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Chapter 9: The Digital Video System > Digital video camcorders and formats - Pg. 222

Chapter 9 the Digital Video System true 29.97 video time after 1 hour is 108 frames, or 3 seconds and 18 frames. By using nondrop-frame timecode, when the timecode numbers display 1 hour (01:00:00:00) your video will in fact be shorter by 3 seconds and 18 frames (00:59:26:12). That may not seem like such a big deal, but in broadcast television, where programs and commercials must conform to frame-accurate timing, it is crucial to have a precise frame count. Nondrop-frame timecode is usable when you are shooting and editing HD footage that will remain in the HD realm (or PAL). But any program that you anticipate distributing in SD formats (like SD broadcast and DVDs) should use nondrop-frame timecode. For all SD DV applications, drop-frame timecode is the standard and default method for counting and addressing frames with ID numbers. Drop-frame timecode does not actually drop any video frames, but it does skip over some timecode numbers from time to time in order to adjust the frame count to accurately reflect the true 29.97 fps of SD video. To be precise, the drop-frame TC system skips over the :00 and :01 frame numbers once every minute, except for the 10th minute. Here is how the TC numbers change at each minute of foot- age (except for every 10th minute): 00;09;26;28, 00;09;26;29, 00;09;27;02, 00;09;27;03. This method compensates for the slowed-down video frame rate and, in the end, is com- pletely frame accurate. After an hour of drop-frame timecode counting, we will arrive at TC 01;00;00;00 for exactly 1 hour of video footage. 203 When to use WhICh dv ForMat?