.mp4 -ss 00:09:57 -t 00:00:41 -an -vcodec copy -f mpegts -avoid_negative_ts make_zero -y out_temp_00.mp4.ts
  
  
  
  ffmpeg.exe -loglevel warning -ss 00:15:45 -i fullgame.mp4 -t 00:00:28 -filter_complex "[0:a]afade=t=in:st=0:d=0.5[a1]" -map "[a1]" -y out_temp_01.mp4.wav
  
  
  
  ffmpeg.exe -loglevel warning -i fullgame.mp4 -ss 00:15:45 -t 00:00:28 -an -vcodec copy -f mpegts -avoid_negative_ts make_zero -y out_temp_01.mp4.ts
  
  
  
  ffmpeg.exe -loglevel warning -i out_temp_00.mp4.wav -i out_temp_01.mp4.wav -y -filter_complex "[0:a]adelay=0|0[a0];[1:a]adelay=40500|40500[a1];[a0][a1]amix=inputs=2:dropout_transition=68.5,atrim=duration=68.5[outa0];[outa0]loudnorm[outa]" -map "[outa]" -ar 48000 -acodec aac -strict -2 fullgame_Output.mp4.aac
  
  
  
  ffmpeg.exe -loglevel warning -i out_temp_00.mp4.ts -i out_temp_01.mp4.ts -y -i fullgame_Output.mp4.aac  -filter_complex "[0:v]trim=start=0.5,setpts=PTS-STARTPTS[0c];[1:v]trim=start=0.5,setpts=PTS-STARTPTS[1c];[0:v]trim=40.5:41,setpts=PTS-STARTPTS[fo];[1:v]trim=0:0.5[fi];[fi]format=pix_fmts=yuva420p,fade=t=in:st=0:d=0.5:alpha=1[z];[fo]format=pix_fmts=yuva420p,fade=t=out:st=0:d=0.5:alpha=1[x];[z]fifo[w];[x]fifo[q];[q][w]overlay[r];[0c][r][1c]concat=n=3[outv]" -map "[outv]" -map 2:a -shortest -acodec copy -vcodec libx264 -preset ultrafast -b 15000k -aspect 1920:1080 fullgame_Output.mp4

  P.S.

  I already asked for help at an ffmpeg chat room. One guy said he knew what the problem was, but didnt know how to fix it(?) :

  [00:10] <kepstin> oh, wait, you're using -vcodec copy
  
  [00:10] <kepstin> that explains everything.
  
  [00:10] <kepstin> when you're using -vcodec copy, the start time (set with -ss) is rounded to the nearest keyframe
  
  [00:10] <kepstin> it's not exact
  
  [00:11] <kepstin> depending on the keyframe interval, this will result in possibly quite large shifts
  
  [00:11] <kepstin> (also, your commands are applying audio filters on commands with -an, which is confusing/contradictory)
  
  [00:12] <birdboy88> so the problem is that the audio temporary clips are not being extracted from the same excat timepoints?
  
  [00:13] <kepstin> birdboy88: yeah, your audio is being re-encoded to wav so it's being cut sample-accurate, but the video's not being precisely cut.
  
  [00:16] <birdboy88> kepstin: so I need to use slow seek (?) to extract video accurately? Or somehow extract audio only where there are video keyframes?
  
  [00:17] <kepstin> birdboy88: i don't know how to extract audio starting at video keyframes with ffmpeg cli. You're already doing slow seek, which doesn't help (you should move the -ss option to before the -i option to speed it up)
  
  [00:17] <kepstin> if you want accurate video cutting when saving to a file, you have to re-encode the video
  
  [00:18] <kepstin> (doing this in a single ffmpeg command means you don't have to save to a file, so you can avoid the issue)
  
  [00:18] * kepstin is off for a bit now
  
  </kepstin></kepstin></kepstin></birdboy88></kepstin></birdboy88></kepstin></kepstin></kepstin></kepstin></kepstin></kepstin>

  EDIT :
  Everything is done with the latest ffmpeg version.

  I was unable to get Gyan’s code to work. It always loses some audio (audio is either 40.5 or 27.5, so only one audio is used). This is the only one working for me (changes were adelay=40500|40500 and amix=inputs=2[a0] ;[a0]loudnorm) :

  ffmpeg -i fullgame.mp4 -filter_complex "[0]split=2[vpre][vpost];
  
  [0]asplit=2[apre][apost];
  
  [vpre]trim=start='00:09:57':duration='00:00:41',setpts=PTS-STARTPTS[vpre-t];
  
  [apre]atrim=start='00:09:57':duration='00:00:41',asetpts=PTS-STARTPTS,afade=t=out:st=40.5:d=0.5[apre-t];
  
  [vpost]trim=start='00:15:45':duration='00:00:28',setpts=PTS-STARTPTS,format=yuva420p,fade=t=in:st=0:d=0.5:alpha=1,setpts=PTS+40.5/TB[vpost-t];
  
  [apost]atrim=start='00:15:45':duration='00:00:28',asetpts=PTS-STARTPTS,afade=t=in:st=0:d=0.5,adelay=40500|40500[apost-t];
  
  [vpre-t][vpost-t]overlay[v];
  
  [apre-t][apost-t]amix=inputs=2[a0];[a0]loudnorm[a]" -map "[v]" -map "[a]" -y -c:v libx264 -preset ultrafast -b:v 15000k -aspect 1920:1080 -c:a aac fullgame_Output.mp4

  Then I tried using a similar setup but with 3 clips, but on one machine I got error : "Error while filtering : Cannot allocate memory". And my 16 GB memory machine the processing speed is 0.02x ! Any way to avoid this ? This is the code I tried :

  ffmpeg -i fullgame.mp4 -filter_complex "[0]split=3[vpre][vpost][v3];
  
  [0]asplit=3[apre][apost][a3];
  
  [vpre]trim=start=357:duration=41,setpts=PTS-STARTPTS[vpre-t];
  
  [apre]atrim=start=357:duration=41,asetpts=PTS-STARTPTS,afade=t=out:st=40.5:d=0.5[apre-t];
  
  [vpost]trim=start=795:duration=28,setpts=PTS-STARTPTS,format=yuva420p,fade=t=in:st=0:d=0.5:alpha=1,fade=t=out:st=40.5:d=0.5:alpha=1,setpts=PTS+40.5/TB[vpost-t];
  
  [apost]atrim=start=795:duration=28,asetpts=PTS-STARTPTS,afade=t=in:st=0:d=0.5,afade=t=out:st=27.5:d=0.5,adelay=40500|40500[apost-t];
  
  [v3]trim=start=95:duration=30,setpts=PTS-STARTPTS,format=yuva420p,fade=t=in:st=0:d=0.5,setpts=PTS+41Û0.5/TB[v3-t];
  
  [a3]atrim=start=95:duration=30,asetpts=PTS-STARTPTS,afade=t=in:st=0:d=0.5,adelay=68500|68500[a3-t];
  
  [vpre-t][vpost-t]overlay[v1];
  
  [v1][v3-t]overlay[v];
  
  [apre-t][apost-t][a3-t]amix=inputs=3[a0];
  
  [a0]loudnorm[a]" -map "[v]" -map "[a]" -y -c:v libx264 -preset ultrafast -b:v 15000k -aspect 1920:1080 -c:a aac fullgame_Output.mp4