Multichain : Appending Data to Blockchain with DATA STREAMS

 

MultiChain streams enable a blockchain to be used as a general purpose append-only database, with the blockchain providing time stamping, notarization and immutability. This video continues from the earlier video post in playlist and now focuses on populating data in the "nutsbolts" blockchain created earlier. 

 

Erstwhile seen node "A" creates a data stream data1, populates some sample data, which is immediately visible in the other node "B". Node A further grants exclusive permissions to Node "B" for send and writing to data stream data1. The complete demonstration is shown on two separate Linux machines as introduced in M-1 and M-2 videos in Multichain playlist i.e. Node A and Node B. data stream created name: "data1" 

 

 Commands used

 

create stream data1 '{"restrict":"write"}' 

 

listpermissions data1.* publish data1 key1 '{"json":{"name":"kabali","city":"chennai"}}' 

 

liststreams 

 

subscribe data1 

 

liststreamitems data1 

 

grant 1...send 

 

grant 1...data1.write 

 

publish data1 key2 '{"json":{"name":"baasha","city":"mumbai"}}' 

 

subscribe data1 

 

liststreamitems data1 

 

liststreamkeys data1 

 

liststreamkeyitems data1 key1 

 

liststreampublishers data1 

 

liststreampublisheritems data1 1...

Multichain : How to Connect-Receive-Send to a Blockchain node?

Continuing from the first video that was peculiar to basic instruction and installation of Multichain blockchain platform on Node A, this video moves further by connecting another node B. Node B is a independent node on the network in which the Multichain blockchain application is already installed exactly with the steps seen in the first video of Multichain playlist . The set of commands used in this videos are available as below:

Node A 

First command onwards 

multichain-util create nutsbolts 

multichaind nutsbolts -daemon 

 

 Node B multichaind nutsbolts@192.168.10.19:4265 (IP is as I have configured and you are free to choose ur configuration as u wish) and you will get a unique address starting with 1...... 

 

Node A multichain-cli nutsbolts grant 1... connect send receive (Here with you grant exclusive permission to Node B from Node A Node B 

 

multichaind nutsbolts -daemon (Now the blockchain network will be seen connected to) 

 

To get into interactive shell mode simply type this command at both the node terminals 

 

multichain-cli nutsbolts 

and then on either terminal use the following commands to get useful info of the created blockchain and network peers 

 

getinfo : See a list of all available commands: 

help : Show all permissions currently assigned: 

listpermissions : List the addresses in the wallet: 

listaddresses : For each node, get a list of connected peers: 

getpeerinfo: Get peer info of connected nodes

 

 

Multichain Blockchain Platform: Brief Introduction & Installation

This video gives a minimal few minutes introduction to the Multichain blockchain platform followed by quick installation on an Ubuntu 20.04 OS terminal. This is one of the easiest platforms to play with and understand in much better way the mechanics of blockchain. Primarily CLI based, this video installs the multichain with few commands.

 

Why 0.1 + 0.2 = 0.30000000000000004 ?

Have you ever tried simple calculations in usual programming languages like python, ruby, rust or Java etc 

0.1 + 0.2 = 0.30000000000000004 or 

0.1 + 0.7 = 0.7999999999999999 or 

0.2 + 0.7 = 0.8999999999999999 or 0.3 - 0.1 = 0.19999999999999998 

Why do the results show something unexpected? The reason pertains to IEEE standard IEEE-754 that defines 32bit/64 bit formats for storage of numbers in computers. This presentation tries to bring out simply of where the anomaly exists and why do we get these results. Also reaffirms that the normal IEEE-754 floating point standard will not befit for usual finance and banking applications wherein few zero's can lead to undesired losses for some and unexpected gains for few.

Full expanded form of IOTA blockchain?

 Well.... I always used to look for the expanded form of IOTA blockchain but could never get the answer. But today I got the same finally vide a chat as produced below:

" it's not an acronym, but it stands for the smallest unit possible in the greek alphabet, as with IOTA also micropayments are possible, e.g. 0.000001 cent. IOTA is engineered completely different than a traditional blockchain, but the IOTA Foundation is one of the leading orgs for DLT research globally, pioneering the DAG (directed acyclic graph) since 2016. The DAG enables parallel access to the DLT. IOTA is designing a green, secure, feeless and highly scalable DLT, without the negative "issues" of blockchain. This also makes it very suitable for data-driven scenarios like DID. Organizations also do not need to buy/hold cryptocurrency"

Thanks Holger Kother...

