| Term | | Definition
|
| graphics / video | | In ML, these terms are not
synonymous: graphics indicates the graphical
display used for the user-interface on a computer; video
indicates the type of signal sent to a video cassette recorder,
or received from a camcorder.
|
| capability tree | | The hierarchy of all ML devices in the system, containing
information about each ML device. An application may search a capability
tree to find suitable media devices for operations you wish to perform.
|
| system | | The
highest level in the capability tree hierarchy. It is the machine on which
your application is running. This machine is given the name
ML_SYSTEM_LOCALHOST. Each system contains one or more physical
or logical devices.
|
| physical device | | A device that corresponds to device-dependent modules in ML.
Typically, each device-dependent module supports a set of software transcoders
or a single piece of hardware. Examples of devices are audio cards on
a PCI bus, DV camcorders on the 1394 bus, or software DV modules. Each
device-dependent module may expose a number of logical devices.
|
| logical device | | Jacks, paths, or transcoders.
|
| jack | | A logical device that is an interface in/out of
the system. Examples of jacks are composite video connectors and microphones.
Jacks often, but not necessarily, correspond to a physical connector --
it is possible for a single ML jack to refer to several such connectors.
It is also possible for a single physical connector to appear as several
logical jacks.
|
| path | | A
logical device that provides logical connections between memory and jacks.
For example, a video output path transports data from buffers to a video
output jack. Paths are logical entities. Depending on the device, it is
possible for more than one instance of a path to be open and in use at
the same time.
|
| pipe | | The
connections from memory to the transcoder, and from the transcoder to
memory.
|
| transcoder | | A
logical device that takes data from buffers via an input pipe or pipes,
performs an operation on the data, and returns the data to another buffer
via an output pipe. Example transcoders are DV compression and JPEG decompression.
|
| UST | | Unadjusted system time. UST is a
special system clock that runs continuously without adjustment. This
clock is used to synchronize media streams.
|
| MSC | | Media stream count. MSC is a measure of the number
of media samples that have passed though a jack. This measure is useful
to synchronize media streams.
|
