Synchronizing and controlling audio post production equipment
Audio post production is designed to bring together the various sounds that will make up a polished finished production, allowing them to be accurately edited and mixed together into the final audio track.
The sounds may be music, effects or dialogue, but all must run in synchronization with the picture, and do so repeatedly. The sound editor must be able to lay the soundtracks, and the mixer must be able to rehearse and refine his sound mix to perfection. A synchronizing code is needed to achieve this degree of accurate synchronization between the various audio sources and the picture. Film uses sprocket holes, but on electronic recording systems (video and audio) a standard electronic code is used – known as timecode. On computer workstations, where sound is edited and mixed, manufacturers use their own proprietary timecoding systems within the workstations themselves. The timecode may not, in fact, be recorded as a standard timecode signal, but as a reference code to cue files to play when needed. Here the timing information needs to be very accurate – more than ordinary timecode – to allow critical locking to digital signals. But whatever system is used internally in a workstation, the timecode system that talks to the outside world will conform to internationally agreed standards.