Blackmagic Design Ultimatte 12 Manual De Operaciones página 1007

Requesting Changes
To update a Control the client should send a block of the same form Ultimatte sends when
its status changes. For example, to change Matte Density to 100, the client should send the
following block:
CONTROL: ↵
Matte Density: 100 ↵
↵
The block must be terminated by a blank line. On receipt of a blank line, Ultimatte will either
acknowledge the request by responding:
ACK ↵
↵
or indicate that the request was not understood by responding:
NAK ↵
↵
After a positive response, the client should expect to see a status update from Ultimatte
showing the status change. This is likely to be the same as the command that was sent, but
if the request could not be performed, or other changes were made simultaneously by other
clients, there may be more updates in the block, or more blocks. Simultaneous updates could
cancel each other out, leading to a response that is different to that expected.
In the absence of simultaneous updates, a simple control change will result in the following
protocol exchange:
CONTROL: ↵
Matte Density: 0 ↵
↵
ACK ↵
↵
CONTROL: ↵
Matte Density: 0 ↵
↵
The asynchronous nature of the responses means that a client should never rely on the desired
update actually occurring and must simply watch for status updates from Ultimatte and use only
these to update its local representation of Ultimatte's state.
A client may also request Ultimatte to change a control by a relative amount. For example,
to change Matte Density by 10, the client should send the following block:
CONTROL: ↵
Offset Matte Density: 10 ↵
↵
Only controls with numerical ranges support this relative mode.
Requesting a Status Dump
The client may request that Ultimatte resend the complete state of any status block by sending
the header of the block, followed by a blank line. In the following example, the client requests
Ultimatte resend the control status:
CONTROL: ↵
↵
ACK ↵
↵
Developer Information 1007