Ubuntu Multimedia
Sound
To record sound from microphone:
$ parecord file_name
To play back a sound file:
$ paplay file_name
To just speak out some text:
$ spd-say "Hello $(whoami)... How are you doing?"
Images
To resize an image and set the new width to 520px:
$ convert "IMG*.jpg[520x]" -set filename:base "%[base]" \ "%[filename:base]_R.jpg" filename
To resize an image to half:
$ convert "IMG*.png[50%]" -set filename:base "%[base]" \ "%[filename:base]_H.png" filename
To change the modification time of an (image) file to the time present in its EXIF header:
$ exiftool "-DateTimeOriginal>FileModifyDate" filename
The exiftool command is very powerful. You can
get meta information for almost any type of file (besides image files):
$ exiftool /bin/ls