sound.bdmv

Type of format	Audio Clip file
First released	2006
Developer	Blu-ray Disc Association
Max File Size	2 MB
Limits	128 sounds per file
Compression Type	CBR
Channels	2
Bits	16
Sample	48 KHz
Filename extension	sound.bdmv xxxxx.bdmv xxxx.pcm xxxx.lpcm xxxx.wav
Open Format?	Yes
Free Format?	?
Magic Number	BCLK0100 BCLK0200 (BD) BCLK0300 (UHD)

Interactive Audio is used for real-time interactive sound effects, usually for menus or video games.

The sound.bdmv file (or other BDMV audio assets) is preloaded into the player's sound memory buffer before the Primary Video and Audio. It is restricted to PCM (stereo or mono) in 16 bit resolution at 48 kHz. The max size for each sound file (or group of sounds in the same file) is 2 MB. Audio length is 20 seconds in mono and 10 seconds in stereo. Sounds are loaded into the 5 MB sound memory, making it hold 54 seconds of mono audio and 27 seconds of stereo audio.

A single sound file can hold up to 128 sounds as long as it fits in the 2 MB sound.bdmv file. It is capable of playing 8 channels simultaneously*.

Some players, such as the Sony PlayStation 4 and the one's from Oppo, block Interactive Audio by default by automatically disabling the sound.bdmv file in the AUXDATA directory. So, to avoid this, its a good idea to store your sound files outside of the AUXDATA folder if you're making a BD-J application, such as a video game with cool sound effects.

Unclear Information

There are different sources regarding sound memory: Libbluray claims it is 8 MB, and Sony DoStudio claims it is 4 MB. Blu-ray Disc Demystified claims it's 5 MB. Most BD titles that have used this file are always under 2 MB. However, the Pinball mini-game from Surf's Up contains 4.4 MB of compliant sound files (lpcm), so highly assuming it's 5 MB. So, it is unclear what the max sound memory is "officially". Any legit information is appreciated!

Sources

• Tested the BD-J game, Ukko's Journey, sounds effects during gameplay
  
• Programming HD-DVD and Blu-ray Disc: The HD Cookbook
• Blu-play.com 
• Blu-disc Studio User's Guide 
• libbluray.java from VideoLAN
  
• *Hughnews.ca - The Authoritative Blu-ray Disc - 4. Physical, Logical and Application Specifications - BD-J Section
• Cloudy with a Chance of Meatballs - Mini-game can play 4-5 sound effects in the same time (not counting primary audio)

Author(s) : Æ Firestone - Last Updated: 4/22/2026