Hi Steve, In 420 format evey two vertical and horizontal neighbor pixels share one U or V value, so the image Width and Height need to be an even number. One option in case of Odd dimensions is cropping or padding the image to the next even resolution.
Also checking jpeg 2.2.2.5 configuration files (C66x_jpegenc_02_02_02_05_ELF\packages\ti\sdo\codecs\jpegenc\App\Client\Test\TestVecs\Config)
It says that image width/height in Pels, must be multiple of 16.. .
thank you,
Paula