Open the settings window. Hit the plus sign and click on Quick Time.
Open the Inspector and in the Encoder pane click on video settings, From the drop down menu choose the codec of your source file. (im my example it happens to be Pro Res.) Leave fame rate current and other settings automatic.
This will be a custom preset; name it and save. Then drag it to batch window and set a destination to create a target. Drag your source file (the wedding) to the source file well.
Hit submit. Bring that file into iDVD.