[LAD] Audio plugins: Streamable audio ports?

[Tim E. Real]

Are there any plugin architectures that allow
 input data length different than the output length 
 such that the 'run' function can ask for more or less 
 input data, for example via some kind of stream?
Instead of passing 'run' a block of data, host would 
 pass these streams so that 'run' can pull and push 
 whatever lengths it needs.
There would be compatibility information on each
 stream so that other streams could accommodate.

I thought I read of an LV2 extension or something...
Or am I imagining something like Pulse?

Thanks.
Tim.