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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 can several .ts files be converted to one (non-fragmented) .mp4 file using ffmpeg ?

  23 juin 2021, par verified_tinker

  Problem Description

  


  The video player I'm using doesn't support .ts files, but it does play .mp4 files, so I'd like to use ffmpeg to convert my .ts files to .mp4 files.

  


  Goal Solution

  


  Use ffmpeg to download several .ts segments and transcode them into an .mp4 file that I'd load into my video player. Rinse and repeat. It'd add a delay of 10-20 seconds, but that's fine.

  


  The trick is to do the transcoding fast enough so, by the time one .mp4 file is finished playing, the next one is available ; in other words, the transcoding should take less than a second per second of footage. Ideally, it would take significantly less than that, to account for varying processing power on different devices.

  


  To clarify, when I say .mp4, I don't mean fragmented .mp4 files.

  


  ---

  


  If transcoding to some other format is faster, that might be fine, too. For example, I know the .mkv format is playable. I'm still exploring the full range of available formats.

  


  What I've Tried

  


  I tested transcoding 1 .ts file into an .mp4 file, and unfortunately it took about 6 seconds when the file was about 4 seconds long. That was with ffmpeg-wasm. I was hoping the JavaScript bridge might be slowing it down and that batching several .ts segments in 1 call might help.

  


  Command

  


  ffmpeg -i test.ts test.mp4


  


  Log

  