RTL8761B Tobo Mini USB Bluetooth Adapter installation on UBUNTU 20.04

No intro...no discussion....no details....will come direct to the problem and then the solution. :-)

QUERY / PROBLEM: You planning to buy a Bluetooth adapter for your Linux Operating system and are pondering to buy the right one to avoid any driver or installation issues later. Since window OS users have default drivers but not so with most of devices for Linux. So since I recently bought one Tobo Mini USB Bluetooth 5.0 Adapter Wireless Bluetooth Dongle Receiver, I had to search for solutions for smooth installation. So just few lines of code to be run on the terminal and you will be good to go...the drivers for the same are available at the link https://drive.google.com/drive/folders/1-6NI2-PMbX1wmVb1FYbXblaPvZGdKElD 

Once you access this folder you will find the files as seen in pic below:

Download the Linux folder and you will see some thing like below pic

now goto the terminal inside the usb directory and run this command

sudo make install INTERFACE=all

after this command ,next  move to the /home/ur_username/Downloads/rtl8761b/rtkbt-firmware/lib/firmware and run these two commands

sudo cp rtl8761bu_fw /lib/firmware/

sudo cp rtl8761bu_config /lib/firmware/

and that's all...init 6 and checkout...bluetooth will be seen...best wishes.

Byzantine General - Proof of Work consensus and Mining in Bitcoin Blockchain

Analogical to a Byzantine general scenario wherein a number of armies intending to attack an enemy fort need to reach a consensus of day/time to attack, this video explains how Bitcoin nodes attain consensus vide the Proof-of-work method on the same lines. This video builds up from brief history from David Chaum and Adam Bach works onwards to Wei Dai works on Blind signatures, Hash Cash and Proof-of-Work to understand concept of nonce and consensus mechanism in a Bitcoin Blockchain. Further this video brings out the reward mechanics in the Bitcoin eco-system and also Mining methods and types

Hashes & Merkle Trees in Blockchain Mechanics

Hash Functions take input of any length and produce a fixed-length string which means that one can use hashes on something as small as a few characters or as large as an entire document or even files of huge sizes in GBs and above. 

On the other hand enabled by these hash functions, Merkle tree represent hash-based data structure that is a generalization of the hash list and represent structure in which each leaf node is a hash of a block of data, and each non-leaf node is a hash of its children. Both Hash functions and Merkle Trees are cardinal to the mechanics of any Blockchain. 

This video focuses on a simple explanation of understanding Hashes and Merkle Trees. Hash functions SHA-256 and RIPEMD-160 have been discussed in little detail being peculiar to Bitcoin blockchain.

Distributed Ledger Technology in BLOCKCHAIN - Simple explanation

This video post brings out what DLT i.e. Distributed ledger technology is all about and what is it's contribution to blockchain.

Technology amalgamations inside Blockchain

Blockchain is an amalgamation of multiple technologies which have existed already in the IT ecosystem for last few decades. These include majorly cryptography, private-public keys, hashes, proof-of-work and other important technologies. This video post only identifies by name of what major technologies any blockchain is enabled on.

Where to start the "Learning BLOCKCHAIN" journey ?

Related to my earlier post https://anupriti.blogspot.com/2021/05/i-want-to-learn-blockchain-but-where-do.html this post focuses on the same presentation in a video talk version....

Recent Advances and Trends in Lightweight Cryptography for IoT Security and Blockchain Technologies at RGPV Bhopal 27th July 2021

An FDP was held peculiar to domain of  Lightweight Cryptography for IoT Security and Blockchain Technologies at RGPV Bhopal on 27th July 2021.The objective of this FDP was to bring together faculties, researchers, PG and UG students from across the country to learn about security challenges in Modern Cryptography, Blockchain & IoT. FDP aimed to demonstrate security challenges that Modern Cryptography, Blockchain, IoT systems pose, demands users to select a reliable and compatible architecture according to the business requirements to ensure secure flow of data and communication and also define the solution and future prospects related to these challenges. I gave a small 2 hour talk on the same which is available at the youtube link below

 CLICK ON THE IMAGE BELOW TO BE REDIRECTED TO THE YOUTUBE LINK

WHAT BLOCKCHAIN SIMPLY MEANS : A Short attempt

A short simple video to represent the mechanics of blockchain and ends with mentions of technologies running a Blockchain.
 

