Gordian Knot

Gordian Knot contains facilities to do pretty much anything you need in terms of video encoding.

Table of content:

1: Ripping and demuxing
2: Select a project save slot
3: Find the right bitrate
4: Select a resolution


Step 1: Ripping and demuxing

Robot4Rip combines the best tools for the task: DVD Decrypter is used to rip the DVD, then a DVD2AVI project is created, BeSweet is used for audio encoding and if desired VobSub is used to rip subtitles.

Step 2: Select a project save slot

Start up Gordian Knot, select a free slot in the dropdown list at the bottom right of the window, click rename to give it a good name and all your settings will be saved in this slot and can be reused later on.

Step 3: Find the right bitrate

In GKnot go to the bitrate tab.

Load the DVD2AVI project file (.d2v) by clicking on the Open button and selecting the .d2v file you've created before.

If FPS equals 29.970 you did not choose Force Film in DVD2AVI and will have to perform IVTC (explained later on in the guide). For now set FPS to 23.976. In all other cases (FPS = 25.00 or FPS = 23.976) you don't have to do anything.


GKnot automatically reads the number of frames and the framerate from the .d2v file. Selecting your DVD2AVI project file will open another window where you can see the video. Put that window in the background but do not close it.

Then select the DivX3 codec:

Now set your desired filesize and number of CDs:

This is pretty straightforward. Enter the CD size, click on the X CD button or enter a filesize manually.

When creating rips for multiple CDs also select split file into CDs to have your output split by CD size automatically. When you're including VobSub subs for several languages you better uncheck the auto-split though as the subtitle overhead will not be taken into account when splitting.

Then we have the Interleaving and AVI-Overhead options. When you add an audio track to a movie you will notice that the size of the output is larger than the sum of both video and audio input. GKnot can take care of this phenomenon for you so you don't have to worry about getting oversized movies.

The default is to create a VBR MP3 in which case you have to select 1x vbr-mp3 as shown on the left. If you want another type of audio track or multiple tracks please select the appropriate option instead.

Then let's actually configure the audio tracks themselves:

First check Size, then press the select button and select your first audio file. If you have a 2nd audio track repeat this procedure for Audio B.

Step 4: Select a resolution

Then click on the Resolution tab. The first step is the cropping.

Press the Auto Crop button (this button is only available when you have loaded the DVD2AVI project file). GKnot will go through a couple of frames in the preview window then you'll see the results. If they are about what you'd expect select Smart Crop will will give you the ideal crop values to minimize the aspect ratio error.

There's another issue here: If you go to the options tab again you will find the "Follow ITU-R BT.601 Standard" button. As I'm one of the people who thinks PC resizing is okay (and in fact every of my guides is written to respect that resizing rather than this ITU standard) I deactivate this option.

Then set the DAR according to what the value you wrote down in the DVD2AVI step. First you select the TV system (PAL or NTSC) according to the video type DVD2AVI was showing, then you select the actual aspect ratio of the input (16:9 or 4:3 in the Input Pixel Aspect Ratio field) according to the Aspect Ratio field in DVD2AVI. If you were to use an AVI input you'd have to set the Input Pixel Aspect Ratio to 1:1.

You can go to the window that shows your video and select resized from the view menu and check if it truly looks okay. And while you're at it, move the slider to advance in the movie until the end credits start and press the Set Credits Start button.

Now you have to set the resolution by moving the big slider.

You can see the Aspect Ratio error in one of the fields, and as you can see the results are close to perfect. You also have to keep watching the Bits/Pixel values (Output resolution):

It's a bit guesswork as you cannot predict compressibility of your movie but here's some hints:

Mode the slider until you're within this range. These values are the general rule for DivX3 encoding but you should not consider them to be the laws of nature. I've encoded many movies that had a lower value and they still looked great.

In case you had r4r extract the subtitles you'll also have to perform the following:

Use the add button to add your 2 subtitle files so that you'll have enough space to store them onto your CD(s) after the movie has been encoded.


This document was last updated on November 22, 2003