2017-12-31

HOWTO: get a high-resolution version of an image on Blogger

Here is a quite big garbage JPEG picture made of pseudo-random noise.

A noisy picture thumbnail
Thumbnail URL:
https://4.bp.blogspot.com/-sEeS5fhFsls/WkhY4QbN6gI/AAAAAAAAB4Y/h3g9pKlr0UkRE3d4tcHXnMTBdGqOyXd2ACLcBGAs/s320/noise01.jpg
"Big image" direct link URL:
https://4.bp.blogspot.com/-sEeS5fhFsls/WkhY4QbN6gI/AAAAAAAAB4Y/h3g9pKlr0UkRE3d4tcHXnMTBdGqOyXd2ACLcBGAs/s1600/noise01.jpg
And now we can guess a link to even bigger-sized version:
https://4.bp.blogspot.com/-sEeS5fhFsls/WkhY4QbN6gI/AAAAAAAAB4Y/h3g9pKlr0UkRE3d4tcHXnMTBdGqOyXd2ACLcBGAs/s2048/noise01.jpg

2017-12-30

ZyXEL P660RT2 EE command line configuration (Ethernet)

ZyXEL P660RT2 EE is an old ADSL[2+] router that has been quite common in post-USSR/CIS countries.

This router permits to do some things (i. e. configuration and diagnostics) via command line (by Telnet; the default password is 1234).
E. g., you can set the Ethernet port mode manually.
$ telnet 192.168.1.1
Trying 192.168.1.1...
Connected to 192.168.1.1.
Escape character is '^]'.

Password: ****
Copyright (c) 1994 - 2010 ZyXEL Communications Corp.
P660RT2> ether driver config
Usage: driver config [0|1=auto|normal] [0|1=10|100] [0|1=HD|FD] <ch-name>
P660RT2> 
E. g., to set 10 Mbps full-duplex mode:
P660RT2> ether driver config 1 0 1 enet0
Then, maybe you want to reboot the router:
P660RT2> sys reboot
Connection closed by foreign host.
Or you can just exit the CLI instead:
P660RT2> exit
Connection closed by foreign host.
Notes:
  1. the <Backspace> key doesn't work as it should for the router's CLI, but you can use <←> (left arrow) key instead;
  2. after you enter the Ethernet configuration command, the router may become unresponsive for a couple (or dozen) of seconds;
  3. Ethernet configuration is saved into the non-volatile memory, and persists after reboot;
  4. incorrect configuration (or one incompatible with other network equipment) may result in the router becoming unresponsive, seemingly hung-up and unaccessible via its sole Ethernet port;
  5. you can reset it to the factory settings using the "RESET" button hole at its back;
  6. hence, please back up your current router configuration (e. g. via the router's web interface) before touching the settings.
References:
  1. ZyXEL Prestige 650M-6x ADSL Modem User's Guide
  2. ZyXEL P660RT2 EE manuals

ZyXEL P660RT2 EE manuals

ZyXEL P660RT2 EE is an old ADSL[2+] router that has been quite common in post-USSR/CIS countries.

Available manuals
DescriptionDocument URLInfo URL
Quick start guidehttp://download.from.zyxel.ru/download/84887071-3a11-4da9-97e0-cf5a3aa65770/P660RT2_QSG.pdfhttp://download.from.zyxel.ru/download/84887071-3a11-4da9-97e0-cf5a3aa65770/file_id.diz
User's guidehttp://download.from.zyxel.ru/download/d93a81bc-99b6-47c5-b8c7-09aaa696cf97/p660rt2_ee_ug.pdfhttp://download.from.zyxel.ru/download/d93a81bc-99b6-47c5-b8c7-09aaa696cf97/file_id.diz


Notes:
  1. the manuals are in Russian language;
  2. file_id.diz files contain the SHA256 hashes of the PDFs (and also some old and new download URLs).

Reference:

2017-12-29

ZyXEL P660RT2 EE firmware versions

ZyXEL P660RT2 EE is an old ADSL[2+] router that has been quite common in post-USSR/CIS countries.

Known FW versions
VersionArchive URLInfo URL
3.40(AXN.0)D0http://download.from.zyxel.ru/download/525e69ec-341d-46be-b594-484ec4378dbb/340AXN0D0.ziphttp://download.from.zyxel.ru/download/525e69ec-341d-46be-b594-484ec4378dbb/file_id.diz
3.40(AXN.1)D0http://download.from.zyxel.ru/download/2d13f8d6-241e-4cf9-b7f9-6a9974836d0a/340AXN1D0.ziphttp://download.from.zyxel.ru/download/2d13f8d6-241e-4cf9-b7f9-6a9974836d0a/file_id.diz
3.40(AXN.2)D0http://download.from.zyxel.ru/download/0c061795-afb5-4859-bade-80ccfbfef831/340AXN2D0.ziphttp://download.from.zyxel.ru/download/0c061795-afb5-4859-bade-80ccfbfef831/file_id.diz
3.40(AXN.3)D0http://download.from.zyxel.ru/download/a17310da-b9c7-402f-ab46-64a43ba09fc6/340AXN3D0.ziphttp://download.from.zyxel.ru/download/a17310da-b9c7-402f-ab46-64a43ba09fc6/file_id.diz
3.40(AXN.3)D0_20100617http://download.from.zyxel.ru/download/8b436301-004a-42c0-b698-563080eab1e2/340AXN3D0_20100617.ziphttp://download.from.zyxel.ru/download/8b436301-004a-42c0-b698-563080eab1e2/file_id.diz


