what is codec

[axg275]

Hi eveyone.
I was wondering if someone could tell me what a codec is and what it does to your computer and avi file. Also what is a ifo and vob files how can I watch them if I can, and lastly what is a dvd protectiion and how it works????
Thanks for your help
axg275

[lattedfw]

Codec means COder DECoder - the software on your computer that allows programs to decode video and audio files encoded in a particular format. A codec also allows programs to encode a file into a particular format. For example, DVD video is [;ayed back with the MPEG2 codec so you can watch a movie on your PC; audio CDs that you rip to store files on a Rio use the MP3 codec. There are hundreds of video and audio codecs, but most of us only deal with a few of the most popular (MP3, MPEG1, MPEG2, MPEG4, etc.)

An AVI file is just a wrapper around data--inside the AVI file is information on which codecs to use plus the video/audio data. The same concept applies to QuickTime .MOV files.

IFO files are sort of a table of contents for a DVD player when reading a disc. VOB files are Video Object files that contain video, audio, menu, etc. data on a DVD.

Most commercial DVDs have encryption so that you can't do a simple disc-to-disc copy if you have a DVD burner. It also prevents you from simply extracting data from VOB files. You have to use a ripping program to decrypt the data.

[Lost_Soul]

Reading this post made me think if it would be posible to watch a dvd through ur Cd-Rom with an mpeg2 codec? or do u need a dvd rom wots the difference?

[LeeBear]

You can't watch a DVD in a CDROM because you won't be able to read the disc. The information stored on a DVD Disc are stored physically closer together then information on CD Disc, that's why you can fit 4.7 GB on a DVD and only 700MB on a CD. Because the bits are store closer together you need a smaller laser to be able to read them and the laser on CDROM's are not adequate.

So in summary you can't watch a DVD in a CDROM, but you can watch MPEG2 video's on a CD... ie. SVCD. SVCD and DVD uses the same codec, MPEG2, but DVD's are higher resolution and have a higher bitrate that's why the picture is better.

-LeeBear

[El Torro]

I couldn't have sayd it better bear