WPS Extension – Alternating WPS Lines

Provides a better way than using very long scrolling lines to display many items of information on the wps within the limited display space.

This wps extension introduces a concept of alternating “sub-lines”.

An alternating sub-line is defined as a group of wps format items which will be displayed on one line of the wps for a specified time, followed by one or more additional groups of wps format items which will be displayed on the line for a specified time.

Every line of the wps can have it’s own group of sub-lines that are each displayed for a specified time. The display presented on the wps for each line will consist of the alternating consecutive display of each sub-line defined for that line.

The sub-line concept is similar to specifying several formats on one line and using scrolling so that they all can be seen, except that sub-lines are more powerful in the following ways:

1) Sub-lines that fit the width of the LCD will not scroll but will simply be displayed on the line until the next sub-line item is displayed (however sub-lines that are longer than the width of the LCD can still be scrolled).

2) Sub-lines can combine any wps formats, so you can now display a non-scrollable format such as track elapsed time followed by a scrolled format on the same line.

3) The user has control over how long each sub-line item is displayed before the next item is displayed. For example, on one line you can:

a. Display the Artist and Title ID3 tags for 5 seconds (scrolled), and then....

b. Display file bit rate and file frequency for 1 second (not scrolled), and then....

c. Display track elapsed time for 2 seconds (not scrolled), and then repeat the cycle.

4) The ability to control the time that each item is displayed and the fact that long lines can be split into smaller sub-lines that can be displayed with or without scrolling makes for a display where each individual item is much easier to read than if they were all specified on one long line that is continuously scrolled.

Changes To The WPS Format Specification

This wps extension is backward compatible with the current wps specification. Existing wps definition files will still display the same as they do now.

The wps format specification language is extended as follows:

1) The ‘;’ character is used to separate items on a line into sub-lines.

2) The “%t<seconds>” tag is used to specify a time (in seconds) for the sub-line to be displayed before the next sub-line is displayed. Integer seconds, or seconds + tenths of a second can follow the %t tag (example: %t10 or %t1.5). If the %t tag is omitted from the subline specification, a default time of 2 seconds will be used.

3) The “%;” tag can be used to escape the special meaning of the ';' character and display a ‘;’ character on wps line.

Example WPS Sub-Line Specifications

%t5%s%ia - %it;%t1%fb;%t2%pc %pr

This will display the artist and title ID3 tags for 5 seconds (scrolled if it’s longer than the display width), then display the file bit rate for 1 second (not scrolled), then display the track current and remaining time for 2 seconds (not scrolled).

Conditionals can be used within sub-line specifications just as they are currently used for single line specifications.

Here is a more complex sub-line specification that uses conditionals:

%?it<%t8%s%it|%s%fn>;%?ia<%t2%s%ia|%t0>

The format above will do two different things depending if ID3 tags are present:

If the Title and Artist ID3 tags are defined, the wps line will appear as follows:

“<ID3 title>” displays for 8 seconds (scrolled)

“<ID3 artist>” displays for 2 seconds (scrolled)

If the Title and Artist ID3 tags not defined, the wps line will appear as follows:

“<filename>” displays continuously (scrolled)

Note that with the use of conditionals and using a sub-line time of 0 inside the condition branch, a different number of sub-lines can be displayed on the line depending on the branch taken for the conditional.

This extension to the wps specification is primarily useful for the player where you only have 2 lines of 11 characters, but there is nothing player specific in the implementation so it can be used on the recorder also.