On 18 January 2014 23:11, Stephen Scott <stephensc...@videotron.ca> wrote:
> Is there any attempt to maintain the PAL 8-field sequence when aligning > the timestamps with clock time? > > Yes. The specification defines which seconds start with a "field 1", however, the time code signal must also be accurately phased to the TV field sync timing (so you can unambiguously identify each frame). So when resetting the time code generator ("jamming" or "jam-locking"), the generator only sets itself within plus of minus 2 frames of the time reference, so that its output is correctly phased to the sync pulses, and as close as possible to the time reference. Historically the TV sync-pulse generator had an accurate frequency reference, but its timing was completely random with respect to UTC. I'm not sure if that is still the case - modern generators that have a GPS receiver built in could well phase themselves, but we don't have of those :-( Peter
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