DST Driver
2-104
Alternatively, you can create the stream with Tconf (rather than by calling
SIO_create at run-time). To do so, first create and configure two user-
defined devices called split and codec. Then, create an SIO object. Type
4/codec as the Device Control String. Select split from the Device list.
Example 2:
Conversely, you can open an output stream that accepts 1024-word
buffers, but breaks them into 256-word buffers before passing them to
/codec, as follows:
stream = SIO_create("/split4/codec",SIO_OUTPUT,1024, NULL);
To create this output stream with Tconf, you would follow the steps for
example 1, but would select output for the Mode property of the SIO
object.
Example 3:
If, on the other hand, you add a device called split and enter 4 as its
Device ID, you need to open the stream with:
stream = SIO_create("/split/codec", SIO_INPUT, 1024, NULL);
This causes SIO to open a stack of two devices: /split designates the
device called split, which you have configured to read four buffers from
the codec device and copy the data into a larger buffer for your
application. As in the previous example, codec specifies the name of the
physical device that corresponds to the actual source for the data.
When you type 4 as the Device ID, you do not need to type 4 in the
Device Control String for an SIO object created with Tconf. Type
only/codec for the Device Control String.
Data Streaming
DST stacking devices can be opened for input or output data streaming.
Constraints
❏
The size of the application buffers must be an integer multiple of the
size of the underlying buffers.
❏
This driver does not support any SIO_ctrl calls.