National E-Conference on Regulation of Crypto-currency in India - 24 July 2021 at NLIU Bhopal

National E-Conference on Regulation of Crypto-currency in India was held on 24 July 2021. The themes covered in the conference are seen in the below pic:

I was part of the valedictory session of this conference, invited as a chief guest in the evening concluding session. More details of the same available at https://www.barandbench.com/apprentice-lawyer/first-national-e-conference-on-regulation-of-cryptocurrency-in-india-by-rgnclc-nliu-bhopal

Cryptocurrency Technology Foundations and Crimes Investigations

 To fight against the rising challenges of Cyber Crimes, the Gurugram Police in association with Society for Safe Gurgaon, Indo-Israeli cyber security enterprise and SafeHouse Technologies organised the 9th edition of Gurugram Police Internship (GPCSSI 2021) under the mentorship of ACP Cyber crime Karan Goel and the entire Gurugram police cyber crime team in coordination with Rakshit Tandon Advisor Cyber Peace foundation. This presentation talk on cryptocurrency technology and crimes investigation was taken by Anupam Tiwari on 05th July 2021. Sharing for info of interested in domain.

Cryptocurrency Technology F... by Anupam Tiwari

MERGING PDF: UBUNTU 20.04 LTS

This small post shares a one line command in Ubuntu terminal to merge to PDFs. While for the regulars,merging the same online would seem to be the quickest and the best but there are times when you wish your PDFs are not compromised by third party websites offering these mergers for free...so why not use a one line command with the help of a tool pdftk.

The command to install the same is 

sudo apt-get install pdftk

and the command thereafter to merger the PDFs like three files 1.pdf, 2.pdf and 3.pdf is as seen below:

 pdftk 1.pdf 2.pdf 3.pdf cat output 4.pdf

where 4.pdf is the merged final output file.

That's all...no third party website reliance for private files.

TALLINN MANUAL & GLOBAL ATTEMPTS IN CYBER WARFARE POLICIES

The presentation is one unique presentation peculiar to TALLINN MANUAL version 1.0 and 2.0. Along with is discussed cyber policy attempts of other countries.The Tallinn Manual has long been the flagship research initiative of the NATO CCDCOE. The original Tallinn Manual (published in 2013 by Cambridge University Press) addressed the most severe cyber operations followed by version 2.0. The presentation cover the origin details of why this manual arrived at the global scene and what followed around at the global attempts for framing the global cyber policy.

TALLINN MANUAL & GLOBAL CYBER WARFARE POLICIES from anupriti

I want to learn Blockchain, but where do I start from? : Here is My Answer.

I am writing this one exclusive post for guys who just wish to begin their journey in the domain of Blockchain. "Blockchain" term has been buzzing across academia, universities, corporate industries and every where around. In most of the webinars I speak in, I find many inquisitive learners willing to jump in the domain but unable to find that exclusive blockchain sea where to dive in. And if ever they try diving in, the sheer amount of books, videos and sea of information existing on the internet just splashes their visions soon to drown. Herewith I am sharing few slides that are based on my journey in this domain for now over 5 years. The presentation brings out details of topics one should start exploring and dig in followed by few books that I have in person followed and imbibed from.

