Talk:VLC HowTo/Make thumbnails

From VideoLAN Wiki
Jump to navigation Jump to search

(~) I would like to know if it is ok to modify the page like this?

Changes:

I added a linux section, but I'm not sure if it's good or not. Any sugestions? And this is my very first edit so is more like a test for me to get the handle on things.

What I did try to do was give some more information and change some formatting.

(Nimitz Sad Dog 12:15, 10 February 2009 (CET))

How to create a thumbnail from a video

For all those people wanting a thumbnail from a video, use the following command:

(win)

vlc -V image --start-time 0 --stop-time 1 --image-out-format jpg --image-out-ratio 24 --image-out-prefix snap test.mpg vlc://quit

What it does:

When VLC media player runs it 'plays' the video for one second without actually showing the video on screen, and then quits, leaving us with a file named 'snap000000.jpg', containing an image of the first frame of the video.

How it works:

First select the image output with: -V image or --vout image.

Next set the interval (in seconds) you want an image from with: --start-time 0 --stop-time 1 In my example the first second of the video. In that case you could omit the parameter --start-time. If you want an image from the 5th second fill in: --start-time 5 --stop-time 6

The image format will be .jpg because i provided: --image-out-format jpg. You could specify --image-out-format png to get a .png-image instead.

--image-out-ratio 24 specifies we want one image out of 24. In my case the video contains 24 images per second so this is the right value. If your video has more images per seconds you should increase this value to prevend you get more images as one. If the number is too high (for example 500) it still produces only one image, so the actual value is not so important as long as it is higher then the images per second.

--image-out-prefix snap specifies the filename must start with 'snap'. You can prefix with a path, for example c:\snap and resulting images will be created there.

You can specify --image-out-replace. In that case Vlc produces the file 'snap.jpg'. This will prevent VLC from creating multiple images.


test.mpg specifies the video to play and finally vlc://quit forces vlc to quit when ready.

Linux

Fedora

What You Need:

Getting Started

Using this command in the folder that you download the movie(or you can pass the path to the file in the command line).

vlc -V image --start-time 13 --stop-time 14 --image-out-format png --image-out-width 128 --image-out-height 128 --image-out-ratio 24 --image-out-prefix thumbnail --image-out-replace big_buck_bunny_1080p_stereo.ogg vlc://quit

You should get something like this:

Vlc_thumbnail_big_buck_bunny.png

Since I downloaded the big_buck_bunny_1080p_stereo.ogg that is the name of the file that I put in the command line. But you can do it with any video file you want to.
If the name of the file have spaces just put it in single or double quotes.
Ex: 'big buck bunny 1080p stereo.ogg' or "big buck bunny 1080p stereo.ogg" or '/home/[username here]/Desktop/big buck bunny 1080p stereo.ogg'

What Its Happening?

VLC will start playing the movie without the image because the images are not going to the display but to the output file "thumbnail" with the extension PNG that VLC created by now in the folder you launched the command in, and it should close after a second into the video(if the video starts from the begning probably VLC didn't recognize the file header see options references for more details), don't be worried if you hear the soundtrack. After that if you look at the folder you will see a new file called "thumbnail.png".

If you want to understand what is going on read the options reference.

Options Reference

Option Value Default Description Reference
Short Long
-V --vout image
aa
caca
x11
xvideo
glx
opengl
snapshot
dummy
Automatically select
the best method available.
Select the output. This means where to send the video stream to.
Using image as destination means VLC will create a file somewhere.
Video Output
--start-time integer Start time.
The stream will start at this position (in seconds).
ps: Beware that if VLC don't reconize the header of the file this doesn't work well.
VLC Command Line Help
--stop-time integer Stop time
The stream will stop at this position (in seconds).
ps: Beware that if VLC don't reconize the header of the file this doesn't work well.
VLC Command Line Help
--image-out-format png, jpeg png Choose the image file format for the output destination. Image video output
--image-out-width integer -1 You can force an image width.
The default -1 will adapt to the video characteristics.
ps: If you don't set this parameter VLC will save the image with its original size.
Image video output
--image-out-height integer -1 You can force the image height.
The default -1 will adapt to the video characteristics.
ps: If you don't set this parameter VLC will save the image with its original size.
Image video output
--image-out-ratio integer 3 Ratio of images to record. 3 means that one image out of three is recorded.
The ratio is calculate based on the framerate of the video so if your video have a framerate of 24 frames per second and you set the --image-out-ratio to 3 you should get 8 image files.
ps: Beware that if VLC don't reconize the header of the file this doesn't work.
You have to use --image-out-replace instead.
Image video output
--image-out-prefix string img Prefix of the output images filenames.
Output filenames will have the [prefix][NUMBER].[Image Format] form (ex: img101.png).
Starting with VLC 0.9.0 you can also use format time and meta variables.
Image video output
--image-out-replace disabled Always write to the same file. This means that the last image captured will be the one you will see saved. Image video output
vlc://quit Special item to quit VLC.
Works with the comand cvlc too.
VLC Command Line Help


Credits:


Big Buck Bunny was produced by Blender Foundation