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Friday, July 6, 2012

Testing your disks using dd utility and time.

You can execute copies a large block of data to and from disk.

This will minimize disk caching.

Next is one example if our test system has 1GB of RAM.

It is easy ( 1GB = 250,000 blocks ).

$ time sh -c "dd if=/dev/zero of=bigfile bs=8k count=250000 && sync"
250000+0 records in
250000+0 records out
2048000000 bytes (2.0 GB) copied, 37.0113 s, 55.3 MB/s

real 0m40.910s
user 0m0.172s
sys 0m12.641s

It's very hard to argue with this dd test.

Thursday, July 5, 2012

Using DIGITAL PEN CAMERA eheV1-USB-II with mplayer

It's not my camera, I take it just to try to make working on Linux OS.
This is the device.

The dmesg tell me about this camera:
uvcvideo: Found UVC 1.00 device USB2.0 Camera
If you want to see and not to take frames, then use :
mplayer tv:// driver=v4l2:width=640:height=480:device=/dev/video0 -vo null
You can try to take some frames. I use this:
mplayer tv:// -frames 10 -tv fps=20:driver=v4l2:width=640:height=480:device=/dev/video0 -vo jpeg
The result is ten frames.
On this image I draw one line to see how working default.

And using the zoom ...

Friday, June 15, 2012

Working with old video card and also old Ogre 3D engine and Blender 3D.

I make today a new tutorial about the trips and tricks with Ogre 3D engine using Blender 3D.
If you want to see this, you can go on the tutorials part from my site.
This is the just a result of my simple example.
The result is shown in next image sample.