| 摘要 |
<p>An editing device for half-inch video tape applies pulse-width modulation to prerecorded synchronizing pulses in predetermined intervals. The inverval starts with an eleven-bit header (44) compatible with the VASS system. Pulse-width modulated time codes (48) identify the recording session and the elapsed time are then added. A check code (60) completes the modulation for fifty-hz systems, e.g. PAL and SECAM. For sixty-hz systems, e.g. NTSC, a ten-bit dummy code (62) is added to complete the interval. The code is entered without writing over the leading edge of the prerecorded synchronizing pulse, allowing the timing of those pulses to continue without interruption. An editor can locate any desired interval and can then locate an individual frame within that interval by counting synchronizing pulses.</p> |
