Video Resolution

[Silent Bob]

I'm encoding 90 mins of video using divx. At the moment the video is in 720x405 (16:9). I've calculated that the video has to be around 900 kbit/s to fit on to a 700mb cdr.

What is the best resolution encode this at?

Also what effect does dual passing have on the video and should I use this option?

Thanks in advance

[WildmanJoe]

There's no hard and fast rule on what resolution to use. However, the smaller the final movie resolution, the more bits/pixel you can squeeze in and the better the quality. Experiment for yourself by encoding a small portion.

[Enchanter]

At 900 Kbps, a video resolution of 720x() is too high. Reduce to 640x() or, if necessary, 512x(). You will see a definite improment in quality, taking into consideration the lower chances of compression artifacts (that arise from lack of bits).

Dual-pass encoding will yield you maximum quality for a given bitrate and hence should always be activated in this kind of situation.

[shiny#3]

Do not forget to decrease the vertical resolution as well......

I understand that your video now is a 16:9 widescreen
of a 1.78 : 1 proportion. the vertical resolution when choosing
720--> 640 would be 360 (or 352 as all mpeg4 compatible ratio)

for 720--> 512 it would be 288.

I just added this to ensure keeping the right aspect ratio....

by the way..... using Xvid codec in two pass mode does not produce
noticable artifacts at a bitrate of 900 kbits/s using the full resolution of 720x405 compared to the reduced resolution method
this is of course only my opinion!!

[Silent Bob]

Thanks for the help everyone

I've encoded it at 512x288 and it looks close to dvd quality