commandlinefu.com is the place to record those command-line gems that you return to again and again.
Delete that bloated snippets file you've been using and share your personal repository with the world. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.
If you have a new feature suggestion or find a bug, please get in touch via http://commandlinefu.uservoice.com/
You can sign-in using OpenID credentials, or register a traditional username and password.
First-time OpenID users will be automatically assigned a username which can be changed after signing in.
Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.
Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):
Subscribe to the feed for:
Gets all videos in your boxee queue with a URL associated with them and attempts to download each using get_flash_videos
Do you have a large library of flv's you have picked up over the years using FlashGot Firefox plugin?
Do you want to be able to convert them to Ogg Theora (video) at once?
Try out this script...
Is a simple script for video streaming a movie
Creates a 5 minute flv file, with the given sequence of images and audio with 0.5 fps.
The images were created using the following command:
for x in `seq 0 300`; do cp ../head.PNG head-`printf '%03d' $x`.png; done
You can also inject metadata to seek easier using yamdi as follows:
yamdi -i muxed.flv -o video.flv
i have a large video file, 500+ MB, so i cant upload it to flickr, so to reduce the size i split it into 2 files. the command shows the splitting for the first file, from 0-4 minutes. ss is start time and t is duration (how long you want the output file to be).
credit goes to philc: http://ubuntuforums.org/showthread.php?t=480343
NOTE: when i made the second half of the video, i got a *lot* of lines like this:
frame= 0 fps= 0 q=0.0 size= 0kB time=10000000000.00 bitrate= 0.0kbit
just be patient, it is working =)
Streaming HTML5 compatible video (Ogg Theora video with Vorbis sound) to an Icecast server using dvgrab, ffmpeg2theora and oggfwd.
In this example I'm merging stereo sound to mono (-c 1), saving the original dv for later higher quality on-demand video (tee dvstream.dv), saving the theora stream for immediate on-demand video, and publishing the stream in Xiph's stream directory (-p and the name and description).
The URL of the video will be (depending on your server) http://my.icecastserver.com/stream.ogv which will play in newer Firefox, Chrome and Opera web browsers. Cortado (a Java player) can easily be used for IE.
Note also that I'm using port 80, which is not the default port for Icecast, this is to avoid restrictive firewalls.
Also note that ffmpeg2theora 0.25 and will heed the bitrates much better than former versions because of using libtheora 1.1 or newer.
-i = input file name
-s = set frame size, qcif=176x144
-vcodec = force video codec
-r = frame-rate [default = 25]
-b = bit-rate [200 kb/s]
-acodec = force audio codec
-ab = audio bitrate in bits/s [64k]
-ac = no. of audio channels 
-ar = audio sampling frequency [44100 Hz]
-sameq = use same video quality as source (implies VBR)
-f = force format
-y = overwrite output files
This command will transcode a MythTV recording. The target device is a Google Nexus One mobile phone. My recordings are from a HDHomerun with Over The Air content. Plays back nicely on the N1.
Takes two input video files and an external audio track and encodes them together to an MPEG-4 DivX output video file with the correct size ready for uploading.
Reencodes to MPEG-4 DivX output video file from step 1. Audio stream is simply copied. Resizes to 320x240 and deinterlaces as needed. A heading subtitle file is applied as watermark. This heading subtitle file can be a URL.
Rips DVD to lossless encoded video file. Reencodes audio to CBR MP3 for correct audio to video syncing. Be sure to have enough free disk space.
Convert those .mov files that your digital camera makes to .avi
Adjust the bitrate (-b) to get the appropriate file size. A larger bitrate produces a larger (higher quality) .avi file and smaller bitrate produces a smaller (lower quality) .avi file.
Requires ffmpeg (see man page for details)
(tested with canon camera MOV files)
ffmpeg -i input.mov -sameq -vcodec msmpeg4v2 -acodec pcm_u8 output.avi
ffmpeg -i input.mov -b 1024k -vcodec msmpeg4v2 -acodec pcm_u8 output.avi
Rip DVD to YouTube ready AVI file, using MPEG-4 video codec and MP3 audio codec. Resizes to 320x240 and deinterlaces as needed.
change the *.avi to whatever you want to match, you can remove it altogether if you want to check all files.
Create subtitle file heading.ssa with just one entry for the entire video duration. Command line sets that entry's text on top of the video as text watermark. If text is an URL works nice for sending people back to your site from a YouTube clip. Output file is lossless encoded and suitable for further processing. Subtitle file can be a URL so it's saved remotely.
Open a window that displays camera capture.
Framerate, width and height may be changed to match your needs.
Record audio to MP3 stream and video to MPEG-4 stream from webcam to AVI file using mencoder. Gives floating point exception in some mencoder versions.
View webcam output using mplayer, with correct fps and outfmt settings according to my webcam model.
Record from a webcam, audio using ALSA encoded as MP3, video as MPEG-4.
Extracts an MP3 encoded audio stream from an input video file.
Creates a new video file with video stream copied from input file and a different audio stream
Remove sound from input video file, output video stream is copied from input video stream, with no audio.
Gives MPEG-4/DivX output video file ready for uploading to YouTube from FLV file downloaded from the site and your own subtitle file UTF-8 encoded. No resizing needed. (?)
First, we convert the VMware avi (VMnc format) to the Microsoft avi format. Next, we convert the Microsoft avi format to FLV format.
You can play around with the -r switch (rate per second) and the -b switch (bitrate). But, if those get larger, so does your FLV file.