xvid to DVD plus bitrate etc.

[regular14]

Hopefully this is an intelligent question- but here on videohelp.com i found that DVD bitrate is general 5000kb/s where as Xvid is generally 1000kb/s, so does this mean that when i encode XVID-DVD that i can set my bitrate at 1000Kb/s and get the same output clarity/quality as 5000Kb/s??????

[bobkart]

This is a very good question, and one which I do not think can be answered definitively. You're going to have to take your best guess unless someone else comes along that knows better.

Although I do have some ideas as to how this could be determined experimentally for a given video, but to answer that question generally (for all videos) is asking a bit much in my opinion.

[guns1inger]

No. Xvid (an Mpeg4 derivative) and Mpeg2 use different encoding algorythms, which is why the bitrates are so different. When converting Xvid to DVD the general rule is to allow 3 - 4 times the bitrate of the Xvid, just to preserve the quality. And this is without taking into account the fact that most Xvid/Divx avi files are much lower resolution than DVD. I would use as higher bitrate as you can fit on the disc when encoding Xvid up to DVD.

FWIW, personally I believe that most Xvid/Divx files are encoded with a bitrate around half of what is required. 1500 - 2000 kpbs is about what is required to maintain quality at 640 x NNN resolution for this type of avi file when backing up DVDs. Less than that produces obvious and annoying artifacts.