Encoder is off when wifi is on. I think wifi takes the encoder's dma channel away. I "started" video several times while in wifi and all it did was clear everything from the screen. What will be good to investigate here is what the preview frames become when sent to the app. Ideally they are jpeg and we can record them into a movie.
My wifi with the phone freezes so I plan on trying this with a computer and eos utility and scanning camera ram and packets for jpeg data. Best case scenario would be writing video over wifi (maybe slightly better bandwith?) or turning on wifi and writing jpegs to card as mjpeg. Tethering was the only way jpeg worked on 600D so I'm guessing on 6D its related too.