  [info] run FS.writeFile test.ts <349304 bytes binary file>
log.js:15 [info] run ffmpeg command: -i test.ts test.mp4
log.js:15 [fferr] ffmpeg version v0.9.0-2-gb11e5c1495 Copyright (c) 2000-2020 the FFmpeg developers
log.js:15 [fferr]   built with emcc (Emscripten gcc/clang-like replacement) 2.0.8 (d059fd603d0b45b584f634dc2365bc9e9a6ec1dd)
log.js:15 [fferr]   configuration: --target-os=none --arch=x86_32 --enable-cross-compile --disable-x86asm --disable-inline-asm --disable-stripping --disable-programs --disable-doc --disable-debug --disable-runtime-cpudetect --disable-autodetect --extra-cflags='-s USE_PTHREADS=1 -I/src/build/include -O3 --closure 1' --extra-cxxflags='-s USE_PTHREADS=1 -I/src/build/include -O3 --closure 1' --extra-ldflags='-s USE_PTHREADS=1 -I/src/build/include -O3 --closure 1 -L/src/build/lib' --pkg-config-flags=--static --nm=llvm-nm --ar=emar --ranlib=emranlib --cc=emcc --cxx=em++ --objcc=emcc --dep-cc=emcc --enable-gpl --enable-nonfree --enable-zlib --enable-libx264 --enable-libx265 --enable-libvpx --enable-libwavpack --enable-libmp3lame --enable-libfdk-aac --enable-libtheora --enable-libvorbis --enable-libfreetype --enable-libopus --enable-libwebp --enable-libass --enable-libfribidi
log.js:15 [fferr]   libavutil      56. 51.100 / 56. 51.100
log.js:15 [fferr]   libavcodec     58. 91.100 / 58. 91.100
log.js:15 [fferr]   libavformat    58. 45.100 / 58. 45.100
log.js:15 [fferr]   libavdevice    58. 10.100 / 58. 10.100
log.js:15 [fferr]   libavfilter     7. 85.100 /  7. 85.100
log.js:15 [fferr]   libswscale      5.  7.100 /  5.  7.100
log.js:15 [fferr]   libswresample   3.  7.100 /  3.  7.100
log.js:15 [fferr]   libpostproc    55.  7.100 / 55.  7.100
log.js:15 [fferr] Input #0, mpegts, from 'test.ts':
log.js:15 [fferr]   Duration: 00:00:04.00, start: 10.006000, bitrate: 698 kb/s
log.js:15 [fferr]   Program 1 
log.js:15 [fferr]     Stream #0:0[0x100]: Video: h264 (High) ([27][0][0][0] / 0x001B), yuv420p(progressive), 1280x720, 23.98 tbr, 90k tbn, 1411200000.00 tbc
log.js:15 [fferr]     Stream #0:1[0x101]: Audio: aac (LC) ([15][0][0][0] / 0x000F), 48000 Hz, stereo, fltp, 130 kb/s
log.js:15 [fferr] Stream mapping:
log.js:15 [fferr]   Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
log.js:15 [fferr]   Stream #0:1 -> #0:1 (aac (native) -> aac (native))
log.js:15 [fferr] [libx264 @ 0x1f5f080] using cpu capabilities: none!
log.js:15 [fferr] [libx264 @ 0x1f5f080] profile High, level 3.1, 4:2:0, 8-bit
log.js:15 [fferr] [libx264 @ 0x1f5f080] 264 - core 160 - H.264/MPEG-4 AVC codec - Copyleft 2003-2020 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=23 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
log.js:15 [fferr] Output #0, mp4, to 'test.mp4':
log.js:15 [fferr]   Metadata:
log.js:15 [fferr]     encoder         : Lavf58.45.100
log.js:15 [fferr]     Stream #0:0: Video: h264 (libx264) (avc1 / 0x31637661), yuv420p, 1280x720, q=-1--1, 23.98 fps, 24k tbn, 23.98 tbc
log.js:15 [fferr]     Metadata:
log.js:15 [fferr]       encoder         : Lavc58.91.100 libx264
log.js:15 [fferr]     Side data:
log.js:15 [fferr]       cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
log.js:15 [fferr]     Stream #0:1: Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 128 kb/s
log.js:15 [fferr]     Metadata:
log.js:15 [fferr]       encoder         : Lavc58.91.100 aac
log.js:15 [fferr] frame=    3 fps=0.0 q=0.0 size=       0kB time=00:00:00.38 bitrate=   1.0kbits/s dup=1 drop=0 speed=0.521x    
log.js:15 [fferr] frame=   47 fps= 27 q=0.0 size=       0kB time=00:00:02.09 bitrate=   0.2kbits/s dup=1 drop=0 speed=1.22x    
log.js:15 [fferr] frame=   57 fps= 25 q=28.0 size=       0kB time=00:00:02.51 bitrate=   0.2kbits/s dup=1 drop=0 speed=1.13x    
log.js:15 [fferr] frame=   67 fps= 24 q=28.0 size=       0kB time=00:00:02.96 bitrate=   0.1kbits/s dup=1 drop=0 speed=1.08x    
log.js:15 [fferr] frame=   77 fps= 23 q=28.0 size=       0kB time=00:00:03.37 bitrate=   0.1kbits/s dup=1 drop=0 speed=1.03x    
log.js:15 [fferr] frame=   89 fps= 23 q=28.0 size=       0kB time=00:00:03.96 bitrate=   0.1kbits/s dup=1 drop=0 speed=1.04x    
log.js:15 [fferr] frame=   96 fps= 15 q=-1.0 Lsize=      60kB time=00:00:04.01 bitrate= 122.8kbits/s dup=1 drop=0 speed=0.646x    
log.js:15 [fferr] video:55kB audio:1kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 7.249582%
log.js:15 [fferr] [libx264 @ 0x1f5f080] frame I:1     Avg QP:17.20  size: 31521
log.js:15 [fferr] [libx264 @ 0x1f5f080] frame P:24    Avg QP:16.17  size:   735
log.js:15 [fferr] [libx264 @ 0x1f5f080] frame B:71    Avg QP:27.68  size:    91
log.js:15 [fferr] [libx264 @ 0x1f5f080] consecutive B-frames:  1.0%  0.0%  3.1% 95.8%
log.js:15 [fferr] [libx264 @ 0x1f5f080] mb I  I16..4: 26.2% 56.4% 17.4%
log.js:15 [fferr] [libx264 @ 0x1f5f080] mb P  I16..4:  0.1%  0.2%  0.0%  P16..4:  3.5%  0.4%  0.2%  0.0%  0.0%    skip:95.4%
log.js:15 [fferr] [libx264 @ 0x1f5f080] mb B  I16..4:  0.0%  0.0%  0.0%  B16..8:  1.6%  0.0%  0.0%  direct: 0.0%  skip:98.3%  L0:31.0% L1:69.0% BI: 0.0%
log.js:15 [fferr] [libx264 @ 0x1f5f080] 8x8 transform intra:56.5% inter:59.4%
log.js:15 [fferr] [libx264 @ 0x1f5f080] coded y,uvDC,uvAC intra: 17.4% 15.4% 7.5% inter: 0.2% 0.4% 0.0%
log.js:15 [fferr] [libx264 @ 0x1f5f080] i16 v,h,dc,p: 29% 63%  1%  7%
log.js:15 [fferr] [libx264 @ 0x1f5f080] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 51% 31% 14%  0%  2%  1%  1%  0%  1%
log.js:15 [fferr] [libx264 @ 0x1f5f080] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 26% 45% 11%  2%  3%  2%  4%  2%  4%
log.js:15 [fferr] [libx264 @ 0x1f5f080] i8c dc,h,v,p: 76% 17%  6%  1%
log.js:15 [fferr] [libx264 @ 0x1f5f080] Weighted P-Frames: Y:0.0% UV:0.0%
log.js:15 [fferr] [libx264 @ 0x1f5f080] ref P L0: 89.5%  1.6%  6.7%  2.3%
log.js:15 [fferr] [libx264 @ 0x1f5f080] ref B L0: 38.5% 60.9%  0.6%
log.js:15 [fferr] [libx264 @ 0x1f5f080] ref B L1: 97.7%  2.3%
log.js:15 [fferr] [libx264 @ 0x1f5f080] kb/s:111.08
log.js:15 [fferr] [aac @ 0x1f48100] Qavg: 65536.000
log.js:15 [ffout] FFMPEG_END
log.js:15 [info] run FS.readFile test.mp4
(index):38 Time elapsed: 6345 (This one's my own code.)
[info] run FS.readFile test.mp4


