You should be able to play those files IMO. I'd be glad to test it on my system and take a look at the video file if you'd care to either post a short clip or email me one. I will MSG you with my email if you are interested or PM me ? I have a 3770k system with a GTX 780ti so I should be able to test anything that will play them as far as I know.
I did not find much yet except this:
Geforce codecs supported:
GeForce GT 740M | Specifications | GeForce
The desktop one doesn't list codecs support, but i'd guess it is at LEAST as good if not better.
There is a supposed S7 video profile on Reddit:
https://www.reddit.com/r/GalaxyS7/comments/48vrpr/can_galaxy_s7_record_in_h265/
quick mediainfo of a 4k video with default camera app. probably not.
Format : MPEG-4 Format profile : Base Media / Version 2 Codec ID : mp42 File size : 56.7 MiB Duration : 9s 984ms Overall bit rate : 47.7 Mbps Encoded date : UTC 2016-03-04 04:18:17 Tagged date : UTC 2016-03-04 04:18:17 com.android.version : 6.0.1
Video ID : 1 Format : AVC Format/Info : Advanced Video Codec Format profile : High@L5.1 Format settings, CABAC : Yes Format settings, ReFrames : 1 frame Format settings, GOP : M=1, N=30 Codec ID : avc1 Codec ID/Info : Advanced Video Coding Duration : 9s 863ms Source duration : 9s 875ms Bit rate : 47.9 Mbps Width : 3 840 pixels Height : 2 160 pixels Display aspect ratio : 16:9 Frame rate mode : Variable Frame rate : 29.970 fps Minimum frame rate : 22.157 fps Maximum frame rate : 30.161 fps Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Bits/(Pixel*Frame) : 0.193 Stream size : 56.4 MiB (99%) Source stream size : 56.4 MiB (99%) Title : VideoHandle Language : English Encoded date : UTC 2016-03-04 04:18:17 Tagged date : UTC 2016-03-04 04:18:17 mdhd_Duration : 9863
Audio ID : 2 Format : AAC Format/Info : Advanced Audio Codec Format profile : LC Codec ID : 40 Duration : 9s 984ms Bit rate mode : Constant Bit rate : 256 Kbps Channel(s) : 2 channels Channel positions : Front: L R Sampling rate : 48.0 KHz Compression mode : Lossy Stream size : 312 KiB (1%) Title : SoundHandle Language : English Encoded date : UTC 2016-03-04 04:18:17 Tagged date : UTC 2016-03-04 04:18:17