I use Sony DVD player with my Samsung TV and the player is connected by HDMI cable to my TV number 1 HDMI input slot. When I want to change from watching streaming movies using my laptop PC HDMI number 2 cable connect, I use the TV remote to switch from one HDMI source input to the HDMI/DVI source (DVD player). I have other items connected to the TV using composite cables, etc. There is a source button on my TV remote and TV on screen menu pops up allowing me to select which source I want to use with arrows on my TV remote.
You may try a restart on both your TV and DVD player as sometimes solves these types of problems.