Supported video formats
VR Tourviewer supports MP4 video in H.264 and H.265 format for linked MP4 files, video overlays and monoscopic and stereoscopic panorama videos.
360 videos with Oculus Go:
Here you can find information on optimal compression and codec use for 360 videos for display on the Oculus Go: https://creator.oculus.com/blog/encoding-high-resolution-360-and-180-video-for-oculus-go/
Limitation in Windows:
Due to Microsoft removing native support for the H.265/HEVC in Windows 10, H.265 files may not play on your PC. To add support for H.265 on your system you can install the HEVC codec from the Windows Store.
Even with this codec installed, in Windows the H.265 (HEVC) codec is only supported up to a resolution of 4096×2304 pixels. For larger resolutions please use the H.264 codec. For example: when using 3D 360 panoramic video, use H.264 with a recommended size of 4096×4096 pixels, top/bottom, with 30 frames per second.