Playing a BDMV/Blu-ray/AVCHD source uses playlists to combine multiple stream files meaning the best method is opening the parent folder or `index.bdmv` so the player can follow the disc’s layout; `.m2ts` files in `STREAM/` give you the footage directly, and sorting by size helps find the main video, but fragmented playback usually signals that a `.mpls` playlist must be used; failure to play often stems from missing directories, renamed files, or a player lacking Blu-ray support, making it important to keep the structure intact and try a compatible player.

Inside a typical BDMV folder you’re seeing how Blu-ray organizes its assets, where `STREAM/` carries the `.m2ts` video/audio streams (the largest usually being the main program), `PLAYLIST/` holds `.mpls` instructions telling the player which segments to combine, `CLIPINF/` contains `.clpi` data that improves indexing and A/V sync, and navigation files like `index.bdmv`/`MovieObject.bdmv` define startup behavior and available titles, while optional folders such as `AUXDATA/`, `META/`, `BACKUP/`, and `JAR/` help with metadata, backups, or BD-J menus, producing a complete package for Blu-ray playback.

Blu-ray and AVCHD use a folder-based structure rather than a single MP4 because they were built as disc-style playback systems, with transport streams (`.m2ts`) optimized for continuous reading and error tolerance, separate playlist/index files to assemble segments into full titles, and navigation logic for menus and interactive features, creating a small "playback database" that a player interprets—whereas MP4 is meant to be one self-contained file for simple distribution and playback.

Opening the BDMV folder in a player lets the player follow the intended structure because the player loads navigation files like `index.bdmv`, reads playlist instructions from `PLAYLIST/*.mpls`, checks clip metadata from `CLIPINF/*.clpi`, and determines which `.m2ts` streams form the actual movie, ensuring smooth joins and correct timing, while opening a single `.m2ts` may show only part of the title; using Open Folder/Open Disc on the folder containing `BDMV` lets the player build the list of titles for proper viewing.

A `.bdmv` file acts as navigation logic rather than storing video and audio, describing what titles exist and how the player should start or move between them, while the genuine media is in `.m2ts` files inside `BDMV/STREAM/` and supported by `.mpls` playlists and `.clpi` timing data; that’s why opening a `.bdmv` doesn’t show the movie—its role is directing the player to the actual streams.

You can’t usually play video straight from a `. For more info in regards to BDMV file format look into our own web-site. bdmv` because it’s designed as a navigation descriptor, not as a container for video/audio, with the real content in `.m2ts` streams stored in `BDMV/STREAM/`; playlists and clip info files then define how those segments form the actual movie, so a standalone `.bdmv` contains no footage, requiring you to load either the entire BDMV folder or the `.m2ts` streams to see anything.