Interest physics documents

Computation documents

Folder Lock

FL720 : Folder Lock problem.

DVD Sizes

Keep in mind that manufacturers quote the capacity of a writable DVD disc in decimal (base 10) rather than binary (base 2) notation so a 4.7 GB disc stores 4.7 billion bytes [4:700,000,000 bytes ÷ 1000 = 4,700,000 KB ÷ 1000 = 4,700 MB ÷ 1000 = 4.7 GB] . Expressed in binary notation (as is typical with CD-R, CD-RW and most operating systems) the same disc has a capacity of roughly 4.38 GB [4:700,000,000 bytes ÷ 1024 = 4,589,844 KB ÷ 1024 = 4,482.27 MB ÷ 1024 = 4.38 GB]

  • 4.7GB single layer DVD -> 4482MB -> 4.3GB
  • 8.5GB dual layer DVD -> 8106MB -> 7.9GB
  • 25GB single layer blu ray -> 23842MB -> 23.2GB
  • 50GB dual layer blu ray -> 47684MB -> 46.5GB

Split a folder in DVD sizes multi-iso files.

First split the folder in different volumes :

 dirsplit -s 8152M -e2 dir/

If you want in a single layer dvd use -s 4488 or -s 700M for a CD.

This will generate vol_N.list files (1..N) then generate a iso file of this volumes using :

 mkisofs -o vol_1.iso -D -r --joliet-long -graft-points -path-list vol_1.list

Then burn the iso files using a standard cd-burn utility like K3B or cdrecord.

Performance test.

Wrap a file text in vim

first, set the width of the text,

 :set wrapmargin 50

second, apply the wrap,

 :set wrap


Others (my personal tips)

Convert a OGV to an AVI using mencoder

 mencoder input.ogv -ovc xvid -oac mp3lame -xvidencopts pass=1 -o output.avi

Install a cls latex style in my home folder.

Create the folder texmf/tex/latex

 mkdir -p ~/texmf/tex/latex

Copy your cls or sty files there

 cp superstyle.cls ~/texmf/tex/latex

Update the latex databse


Done ;)

Convert file m4v to avi

 ffmpeg -i file.m4v -f avi -sameq -o ouptut.avi

Read mkv file info

 mkvmerge -i file.mkv

Convert mkv to Xvid

Subtitles options is personal.

 mencoder -sub es file.mkv -oac mp3lame -ovc xvid -xvidencopts pass=1 -o output.avi

Used size to movies

 1920x1080 -> FullHD
 1280x720  -> Normal DVD (modern HD)
 720x576   -> The more used in classical DVD players.

to convert using scale use the option :

 mencoder -vf scale=1280:720

Color in terminal (specially ntfs colors)

 dircolors --print-database > ~/.mydircolors

edit your file and set

 STICKY_OTHER_WRITABLE 01;34 # dir that is ....
 OTHER_WRITABLE 01;34 # dir that is ....

Finally for some versions, your bashrc must be modified in :

 `dircolors -b`


 `dircolors ~/.mydircolors`


Files with music

This are my four DVD with music, unorganized.

Volume 1

Volume 2

Volume 3

Volume 4




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