The following camera models support ONVIF and RTSP of the H.265 codec. (As of March 2019)
If you have a lower version, you need to change the codec to H.264 or upgrade firmware.

DC-V3213XJ / 1.3.0 or higher
DC-S3283WHX / 1.1.0 or higher
DC-D3533HRX / 1.2.0 or higher
DC-D3233HRXL  / 1.2.0 or higher
DC-T3233HRXL  / 1.2.0 or higher
DC-D4212R / 1.2.0 or higher
DC-T3C33HRX  / 2.0.0 or higher
DC-T3533HRX / 1.3.0 or higher
DC-S3833HRX, DC-S3533HRX / 1.2.0 or higher
DC-Y3C14WRX  / 1.2.0 or higher
DC-D3233HRX, DC-D3233WRX / 1.5.0 or higher
DC-T3233HRX, DC-T3243HRX / 1.8.0 or higher
DC-E4212WR / 1.2.0 or higher