vcs should be run from the command line. Through the use of command-line options or configuration files its behaviour can be configured to fit your needs.
When run with no arguments, vcs will show the following traits:
$ vcs “some file.avi”will produce
vcswon't ever overwrite files (unless a bug slips). If the output file exists it will add a numbered suffix before the extension, so if
output.pngexists it will create
output.avi-3.pngand so on)
There's two ways to decide how many captures are made: at intervals or a fixed number. These correspond to the command-line options
-n respectively (long options:
The fixed number mode is aesthetically preferable because it can always fill the contact sheets, while the interval mode might leave some empty spaces.
Intervals can be specified in number of ways, see Time/Interval syntax for details. To take a capture every minute you could use
$ vcs -i 1m file.avi.
vcs will show how many captures will make in total while working, e.g.:
Generating capture #1/7 (04:16.15)... Generating capture #2/7 (08:32.31)... Generating capture #3/7 (12:48.46)... Generating capture #4/7 (17:04.62)... [...]
In this example 7 captures are to be made, 4 have been completed already.
Setting a fixed number on captures is straightforward, just follow the appropriate option with the number of captures, e.g. to make 8 captures:
$ vcs -n 8 file.avi.
Note it (obviously) doesn't make sense to use both
-i. The last one in the command line will prevail.
The number of columns produced is dictated by the
--columns) argument. Follow it by the number of columns.
The number of rows can't be manually set, there will always be as many as needed to accommodate the number of columns and captures.
Size of the captures can be set by defining their height and/or their aspect ratio. Width is always derived, this is by design although by combining height and aspect ratio you can manually set both width and height (explained below). The size of the full contact sheet can't be directly controlled.
To set the capture height use the
--height) option followed by the height in pixels or a percentage (with a percentage, height will be computed from the source height).
To set the aspect ratio use the
--aspect) option followed by the aspect ratio either as a (floating point) number or a fraction (both 1.33 and 4/3 are valid formats).
To force a certain width combine height and aspect ratio, e.g. if you want your captures to be 300×200 pixels you can use
-H 200 -a 300/200 (in case it isn't obvious, an image 200px high and having a 300/200 –same as 3/2, 1.5– aspect ratio must be 300×200 pixels).
--autoaspect) to let
vcs try to guess aspect ratio. Guesses are only made on well known resolutions (i.e. VCD and DVD family of resolutions), note that for cases in which both a 4:3 and a 16:9 resolution are possible 4:3 is chosen. If it can't be guessed the original aspect ratio will be used.
vcs 1.11 and higher only
The output filename can be set with the
–output) option. Repeat for each input filename.
Additionally the file extension of the output filename can also control the file format.
$ vcs input.avi -o output.jpg
Save output of
output1.jpg, output of
output2.png and output of
$ vcs file1.avi file2.avi file3.avi -o output1.jpg -o output2
A title like can be added through the
--title) option. The title will be displayed in a big font below the meta-information heading.
$ vcs -T "Some title" file.avi
See also Parts of a contact sheet.
See Setting Contact Sheet Colours for details.