Open Source Java USITT ASCII Cue Data

ASCII Text Representation for Lighting Console Data is a standard protocol developed by USITT that allows data from lighting consoles to be exchanged by simple text files. ASCII data can be very useful for archiving and editing lighting cue information. Many offline editing programs for consoles support importing and exporting these files. Because USITT ASCII files are plain text, they can be opened and edited with simple word processors such as Windows Notepad or MacOS TextEdit.

LXAscii Applet is java source code for an applet that could be embeded in a web page. Currently there are two operations you can perform on ASCII data using the applet:

1) Replace hexadecimal values with percentage values.

2) Find and replace channels from a list.

The files in the source archive consist of the following:


The files in the archive can be used to compile a java applet that demonstrates a parser that reads USITT ASCII text and then can perform one of two operations.

The generic AbstractASCII parser class reads an parses a USITT ASCII string. However, to be useful, you must override the class. Three examples of this are included. The ParrotASCIIParser class will simply create an output string from the input string with no manipulation. By Modifying this class, you can perform operations on the parsed data. For example, the HexConverterASCIIParser class overrides ParrotASCIIParser and converts levels in hexadecimal to percentage in its output.

The PatchingASCIIParser class also overrides ParrotASCIIParser and allows you to build a table of channel substitutions that are then applied to your ASCII data. The PatchTable and PatchTableEntry classes are used to translate channels as they are added to the output.

Replacing Channels

An advantage of USITT ASCII protocol is that it exposes the cue information for easy manipulation. You can, for example, copy cues from one show and paste them into another. This is a huge advantage in Dance where pieces from one concert are often included in another. The challenge to this type of use comes when the channels are not exactly identical from show to show or venue to venue.

The applet allows you to build a table of channel substitutions that are then applied to your ASCII data.

How It Works

This operation requires that you build a table of replacement values by inserting statements into your input text. These statements follow manufacturer keyword guidelines as defined in the USITT standard. When the parser encounters a channel in cue, group or sub data, it looks in the table to see if there is a replacement or replacements specified. If so, it substitutes the original channel with the new value. In the case where there are multiple values for a channel in the table, the parser adds additional elements to the data.

This operation actually parses the ASCII Data. The messages view will inform you of exceptions or errors encountered in the operation. Also, the output text will be reformatted. The parser is fairly tolerant and will accept more than is strictly valid in the USITT standard. However, the it does require the channel data to be preceded by a valid Cue, Group or Sub record.

Table Building Statements

$$patchchan in_chan out_chan (in_chan out_chan)...

$$Patchchan adds or alters entries in the replacement table. For each input channel (in_chan) it stores the corresponding output value (out_chan).

$$patchchans in_chan out_chan (out_chan...)

$$Patchchans adds multiple entries into the replacement table. It has a single input channel (in_chan) and multiple output values (out_chan).

Clear $$chanpatch

This is an extension of the standard CLEAR record. It removes all entries from the replacement table.


$$patchchan 3>4
$$patchchans 2>2 3
cue 1
chan 1@25 2@50 3@75
Cue 1
Chan 1@25
Chan 2@50 3@50
Chan 4@75

Although valid channels are necessary to produce output that can be used by a console, you can replace channels to make your cue data human friendly. Consider the following example:


$$patchchan 1>WarmSL 2>WarmCS 3>WarmSR
cue 1
chan 1@25 2@50 3@75
Cue 1
Chan WarmSL@25 WarmCS@50 WarmSR@75

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