Vamp Plugin Tester

Vamp Plugin Tester

==================

This program tests Vamp audio feature extraction plugins

(http://vamp-plugins.org/) for certain common failure cases.

To test a single plugin, run vamp-plugin-tester with the name of your

plugin library and plugin identifier, separated by a colon.  For example,

  $ vamp-plugin-tester vamp-example-plugins:amplitudefollower

The plugin library must be installed in the Vamp plugin path (you

cannot give the path to the library file).

If you run vamp-plugin-tester with no arguments, it will test all

plugins found in your Vamp plugin path.

Options

=======

Supply the -v or --verbose option to tell vamp-plugin-tester to print

out the whole content of its returned feature log for diagnostic

purposes each time it prints an error or warning that arises from the

contents of a returned feature.

Supply the -n or --nondeterministic option to tell vamp-plugin-tester

that your plugins are expected to return different results each time

they are run.  The default behaviour is to treat different results on

separate runs with the same input data as an error.

Errors and Warnings

===================

Each test may cause one or several notes, warnings, or errors to be

printed.  A note is printed when behaviour is observed that may be

correct behaviour but that is not always anticipated by the plugin

developer.  A warning is printed when behaviour is observed that is

technically legal but that in practice most often happens by mistake.

An error is printed when behaviour is observed that cannot be correct.

vamp-plugin-tester prints all of its commentary to the standard

output.  Standard error is usually used for diagnostic output printed

by the plugins themselves.

In addition to reports, vamp-plugin-tester runs some tests that are

intended to provoke the plugin into unexpected behaviour such as

memory errors.  If vamp-plugin-tester crashes during a test, this may

be why.  If you have access to a memory checker utility such as

valgrind, you are advised to run vamp-plugin-tester under it so as to

be informed of any memory errors that do not happen to cause crashes

(as well as memory leaks).  The vamp-plugin-tester binaries

distributed by QMUL have been compiled with debug information

included, in order to facilitate this type of use.

Error and Warning Reference

===========================

 ** ERROR: Failed to load plugin

 The plugin could not be loaded.  Remember that the plugin must be

 installed in the Vamp plugin path.

 ** ERROR: (plugin|parameter|output) identifier <x> contains invalid characters

 An identifier contains characters other than the permitted set (ASCII

 lower and upper case letters, digits, "-" and "_" only).

 ** ERROR: <field> is empty

 A mandatory field, such as the name of a parameter or output,

 contains no text.

 ** WARNING: <field> is empty

 An optional field, such as the description of a parameter or output,

 contains no text.

 ** ERROR: Plugin parameter <x> maxValue <= minValue

 The minimum and maximum values given for a parameter are equal or in

 the wrong order.

 ** ERROR: Plugin parameter <x> defaultValue out of range

 The default value for a parameter is not within the range defined by

 the minimum and maximum values for the parameter.

 ** ERROR: Plugin parameter <x> is quantized, but quantize step is zero

 The quantizeStep value in a parameter with isQuantized true is set to

 zero.

 ** WARNING: Plugin parameter <x> value range is not a multiple of quantize step

 A parameter's stated maximum value is not one of the possible values

 obtained by adding multiples of the quantize step on to the minimum

 value.

 ** WARNING: Plugin parameter <x> has (more|fewer) value names than quantize steps

 A quantized parameter lists some value names for its quantize steps,

 but not the right number.

 ** WARNING: Plugin parameter <x> default value is not a multiple of quantize

 step beyond minimum

 The default value for a parameter is not a value that the user could

 actually obtain, if only offered the quantized values to choose from.

 ** ERROR: Data returned on nonexistent output

 The output number key for a returned feature is outside the range of

 outputs listed in the plugin's output descriptor list.

 ** NOTE: No results returned for output <x>

 The plugin returned no features on one of its outputs, when given a

 simple test file.  This may be perfectly reasonable behaviour, but

 you might like to know about it.

 ** NOTE: Plugin returns features with timestamps on OneSamplePerStep output

 ** NOTE: Plugin returns features with durations on OneSamplePerStep output

 Hosts will usually ignore timestamps and durations attached to any

 feature returned on a OneSamplePerStep output.

 ** ERROR: Plugin returns features with no timestamps on VariableSampleRate output

 Timestamps are mandatory on all features associated with a

 VariableSampleRate output.

 ** WARNING: Plugin returned one or more NaN/inf values

 The plugin returned features containing floating-point not-a-number

 or infinity values.  This warning may be associated with a test

 involving feeding some unexpected type of data to the plugin.

 ** ERROR: Consecutive runs with separate instances produce different results

 The plugin was constructed and run twice against the same input data,

 and returned different features each time.

 If you give the -n or --nondeterministic option, vamp-plugin-tester

 will downgrade this error to a note.

 ** ERROR: Consecutive runs with the same instance (using reset) produce different results

 The plugin was constructed, initialised, run against some input data,

 reset with a call to its reset() function, and run again against the

 same data; and it returned different features on each run.  This is

 often a sign of some simple error such as forgetting to implement

 reset().

 If you give the -n or --nondeterministic option, vamp-plugin-tester

 will downgrade this error to a note.

 ** ERROR: Simultaneous runs with separate instances produce different results

 Two instances of the plugin were constructed and run against the same

 input data, giving each block of data to one plugin's process call

 and then to the other's, "interleaving" the processing between the

 two instances (but within a single application thread); and the two

 instances returned different features.  This may indicate ill-advised

 use of static data shared between plugin instances.

 If you give the -n or --nondeterministic option, vamp-plugin-tester

 will downgrade this error to a note.

 ** WARNING: Consecutive runs with different starting timestamps produce the same result

 The plugin was run twice on the same audio data, but with different

 input timestamps, and it returned the same results each time.  While

 this is often unproblematic, it can indicate that a plugin failed to

 take the input timestamp into account when calculating its output

 timestamps (if any).

 If you give the -n or --nondeterministic option, vamp-plugin-tester

 will downgrade this warning to a note.

 ** ERROR: Explicitly setting current program to its supposed current value changes the results

 The plugin was constructed and run twice on the same data, once

 without changing its "program" setting, and again having set the

 program to the vaule returned by getCurrentProgram() (i.e. the same

 program that was supposed to be in effect already).  It returned

 different results for the two runs, suggesting that some internal

 data was changed in selectProgram in a way that differed from its

 default.

 If you give the -n or --nondeterministic option, vamp-plugin-tester

 will downgrade this error to a note.

 ** ERROR: Explicitly setting parameters to their supposed default values changes the results

 The plugin was constructed and run twice on the same data, once

 without changing any of its parameters, and again having set the

 parameters to their specified default values.  It returned different

 results for the two runs, suggesting that some internal data was

 changed when a parameter was set to its default, in a way that

 differed from the plugin's initially constructed state.

 If you give the -n or --nondeterministic option, vamp-plugin-tester

 will downgrade this error to a note.

 ** WARNING: Constructor takes some time to run: work should be deferred to initialise?

 The plugin took a long time to construct.  You should ensure that the

 constructor for the plugin runs as quickly as possible, because it

 may be called by a host that is only scanning the properties of all

 available plugins on startup.  Any serious initialisation work should

 be done in the initialise() function rather than the constructor.

Authors

=======

This program was written at the Centre for Digital Music at Queen

Mary, University of London, by Chris Cannam.  Copyright (c) 2009 QMUL.