Faced this issue a few weeks back in my Nokia X2. The device would stay warm to the touch, and battery life would be not more than 6 hours after a full charge. Checking the usage would indicate that the "mediaserver" is using over 70% of my battery. This was very annoying. I removed some applications, no help. Un-installed every player, app etc that could be using it, no help. I switched the SIM and Memory card to the Redmi 2. Found that the issue was the same. The Redmi 2 would run hot to the touch, and battery life was abysmal. I thought it could be something related to the SIM card. Went to Airtel and got a replacement SIM. Nothing. Finally I thought of a possible malware in the SD card, causing the high CPU usage and battery burn. Did a full format of the SD card (16Gig). The formatting took time, but once it was formatted, no issues what so ever. Sharing this in the hope that if ever, anyone else has this issue, the Memory card would be a good starting place. Hope this helps!