How to Start Learning BLOCK... by Anupam Tiwari

Technology Internals behind Blockchain Technology

I have erstwhile shared and uploaded a number of presentations on Blockchain technology and crypto crimes though. This presentation solely focuses on internals of blockchain technology and has additional details starting from scratch for newbies to develop an initial understanding of this awesome technology. Anyone with any clarifications on any slide may contact back at the email mentioned at end of the presentation. Also sharing a picture of my books peculiar to my blockchain exploring interest

Technology Internals behind Blockchain Technology by Anupam Tiwari on Scribd

Blockchain Forensics & Cryptocurrencies : NFSU FDP 09 April 2021

The School of Cyber Security and Digital Forensics, National Forensic Sciences University, Gandhinagar organised a 5 day online Faculty Development Program (FDP) on 'Advanced Trends in Digital Forensics' from 05 Apr-09 Apr 2021.The aim of this FDP was to promote research and strengthen the Digital Forensic Investigation Techniques which include topics like crime investigation, latest trends in Digital Forensics, Fake News Detection, and Drone & Crypto Forensics. I was a invited speaker here and am sharing my presentation deck here on blockchain and cryptocurrency forensics.

 

 

Cryptocurrency Forensics and Blockchain Technology by Anupam Tiwari on Scribd

BRAVE Web Browser : How much advertisements I blocked in a week ?

Hello friends, herewith first I am sharing screen shots of my brave browser dashboard that I captured over a week from 30 Jan 2021 to 6 Feb 2021.The screen shots I have taken pertain to morning hours whenever I login for the day. I am generally on my PC for about 8-9 hours a day. I majorly watch YouTube videos and surf across multiple sites in a day that range from 50-100 at times. So what I am bringing out here that how many ads Brave browser has blocked in this duration and whilst this surfing times.

30 Jan 2021 : 70517 blocked : Counter 0

 31 Jan 2021 : 77744 blocked : Counter 7227  in day( i.e. 30 Jan 2021)

01 Feb 2021 : 92342 blocked : Counter 14598  in day( i.e. 31 Jan 2021)

02 Feb 2021 : 97440 blocked : Counter 5098  in day( i.e. 01 Feb 2021)

03 Feb 2021 : 105386 blocked : Counter 7946  in day( i.e. 02 Feb 2021)

04 Feb 2021 : 108354 blocked : Counter 2968  in day( i.e. 03 Feb 2021)

05 Feb 2021 : 112036 blocked : Counter 3682  in day( i.e. 04 Feb 2021)

06 Feb 2021 : 114870 blocked : Counter 2834  in day( i.e. 05 Feb 2021)

So,total ads blocked over a week is 44353 that deduces to approx average of 6336 ads/day. That's phenomenal to say. Each of these trackers would be definitely linked to thousands of other trackers also giving them unrestricted access to all the user behavior ,privacy and profiles. While there is not much a normal user can do about these trackers, I feel just blocking these thousands of ads will not make any one absolutely free of tracking,but still better than surfing without blockers. Because if the ad companies know that users are blocking by means of plugins and such browsers,they would have already found ways to still track you. After all that's their means of living and minting economy.

REMOVE METADATA FROM IMAGES: UBUNTU with exiftool utility

Just few commands in Ubuntu to check the meta data and thereafter remove the same.I am using a utility exiftool which does not come inbuilt to most of the Linux systems,but we need to install them.

INSTALL COMMAND

sudo apt-get install libimage-exiftool-perl

USAGE COMMAND

exiftool -all= IMG_20200504_215424.jpg

(The above command creates a separate copy of the original file and the new file which is created with removed metadata)

or

exiftool -overwrite_original -all= IMG_20200504_215424.jpg 

(The above command overwrites the original file with the new file created with removed metadata)

Showing you output of one file prior to removal of meta data and thereafter removing the meta data

ORIGINAL FILE

kabali@Kabali:~/Desktop/ddd$ jhead IMG_20200504_215424.jpg
File name    : IMG_20200504_215424.jpg
File size    : 3588382 bytes
File date    : 2021:01:31 14:10:13
Camera make  : Xiaomi
Camera model : Mi A2
Date/Time    : 2020:05:04 21:54:24
Resolution   : 4000 x 3000
Orientation  : rotate 90
Flash used   : No
Focal length :  4.1mm  (35mm equivalent: 4mm)
Exposure time: 0.050 s  (1/20)
Aperture     : f/1.8
ISO equiv.   : 1000
Whitebalance : Auto
Metering Mode: center weight
GPS Latitude : ? ?
GPS Longitude: ? ?
JPEG Quality : 98

