class SetInputBufferPartialSettings

When the client is not using dynamic buffers, a single

SetInputBufferPartialSettings() provides the StreamProcessor with the

client-specified input settings and a BufferCollectionToken which the

StreamProcessor will use to convey constraints to sysmem. Both the

client and the StreamProcessor will be informed of the allocated buffers

directly by sysmem via their BufferCollection channel (not via the

StreamProcessor channel).

The client must not QueueInput...() until after sysmem informs the

client that buffer allocation has completed and was successful.

The server should be prepared to see QueueInput...() before the server

has necessarily heard from sysmem that the buffers are allocated - the

server must tolerate either ordering, as the QueueInput...() and

notification of sysmem allocation completion arrive on different

channels, so the client having heard that allocation is complete doesn't

mean the server knows that allocation is complete yet. However, the

server can expect that allocation is in fact complete and can expect to

get the allocation information from sysmem immediately upon requesting

the information from sysmem.

Mixing of AddBuffer and SetInputBufferPartialSettings is not allowed

while there are any buffers still active on the port. To successfully

switch modes for a port, most clients will want to just start over with

a new StreamProcessor instance. This can also be done reliably by first

ensuring that every added buffer under the port up to "now" (including

those with older buffer_lifetime_ordinal) has completed a RemoveBuffer

request. Only then is it known ok to switch modes for that port under

the same StreamProcessor. Most clients will just use one way or the

other to add buffers and never need to switch to the other way,

especially within the same StreamProcessor.