annotate vamp-support/LoaderRequests.h @ 293:ae7397deffaa

Improve error handling (i.e. add some) for failure to initialise

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Piper C++

    An API for audio analysis and feature extraction plugins.

    Centre for Digital Music, Queen Mary, University of London.
    Copyright 2006-2016 Chris Cannam and QMUL.
  
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    obtaining a copy of this software and associated documentation
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*/

#ifndef PIPER_LOADER_REQUESTS_H
#define PIPER_LOADER_REQUESTS_H

#include "PluginStaticData.h"
#include "PluginConfiguration.h"
#include "PluginProgramParameters.h"
#include "StaticOutputRdf.h"
#include "RequestResponse.h"

#include <vamp-hostsdk/PluginLoader.h>

#include <map>
#include <string>
#include <iostream>

namespace piper_vamp {

class LoaderRequests
{
public:
    ListResponse
    listPluginData(ListRequest req) {

	auto loader = Vamp::HostExt::PluginLoader::getInstance();

//        std::cerr << "listPluginData: about to ask loader to list plugins" << std::endl;
        
        std::vector<std::string> keys;
        if (req.from.empty()) {
            keys = loader->listPlugins();
        } else {
            keys = loader->listPluginsIn(req.from);
        }

//        std::cerr << "listPluginData: loader listed " << keys.size() << " plugins" << std::endl;
        
	ListResponse response;
	for (std::string key: keys) {
//            std::cerr << "listPluginData: loading plugin and querying static data: " << key << std::endl;
	    Vamp::Plugin *p = loader->loadPlugin(key, 44100, 0);
	    if (!p) continue;
	    auto category = loader->getPluginCategory(key);
            PluginStaticData psd =
                PluginStaticData::fromPlugin(key, category, p);
            psd.staticOutputInfo = StaticOutputRdf().loadStaticOutputInfo(key);
	    response.available.push_back(psd);
	    delete p;
	}

	return response;
    }

    LoadResponse
    loadPlugin(LoadRequest req) {

	auto loader = Vamp::HostExt::PluginLoader::getInstance();
	
	Vamp::Plugin *plugin = loader->loadPlugin(req.pluginKey,
						  req.inputSampleRate,
						  req.adapterFlags);

	LoadResponse response;
	response.plugin = plugin;
	if (!plugin) return response;

	response.plugin = plugin;
	response.staticData = PluginStaticData::fromPlugin
	    (req.pluginKey,
	     loader->getPluginCategory(req.pluginKey),
	     plugin);
        
        response.staticData.staticOutputInfo =
            StaticOutputRdf().loadStaticOutputInfo(req.pluginKey);

	int defaultChannels = 0;
	if (plugin->getMinChannelCount() == plugin->getMaxChannelCount()) {
	    defaultChannels = int(plugin->getMinChannelCount());
	}
	
	response.defaultConfiguration = PluginConfiguration::fromPlugin
	    (plugin,
	     defaultChannels,
	     int(plugin->getPreferredStepSize()),
	     int(plugin->getPreferredBlockSize()));

        response.programParameters = PluginProgramParameters::fromPlugin
            (plugin, response.defaultConfiguration);
        
	return response;
    }

    ConfigurationResponse
    configurePlugin(ConfigurationRequest req) {
	
	for (PluginConfiguration::ParameterMap::const_iterator i =
		 req.configuration.parameterValues.begin();
	     i != req.configuration.parameterValues.end(); ++i) {
	    req.plugin->setParameter(i->first, i->second);
	}

	if (req.configuration.currentProgram != "") {
	    req.plugin->selectProgram(req.configuration.currentProgram);
	}

	ConfigurationResponse response;

	response.plugin = req.plugin;

        if (req.configuration.framing.stepSize == 0 ||
            req.configuration.framing.blockSize == 0) {
            return response;
        }

        Framing pluginPreferredFraming;
        pluginPreferredFraming.stepSize = req.plugin->getPreferredStepSize();
        pluginPreferredFraming.blockSize = req.plugin->getPreferredBlockSize();
        
	if (req.plugin->initialise(req.configuration.channelCount,
				   req.configuration.framing.stepSize,
				   req.configuration.framing.blockSize)) {

	    response.outputs = req.plugin->getOutputDescriptors();

            // If the Vamp plugin initialise() call succeeds, then by
            // definition it is accepting the step and block size
            // passed in
            response.framing = req.configuration.framing;

	} else {
           
            // If initialise() fails, one reason could be that it
            // didn't like the passed-in framing (step and block
            // size).
            // 
            // Vamp and Piper have quite different mechanisms for
            // negotiating step and block size:
            //
            // - If a Vamp plugin doesn't like the step and block size
            // passed to initialise(), it fails the initialise() call,
            // returning false from it. The host is expected to have
            // called getPreferredStepSize()/BlockSize() after it made
            // any parameter changes that might have affected these
            // preferences (but before calling initialise).
            //
            // - If a Piper server doesn't like the step and block
            // size passed in a configure request, but if everything
            // else about the configure request is OK, then it returns
            // a successful configure response including its preferred
            // step and block sizes in the response (which the host
            // must then use). The important thing to note is that
            // this is still a successful response, something we do
            // not yet have here.
            //
            // We need to check whether the passed-in framing differs
            // from the plugin's preferences; if so, then we form a
            // working supposition that initialise() failed because of
            // this. Vamp contains nothing to allow us to test this,
            // except to try initialise() again with different
            // values. So we try again with the values the plugin told
            // us it would prefer and, if that succeeds, return them
            // in a successful response in the Piper manner.
            //
            // Note that if the "other side" (i.e. the client) wants
            // to interpret this as if it were dealing with a Vamp
            // plugin, then it's going to need some equal-but-opposite
            // acrobatics.

            if (req.plugin->initialise(req.configuration.channelCount,
                                       pluginPreferredFraming.stepSize,
                                       pluginPreferredFraming.blockSize)) {

                response.outputs = req.plugin->getOutputDescriptors();
                response.framing = pluginPreferredFraming;

            } // ... else we return no outputs, which is the error
              // case (presumably to be converted to Piper error
              // response).
        }

	return response;
    }
};

}

#endif