Why to convert DAT-->MPG

[maniktushar]

I dont understand this in this guide on doom9 http://www.doom9.org/index.html?/mpg/vcd2divx.htm
asks u to convert DAT to MPG. Doesnt VirtualDub already accept DAT files then whats the sense behind conversion. Moreover when I converted a few clips from DAT-->MPG one of the MPG files had some error in audio stream and thus the file couldnt be reencoded I just used the original DAT file in VirtualDub to reencode and it worked just fine.

[lordsmurf]

A DAT is not an MPEG.
A DAT is an MPEG with other data attached.
This other data can cause problems.

[yoda313]

Hello,

Lordsmurfs right. Dat is a container for the vcd spec. The authoring program makes the videocd (or svcd) structure so that the player can read it as a vcd. It's the same way when a dvd authoring program makes a dvd structure from an mpg. It creates the video_ts folder with the vobs/ifos/bups that the dvd player needs to know that it IS a dvd.

Kevin

[maniktushar]

But then when VirtualDub loads the dat file and converts to AVI directly then why do we need to convert it using VCD Gear at all. Is there a change in quality or something if u use a DAT file as source directly?

[Cornucopia]

You are MUCH less likely to get pic decoding or audio sync errors on your output file from VDub if you extract the *.MPG from the *.DAT 1st. The extra RIFF headers just confuse the (many) programs.

Use VCDGear, VCDEasy etc.

Sometimes you'll find using a *.DAT may work, but I wouldn't count on it.

Scott

[maniktushar]

thanks for clarifying