  


  (I'm running this on the browser. For the purposes of this question, consider the HTML player unavailable for use.)

  


  ---

  


  I also tested feeding the HLS live-stream URL as input to ffmpeg and outputting a single .mp4 file, but I couldn't play it until I ended the live-stream and ffmpeg finished downloading it.

  


  This one I ran on the (Windows) PC ; not the browser.

  


  Command

  


  ffmpeg -i https://stream.mux.com/lngMYGqNpHhYg2ZXqpH8WODVGzuenaZuhckdyunGpzU.m3u8 -acodec copy -bsf:a aac_adtstoasc -vcodec copy out.mp4


  


  Log

  


  The log is too large and StackOverflow won't let me paste it here, so I uploaded it to PasteBin : https://pastebin.com/FqvPQ1DZ

  


• Still getting FFMPEG "Segmentation fault" with network stream source with the AmazonLinux 2023 distro [closed]

  28 décembre 2023, par Matthew Drooker

  After referencing https://docs.yucca.app/en/troubleshooting/Segmentation_fault_core_dumped

  


  And using

  


  FFMPEG "Segmentation fault" with network stream source

  


  I thought I had this solved.
But still having the same issue as documented as fixed.

  


  Im using AmazonLinux 2023 distro in a Lambda custom image.

  


  Im trying to use baseImage from FROM --platform=linux/amd64 public.ecr.aws/lambda/nodejs:20

  


  Then doing- RUN dnf install nscd  -y in my Dockerfile allowing the nscd service to be installed per the answer.

  


  But, Im still getting the ffprobe was killed with signal SIGSEGV error with the new AmazonLinux Distro.

  


  Has anyone else faced this with the 2023 Distro ? Or have an answer to this question ?