Distributor has no reference clock

[kozmaz87]

The issue noticed in the UIP->distributor->filesystem chain leaving the filesystem output carriage mechanism short of a valid availability time. The issue stems from the fact that the distributor does not have a matching reference clock for every conceiveable sequence ready and the information necessary to construct a clock for media timeBase needs an external offset parameter that sets the 0 time on that clock. This information is not shipped within a document and it is considered an external requirement BUT the filesystem carriage mechanism for sake of reproducibility of a transmission records the availability time of each document in a manifest file.

Suggested solutions:

1. sequenceIdentifier - clock settings mapping in configuration. Possible unknown sequence not distributed... or similar mapping in the filesystem output carriage config
2. assume unknown availability time to be 0 (hurts relative availability reproduction between documents)
3. Launch a media and a local clock in the filesystem output carriage when the application starts and use that as fallback if availability is unknown. 3.1. A possible improvement here is to keep a clock for each encountered sequence with a discard mechanism of sorts.

[kozmaz87]

For now I am choosing number 3. This seems to be the most user friendly.

[nigelmegitt]

OK sounds reasonable. Option 1 could work too, but I'm happy to go with option 3 as a starting point for now.