iRiffs Video Tips
» Get the audio from your source (Do this by saving a .wav file out of a program like Virtualdub) and your commentary track. Use an audio editing program like Audacity or (in our case) Adobe Audition to normalize the tracks so that they, roughly, hit the same levels.
» Save your audio files and load them into your preferred video editing software along with your video (Sony Vegas 8 in Rifftrax’s case) Switch out the audio track included with your video with the source audio you just normalized. To do this you may have to unlink or remove the audio and video from a group – this depends on your software. Now make sure your source audio syncs up with your video – best accomplished by watching a scene with a generous amount if dialog.
» Use your sync lines (or whatever method you use to line up the riff with the source) to sync to two audio files. If you do use sync lines, now is the time to edit them out so that they will not be in the final merged video.
» Watch your audio levels and adjust them so that your riff audio is peaking slightly higher than your video audio (generally 2 or 3 db in our case) Make sure that nothing is clipping or going “into the red” to avoid distortion.
» To duck the audio Rifftrax uses the Sidechain Compressor from db Audioware. This makes the riff audio automatically lower the level of the video audio whenever someone in the riff talks. There are several different sidechain compressors available and you need to adjust the setting until you find the configuration you feel sounds the best. When doing this, make sure your riff audio is set to “send” and your video audio is set to “receive”.
Example settings – Rifftrax uses the following settings with the sidechain compressor:
» Video Audio – Thresh: -50 Ratio: 1.5:1 Attack: 9.99ms Release: 458ms Knee:25.5
» Riff Audio – Simply set to “send” and change nothing else.
Additional Info – Audacity Tutorial for ducking
» If your source video was originally shot in 30 or 29.97 frames per second you will need to perform a 3:2 Pulldown (Short version: If you don’t, the interlace scan lines will be offset creating a very visible artifact in the video). Luckily, there are various plugins around that will de-interlace and perform the pulldown for you. Most of the time, Rifftrax does this manually within Adobe After Effects. On the occasions when a manual pulldown isn’t an option we use the RE: Vision Effects – Fieldskit Plugin. You should be able to determine whether or not your editing software can perform a 3:2 pulldown or if it includes a de-interlacing filter by checking the help documents or readme that should accompany it. Final Cut Pro includes a de-interlacing plugin. There are also third party de-interlace filters available for Virtualdub in addition to the filter included with the software.
» Depending on what software you use, you may have to render out the merged video and then perform the pulldown in another program – so be prepared to take the extra time to get good results. Typical workflow for Rifftrax, beginning to end, usually looks like this:
Normalize Audio in Adobe Audition > Merge Riff and Video in Sony Vegas Render out high quality avi > Perform Pulldown in Adobe After Effects and render out final file formats.