Exported pitch track should represent absent frames with frequency 0
|Assignee:||Chris Cannam||% Done:|
(Couldn't find an issue for this long-standing request)
Many evaluation tools expect pitch tracks to be expressed in a format in which "absent" (unvoiced) frames are not just skipped, but instead associated with a special frequency value such as 0.
Tony v0.6 doesn't do this, instead it skips any frames that have no associated pitch values and omits them from the export.
We should make it export the absent frames with 0Hz frequency instead.