Filename extension .mj2, .mjp2 Type of format moving image | Internet media type video/mj2 Container for video, sound | |
Magic number 12 byte string: X'0000 000C 6A50 2020 0D0A 870A' Developed by Joint Photographic Experts Group | ||
Motion JPEG 2000 (MJ2 or MJP2) is a file format for motion sequences of JPEG 2000 images and associated audio, based on the MP4/QuickTime format. Filename extensions for Motion JPEG 2000 video files are .mj2 and .mjp2, as defined in RFC 3745.
Contents
ISO Standards
MJ2, first defined by Part 3 of the ISO Standard for JPEG 2000 ISO/IEC 15444 in November 2001 (ISO/IEC 15444-3:2002) as a standalone document, has later been defined by ISO/IEC 15444-3:2007, ISO/IEC 15444-3:2007/Amd 1:2010, additional profiles for archiving applications, and by ISO/IEC 15444-12 which defines the JPEG 2000 base media format, which contains the timing, structure, and media information for timed sequences of media data.
The standard is available for download from ITU-T as their Recommendation T.802.
MPEG vs MJ2
Motion JPEG2000 was always intended to coexist with MPEG. Unlike MPEG, MJ2 does not implement inter-frame coding; each frame is coded independently using JPEG 2000. This makes MJ2 more resilient to propagation of errors over time, more scalable, and better suited to networked and point-to-point environments, with additional advantages over MPEG with respect to random frame access, but at the expense of increased storage and bandwidth requirements.