High Efficiency Video Coding (HEVC) or also called H.265 is become more and more popular.
H.265 should use much less space and offer compression quality than H.264(Learn difference between H.265 and H.264). The only problem is that H.265 is still not supported by iPad Mini 3. To enjoy the Samsung NX1 H.265 videos on iPad Mini 3, a necessary tool seems to be a H.265 Converter for Samsung NX1. 
Read some other users’ feedback online, Pavtube Video Converter Ultimate is the highly recommended as the best H.265 Video Converter for Samsung NX1 footage or other H.265 video source. Overall, this program is a completely professional H.265/HEVC encoder, decoder, player and editor. It provides three new output format presets for H.264, and one for H.265 in Common Video Option for better playback. In addition, this H.265 Converter is also available to customize the output resolutions to any size the users want. For Mac users, turn to iMedia Converter for Mac. Now just download it and follow the steps below to finish the H.265 to iPad Mini 3 MP4 conversion.
How to Convert and Sync H.265 video to iPad Mini 3 ?
Step 1. Best H.265 Video Converter for iPad Mini 3
Download this best H.265 Video Converter, Drag the H.265 video files to the software. Or you can also click “Add Video” button on the top of the main interface to import video to the program. If you want to merge H.265 clips, just need to check the “Merge into one” box. 
Step 2. Choose an output format for iPad Mini 3
Click on “Format” bar, select “iPad>iPad Mini HD Video (*.mp4)” as output. You can choose regular video formats like AVI, MP4, WMV, FLV, MKV, MOV, etc from Common Video. 
Step 3. Optimize audio/video settings for iPad Mini 3 (Optional)
In “Profile Settings” screen, you can change parameters like size, bitrate, frame rate, and sample rate according to your need.
Step 4. Start convert H.265 videos to iPad Mini 3
Click “Convert” to start converting H.265 videos to iPad Mini 3. When the conversion done, click Open button to get the ripped videos, then, transfer the converted files to iPad Mini 3 for much more convenient playback. Enjoy.
See Also:
Top 6 H.265/HEVC Video Converters Review
Import 4K H.265 Video from Samsung NX1 to Premiere Pro CC
How to edit Samsung NX1 H.265 video in Adobe Premiere Pro CC/CS?