Also try to document the rational behind it.
This might fix Ticket2376
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
together by the same amount. AV sync, subtitle sync and relative timestamp
differences are preserved compared to how they would have been without
shifting.
+When avoid_negative_ts is used together with copyts, vsync or async then
+avoid_negative_ts is applied last. This is neccessary so that containers
+which do not support negative timestamps wont get any and can be used
+with vsync/async and copyts.
@end table
@c man end FORMAT OPTIONS