Architecture Topics

The following are some related pages.

• CoreMidi Framework A list of functiouns, classes, and data structures. This page also contains some information on parts of the Core Foundation Framework used with CoreMIDI.
• CoreMIDI header information This section used Doxygen to extract information from the header files belonging to the CoreMIDI framework.
• BRossTools Doxygen autodocumentation files This set of documentation was created by running Doxygen against the BRossTools Xcode project.
• Root page for documentaton on BRossTools Xcode project.

MIDI 2.0

In order to support MIDI 2.0, there had to be a number of changes to the CoreMIDI library. In the table below, Original Architecture refers to the architecture before blocks were introduced, such as the functions making use of MIDINotifyProc and MIDIReadProc, Old Architecture refers to the software items associated with MIDI 1.0, and New Architecture refers to the functions that can support both MIDI 1.0 and MIDI 2.0 systems. The term Universal MIDI Packet (UMP) refers to a method for encoding data for use both MIDI 1.0 and MIDI 2.0, with the software making the appropriate transformations to the information sent to and received from the MIDI devices.

The items MIDIClientCreate, MIDINotifyProc, MIDIDestinationCreate, MIDIInputPortCreate, and MIDIReadProc should not be used because of potential interference between threads.

Devices with USB Drivers

When a piece of hardware is connected via a USB (Universal Serial Bus) cable to a computer, it initiates a process known as "handshaking". In this process the device shares information with the computer and the computer connects the device using the most appropriate driver the operating system looks for an associated piece of software known as a driver. Some types of devices such as mice, keyboards, ethernet connections, and telephone connections, there are default drivers that are part of the operating system and will be used unless a more appropriate driver is found. These drivers are usually supplied by the vendor on their website and will provide additional capability for the vendor's products. As part of the handshake, the device sends some information about itself. The result is that the CoreMIDI software always knows how to exchange information with the MIDI devices.

External Devices

If the MIDI device is conneced with 5 pin MIDI cables, the CoreMIDI software can't identify the attached equipment. Hoeever, you can use CoreMIDI to set up external devices using MIDIExternalDevcesCreate, MIDISetupAddExternalDevice, and MIDISetupRemoveExternalDevice.

Virtual Ports and Endpoints

The software components that send and receive MIDI information with other devices are known as MIDI clients.

Non-Musical MIDI Commands

There are a number of MIDI commands where the status byte is in the range 0xF0 to 0xFF. These are known as non musical commands.