Here are the details of the file format based on your description:
ESubs (Embedded/External Subtitles usually in English). File Format: .mkv (Matroska Video File). Here are the details of the file format
1080p (1920x1080 pixels), high-definition quality. high-definition quality. x264 (H.264)
x264 (H.264), a widely compatible video compression format. a widely compatible video compression format.