MCF specification, technical part/history

This is a subpage of MCF-specification.

Latest changes (new ones on top)

• MultiSeg started (search for the word here).
• Some parts frozen now.
• Bit 0 is the LSB, but some thought that it was the highest.
• Seek Entries renamed to Seek Header. Special entries added.
• Gap system added.
• Number of Seek Entries removed from Track Entry.
• Seek Entries redesigned; overhead reduced again and seeking might be a bit faster.
• Due to many big changes being WIP, there may be big errors in the spec.
• Broadcast updated a bit (still WIP).
• Stream end marker (Magic Block 0xFF) is mandatory.
• Broadcast file extensions removed (merged), .media.mcf removed (not used yet/soon).
• Broadcast and normal MCF merged. Lot of work still to be done.
• Number of Blocks in Actual Header changed informational
• Some changes in RSACI
• Cluster Size includes Cluster Footer too (this detail was formerly missing from specs)
• Karaoke specs
• New fields added to Actual Header: muxing app, writing app
• Broadcast-format flag added to Actual Header
• Cluster frozen
• New field in Main Header for Cluster Footer size
• Streaming/broadcasting specs written
• Block Header rearranged and no longer has negative offsets
• Cluster Footer added, checksum moved to it, and Cluster Header rearranged
• MCF-CD info minor updates (and code); formats minor updates
• Some information about levels (especially framing) written
• Lacing documented
• MCF-CD draft added
• Codec Header info added.
• Codec Header position in Track Entries removed: it is in Actual Header now.
• All elements now have a 4 octets ASCII identifier in front of 'em.
• Space-efficiency calculation updated. Overhead down to 0.4 %, thanks to Clusters.
• Some outdated info fixed (structure).
• Actual Header redesigned (everything rearranged, some things changed) and will freeze on 2002-04-08.
• Type Header strings now padded with 0x20, not 0x00.
• Actual Header: 1st Block changed to 1st Cluster; last Cluster ending position added
• Some logos etc. added
• Interlaced video dimensions are field dimensions now, not frame
• Audio channel mapping is now done in DirectShow style
• RSACI Rating UI defined
• Extended Info UI defined, Content-specific Info defined (but both are subject to change)
• IMPORTANT: Checksum Entries got replaced by Clusters - causing many big structural changes
• Subtitle flag added for Titles Track
• The number of Control Tracks is not limited: the false paragraph claiming so got removed
• Some updates on the front page (including recalculated space efficiency)
• Number of keyframes added to Track Entry
• Several little changes on formats page
• Track Entry checksum positioning is now relative to end of header
• Samplerate is now uint32, several fields in Audio Track Header got moved
• Editing date added to Extended Info
• Format minimum read-version added to Track Entry
• Track number removed from Track Entries (no need for such protection)
• Cosmetical: many hyphens got removed, typos fixed, old information cleared out, etc.
• Block-entries got replaced by Seek Entries - this greatly reduces our overhead

Current problems (work in progress)

• Video-window size should either be defined somewhere or auto-determined, for the case when there are no video-tracks
• We need someone to implement cryptography in our library, so that no external libraries are required