DataLine adds media-related functionality to itssuperinterface, . This functionality includes
transport-control methods that start, stop, drain, and flush
the audio data that passes through the line. A data line can also
report the current position, volume, and audio format of the media.
Data lines are used for output of audio by means of the
subinterfaces or
, which allow an application program to write data. Similarly,
audio input is handled by the subinterface ,
which allows data to be read.
adds media-related functionality to its superinterface,. This functionality includes transport-control methods that start, stop, drain, and flush the audio data that passes through the line. A data line can also report the current position, volume, and audio format of the media. Data lines are used for output of audio by means of the subinterfacesor, which allow an application program to write data. Similarly, audio input is handled by the subinterface, which allows data to be read.
A data line has an internal buffer in which
the incoming or outgoing audio data is queued. The
drain()
becomes empty, usually because all queued data has been processed. The
flush()
from the internal buffer.
A data line produces START
STOP
it begins or ceases active presentation or capture of data. These events
can be generated in response to specific requests, or as a result of
less direct state changes. For example, if start()
on an inactive data line, and data is available for capture or playback, a
START event will be generated shortly, when data playback
or capture actually begins. Or, if the flow of data to an active data
line is constricted so that a gap occurs in the presentation of data,
a STOP event is generated.
Mixers often support synchronized control of multiple data lines.
Synchronization can be established through the Mixer interface’s
synchronize
See the description of the Mixer
for a more complete description.
