mkvextract your_movie.mkv tracks 0:video.hevc

: This generates a raw HEVC file ( BL_RPU.hevc ) which you must then remux with your original audio and subtitles using MKVToolNix . Critical Considerations

Ultimate Guide: How to Convert Dolby Vision Profile 7 to Profile 8 (New Methods)

Converting a true FEL file is more complex and involves a technical trade-off. The FEL contains high-bitrate 12-bit video data. Since Profile 8 has no concept of a separate enhancement layer, this FEL data cannot be preserved.