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• Alias Artifacts

  26 avril 2013, par Multimedia Mike — General

  Throughout my own life, I have often observed that my own sense of nostalgia has a window that stretches about 10-15 years past from the current moment. Earlier this year, I discovered the show “Alias” and watched through the entire series thanks to Amazon Prime Instant Video (to be fair, I sort of skimmed the fifth and final season which I found to be horribly dull, or maybe franchise fatigue had set in). The show originally aired from 2001-2006 so I found that it fit well within the aforementioned nostalgia window.

  
  
  

  But what was it, exactly, about the show that triggered nostalgia ? The computers, of course ! The show revolved around spies and espionage and cutting-edge technology necessarily played a role. The production designer for the series must have decided that Unix/Linux == awesome hacking and so many screenshots featured Linux.

  Since this is still nominally a multimedia blog, I’ll start of the screenshot recon with an old multimedia player. Here is a vintage Mac OS desktop running an ancient web browser (probably Netscape) that’s playing a full-window video (probably QuickTime embedded directly into the browser).

  
  

  

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  Let’s jump right into the Linux side of things. This screenshot makes me particularly sentimental since this is exactly what a stock Linux/KDE desktop looked like circa 2001-2003 and is more or less what I would have worked with on my home computer at the time :

  
  

  

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  Studying that screenshot, we see that the user logs in as root, even to the desktop environment. Poor security practice ; I would expect better from a bunch of spooks.

  Echelon
  Look at the terminal output in the above screenshot– it’s building a program named Echelon, an omniscient spy tool inspired by a real-world surveillance network of the same name. In the show, Echelon is used to supply plot-convenient intelligence. At one point, some antagonists get their hands on the Echelon source code and seek to compile it. When they do, they will have access to the vast surveillance network. If you know anything about how computers work, don’t think about that too hard.

  Anyway, it’s interesting to note that Echelon is a properly autotool’d program– when the bad guys finally got Echelon, installation was just a ‘make install’ command away. The compilation was very user-friendly, though, as it would pop up a nice dialog box showing build progress :

  
  

  

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  Examining the build lines in both that screenshot and the following lines, we can see that Echelon cares about files such as common/db_err.c and bt_curadj.c :

  
  

  

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  A little googling reveals that these files both belong to the Berkeley DB library. That works ; I can imagine a program like this leveraging various database packages.

  Computer Languages
  The Echelon source code stuff comes from episode 2.11 : “A Higher Echelon”. While one faction had gotten a hold of the actual Echelon source code, a rival faction had abducted the show’s resident uber-nerd and, learning that they didn’t actually receive the Echelon code, force the nerd to re-write Echelon from scratch. Which he then proceeds to do…

  
  

  

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  The code he’s examining there appears to be C code that has something to do with joystick programming (JS_X_0, JS_Y_1, etc.). An eagle-eyed IMDb user contributed the trivia that he is looking at the file /usr/include/Linux/joystick.h.

  Getting back to the plot, how could the bad buys possibly expect him to re-write a hugely complex piece of software from scratch ? You might think this is the height of absurdity for a computer-oriented story. You’ll be pleased to know that the writers agreed with that assessment since, when the program was actually executed, it claimed to be Echelon, but that broke into a game of Pong (or some simple game). Suddenly, it makes perfect sense why the guy was looking at the joystick header file.

  This is the first bit of computer-oriented fun that I captured when I was watching the series :

  
  

  

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  This printout purports to be a “mainframe log summary”. After some plot-advancing text about a security issue, it proceeds to dump out some Java source code.

  SSH
  Secure Shell (SSH) frequently showed up. Here’s a screenshot in which a verbose ‘ssh -v’ connection has just been closed, while a telnet command has apparently just been launched (evidenced by “Escape character is ‘^]’.”) :

  
  

  

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  This is followed by some good old Hollywood Hacking in which a free-form database command is entered through any available command line interface :

  
  

  

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  I don’t remember the episode details, but I’m pretty sure the output made perfect sense to the character typing the command. Here’s another screenshot where the SSH client pops up an extra-large GUI dialog element to notify the user that it’s currently negotiating with the host :

  
  

  

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  Now that I look at that screenshot a little more closely, it appears to be a Win95/98 program. I wonder if there was an SSH client that actually popped up that gaudy dialog.

