by ·2 Comments

avconv must be installed

Make sure you have a list of JPEG files in one directory and that they are named sequentially i.e.

DSC_5015.JPG
DSC_5016.JPG
DSC_5017.JPG
...
...

Some versions of avconv will insist on the files starting with ‘0000’ somewhere in the first file. To rename the files, use the following command:-

ls *.JPG| awk 'BEGIN{ a=0 }{ printf "mv %s myfile%04d.JPG\n", $0, a++ }' | bash

This will rename all your files to:-

myfile0000.JPG
myfile0001.JPG
myfile0002.JPG
...
...

If you wan to create a clip with the original resolution (4256 x 2832 in this case) with high quality, use the following command:-

avconv -y -r 10 -i myfile%4d.JPG -r 10 -vcodec libx264 -q:v 3  -vf crop=4256:2832,scale=iw:ih tlfullhiqual.mp4;

-y forces avconv to overwrite any file
-r 10 creates a clip with 10 frames per seconds (for some versions of avconv you have to specify it twice)
-i specifies the input file(s). %4d means any 4 decimal numbers
-vcodec specifies the video codec to be used (H.264 in this case)
-q:v specifies the quality, value ranges from 1 (best) to 31 (worse)
crop= specifies which area of the images will be cropped
scale= indicates how much scaling must take place (in the above example iw:ih indicates that the output width and height will be that of the in width and in height)
the last parameter is the output file

To create a clip that is a quater of the height and width as the original with less image quality, use the following command:-

avconv -y -r 10 -i myfile%4d.JPG -r 10 -vcodec libx264 -q:v 20 -vf crop=4256:2832,scale=iw/4:ih/4 tlsmallowqual.mp4;

To create a .flv file

avconv -y -r 10 -i myfile%4d.JPG -r 10 -vcodec libx264 -q:v 3 -vf crop=4256:2832,scale=320:-1 -c:v flv tlsmallest.flv;

Here I moved the quality up, because the resolution is low

by ·0 Comments

To resize all the JPEG files in a directory so that one of the dimensions is maximum 800 pixels.
The \> implies that the images will only be made smaller, never bigger

ImageMagick must be installed

 mkdir tmp  
 for file in `ls *jpg`; do echo $file; convert $file -resize 800x800\> tmp/$file; done

by ·27 Comments

If you, like me, often work with an extra screen attached to your notebook,
you would surely have come across the problem where your applications open ‘off-screen’
or in other words, on your secondary screen, even when it is not plugged in.

WinAmp is especially finicky with this one and the solution is not as straightforward
as many people might have you believe. Or should I rather say, in Windows 7 the
solution is not as simple as expected.

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