I'm on the new Chromecast with GoogleTV & there are no channel buttons like TiVo Stream has. I want to assign a couple buttons to change channels for YTTV. I don't see a specific Channel +/- option in the Button Mapper app. Is there any other option in Button Mapper that might perform this function? I tried Scroll up/down & Next track functions but no luck.
There is in a way but you'll need to get your hands dirty a bit. You'll need to use the "custom keycode" under "advanced". It'll involve some ADB commands beforehand to make it work though. Messed around with it myself lately and I can tell you the settings that seemed to work best were the "low latency keycode" option and under "Troubleshooting" enable "Alternate button handling".
I tried remapping the dpad first but that caused too many headaches so in the end settled for remapping the Apps button (little squares) so that a single press is Ch down, double is Ch up.