Linux Commands Examples

A great documentation place for Linux commands


a lightweight tool to stream one or more pixel components of the image or portion of the image to your choice of storage formats.


stream [options] input-file output-file

add an example, a script, a trick and tips

: email address (won't be displayed)
: name

Step 2

Thanks for this example ! - It will be moderated and published shortly.

Feel free to post other examples
Oops ! There is a tiny cockup. A damn 404 cockup. Please contact the loosy team who maintains and develops this wonderful site by clicking in the mighty feedback button on the side of the page. Say what happened. Thanks!



Baby monitor with netbook and smartphone


The cWatchTheHamster project presents a very efficient client-/server backend to stream images from any webcam connected to a linux pc to nearly every kind of client. The server-backend uses v4l4j, client- and server-backend are completely written in java. There is a swing frontend using the client (like hosted in this project) and a beautiful android client (+widget) available in the android market.


How linux command ":>" works?

The command isn't :> it's just :. In bash (and probably some other shells) it's a built-in no-op command. The > redirects output to a file (truncating it first). Since : has no output, the net result of your command line : > file.log just makes file.log zero length.

From my local bash man page:

  : [arguments]
          No  effect;  the command does nothing beyond expanding arguments
          and performing any specified redirections.  A zero exit code  is


Linux DLNA Server

This post gives a pretty good breakdown of a lot of choices.


Cheap internet radio player computer configuration

Sure, they sell netbooks for around $100. You could use a windows based one with a startup script launching VLC:


Streaming audio over SSH.

You can use pulseaudio for streaming audio.

But i would suggest mounting remote filesystem on a local folder using sshfs and playing files from there.

mkdir mountfolder
sshfs username@remotehost:/ mountfolder


Simple webcam server

See for example: Setting up a Live Webcam Feed.


How do you combine multiple ffserver streams into a grid in real time?

You are handling 16 streams, so your CPU has a hard job on it to convert. You seriously need enough CPU power to handle all that data.

I also see you are scaling each video. Scaling is a very time consuming process in a CPU. Maybe you can set up your camera streams to provide a scaled video already, so your CPU only needs to put them together.

You can also look for other options of encoding/decoding, because some encoders are like 10 times faster than the others.


Recommendations for a really good DVB-T card for linux

My recommendation is the Hauppauge WinTV-HVR-2200. A linux driver has recently been developed (though it only supports the digital tuners at present).

It's a really nice card - dual tuner, support for HD, MPEG capture and it gives us a perfect signal on all UK free-to-air DVB-T channels where other cards have struggled finding more than two or three multiplexes.

Take a look to see if does all the stuff you want, but I can't recommend it enough. It's also relatively cheap for a dual tuner card.

Edit: I should mention that I've only been using it under Windows so under Linux YMMV, but the LinuxTV drivers are normally very trustworthy.


Is it possible to push multimedia content on DLNA TV from Linux?

Yes it's possible, check out servioo and this superuser question.


Linux: set up media server to stream video via the Internet?

You can do it with ffserver(a component of ffmpeg). Details here.


Image Settings:
-authenticate value decrypt image with this password
-channel type apply option to select image channels
-colorspace type alternate image colorspace
-compress type type of pixel compression when writing the image
-define format:option
define one or more image format options
-density geometry horizontal and vertical density of the image
-depth value image depth
-extract geometry extract area from image
-identify identify the format and characteristics of the image
-interlace type type of image interlacing scheme
-interpolate method pixel color interpolation method
-limit type value pixel cache resource limit
-map components one or more pixel components
-monitor monitor progress
-quantize colorspace reduce colors in this colorspace
-quiet suppress all warning messages
-regard-warnings pay attention to warning messages
-sampling-factor geometry
horizontal and vertical sampling factor
-seed value seed a new sequence of pseudo-random numbers
-set attribute value set an image attribute
-size geometry width and height of image
-storage-type type pixel storage type
-synchronize synchronize image to storage device
-transparent-color color
transparent color
-verbose print detailed information about the image
-virtual-pixel method
virtual pixel access method

Miscellaneous Options:
-debug events display copious debugging information
-help print program options
-log format format of debugging information
-list type print a list of supported option arguments
-version print version information

By default, the image format of ’file’ is determined by its magic number. To specify a particular image format, precede the filename with an image format name and a colon (i.e. ps:image) or specify the image type as the filename suffix (i.e. Specify ’file’ as ’-’ for standard input or output.


Copyright (C) 1999-2012 ImageMagick Studio LLC. Additional copyrights and licenses apply to this software, see file:///usr/share/doc/imagemagick/www/license.html or


Stream is a lightweight tool to stream one or more pixel components of the image or portion of the image to your choice of storage formats. It writes the pixel components as they are read from the input image a row at a time making stream desirable when working with large images or when you require raw pixel components.

For more information about the stream command, point your browser to file:///usr/share/doc/imagemagick/www/stream.html or

see also


How can this site be more helpful to YOU ?

give  feedback