  There’s a lot of gibberish in this screenshot and I wish I had written down some details about what it represented according to the episode’s plot :

  
  

  

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  It almost sounds like they were trying to break into a network computer. Analyzing MD5 structure… public key synthesized. To me, the funniest feature is the 7-digit public key. I’m a bit rusty on the math of the RSA cryptosystem, but intuitively, it seems that the public and private keys need to be of roughly equal lengths. I.e., the private key in this scenario would also be 7 digits long.

  Gadgets
  Various devices and gadgets were seen at various junctures in the show. Here’s a tablet computer from back when tablet computers seemed like fantastical (albeit stylus-requiring) devices– the Fujitsu Stylistic 2300 :

  
  

  

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  Here’s a videophone from an episode that aired in 2005. The specific model is the Packet8 DV326 (MSRP of US$500). As you can see from the screenshot, it can do 384 kbps both down and up.

  
  

  

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  I really regret not writing down the episode details surrounding this gadget. I just know that it was critical that the good guys get it and keep from falling into the hands of the bad guys.

  
  

  

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  As you can see, the (presumably) deadly device contains a Samsung chip and a Lexar chip. I have to wonder what device the production crew salvaged this from (probably just an old cell phone).

  Other Programs

  The GIMP photo editor makes an appearance while scrubbing security camera footage, and serves as the magical Enhance Button (at least they slung around the term “gamma”) :

  
  

  

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  I have no idea what MacOS-based audio editing program this is. Any ideas ?

  
  

  

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  FTP shows up in episode 2.12, “The Getaway”. It’s described as a “secure channel” for communication, which is quite humorous to anyone versed in internet technology.

  
  

  

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• Video encoder & segmenter for HLS VoD poor quality

  10 juillet 2017, par Murilo

  I am trying to encode and segment video for HLS on demand(VoD).
  I am using the following code for such :

  ffmpeg -i 20170706_174314.mp4 -c 24 \
  
          -vcodec libx264 -acodec aac -ac 1 -strict -2 -b:v 128k \
  
          -profile:v baseline -maxrate 400k -bufsize 1835k \
  
          -hls_time 10 -hls_playlist_type vod -vsync 1 \
  
          video_chunks/index1.m3u8 \
  
          -c 24 -vcodec libx264 -acodec aac -ac 1 -strict -2 -b:v 128k \
  
          -profile:v baseline -maxrate 700k -bufsize 1835k \
  
          -hls_time 10 -hls_playlist_type vod -vsync 1 \
  
          video_chunks/index2.m3u8

  I tried this other code also just for segmenting but had the same exactly problem :

  ffmpeg -i 20170706_174314.mp4 \
  
  -c:a libmp3lame -ar 48000 -ab 64k  -c:v libx264 -b:v 128k -flags \ 
  
  -global_header -map 0 -f segment \
  
  -segment_list video_chunks/test.m3u8 -segment_time 10 -segment_format mpegts \
  
  video_chunks/segment_%05d.ts

  Later on I create another playlist with bandwidth separators to call on the two other playlists generated with the code above.

  This code was working great on some videos but yesterday I recorded a video with my Samsung J7 Prime phone to test since the videos will be generated by phone and this video was poorly encoded. The quality sucks and some parts of the video turned Black&White.

  Another thing I noticed on this video is that the following message kept appearing in loop until the end of the encoding&segmenting process.

  Past duration X too large

  Where X is a decimal really close to

  0.675316

  The link to the video is below :

  Dropbox Link

  My FFmpeg version :

  ffmpeg --version
  
  ffmpeg version N-86482-gbc40674 Copyright (c) 2000-2017 the FFmpeg developers
  
    built with gcc 7.1.0 (GCC)
  
    configuration: --enable-gpl --enable-version3 --enable-cuda --enable-cuvid --enable-d3d11va --enable-dxva2 --enable-libmfx --enable-nvenc --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenh264 --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-zlib
  
    libavutil      55. 66.100 / 55. 66.100
  
    libavcodec     57. 99.100 / 57. 99.100
  
    libavformat    57. 73.100 / 57. 73.100
  
    libavdevice    57.  7.100 / 57.  7.100
  
    libavfilter     6. 92.100 /  6. 92.100
  
    libswscale      4.  7.101 /  4.  7.101
  
    libswresample   2.  8.100 /  2.  8.100
  
    libpostproc    54.  6.100 / 54.  6.100

  SO : Windows 10

  EDIT1 : Link to the output
  If you see the output it might be worth saying I am also seeing the message

