-Miracle Control Protocol (DVCP) Reference Documentation
+MLT Video Control Protocol (MVCP) Reference Documentation
-Copyright (C) 2004 Ushodaya Enterprised Limited
+Copyright (C) 2004-2009 Ushodaya Enterprised Limited
+Copyright (C) 2010-2011 Dan R. Dennedy
Author: Dan Dennedy <dan@dennedy.org>
-Last Revision: 2004-03-20
+Last Revision: 2011-04-17
General Format
--------------
- DVCP is an ASCII-based request/response TCP protocol much like FTP and
- inspired by the SGI MVCP (Multiport Video Computer Protocol). Each
+ MVCP is an ASCII-based request/response TCP protocol much like FTP and
+ inspired by the SGI MVCP [1] (Multiport Video Computer Protocol). Each
command is three to eight characters long followed by zero or more
arguments. Every item (command or argument) in the request is delimited
by a space and terminated with a new line. Arguments that contain spaces
a line feed optionally preceeded by a carriage return. There are no
request header lines or body.
+ [1] http://techpubs.sgi.com/library/tpl/cgi-bin/getdoc.cgi?coll=0650&db=bks&fname=/SGI_EndUser/MSB3xx_UG/ch09.html
+
Response Codes
--------------
Establishing a Connection
-------------------------
- One can connect to the miracle server using telnet or a custom client,
- preferrably one developed using the valerie client API. The default port
+ One can connect to the melted server using telnet or a custom client,
+ preferrably one developed using the libmvcp client API. The default port
is 5250. Connections can be broken at will or use the BYE command to
request the server to terminate the connection.
All commands are case insensitive. Arguments may or may not be case
sensitive. There are two categories of commands: global and unit. Global
commands operate at the server level. Unit commands address a specific
- unit. miracle is a multi-unit system. Units are named as U? where ?
+ unit. melted is a multi-unit system. Units are named as U? where ?
is the unit number, for example, U0. As units are added to the server,
the unit number increases; the first unit is U0.
The response body contains each command sent along with its arguments,
followed by each command's response status code and response body.
-
STATUS
Responds with the output of USTA for each unit and accepts no further
input. Each time the state of the unit changes, a new row is returned by
the server containing the state of the unit.
+
Unit Management
- The following global commands manage the DV units within the server.
+ The following global commands manage the playout units within the server.
Currently there is a maximum of four units, and units can not be
removed. Each unit may be in an online or offline state. Offline units
can not be used, and any unit commands issued against an offline unit
results in a 403 response.
NLS
- * NOT IMPLEMENTED IN MIRACLE YET *
-
+ * NOT IMPLEMENTED IN MELTED YET *
UADD mlt-consumer[:argument]
Add a unit based upon the mlt-consumer id and optional constructor
server containing the following columns:
- unit name (one of U0, U1, U2, or U3)
- mlt-consumer[:argument] from uadd
- - 1394 node GUID (defunt - always 0 with miracle for now)
+ - 1394 node GUID (defunt - always 0 with melted for now)
- online flag (1 = online, 0 = offline)
SHUTDOWN
Property "points" determines whether the playback engine restricts the
playback region to the in and out points. It takes one of the following
- values: use, ignore.
+ values: use, ignore. (not currently implemented)
UGET {unit} {key}
Get a unit's configuration property.
Sets the current position to the first frame in the clip.
Preface the filename with '!' to tell the disk reader thread to remove only
duplicate frames from the tail of its buffer queue (from a previously loaded
- and playing clip). Otherwise, miracle flushes all of its buffers upon LOAD
+ and playing clip). Otherwise, melted flushes all of its buffers upon LOAD
to make the effect of LOAD instantaneous. The LOAD !, USET eof=pause, and
extended USTA information can be used for client-side playlists (see the
demo programs).
currently playing clip index.
CLEAN {unit}
- Removes all by the playing clip.
+ Removes all but the playing clip.
WIPE {unit}
Removes all clips before the playing clip.
(200%).
If the unit is stopped, then the frame position is reset to the first
frame. First frame depends upon the "points" unit configuration property
- and whether an in point has been established for the clip using the SIN
- command.
- Set the currently loaded clip's in point.
- Frame is zero-based and absolute. It is not dependent upon the clip's
- current in point.
- A frame-number of -1, resets the in point to 0.
+ (not currently implemented) and whether an in point has been established
+ for the clip using the SIN command.
FF {unit}
Fast forward the unit.
in reverse).
If the unit is stopped, then the frame position is reset to the first
frame. First frame depends upon the "points" unit configuration property
- and whether an in point has been established for the clip using the SIN
- command.
+ (not currently implemented) and whether an in point has been established
+ for the clip using the SIN command.
STEP {unit} {number-of-frames}
Adjust the current frame position by the number of frames specified.
The clip inherently includes the in- and out-point information.
The target unit's "points" configuration property is set to "use."
-
-
-
+PUSH {unit}
+{size}
+{XML}
+ Append an in-band MLT XML document to the unit.
+ Do note that the size and XML arguments are on new lines.
+ Size is the size of the XML payload in bytes.
+ Returns 404 if the XML is malformed or if the XML producer fails parsing.
projects / melted / blobdiff