REMOVED METADATA FILE

kabali@Kabali:~/Desktop/ddd$ jhead IMG_20200504_215424.jpg

File name    : IMG_20200504_215424.jpg
File size    : 3556853 bytes
File date    : 2021:01:31 14:30:08
Resolution   : 4000 x 3000
JPEG Quality : 98

 

REMOVING META DATA FROM VIDEO FILES : UBUNTU TERMINAL COMMANDS

Hello everyone, this post focuses on removing metadata from a video file using ffmpeg inbuilt utility in Ubuntu OS. The following command includes the original file MAH08207.mp4 being stripped of metadata and being output into a new file as output.mp4.

ffmpeg -i MAH08207.mp4 -map 0 -map_metadata -1 -c copy output.mp4

The output of the command is as below:

ffmpeg version 4.2.4-1ubuntu0.1 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 9 (Ubuntu 9.3.0-10ubuntu2)
  configuration: --prefix=/usr --extra-version=1ubuntu0.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'MAH08207.mp4':
  Metadata:
    major_brand     : MSNV
    minor_version   : 22675568
    compatible_brands: MSNVmp42isom
    creation_time   : 2020-11-09T00:48:18.000000Z
  Duration: 00:00:44.16, start: 0.000000, bitrate: 12146 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709/bt709/iec61966-2-4), 1440x1080 [SAR 4:3 DAR 16:9], 12016 kb/s, 25 fps, 25 tbr, 25k tbn, 50 tbc (default)
    Metadata:
      creation_time   : 2020-11-09T00:48:18.000000Z
      handler_name    : Video Media Handler
      encoder         : AVC Coding
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 127 kb/s (default)
    Metadata:
      creation_time   : 2020-11-09T00:48:18.000000Z
      handler_name    : Sound Media Handler
Output #0, mp4, to 'output.mp4':
  Metadata:
    encoder         : Lavf58.29.100
    Stream #0:0: Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709/bt709/iec61966-2-4), 1440x1080 [SAR 4:3 DAR 16:9], q=2-31, 12016 kb/s, 25 fps, 25 tbr, 25k tbn, 25k tbc (default)
    Stream #0:1: Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 127 kb/s (default)
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (copy)
Press [q] to stop, [?] for help
frame= 1104 fps=0.0 q=-1.0 Lsize=   65489kB time=00:00:44.13 bitrate=12154.5kbits/s speed= 540x    
video:64774kB audio:688kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.039428%

The size of the original file and the stripped of file is

-rw-r--r-- 1 kabali kabali 67050400 Nov  9 06:19 MAH08207.mp4
-rw-rw-r-- 1 kabali kabali 67060450 Jan 29 20:23 output.mp4 

Thus difference between the files is the meta data removed.

I am also showing the output of ffprobe utility run on the two files to show you the difference of meta data removed too.

ffprobe MAH08207.mp4

 ffprobe version 4.2.4-1ubuntu0.1 Copyright (c) 2007-2020 the FFmpeg developers
  built with gcc 9 (Ubuntu 9.3.0-10ubuntu2)
  configuration: --prefix=/usr --extra-version=1ubuntu0.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'MAH08207.mp4':
  Metadata:
    major_brand     : MSNV
    minor_version   : 22675568
    compatible_brands: MSNVmp42isom
    creation_time   : 2020-11-09T00:48:18.000000Z
  Duration: 00:00:44.16, start: 0.000000, bitrate: 12146 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709/bt709/iec61966-2-4), 1440x1080 [SAR 4:3 DAR 16:9], 12016 kb/s, 25 fps, 25 tbr, 25k tbn, 50 tbc (default)
    Metadata:
      creation_time   : 2020-11-09T00:48:18.000000Z
      handler_name    : Video Media Handler
      encoder         : AVC Coding
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 127 kb/s (default)
    Metadata:
      creation_time   : 2020-11-09T00:48:18.000000Z
      handler_name    : Sound Media Handler

ffprobe output.mp4 

 ffprobe version 4.2.4-1ubuntu0.1 Copyright (c) 2007-2020 the FFmpeg developers
  built with gcc 9 (Ubuntu 9.3.0-10ubuntu2)
  configuration: --prefix=/usr --extra-version=1ubuntu0.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'output.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.29.100
  Duration: 00:00:44.16, start: 0.000000, bitrate: 12148 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709/bt709/iec61966-2-4), 1440x1080 [SAR 4:3 DAR 16:9], 12016 kb/s, 25 fps, 25 tbr, 25k tbn, 50 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 127 kb/s (default)
    Metadata:
      handler_name    : SoundHandler

