view transform/FeatureWriter.h @ 631:3a5ee4b6c9ad

* Complete the overhaul of CSV file import; now you can pick the purpose for
  each column in the file, and SV should do the rest.  The most significant
  practical improvement here is that we can now handle files in which time
  and duration do not necessarily appear in known columns.

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

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.

    Sonic Annotator
    A utility for batch feature extraction from audio files.

    Mark Levy, Chris Sutton and Chris Cannam, Queen Mary, University of London.
    Copyright 2007-2008 QMUL.

    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
    published by the Free Software Foundation; either version 2 of the
    License, or (at your option) any later version.  See the file
    COPYING included with this distribution for more information.
*/

#ifndef _FEATURE_WRITER_H_
#define _FEATURE_WRITER_H_

#include <string>
#include <map>
#include <vector>

#include <QString>

#include "Transform.h"

#include <vamp-hostsdk/Plugin.h>

using std::string;
using std::map;
using std::vector;

class FeatureWriter
{
public:
    virtual ~FeatureWriter() { }

    struct Parameter { // parameter of the writer, not the plugin
        string name;
        string description;
        bool hasArg;
    };
    typedef vector<Parameter> ParameterList;
    virtual ParameterList getSupportedParameters() const {
        return ParameterList();
    }

    virtual void setParameters(map<string, string> &params) {
        return;
    }

    struct TrackMetadata {
        QString title;
        QString maker;
    };
    virtual void setTrackMetadata(QString trackid, TrackMetadata metadata) { }

    class FailedToOpenOutputStream : virtual public std::exception
    {
    public:
        FailedToOpenOutputStream(QString trackId, QString transformId) throw() :
            m_trackId(trackId),
            m_transformId(transformId)
        { }
        virtual ~FailedToOpenOutputStream() throw() { }
        virtual const char *what() const throw() {
            return QString("Failed to open output stream for track id \"%1\", transform id \"%2\"")
                .arg(m_trackId).arg(m_transformId).toLocal8Bit().data();
        }            
        
    protected:
        QString m_trackId;
        QString m_transformId;
    };

    // may throw FailedToOpenFile or other exceptions

    virtual void write(QString trackid,
                       const Transform &transform,
                       const Vamp::Plugin::OutputDescriptor &output,
                       const Vamp::Plugin::FeatureList &features,
                       std::string summaryType = "") = 0;

    /**
     * Throw FailedToOpenOutputStream if we can already tell that we
     * will be unable to write to the output file.  This is called to
     * test the output stream before processing begins.  The writer
     * may legitimately succeed here but still fail later -- this is
     * really an optimisation to ensure that easy-to-recognise failure
     * cases fail early.
     */
    virtual void testOutputFile(QString trackId, TransformId transformId) { }

    virtual void flush() { } // whatever the last stream was

    virtual void finish() = 0;

    virtual QString getWriterTag() const = 0;
};

#endif