i use two vfcc instances in OMTB,
#first
omx api gethandle tvp 0 0
omx api gethandle vfcc 0 0
omx api gethandle dei 0 0
omx api gethandle h264venc 0 0
omx api gethandle vfdc 0 0
omx api gethandle dc 0 0
#second
omx api gethandle tvp 1 0
omx api gethandle vfcc 1 0
omx api gethandle dei 1 0
omx api gethandle h264venc 1 0
omx api gethandle vfdc 1 0
omx api gethandle dc 1 0
but the second will block in the following line:
omx api sendcommand state vfcc 1 waitforsem