Your TV is most likely a 16:9 aspect ration while all iPads are 4:3.
The aTV won't "stretch" it out.
Although most people won't have the software, I just generated a 1080i HD video using Adobe Premiere Pro and got it transferred onto my iPad mini. I used the digital AV adapter (lightning version) with no issue mirroring to display. The problem I had was a user error. I was plugging in the wrong HDMI cable (using an existing setup). Once I found the correct one that actually connected to the HDTV. It worked like a charm. No video stretching as my original video is of 1080i quality.
So, just plug in the HDMI cable to the output device and used the Video application, and play the video using the Video app. No change of aspect ratio necessary as it displays as 16x9 (or 1920 x 1080 res.).
Although most people won't have the software, I just generated a 1080i HD video using Adobe Premiere Pro and got it transferred onto my iPad mini. I used the digital AV adapter (lightning version) with no issue mirroring to display. The problem I had was a user error. I was plugging in the wrong HDMI cable (using an existing setup). Once I found the correct one that actually connected to the HDTV. It worked like a charm. No video stretching as my original video is of 1080i quality.
So, just plug in the HDMI cable to the output device and used the Video application, and play the video using the Video app. No change of aspect ratio necessary as it displays as 16x9 (or 1920 x 1080 res.).