DivX5 guide

Since version 0.25 Gordian Knot natively supports DivX5 making DivX5 encoding a breeze while still offering many features like BeSweet support for superb audio encoding, Decomb for IVTC, but also regular GKnot features like multiple audio tracks, batch encoding, etc.

You will need the following software for this guide:

GordianKnot Rippack & update
GordianKnot Codec pack

What's the difference between DivX5 and DivX5 Pro? The latter has advanced the following features that the standard edition does not have: B frames, QPel motion compensation, Global Motion Compensation, integrated preprocessing, resizing and cropping and deinterlacing/IVTC. Basically, you should be mostly concerned about the first 3 features, which result in slower processing speed but also can improve quality. In order to finance the MPEG-4 licensing fees that DivXNetworks may have to pay they've invluded the GAIN program that will display some ads from time to time. If that gets on your nerves here's a legal solution to the problem.

There's a very comprehensive document on the new codec at the official DivX site. It will explain additional stuff like how the playback filter works and give you a complete featurelist.

Step 0: First time setup

You will only have to perform this step once.

Install the GordianKnot Rippack, then install the GordianKnot system pack. When installing the codec pack, only select the codec you really want to include. As for the selection of DivX5.02 or DivX5.04 I leave that up to you. Version 5.03 introduced several new features like multipass encoding (where multi means larger than two) but also introduced a few bugs that should be squashed by now. The guide deals with DivX5.04 but setting up Gordian Knot for DivX5.02 is very similar, all the options are the same, they are just to be found in different places in the codec setup phase.

After installation start Nandub and VirtualDubMod manually one time and click OK to every warning that might appear after startup. You can find the link to both applications in your start menu under Programs - Gordian Knot - Apps.

Then start up Gordian Knot and click on the options tab. Then configure the DivX5 codec by clicking on the buttons for First Pass, Nth Pass and Credits. When doing multipass with more than 2 passes, it's also possible to use different settings for the last pass but I've never used that feature.

Let's do the first pass first. The first thing you have to decide on are the DivX profiles. DivX Networks has created 4 profiles, targeting different hardware devices. Hardware manufacturers can have their devices tested and will be awared a certification (you can see the certification symbol for a DivX certified DVD player in the next screenshot). That certification guarantees that every file encoded using the matching profile can be played without any problems. You can find more info about the DivX certification program here.

In order to remain compatible, the standard profile "Home Theater" disables certain features of DivX Pro: GMC and Quarterpel motion estimation. So far, DivXNetwork has not see fit to create a certification including those features because the hardware wasn't up to it. This has changed recently and starting in December 2003, the first devices capable of playing DivX encoded content even with GMC and QPel enabled will hit the retail channels. And if you are not targeting a hardware player, there's no need to stick to a profile either. So, if playback on any DivX compatible device is important for you, stick to the Home Theater profile. If not (remember: the next generation of players will not have those limits anymore), don't bother with the profiles.

In order to disable profiles, click on Select Profile Wizard, then check Disable Profiles in step one and press Next. Then you can enable GMC (and QPel as well if you want - I'm still not convinced it really contributes to a good encoding session but you may want to check it out and see if the results please you) and by pressing Finish you can save these settings.

Then there's the performance / quality slider.

In DivX versions prior to 5.05, you'd set this to Slowest. However, starting with DivX 5.05, the Standard setting now corresponds to the Slowest setting in previous versions. If you move the slider to the left, you trade encoding speed for a potential (if you have the time try if you get better results) gain in quality.

Don't touch the other settings in this screen (DivXNetwork no longer suggests the use of a MV file, which slows down encoding a bit but helps quality a bit) and go to the video tab.

Do NOT enable crop and resize. We're going to use GordianKnot for that.

If you want, you can enable the Psychovisual Enhancements, which use a model of the human eye to save bits in areas where the eye wouldn't notice. This might help quality for 1 CD rips but should generally stay disabled for 2 CD rips or short movies on one CD.

Then press OK to save those settings as default. Then press the Nth pass button and make sure the settings correspond to what you set for the first pass. For credits I suggest you use the defaults, that is 1 pass constant quality at quality 20. The higher the quality number the lower the quality for your credits by the way.

Now as previously mentioned, you'll make those settings once and they are then used for each encoding session. But of course you can always change the defaults, or use special parameters just for a specific movie. In that case you can manipulate the codec settings just before you start encoding (and they will only be applied to the movie you're about to encode).

Step 1: Basic GKnot Setup

This step will teach you how to set up GKnot for a perfectly good looking rip.

Step 2: Encoding video

Only a few more steps and GKnot will automatically encode video and multiplex audio for you without any further manual interaction.

Step 3: Splitting (if required)

If you created a movie for more than 1 CD and didn't use the autosplit feature, you have to split it up now. The same goes for VobSub subtitles, which are also not split automatically.

This document was last updated on November 22, 2003