VFPC scaler configuration

I am using the VFPC INDTXSCWB scaler on the DM8168 through the OpenMAX interface (with EZSDK 5.03.01).  Creating multiple instances simultaneously doing both up and down scaling from YUV420 to YUYV formats (for the VFDC input) all works very well.

I have two questions on slightly different use:


1) Is it possible for the scaler to output images in YUV420 rather than YUYV format?

Setting port.format.video.eColorFormat on the OMX_PARAM_PORTDEFINITIONTYPE structure appears to work initially, but the scaler then hangs on the state transition from Loaded to Idle.  (This configuration works otherwise - changing only that parameter makes the difference between the hang and proceeding as expected.)

Note that the use case for this is as an input to the encoder when we want to change the input resolution mid-stream - the documentation for that is very clear that it only accepts the YUV420 semiplanar format so I am assuming there will be no way to change the other side of the problem.


2) How can the input resolution to the scaler be changed at runtime?

Changing the output resolution via OMX_SetConfig(..., OMX_TI_IndexConfigVidChResolution, ...) appears to work as I expect, but changing the input resolution doesn't seem to do anything (the SetConfig succeeds but nothing changes).  (Given that one side works but not the other I'm mainly expecting that I've missed some other bit of configuration to let it do this...)

Currently I am working around the problem by destroying and rebuilding the OMX components every time a change is needed - this does work, but also introduces more latency that I would like.


Any help on either of these questions would be most welcome.

Thanks,

- Mark