SPLIT VIDEOS IN UBUNTU: SINGLE LINE COMMAND{ffmpeg utility}

Sharing here just a single line command of ffmpeg utility which can split a video with time duration's specified.So if your video is suppose 05:03(min:sec) long and you wanna split it into two sizes with part 1 as 00:00 to 02:28 and the other part 2 as 02:28 to 05:03,the commands to be executed will be

ffmpeg -i VID_20210129_115611.mp4 -ss 00:00:00 -t 00:02:28 part1.mp4

ffmpeg -i VID_20210129_115611.mp4 -ss 00:02:28 -t 00:05:03 part2.mp4

where VID_20210129_115611.mp4 is the main file and part1.mp4/part2.mp4 are the respective output files.

MERGE VIDEOs IN UBUNTU: TWO TERMINAL COMMANDS

Hi guys...no time waste here...I m mentioning two commands to simply merge your multiple videos quickly in an Ubuntu OS.No GUI or other applications to download or use. The ffmpeg command inbuilt to Ubuntu easily merges without hassles.

So,the first command is 

find "$(pwd)" -type f -name '*.mp4' -printf "file '%p'\n" | tee mp4_compile.txt

The above command will simply find your all mp4 files in the directory wherein you run this command in the terminal directory and compile them into one text file. This text file is named here as mp4_compile.txt. You can name it any thing.

The second command is as given below:

ffmpeg -f concat -safe 0 -i mp4_compile.txt -c copy merged.mp4

This command will merge all the files compiled in the txt file and merge into one output file names as merged.mp4

Thats all...I actually went through a lot of softwares and applications...tried online merge too but all had some kind of limitation in size...till I found these commands.So happy sharing and happy merging.

NOTHING BLOCKCHAIN ABOUT IT :-)

Ubuntu 20.04 LTS brightness control with command line[SOLVED]

While I moved my kernel face from 18.04  to 20.04 LTS,there were few irritants while I got adapted to new interface and features…and one of them was the missing brightness tab in Ubuntu 20.04 LTS. Don’t know why it was removed,but then may be a small community used it and so was discontinued. So I tried third party plugins, few new brightness apps also tried brightness controller but somehow was not happy with the desired screen brightness control.Though Ubuntu 20.04 has night light feature wherein you can tweak with color temperatures from  less warm to more warm but that too fall short of my requirement. So I just wanted a clean hassle free solution. So I got to know about the xrandr command. Xrandr is used to set the size, orientation and/or  reflection  of  the outputs for a screen. It can also set the screen size. 

The good thing is that this utility comes pre-installed with the OS. You just need to use it vide few command line inputs and these are as below:

The first command is

xrandr | grep " connected" | cut -f1 -d " "

This command basically gives you an output of the name of your monitor. In my case it gives HDMI-0.

 

After this command you need to use the same command with different switch and adjusting the brightness to suit your eyes. While 1 refers to highest brightness 0.1 refers to the lowest.So in bright rooms if you wish to set like me,I generally prefer 0.7.The command line goes like this:

 xrandr --output HDMI-0 --brightness 0.7

Other functions that this utility can assist you are with setting resolution and refresh rates. The command lines are mentioned below:

 

SETTING RESOLUTION

xrandr --output HDMI-0--mode 1680x1050

SCREEN REFRESH RATE

xrandr --output HDMI-0--mode 1680x1050 --rate 60.00

Another switch –q will query your monitors and give details as seen below

 Just remember to change your screen name as per your monitor name...in my case like I said...it is HDMI-0.

CQ 100: Meet India’s Most Influential Cyber Warriors

First post in this year...though little delayed comes as a pleasant surprise from the cyberosphere.....Sharing here the link of a post that has identified India’s most influential cyber warriors  and has listed me too....

https://www.the420.in/cq-100-meet-indias-most-influential-cyber-warriors-top-cyber-experts/

Screenshot as below: