Hello,
I have a TV to which I connect computer and watch videos. However, I sometimes want to pause video and are too lazy to go to the computer. So, is it possible that I can use Arduino with an IR receiver with remote control, so that Arduino pauses video through HDMI cable? Do I need to take some wires from HDMI cable and give a signal on them? Or it's not possible and I have to get USB cable and use Arduino as a keyboard?
Thanks for help.
I think all your problems are at the PC end - this is not an Arduino problem. I'm betting that no amount of fartarsing with the HDMI cable will pause the player, but I believe is possible to get Arduino to emulate a keyboard and/or a mouse, so that might be an option.
OTOH, why don't you use your phone as a mouse? I imagine that is what all the other lazy people do.
jacekk:
and are too lazy to go to the computer.
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Do I need to take some wires from HDMI cable and give a signal on them?
Do you currently walk to the computer and start fiddling with the HDMI when you want to pause the video 
I doubt it.
An Arduino based solution will consist of an Arduino that can act as a HID (e.g. Leonardo or Micro) and a bluetooth module to communicate with your phone.
I would use the Arduino connected to your computer with a USB cable to do keyboard emulation (using the Keyboard library). It should be possible to use a keyboard shortcut to pause/resume playback on your computer.