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#include "qgstreameraudiodecoderserviceplugin.h"

#include "qgstreameraudiodecoderservice.h"
#include <private/qgstutils_p.h>

#include <QtCore/qstring.h>
#include <QtCore/qdebug.h>
#include <QtCore/QDir>
#include <QtCore/QDebug>

// #define QT_SUPPORTEDMIMETYPES_DEBUG

QMediaService* QGstreamerAudioDecoderServicePlugin::create(const QString &key)
{
    QGstUtils::initializeGst();

    if (key == QLatin1String(Q_MEDIASERVICE_AUDIODECODER))
        return new QGstreamerAudioDecoderService;

    qWarning() << "Gstreamer audio decoder service plugin: unsupported key:" << key;
    return 0;
}

void QGstreamerAudioDecoderServicePlugin::release(QMediaService *service)
{
    delete service;
}

QMultimedia::SupportEstimate QGstreamerAudioDecoderServicePlugin::hasSupport(const QString &mimeType,
                                                                     const QStringList &codecs) const
{
    if (m_supportedMimeTypeSet.isEmpty())
        updateSupportedMimeTypes();

    return QGstUtils::hasSupport(mimeType, codecs, m_supportedMimeTypeSet);
}

void QGstreamerAudioDecoderServicePlugin::updateSupportedMimeTypes() const
{
    //enumerate supported mime types
    gst_init(NULL, NULL);

    GList *plugins, *orig_plugins;
    orig_plugins = plugins = gst_default_registry_get_plugin_list ();

    while (plugins) {
        GList *features, *orig_features;

        GstPlugin *plugin = (GstPlugin *) (plugins->data);
        plugins = g_list_next (plugins);

        if (plugin->flags & (1<<1)) //GST_PLUGIN_FLAG_BLACKLISTED
            continue;

        orig_features = features = gst_registry_get_feature_list_by_plugin(gst_registry_get_default (),
                                                                        plugin->desc.name);
        while (features) {
            if (!G_UNLIKELY(features->data == NULL)) {
                GstPluginFeature *feature = GST_PLUGIN_FEATURE(features->data);
                if (GST_IS_ELEMENT_FACTORY (feature)) {
                    GstElementFactory *factory = GST_ELEMENT_FACTORY(gst_plugin_feature_load(feature));
                    if (factory
                       && factory->numpadtemplates > 0
                       && (qstrcmp(factory->details.klass, "Codec/Decoder/Audio") == 0
                          || qstrcmp(factory->details.klass, "Codec/Demux") == 0 )) {
                        const GList *pads = factory->staticpadtemplates;
                        while (pads) {
                            GstStaticPadTemplate *padtemplate = (GstStaticPadTemplate*)(pads->data);
                            pads = g_list_next (pads);
                            if (padtemplate->direction != GST_PAD_SINK)
                                continue;
                            if (padtemplate->static_caps.string) {
                                GstCaps *caps = gst_static_caps_get(&padtemplate->static_caps);
                                if (!gst_caps_is_any (caps) && ! gst_caps_is_empty (caps)) {
                                    for (guint i = 0; i < gst_caps_get_size(caps); i++) {
                                        GstStructure *structure = gst_caps_get_structure(caps, i);
                                        QString nameLowcase = QString(gst_structure_get_name (structure)).toLower();

                                        m_supportedMimeTypeSet.insert(nameLowcase);
                                        if (nameLowcase.contains("mpeg")) {
                                            //Because mpeg version number is only included in the detail
                                            //description,  it is necessary to manually extract this information
                                            //in order to match the mime type of mpeg4.
                                            const GValue *value = gst_structure_get_value(structure, "mpegversion");
                                            if (value) {
                                                gchar *str = gst_value_serialize (value);
                                                QString versions(str);
                                                QStringList elements = versions.split(QRegExp("\\D+"), QString::SkipEmptyParts);
                                                foreach (const QString &e, elements)
                                                    m_supportedMimeTypeSet.insert(nameLowcase + e);
                                                g_free (str);
                                            }
                                        }
                                    }
                                }
                                gst_caps_unref(caps);
                            }
                        }
                        gst_object_unref (factory);
                    }
                } else if (GST_IS_TYPE_FIND_FACTORY(feature)) {
                    QString name(gst_plugin_feature_get_name(feature));
                    if (name.contains('/')) //filter out any string without '/' which is obviously not a mime type
                        m_supportedMimeTypeSet.insert(name.toLower());
                }
            }
            features = g_list_next (features);
        }
        gst_plugin_feature_list_free (orig_features);
    }
    gst_plugin_list_free (orig_plugins);

#if defined QT_SUPPORTEDMIMETYPES_DEBUG
    QStringList list = m_supportedMimeTypeSet.toList();
    list.sort();
    if (qgetenv("QT_DEBUG_PLUGINS").toInt() > 0) {
        foreach (const QString &type, list)
            qDebug() << type;
    }
#endif
}

QStringList QGstreamerAudioDecoderServicePlugin::supportedMimeTypes() const
{
    return QStringList();
}

