Introduction to Streamers
Back in the old days of film music, a clever but work-intensive method for synchronizing music to picture was invented. The music editor would find certain key musical points in a cue, and use a system of visual cues called streamers and punches to show the conductor when those points occurred. Streamers were made by marking a long diagonal line across a copy of the film with a grease pencil (or scratching off the emulsion), ending at the frame that was to be synchronized; this gave the appearance of an almost-vertical line streaming across the screen when the film was played back. Punches were achieved by punching a hole in the center of a frame, and a flutter punch effect was possible by punching every other frame.
Eventually the Iron Age dawned, bringing with it the advent of analog video technology. This provided for a new way of displaying streamers and punches, using specialized hardware triggered by MIDI (Musical Instrument Digital Interface) data from a sequencer. This was a tremendous advantage, as it dramatically reduced the preparation time needed on the music editor's part. However, it dramatically increased the cost involved; the hardware ran into the thousands of dollars (while grease pencils remain somewhat less expensive).
Now that the Information Age has spawned technologies such as digital video and computerized sequencing, streamers and punches are entering a new phase of their existence. Streamers (the software) eliminates the need for the old specialized hardware by drawing streamers and punches entirely in software. This means no hardware is required except the same computer that is already running the sequencer, and an inexpensive video adapter.*
Streamers avoids having to genlock, or alter the video pathway in any way, by working entirely in software. It does this by rendering streamers, punches, and a free-time clock directly on its own video display, or alternatively, onto a transparent window that sits over a sequencer's movie window. Visual events are sequenced and automated within Streamers, or triggered by MIDI commands—much like hardware streamer boxes, but again, entirely within software. Since Streamers works with windows on a display, rather than directly with video output devices, the only hardware that is needed is a composite video adapter, which at the time of this writing are easily procured for less than $20.
* A note about hardware: Streamers will not output to FireWire DV boxes, MJPEG capture cards, or other hardware that requires a direct stream of digital video data. Streamers will only appear where a window can appear; i.e., on a monitor that is recognized by the Mac OS as a display. If you are uncertain about your hardware, go to the Displays pane of System Preferences. If your hardware appears as a display there, Streamers should work quite happily with it.
Also note that Apple has begun removing analog video output from some of their computers (such as laptops with Mini DisplayPort connectors), so if you require composite video output, you will need a digital-to-analog video adapter or scan converter.