Therefore, it's time to try some trustworthy VLC alternatives. There is a long list of free and paid conversion programs and tools available. But if you do not want to be held back by slow processing, poor output quality and to look for the best option to convert MKV files to MP4 (H.264/H.265), DumboFab Video Converter is there for you.
It's a no-brainer for VLC to play and convert the standard video or 1080p video formatted by MP4, MKV, MOV, AVI, MPEG-2, H264, etc. But when it comes to the compute-intensive 4K HEVC video, especially HEVC 4K 60FPS video, the playback errors emerge one after another. "VLC 3.0.4 poor performance with H.265 mkv. Win 7 x64, 4790K, GTX 980. Here is how: go to Tools > Preferences > Audio and make sure Enable audio is ticked. Then go to Output and try a different default. If it still doesn’t work after trying the solutions above, you may convert the original video to another format, because VLC may have troubles playing some MKV or MP4 media file.