DV/HDV tape drive synchronization for immediate preview of dual camera recordings

摘要

Dual DV or HDV camcorder setups are widely used to record stereoscopic video content. However, even when using a remote control to operate the camcorders synchronously, the number of recorded frames per scene is slightly different on the left and right tape. The different lengths make it impossible to play back the recorded content immediately. Up to now, both tapes had to be transferred to a hard disc and edited scene by scene. This paper presents a software-only solution to synchronize a pair of DV or HDV camcorders: Playback is assumed to be out of sync whenever a scene change does not occur at exactly the same time on the left and right tape. In such a case, the first tape is stopped until the scene change occurs on the second tape as well. Once both tapes have reached the scene change, playback on both drives is resumed. Detecting scene changes by means of image analysis is unreliable and CPU intensive. Consequently, we suggest a better method based on the recording date and time embedded in the compressed stream. To test the suggested solution, tape synchronization capabilities have been added to the Stereoscopic Multiplexer, a multiplexing solution for the Microsoft Windows platform.