The T2i and all other DSLRs for that matter can’t output full resolution over HDMI for live view/recording, it says it’s 1080i when you are not recording but the resolution is really lower. All of them downres to a certain extent and add black bars to the image. On the T2i and 5d when you press record it switches the HDMI signal to 480p with black bars, so you are essentially getting less than standard Definition. The only way to do any proper full resolution recording is with the internal H264 recording built into the cameras, that’s one of the bullets you just have to bite when you use DSLRs for video.