avfilter/vf_v360 interprets commands as relative rotation offsets
|Reported by:||Saul Baker||Owned by:|
|Cc:||Saul Baker||Blocked By:|
|Blocking:||Reproduced by developer:||no|
|Analyzed by developer:||no|
Summary of the bug:
Use sendcmd to update the yaw,pitch or roll values of the v360 filter, contrary to the behaviour of other filters, the value sent is interpreted as an offset to apply to the current value rather than a value to set the property to.
This behaviour was switched in https://github.com/FFmpeg/FFmpeg/commit/d6e903b09b29fece449de37d5f8d6b20f3aa3333
This makes the filter stateful and hard to deal with, for example a smooth pan can no longer be achieved by applying lerp between two timestamps and instead spins the view wildly, generally position cannot be set to a known value without tracking an external copy of the rotation state.
The stateful 'relative rotation' approach seems at odds with the other filter behaviours that set the filter values rather than mutate them.