Here’s yet another thing to keep in mind. Remember the countdown when watching video clips? 10…9…8…7…6…5…4…3…2…BEEP. Beep? The beep when the counter gets to 2 is called a “2-pop”, and all of your audio tracks should have them. What is a “2-pop” for and why should you have them? The 2-pops are short tones exactly 2 seconds before the video segment starts. The purpose of a 2-pop is to serve as a last ditch synchronization point. If the wrong frame rate is used, or perhaps if the SMPTE time code gets corrupted, the 2-pop can be your knight in shining armor. Just line up the audio 2-pop exactly 2 seconds before the video starts and that should be a pretty close indicator of where the audio should go.

House Sync and Word Clock Generator.

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Now that we have all the formalities out of the way, let’s get into the fun stuff, which means actually using the equipment! First things first--timing reference! You must have a common timing reference (just like word clock) running to every piece of gear in your studio. When working with video a “house sync” generator is used. House sync is basically a composite video signal, and is generally a black burst or color bars. A house sync signal should run to every piece of video gear and digital audio gear in your studio. What if your gear doesn’t have a video sync input? You’ll need to get a house sync generator that puts out the proper word clock, or get a video sync to word clock converter. For the extremely budget conscious studio here’s a trick. Take any old half-decent VCR you can buy at any electronics store. It doesn’t have to have a video sync input. Take the video output of that VCR and use that as your video sync reference going to your DAW or workstation. This is a really “quick and dirty” way of achieving video sync in a small setup. But I wouldn’t recommend it for any mid- to high-end work.

Be careful you don’t confuse SMPTE with house sync. SMPTE time code should originate from your video deck or your DAW if you are using non-linear video, and be sent to every piece of gear following SMPTE. House sync does not replace the SMPTE connection, so be sure you have both on anything that’s chasing or generating time code.

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Video Sources? The cheapest way (besides my little trick above) to employ video in your studio is using an inexpensive “pro” VHS deck that has a video reference input, so it can follow along happily in sync. Other alternatives are Digital Beta, or now days its not uncommon to find older _” decks for sale. Non-linear video running on hard disk is the best option, due to the fact that no one likes rewinding to find the correct spot on the tape.

Pro-Tools, for example, uses QuickTime movies to run along in time with the audio, and works quite well with video using one of their specified video cards. However, beware of cheap digital transfers from video to QuickTime. QuickTime commonly uses 15 frames per second, nowhere near the 29.97 you will be working with. The ideal situation would be to have a “pro” video deck and a DAW with the proper video capture hardware to grab a full 29.97fps. That way you can have a client hand you a tape, transfer it to hard disk, and edit away to your heart’s content. You can even bounce your audio/video mixes back to your video deck for client approval.

There are multitudes of issues to keep in mind when synchronizing audio to picture. If you keep the basic concepts in mind you can avoid many of the pitfalls that can turn the joy of working with picture into a nightmare. Happy sync!

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