xl block-attach - cool!

Just wanted to copy something from usb flash drive inside my vm.
Wondered what's the fastest and easiest way to do it and viola:

#> xl block-attach 10 phy:/dev/sdb1 xvdf1 w

then, inside vm mount /dev/xvdf1

afterwards detach it (after freeing resources):

># xl block-detach 10 xvdf1

The interesting thing is that the I got about 20MB/s speed from the usb (it is usually that fast - 3.0 usb drive, plugged in 2.0 port).

Screencast with ffmpeg

Source: http://www.upubuntu.com/2012/10/some-useful-ffmpeg-commands.html

Some Useful FFMPEG Commands (Screencasting, Rotate Video, Add Logo, etc.)

In this tutorial we will see some useful FFMPEG commands that you can use on Ubuntu/Linux Mint to make screencasting videos, rotate videos, add logo/text watermarks to a video, insert shapes, and so on.

To install ffmpeg and some other packages on Ubuntu/Linux Mint, open the terminal and run these commands:

sudo apt-get install ubuntu-restricted-extras

sudo apt-get install ffmpeg x264

sudo apt-get install frei0r-plugins mjpegtools

Note: The file formats used in this tutorial are selected randomly and you can set any other extension of your choice.

1. Screecasting

To record your screen withh FFMPEG, you can use this command:

ffmpeg -f x11grab -follow_mouse 100 -r 25 -s vga -i :0.0 filename.avi

Now the command will record every spot on your screen you hover your mouse cursor over. Press Ctrl+C to stop recording. If you want to set a screen resolution for the video to be recorded, you can use this ffmpeg command:

ffmpeg -f x11grab -s 800x600 -r 25 -i :0.0 -qscale 5 filename.avi

To show the region that will be recorded while moving your mouse pointer, use this command:

ffmpeg -f x11grab -follow_mouse centered -show_region 1 -r 25 -s vga -i :0.0 filename.avi

If you want to record in fullscreen with better video quality (HD), you can use this command:

ffmpeg -f x11grab -s wxga -r 25 -i :0.0 -sameq video.mp4

Her is a video example created with the latter command:

2. Add Audio To A Static Picture

If you want to add music to a static picture with ffmpeg, run this command from the terminal:

ffmpeg -i audio.mp3 -loop_input -f image2 -i file.jpg -t 188 output.mp4

3. Add Image Watermarks to A Video

To add an image to a video using ffmpeg, you can use one of these commands:

Picture Location: Top Left Corner

ffmpeg -i input.avi -vf "movie=file.png [watermark]; [in][watermark] overlay=10:10 [out]" output.flv

Here is an example:

Picture Location: Top Right Corner

ffmpeg –i input.avi -vf "movie=watermarklogo.png [watermark]; [in][watermark] overlay=main_w-overlay_w-10:10 [out]" output.flv

Picture Location: Bottom Left Corner

ffmpeg –i input.avi -vf "movie=watermarklogo.png [watermark]; [in][watermark] overlay=10:main_h-overlay_h-10 [out]" output.flv

Picture Location: Bottom Right Corner

ffmpeg –i input.avi -vf "movie=watermarklogo.png [watermark]; [in][watermark] overlay=main_w-overlay_w-10:main_h-overlay_h-10 [out]" output.flv

4. Add Text Watermarks To Videos

To add text to a video, use this command:

ffmpeg -i input.mp4 -vf drawtext="fontfile=/usr/share/fonts/truetype/freefont/FreeSans.ttf: text='YOUR TEXT HERE':fontcolor=red@1.0:fontsize=70:x=00: y=40" -y output.mp4

An example:

To use another text font, you can list them from the terminal with this command:

ls /usr/share/fonts/truetype/freefont/

4. Rotate Videos

To rotate a video 90 degrees with ffmpeg, run this command:

ffmpeg -i input.avi -vf transpose=1 output.avi

Here is an example for a video rotated with ffmpeg:

Here is all parameters:

0 = 90 degrees CounterCLockwise (Vertical Flip (default))
1 = 90 degrees Clockwise
2 = 90 degrees CounterClockwise
3 = 90 degrees Clockwise (Vertical Flip)

5. Adjust Audio/Video Volume
You can use ffmpeg to change volume of a video file with this command:

ffmpeg -i input.avi -vol 100 output.avi

To change volume of an audio file, run this command:

ffmpeg -i input.mp3 -vol 100 -ab 128 output.mp3

6. Insert A Video Inside Another Video

To do this, run this command:

ffmpeg -i video1.mp4 -vf "movie=video2.mp4:seek_point=5, scale=200:-1, setpts=PTS-STARTPTS [movie]; [in] setpts=PTS-STARTPTS, [movie] overlay=270:240 [out]" output.mp4

Here is an example:

7. Add a Rectangle To A Video

To draw for example an orange rectangle in a video, you can use this command:

ffmpeg -i input.avi -vf "drawbox=500:150:600:400:orange@0.9" -sameq -y output.avi

Migrating contacts from IPhone to Android

If you want to use GMail sync - then it's easy.
Simply sync from the IPhone to GMail then on the android sync back.

If you don't want to use the Gmail option - it turned out to be pretty tough to transfer them.
I've used Export Contacts 1.6 app on the IPhone - it starts a service and then from any browser you can export contacts as vCard, CSV or PDF. vCard has two formats: single vCard and ZIP with many vCards (outlook option).
After I've downloaded single vCard file with all my contacts I've uploaded the file to another webserver, opened the direct url on the Android phone (with Firefox if that matters) and it asked me to open or import the vCard.
I told it to import vCard file and voila all my contacts are now there with all fields. Birthdays are kind of crappy and pics are missing (Export contacts didn't expored the pics)...

ps. If your iPhone is with broken display and has a lock pass code and you can't unlock it so you can sync with iTunes then DFU mode will do the trick. Hold the home button and sleep button for 10 seconds and then release the sleep button while continuing to hold the home button. iTunes should not show the message that a phone has been detected in recovery mode.

P.S. I've imported the contacts like this but noticed some of them (about 50% of ~600) are missing. Well... I ended up Installing a http://funambol.com/ server + outlook plugin + iphone app + android app - now I have my contacts transferred as expected and also I have a 'backup' place ( my custom funambol server).

Q&A for apache in debian

Q: Why does Apache Web server in Debian has 'It works!' page as it's default host?
A: Because after you have setupped a complex VirtualHost configuration for half an hour or more (yesh, there can be such), it's nice to see that 'It worked!'
--answered by valqk. :-D

FUN: WTFs per minute ... wtf/min :)

How do we understand when a project is well coded or is a piece of..... fish?
Well, have you heard of WTFs per minute?
See this :-)

thanks to OSnews.com/comics for this one!