Why re-encode MPEG-2 to author DVD?

[joelson]

Hi folks!

Just 2 questions:

1) When I author a dvd with AVI downloaded files, I usually convert it to MPEG-2 (with TMPGEnc), which is the DVD format. Is it necessary?

2) When I have this MPEG-2 file and author the DVD, why does it re-encode? Isn't it already in the format?

[redwudz]

You have to encode an AVI to MPEG-2 to use it for a DVD. When you author you are just putting the video and audio files into a format that the DVD player can use, it's not re-encoded.

[joelson]

But isn't the MPEG-2 already the format understood by the dvd-player?

Can't I put directly the AVI file in the authoring software?

[redwudz]

I'm not sure what you mean. An AVI formatted video is not DVD compatable. You need to encode an AVI video to MPEG-2. If it is already in MPEG-2 format, you only need to put it into an authoring program, then burn to DVD. You might look at the 'Glossary' to the left for AVI and MPEG-2.

EDIT: Are you asking about DIVX video files?

[teegee420]

If you have a DVD player that plays mpeg-4(Divx/Xvid) you don't have to re-encode the avi. You probably don't have one of these, as you would have mentioned it if you did.

Once you convert to mpeg with TMPGEnc the audio and video are in the correct format, but not the correct file stucture. That's where the authoring stage comes in. It's kind of like making an audio cd out of mp3 files. You can't just burn your mp3's to cd and expect the disc to play in a standard cd player. It needs to be in the correct file structure in order for the disc to be recognized.

[BobK]

> Can't I put directly the AVI file in the authoring software?

Depends on the authoring software. But if you use authoring software that will accept avi files then it has to re-encode to get it to mpeg-2.