Programmer Guide/Command Reference/SEGMENT

Evaluate a segment expression.

Usage 1

SEGMENT segexpr [/S | /?]

segexpr

segment expression (see description)

/S, /?

Result 1

begin end length (evaluated expression in samples) or an empty string (on error)

Description 1

The expression is evaluated using the sampling rate and length of the current soundfile. If no soundfile is selected (see LOAD SOUNDFILE or the expression is ill-formed, the command fails.

SEGMENT

Convert a segment expression into it's equivalent in samples or extract a segment expression from a segment element in an XML file item. If an XML file is specified, then the currently selected audio set is searched for an element with the tag segTag and the id idAttr.

Usage:

var := SEGMENT segmentExpression [ samplingRate sampleCount ] [ /S ]

var := SEGMENT segmentExpression xmlFile srAttr segTag idAttr pAttr lAttr [ /S ]

Parameters:

segmentExpression

A valid segment expression. If samplingRate and sampleCount are specified, segmentExpression cannot contain segment names. See Specifying Signal Segments for details about valid segment expressions. Note that if this is the only argument, the parameters of the current soundfile are used for calculations.

samplingRate

The sampling rate to use for calculations. If this parameter is specified, it takes precedence over the sampling rate of the current soundfile.

sampleCount

The number of samples.

xmlFile

An XML file item id. The file's selected element must be an audio set. The status and context of the file are not changed by the SEGMENT command.

srAttr

The name of the sampling rate attribute in the currently selected audio set. E.g. 'SR' for an STx AFile element.

segTag

The XML tag containing the segment data in the currently selected audio set. E.g 'ASeg'.

idAttr

The id of the segment to evaluate.

pAttr

The name of the attribute containing the starting address in samples. E.g. 'P' in an ASeg element.

lAttr

The name of the attribute containing the length of the segment in samples. E.g. 'L' in an ASeg element.

/S

If specified, errors will generate warning messages rather than error messages. See The Silent Flag for details.

Result:

Returns a string in the following format:

'beginning end length'

All values are in samples.