When using DVSDK 1.20 on DM6446 EVM, please note that by default the Linux kernel (uImage) has resizer driver (used by demos) disabled. To enable resizer driver, launch menuconfig using the following command
host $
make ARCH=arm CROSS_COMPILE=arm_v5t_le- menuconfigThen navigate to 'Device Drivers->Character devices ->DaVinci Resizer Driver' within menuconfig and enable this driver. Rebuild uImage per Getting Started Guide and you should be good to go when you start using this new uImage with resizer driver enabled.