2010. november 18.

OGM to AVI with hardcoded subtitles

I was trying to hardcode a subtitle while "-ovc copy". How silly of me. It is only possible to hardcode a subtitle if mencoder has to process the video file frame by frame, as it modifies the pictures when hardcoding.

For whatever reason MEncoder didn't want to work for me recoding a Vorbis audio stream to mp3 with Lame, so two steps were added in between.

#1. Demuxing OGM to separate stream-files
ogmdemux input.ogm

#2. Converting audio track to mp3
soundconverter -b -m audio/mpeg -s .mp3 input.ogm-a1.ogg

#3. Muxing video, audio and subtitle into an avi
mencoder input.ogm-v1.avi -o output.avi -audiofile input.ogm-a1.mp3 -oac copy -ovc lavc -lavcopts vcodec=mpeg4 -sub input.ogm-t1.str

#1-3. Of course at the end I managed to do steps 1-3 in a single step:
mencoder input.ogm -aid 1 -sub input.srt -o output.avi -oac mp3lame -lameopts cbr=128 -ovc lavc -lavcopts vcodec=mpeg4

I guess to achieve the all inclusive #1-3, I had to install some stuff and make mplayer for myself...
sudo apt-get install libasound2-dev libfreetype6-dev zlib1g-dev libmp3lame-dev libfontconfig1-dev libexpat1-dev ogmtools
./configure --enable-theora --enable-libdv --enable-mp3lame --enable-mp3lame-lavc --enable-mp3lib --enable-debug
But of course I don't know what exactly did the trick.

For a better quality it's possible to use extra options, like -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=5000:mbd=2:trell
To get needed value of vbitrate do a mencoder -ovc frameno -o frameno.avi -oac copy input.avi and read your value in the terminal window.

Gentoo Forums

2010. november 14.

ImageMagick BMP compression

To make uncompressed BMP files, or to decompress BMP files in ImageMagick, use the -compress none option.

To make less then 24-bit BMP files in ImageMagick, use the -colors 256 option, which would make a 8-bit BMP file.

Use these settings to be able to import scores into Neuratron PhotoScore.

2010. november 13.

image to pdf

I really can't handle ImageMagick when it comes to pdf files. It creates such huge files they are completely useless.

I tried out another way: pbm -> ps -> pdf:

first I ImageMagick convert pbm-s:
mogrify -format ps -density 300x300 *.pbm
then put them into ps2pdf:
lista=(`find -iname '*.ps' | sort`)
for i in "${lista[@]}"
ps2pdf -r300 -g1880x2688 $i $i.pdf

and bind them:
pdfjoin *.pdf --outfile output.pdf

It worked brilliantly. This way my pdf is 8 times smaller then my original pdf, and it's only 1.5 times bigger then the djvu I made from the same images.

Djvu was made directly from pbm files, converted with cjb2 and binded with djvm. No special option was used.

2010. november 7.

Image INFO through ImageMagick

identify -verbose image.jpg

To get only what you want to see you can use GREP like this:

identify -verbose image.ps | egrep "Resolution|Geometry"

This will return you the lines with Resolution and Geometry. Just what I need to make good compressed pdf files with ps2pdf.