Notes:
  1. the latest firmware version is 3.40(AXN.3)D0_20100617;
  2. file_id.diz files contain the SHA256 hashes of the ZIP archives (and also some old and new download URLs);
  3. usually, it's recommended to reset the router configuration after the firmware upgrade (you can find the "RESET" button hole at the back of the router).

Reference:

2017-12-28

HOWTO: grab online video stream with FFmpeg

Usually, it's quite easy to save some free online (live) video streams with FFmpeg.

Example: grabbing some HLS stream with MPEG-4 (H.264) video and AAC (or MP3) audio.
$ ffmpeg -i "http://some.streaming.server/favorite_stream.m3u8" -codec copy -f mpegts stream01.ts
(Generally, the output format can be guessed by extension automatically, so we can shorten the command line).
$ ffmpeg -i "http://some.streaming.server/favorite_stream.m3u8" -codec copy stream02.ts
The TS file is usually playable during download.
Usually, you can stop the grabbing operation at any time by pressing the <q> key.
After the stream dumping is finished, you can convert (remux) your video to a more familiar MP4 container format.
$ ffmpeg -i stream01.ts -codec copy stream01.mp4
(Usually, you'd prefer a playback-optimized output file).
$ ffmpeg -i stream02.ts -codec copy -movflags faststart stream02.mp4

Reference:

2017-12-25

HOWTO: optimize MP4 video for fast loading with FFmpeg

MP4 video loading can be accelerated (e. g., allowing playback of partially downloaded videos) by moving the metadata (the "moov atom") to the beginning of the file. And that's a lossless procedure (no video, audio or subtitle data gets lost)!
  1. Can be performed very fast and easily with the qt-faststart utility (targeted primarily at Apple QuickTime MOV files, but should work for most MP4 base media files too); you can find that utility in your favorite FFmpeg distribution.
    $ qt-faststart in01.mov out01.mov
    $ qt-faststart in02.mp4 out02.mp4
  2. More thorough method involves remuxing with the universal ffmpeg program (just only a little bit slower):
    $ ffmpeg -i in10.mp4 -codec copy -movflags faststart out10.mp4
Reference:

2017-12-23

Websites: VirusTotal

VirusTotal is a great online virus scanner, a Google subsidiary.
You can either scan a local file, or submit a remote URL; you can also search the database by file hash (SHA256, SHA1, MD5).
There is also a rating system for registered users.
Warning: all files you try to scan using this online service are actually get uploaded onto the remote server (or "cloud") for scanning, and subsequently can be shared with antivirus software developers in the future, so you should avoid scanning any confidential documents with this service ;-)
By uploading new malware, we can somehow improve the contemporary anti-virus solutions!

Links:

2017-04-21

HOWTO: decompress WOFF2 fonts

Once upon a time you can stumble upon a WOFF2 font file; it's in WOFF 2.0 format, an improved version of Web Open Font Format.
And it's quite easy to unpack such compressed files to get the usual TTF (and maybe OTF) fonts -- just use the woff2_decompress utility from the woff2 Google project on GitHub:
$ woff2_decompress myfont.woff2
(please note: you need to compile that project before use, and it's much easier to do in GNU/Linux and other Unix-like environments, than in MS Windows).

2017-04-01

Websites: BugMeNot (shared logins)

Have you ever visited an ugly site requiring registration to access some ordinary info? Tired of countless one-time registrations?
BugMeNot can help: it's the site where you and other ordinary users can share their useless login info (disposable email addresses are usually used for such registrations) for a variety of useless sites :-)

Disclaimer: no warranties, only for educational use, some sites get blocked from the site, and please don't abuse it etc. ;-)

External links:
  1. BugMeNot: share logins
    1. microsoft.com passwords - BugMeNot
  2. BugMeNot - Wikipedia

2017-03-30

HOWTO: base64 manipulations in Linux

Do you want to decode some base64-encoded strings (or any other data), or convert some binary file to text (in base64)?
It's quite easy to do that in Debian GNU/Linux: base64 utility is a part of coreutils package (that package has a "required" priority, i. e., it's an essential package for the system to work).

When you finish typing your strings, don't forget to press <Enter> followed by <Ctrl> + <D> (or <Ctrl> + <D> twice, if you don't like newlines).
$ base64
Hello, world!
SGVsbG8sIHdvcmxkIQo=
$ 
$ base64 -d
SGVsbG8sIHdvcmxkIQo=
Hello, world!
But it may be safer to use file input-output, e. g.:
$ base64 -d in.txt > out.dat

References:
  1. man base64
  2. GNU Coreutils: base64 invocation
  3. Base64 - Wikipedia

See also: