resolution too low

[Praetorian]

hi! i need some advice for encoding a pal movie. the movie is pal,16:9,almost 3hours and it's meant for 2x700mb. i try to get between those fine comp check values (60-80%) but it seems impossible because i can reach only 38% with a "still favourable" resolution of 512x208. in order to reach 60% i would have to go maybe under 400w resolution which you would agree is too low. what should i do?

[jggimi]

Hello, and welcome to the forum.

If you are using the "Pro" version of DivX 5, enable bi-directional encoding (B-frames), if you are not already using them. B-frames improve compressibility.

You might consider noise reduction (temporal smoothing) to improve compressibility. This does remove detail, but may help compression.

You might consider going to 3 CDs.

You might consider encoding a small test at a lower resolution, to see if 400w is acceptable.

[Praetorian]

thank you for answer. i need to be reassured by an expert that i'm not going the wrong way... i'm using divx pro 5.1 so the settings should be on by default but i'll try that noise reduction and see if it helps. anyway i understood that it's more a matter of visual checking of the compressed video than having the settings just correct and fine. then even a very low resolution might look acceptable.

[jggimi]

...so the settings should be on by default...I don't think so.

You should confirm if Bi-directional encoding is being used: Select Gknot's Options tab.

Select First Pass in the DivX 5 default codec settings box.

Select the Profiles tab in the DivX 5 settings window.

Look in the MPEG4 Tools box, and see if Use Bidirectional Encoding is enabled. You may have to clear the 1 - Choose your profile box to enable MPEG-4 settings.

Repeat for the Nth Pass as well.

[Praetorian]

you're pretty right about the defaults ;) i never thought of disabling that profile stuff rather expected they (at divX networks) tried to make things easier but still with maximum quality... what shall i do with the rest: gmc (guide says yes), quarter pixel (guide omits), psychovisual enhancements fast/slow? please have patience with me :)

[jggimi]

Your questions, in the main, are answered by Doom9's DivX 5 Encoding Guide (http://www.doom9.org/gknot-main3.htm). As to fast/slow ... if you are using DivX 5.05, follow Doom9's guide.

But, if you are using DivX 5.1 ... then you'll need to read the discussions about the different encoding modes of 5.1 in the DivX 5 forum. The general consensus, if I'm not mistaken, is to use Slow or Slowest only for the final pass, and only when you don't mind the time it takes.