  VBV underflow(Frame X, -Y bits)

• Delphi android, deploying AND dynamic loading (external) libraries

  13 décembre 2020, par coban

  I am trying to start creating an application to test FFmpeg libraries, kind of a mediaplayer application, for ANDROID using Delphi 10.3/10.4

  


  I am getting some (strange ?) behaviors on different machines and locations of the files on the phone/tablet.

  


  The very first question should be ; what folder is the right one to put (external) libraries for dynamic/static loading ?

  


  I tried 2 locations ; '.\assets\internal' -> 'files' folder of the app
and 'library\lib\armeabi-v7a' -> bin folder (if i'm right)

  


  behavior on mobile phone Android 8

  


  when I choose to place the (FFmpeg) libraries in the Files folder '.\assets\internal' and try to load the libraries, 3 of the 7 libraries succesfully loads, while the other does not. Every tiem the same libraries which fail and succeeds to load. The succesfully loading libraries are 'libavutil.so', 'swresample.so' and 'libswscale.so'.

  


  When I choose to place the libraries in the bin folder 'library\lib\armeabi-v7a', all libraries are succesfully loaded.

  


  behavior on tablet android 4.4.4

  


  When choosing to put the libraries in the 'Files' folder, exact the same behavior as "Android 8 phone".

  


  The strange thing is ; When I choos the bin folder, none of the libraries are being loaded ?

  


  I did not compile/build the (FFmpeg) libraries myself, I downloaded them.
I tried libraries from different places.
In every attempt I checked for the existance of the files.
I used 'loadlibrary' function, after some reading and suggestions on the internet I allso tried 'dlopen' function directly which looks like unnecessary to use it directly after all.
I was not able to debug using D10.4 and Android 4.4.4 tablet, because of the minsdk version. Using D10.3 I am able to try on both machines.

  


  Delphi10.3 'Android SDK 25.2.5 32bit', 'jdk1.8.0_60'

  


  Delphi10.4 'Android SDK 25.2.5 32bit', 'AdoptOpenJDK jdk-8.0.242.08-hotspot'

  


  Any idea why 3 of the libraries are able to load in case of they are in the 'Files' folder while all of them can be loaded when they are in the 'BIN' folder (android 8) ?
And why does nothing load by android 4.4.4 when the files are in the 'Bin' folder while 3 of them are able to be loaded when they are placed in the 'Files' Folder ?

  


  I've been using FFmpeg libraries for windows (allmost)without issues, my question should not be FFmpeg specific but Delphi+android+(external)libraries specific except if this behavior is FFmpeg specific.

  


  Both are Samsung machines,

  


  Android 4.4 tablet cpu (using 'syscheck' embarcadero recommends);

family = ARM
processor = ARMv7 processor rev 5(v7I)
CPU Cores = 4
neon supported  yes
armv7 (ARMv7 compatible architecture)  yes

Android 8 phone cpu

Family   ARM
processor   unknown
CPU Cores   8
Neon   yes
armv7 = Arm
armv7 (ARMv7 compatible architecture)   yes


  


  Edit

  


  Test on Android 10, redmi note 10 lite

  


  None of the library files are being loaded from the 'Files'->'.\assets\internal' folder. All library files are being succesfully loaded from the 'Bin'->'library\lib\armeabi-v7a' Folder.

  


  I'll need an reasonably explanation for this. It looks like Andrid specific behavior ?

  


  Edit 2

  


  One of the reasons seems like that some those FFmpeg libraries are loading other FFmpeg libraries, even if they are in the same directory, if they are outside the folder of the EXE file, or not in a (library) folder where the OS searches by default, they cannot find/load eachother.

  


  This looks like the explanation why some of them are able to load in the 'Files'->'.\assets\internal' folder.