We directly use an instance of RangeDescriptor to avoid incurring
the memory cost of using a StagingBuffer here. It's unnecessary
since these stencils will always be 32bits large.
We modify the semantics/meaning of the ambience stim feature.
It now represents the number of frames whose average intensity
is below the ambienceLowVal.
We can now implement the postrin as the event wherein the number
of frames whose intensity <= ambienceLowVal exceeds
postrin-interest-threshold.
We now allocate all the stimFrames for a StimBuffer using a
single StagingBuffer. This gives us all the benefits we're
looking for (pinning, alignment, etc).
* PcloudStimulusProducer now has member sh_ptr<StimulusBuffer>s.
* StimulusProducer now has a vector<sh_ptr<StimulusBuffer>s.
Created new stimbuff-type-specific
Pcloud[Xyz|I|Ambience]StimulusBuffer classes for representing each
stim feature exposed by livoxGen1's PcloudStimulusProducer.