What's the usecase for the Cortex-M4s? Is it smart enough to off-load non-computationally intensive work to the 16-bit chips for "low power", or are they serving some other purpose?
Being ARM Cortex processors, they are 32 bit. Allocate them a chunk of RAM, upload a program and set them running. TI has a driver infrastructure and sample gstreamer CODECs.
http://processors.wiki.ti.com/index.php/OMAP5_GLSDK_Software...