What is the BDMV file format?
Files with .bdmv extension store information about Blu-ray Disc contents. These files do not hold actual video or audio data; they are compact binary index and navigation files. .bdmv files can be described as metafiles - they describe the structure of video, audio, menu and other elements stored on the disc, pointing players to the correct .m2ts streams. .bdmv files are stored in the main BDMV disc folder, alongside a BACKUP subfolder that mirrors the two most critical index files. .bdmv files may also be found on a ripped Blu-ray disc, but they are useless unless a proper player that understands the full directory tree is used to open them.
The most common files with the .bdmv extension are:
index.bdmv- describes the top-level title index of the disc; exactly one copy exists in theBDMVfolder and one inBDMV/BACKUP.MovieObject.bdmv- describes the HDMV movie objects and navigation commands; just asindex.bdmv, only a single such file can be present on the disc.id.bdmv- contains disc identity and certificate information used for player authentication.sound.bdmv- a less common file that stores HDMV Interactive Graphics audio stream data, typically saved in theAUXDATAfolder.
Movies that use .bdmv navigation files can be played on a computer using dedicated tools. The Blu-ray format was developed and is maintained by the Blu-ray Disc Association (BDA). The internal format version is embedded in each file's 8-byte header - version 0200 is standard for most Blu-ray discs, while 0300 appears on some UHD/4K Blu-ray releases. AVCHD camcorder recordings also reuse the same BDMV folder structure.
Security & safety
RISK: LOWA .bdmv index file is small binary metadata, not executable and not video - opening it is harmless (and does nothing visible). The real cautions are legal and source-related: ripping retail Blu-rays bypasses AACS copy protection, which is restricted in some jurisdictions, and "free Blu-ray player / BDMV codec" download sites are a common vector for bundled adware/PUP - get VLC, MakeMKV and HandBrake only from their official sites. A BDMV folder copied from an untrusted source is just data, but treat unexpected disc images with normal caution.
Format details
in a nutshellPrograms that open BDMV files
Windows4 apps
VLC media player
Open-source Media > Open Disc and point at the Blu-ray, or open the folder ABOVE BDMV - VLC reads index.bdmv and plays the title. Don't open index.bdmv alone. 
Cyberlink PowerDVD
Paid The mainstream commercial Blu-ray player; opens the disc/BDMV folder and handles menus and AACS-protected retail discs. 
Leawo Blu-ray Player
Free Free Blu-ray/BDMV folder player with menu support - open the disc or the BDMV's parent folder.
MakeMKV
Freemium Not a player but a ripper: open the BDMV folder/disc to extract titles to MKV (decrypts retail discs). Use to turn a BDMV into a watchable file. 
macOS2 apps
VLC media player
Open-source Open the folder containing BDMV (or the disc). VLC follows index.bdmv to the streams. 
Linux2 apps
VLC media player
Open-source Open the disc or the BDMV parent folder; install libaacs/libbdplus for protected discs. Plays via the index. Technical details
deep spec| Encoding | Binary (big-endian byte order throughout) |
| File header | 8-byte ASCII type + version string at offset 0; e.g., `INDX0100` for `index.bdmv`, `MOBJ0200` for `MovieObject.bdmv` |
| Internal version field | ASCII substring embedded in the header: `0100`, `0200` (standard BD), or `0300` (UHD/4K Blu-ray) |
| Typical file size | A few hundred bytes to a few KB; both `index.bdmv` and `MovieObject.bdmv` are small navigation tables |
| Compression | None - files consist of fixed-field offset tables and navigation data |
| Encryption | None - `.bdmv` index files are unencrypted; disc video streams may use AACS or BD+ |
| Disc location | `BDMV/` root directory; redundant copies of `index.bdmv` and `MovieObject.bdmv` kept in `BDMV/BACKUP/` |
| MIME type | application/octet-stream |
| Role in disc structure | Navigation and index only; video resides in `BDMV/STREAM/*.m2ts`, playlists in `BDMV/PLAYLIST/`[`.mpls`](/format/mpls), clip info in `BDMV/CLIPINF/*.clpi` |
| Compatible disc types | BD-ROM (Blu-ray Disc) and AVCHD camcorder discs share the same BDMV folder layout |
| Named file variants | `index.bdmv`, `MovieObject.bdmv`, `id.bdmv`, `sound.bdmv` |
| Standalone usability | Meaningless without the surrounding BDMV folder tree; players must open the folder or an [ISO image](/format/iso), not the `.bdmv` file alone |
| Backup and integrity | No per-file checksum; integrity relies on mandatory mirror copies of `index.bdmv` and `MovieObject.bdmv` in `BDMV/BACKUP/` |
| Released | 2006 (Blu-ray Disc / BD-ROM specification) |
| Latest version | BDMV version 0200 (BD); 0300 used on some UHD/4K Blu-ray discs |
| Specification | blu-raydisc.com |
BDMV conversions
Community Q&A
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