Ok, something I dont check that often, but did last night.
The 70D clean outs. If you plug in an HDMI cable the LCD goes blank.
But if you plug in a usb cable, and use a PC/EOS utility or Android/DSLR Controller app, you can still control the camera and see its picture.
The magic lantern feature, is clear overlays, set it to "always".
Now you can live stream HDMI with your 70D (or even your rebel series).
The part I only recently realized is that HDMI stream is 4:2:2 compression! H264 is only 4:2:0.
However Canon had to lame the 70D because its not a XD series, so it shoots less less than 1080p.
The ML wiki states:
http://magiclantern.wikia.com/wiki/HDMI_Output" HDMI output from the Canon HDMI is limited to 1620x1080 (3:2) while the camera is not recording.
This requires the user to crop the footage from the external recorder to 1620x910 (16:9) and
then resize it to either 1280x720 (79%) or 1920x1080 (119%)."
Yes it works in Aug-22 release.
Next I am going to try if you shoot 720p to see if the HDMI out is 720p (no crop required?).
Really this is just for live streaming, but a 720p is very OK for internet.