MIDI timecode - Definition and Overview

MIDI time code embeds the same timing information as standard SMPTE time code as a series of small 'quarter-frame' MIDI messages. There is no provision for the user bits in the standard MIDI time code messages, and SysEx messages are used to carry this information instead. The quarter-frame messages are transmitted in a sequence of eight messages, thus a complete timecode value is specified every two frames.

Unlike standard SMPTE timecode, the eight-message MIDI timecode sequence carries a two-bit flag value that identifies the rate of the timecode, specifiying it as either:

• 24 frame/s (standard rate for film work)
• 25 frame/s (standard rate for PAL video)
• 30/1.001 frame/s (Drop-Frame timecode for color NTSC video)
• 30 frame/s (monochrome US video)

See also:

• Linear timecode
• Vertical interval timecode
• Burnt-in timecode
• AES-EBU embedded timecode

External links

• MIDI Time Code information (http://www.borg.com/~jglatt/tech/mtc.htm)