Wednesday, March 17, 2010

7-Zip

The guys at Tom's Hardware have done some benchmarks of recent compression tools.
It turns out 7-Zip is most efficient in terms of compression speed and ratio.
It can also extract many other formats like RAR.
Considering that this tool is also free and open source you may seriously consider switching to it.

Saturday, March 6, 2010

Extracting MPEG2 streams from DVD-RAM

DVD-RAM
Using DVD-RAM discs with camcorders is quite convenient. Recording on this meadia is much more reliable. You can also edit your videos on the camera - delete, cut, join etc. The downside is incompatibility. Most DVD players do not play DVD-RAM discs. But recent PC optical drives do read them. So when I get the disc out of my camera and put it in my PC, it shows this file system


C:\temp>dir e:\DVD_RTAV
 Volume in drive E is DVD_CAMERA
 Volume Serial Number is 57DC-951A

 Directory of e:\DVD_RTAV

31.01.2010  16:42    <DIR>          .
31.01.2010  16:42    <DIR>          ..
03.03.2010  16:49            11 961 VR_MANGR.IFO
03.03.2010  16:49            11 961 VR_MANGR.BUP
03.03.2010  16:49       713 383 936 VR_MOVIE.VRO
               3 File(s)    713 408 142 bytes
               2 Dir(s)     688 580 608 bytes free

Actually it seems the video (and audio) is recorded in MPEG2, just like in ordinary DVD but it is packaged differently (probably to facilitate editing on the disc).

DVD-VR
Fortunately a nice guy Pádraig Brady wrote a simple open source tool dvd-vr that extracts MPEG2 streams from DVD-RAM. It is written for Linux but with cygwin it compiles to dvd-vr.exe. dvd-vr extracts each video clip into a separate .vob file. You can play these directly on your PC. If your media player does not recognize these files, you can rename them to .mpeg.
Having a separate file for each clip is very convenient. You can arrange them as you see fit, much like your photos.
You can also record selected clips on a regular DVD to share with your friends. You can do this with various tools like DVD Flick for example - another free and easy to use app.

Happy shooting!