Wait..May be there wasn't any issue at all!
I read thru many forums people complaining about unable to cast OPO screen or expressing their annoyance that Chromecast is not supporting OPO for screencast yet..
Here is one of the popular and working solutions by an xDA member, Thanks @r3pwn :
But hey..! There may be an easy way! CynogenMod OPO doesn't need any Chromecast support! Not even Chromecast itself!
There may be a other solution posted somewhere, but I did not find any. So I'll just go ahead and post this guide. I'm pretty sure it's gonna help somebody!
Here is what I did to cast my OPO to my Samsung Smart TV. Easy peasy!
1. Make sure your OPO and TV are on same Wi-Fi network. (This step may not be necessary, but I haven't tested yet without this step.)
2. Many of you are aware that there is an option for OPO in the Settings > Display and Light > Cast Screen > "On"
3. Even after that you most probably won't see you TV listed there. Now here's the catch on next step. Follow Either Step 4a or 4b, whichever works for you. (Either should work, but just in case..)
4a. In OPO, go to Setting > Wi-Fi > Options Menu > Wi-Fi Direct. You should see your TV listed there. Select that, and allow for any Connection Prompt on OPO or TV.
4b. In TV (samsung Samrt TV in my case), go to Menu > Network > Wi-FI Direct. Your OPO should be listed here. Select that, and allow for any Connection Prompt on OPO or TV.
5. Now in TV, go to Menu > Network> Allshare Settings> Screen Mirroring. The TV will be ready to receive the stream from OPO.
6. After this, go to the Settings > Display and Light > Cast Screen on OPO. We've already turned it on, so now you shold be able to see your TV there. Just click on it and that's it!
You should now be able to see your OPO screen on your TV (Samsung Smart TV for sure). Response is pretty fast; it may not be suitable for high accurate timing games, but other than that, this works like a charm..! Oh, and the TV screen is fully filled when rotating your OPO in landscape mode. I was able stream 1080p video file without any jittering or quality loss! Complete audio and video! Do post back on your experiences..
I believe, the pairing for Wi-Fi Direct was the key step here. I assume everyone who failed to cast their screen did not paired for Wi-Fi Direct.
This guide should work for other phones and/or TVs, as long as DLNA, Wi-Fi Direct, and Screen Mirroring is supported on both devices. Steps and menus will vary a bit, but that's all!
If any of you get other devices working , please feedback...
My Device: Oneplus One - A0001 - Stock ROM & Kernel - CynogenMod 11.0-XNPH38R - Android 4.4.4 - TWRP 18.104.22.168 - SuperSU 2.01
My TV: Samsung LED F6400 Series Smart TV - 46” Class (45.9” Diag.) - UN46F6400AFXZA