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#include "qgstreamervideoencode.h"

#include "qgstreamercapturesession.h"

#include "qgstreamermediacontainercontrol.h"

#include <QtCore/qdebug.h>

#include <math.h>

QGstreamerVideoEncode::QGstreamerVideoEncode(QGstreamerCaptureSession *session)

    :QVideoEncoderControl(session), m_session(session)

{

    QList<QByteArray> codecCandidates;

    codecCandidates << "video/h264" << "video/xvid" << "video/mpeg4" << "video/mpeg1" << "video/mpeg2" << "video/theora";

    m_elementNames["video/h264"] = "x264enc";

    m_elementNames["video/xvid"] = "xvidenc";

    m_elementNames["video/mpeg4"] = "ffenc_mpeg4";

    m_elementNames["video/mpeg1"] = "ffenc_mpeg1video";

    m_elementNames["video/mpeg2"] = "ffenc_mpeg2video";

    m_elementNames["video/theora"] = "theoraenc";

    m_codecOptions["video/h264"] = QStringList() << "quantizer";

    m_codecOptions["video/xvid"] = QStringList() << "quantizer" << "profile";

    m_codecOptions["video/mpeg4"] = QStringList() << "quantizer";

    m_codecOptions["video/mpeg1"] = QStringList() << "quantizer";

    m_codecOptions["video/mpeg2"] = QStringList() << "quantizer";

    m_codecOptions["video/theora"] = QStringList();

    foreach( const QByteArray& codecName, codecCandidates ) {

        QByteArray elementName = m_elementNames[codecName];

        GstElementFactory *factory = gst_element_factory_find(elementName.constData());

        if (factory) {

            m_codecs.append(codecName);

            const gchar *descr = gst_element_factory_get_description(factory);

            m_codecDescriptions.insert(codecName, QString::fromUtf8(descr));

            m_streamTypes.insert(codecName,

                                 QGstreamerMediaContainerControl::supportedStreamTypes(factory, GST_PAD_SRC));

            gst_object_unref(GST_OBJECT(factory));

        }

    }

    //if (!m_codecs.isEmpty())

    //    m_videoSettings.setCodec(m_codecs[0]);

}

QGstreamerVideoEncode::~QGstreamerVideoEncode()

{

}

QList<QSize> QGstreamerVideoEncode::supportedResolutions(const QVideoEncoderSettings &, bool *continuous) const

{

    if (continuous)

        *continuous = m_session->videoInput() != 0;

    return m_session->videoInput() ? m_session->videoInput()->supportedResolutions() : QList<QSize>();

}

QList< qreal > QGstreamerVideoEncode::supportedFrameRates(const QVideoEncoderSettings &, bool *continuous) const

{

    if (continuous)

        *continuous = false;

    return m_session->videoInput() ? m_session->videoInput()->supportedFrameRates() : QList<qreal>();

}

QStringList QGstreamerVideoEncode::supportedVideoCodecs() const

{

    return m_codecs;

}

QString QGstreamerVideoEncode::videoCodecDescription(const QString &codecName) const

{

    return m_codecDescriptions.value(codecName);

}

QStringList QGstreamerVideoEncode::supportedEncodingOptions(const QString &codec) const

{

    return m_codecOptions.value(codec);

}

QVariant QGstreamerVideoEncode::encodingOption(const QString &codec, const QString &name) const

{

    return m_options[codec].value(name);

}

void QGstreamerVideoEncode::setEncodingOption(

        const QString &codec, const QString &name, const QVariant &value)

{

    m_options[codec][name] = value;

}

QVideoEncoderSettings QGstreamerVideoEncode::videoSettings() const

{

    return m_videoSettings;

}

void QGstreamerVideoEncode::setVideoSettings(const QVideoEncoderSettings &settings)

{

    m_videoSettings = settings;

}

GstElement *QGstreamerVideoEncode::createEncoder()

{

    GstBin *encoderBin = GST_BIN(gst_bin_new("video-encoder-bin"));

    Q_ASSERT(encoderBin);

    GstElement *capsFilter = gst_element_factory_make("capsfilter", "capsfilter-video");

    gst_bin_add(encoderBin, capsFilter);

    GstElement *colorspace = gst_element_factory_make("ffmpegcolorspace", NULL);

    gst_bin_add(encoderBin, colorspace);

    QString codec = m_videoSettings.codec();

    //qDebug() << "create encoder for video codec" << codec;

    GstElement *encoderElement = gst_element_factory_make( m_elementNames.value(codec).constData(), "video-encoder");

    gst_bin_add(encoderBin, encoderElement);

    gst_element_link_many(capsFilter, colorspace, encoderElement, NULL);

    // add ghostpads

    GstPad *pad = gst_element_get_static_pad(capsFilter, "sink");

    gst_element_add_pad(GST_ELEMENT(encoderBin), gst_ghost_pad_new("sink", pad));

    gst_object_unref(GST_OBJECT(pad));

    pad = gst_element_get_static_pad(encoderElement, "src");

    gst_element_add_pad(GST_ELEMENT(encoderBin), gst_ghost_pad_new("src", pad));

    gst_object_unref(GST_OBJECT(pad));

    if (encoderElement) {

        if (m_videoSettings.encodingMode() == QtMultimediaKit::ConstantQualityEncoding) {

            QtMultimediaKit::EncodingQuality qualityValue = m_videoSettings.quality();

            if (codec == QLatin1String("video/h264")) {

                //constant quantizer mode

                g_object_set(G_OBJECT(encoderElement), "pass", 4, NULL);

                int qualityTable[] = {

                    50, //VeryLow

                    35, //Low

                    21, //Normal

                    15, //High

                    8 //VeryHigh

                };

                g_object_set(G_OBJECT(encoderElement), "quantizer", qualityTable[qualityValue], NULL);

            } else if (codec == QLatin1String("video/xvid")) {

                //constant quantizer mode

                g_object_set(G_OBJECT(encoderElement), "pass", 3, NULL);

                int qualityTable[] = {

                    32, //VeryLow

                    12, //Low

                    5, //Normal

                    3, //High

                    2 //VeryHigh

                };

                int quant = qualityTable[qualityValue];

                g_object_set(G_OBJECT(encoderElement), "quantizer", quant, NULL);

            } else if (codec == QLatin1String("video/mpeg4") ||

                       codec == QLatin1String("video/mpeg1") ||

                       codec == QLatin1String("video/mpeg2") ) {

                //constant quantizer mode

                g_object_set(G_OBJECT(encoderElement), "pass", 2, NULL);

                //quant from 1 to 30, default ~3

                double qualityTable[] = {

                    20, //VeryLow

                    8.0, //Low

                    3.0, //Normal

                    2.5, //High

                    2.0 //VeryHigh

                };

                double quant = qualityTable[qualityValue];

                g_object_set(G_OBJECT(encoderElement), "quantizer", quant, NULL);

            } else if (codec == QLatin1String("video/theora")) {

                int qualityTable[] = {

                    8, //VeryLow

                    16, //Low

                    32, //Normal

                    45, //High

                    60 //VeryHigh

                };

                //quality from 0 to 63

                int quality = qualityTable[qualityValue];

                g_object_set(G_OBJECT(encoderElement), "quality", quality, NULL);

            }

        } else {

            int bitrate = m_videoSettings.bitRate();

            if (bitrate > 0) {

                g_object_set(G_OBJECT(encoderElement), "bitrate", bitrate, NULL);

            }

        }

        QMap<QString,QVariant> options = m_options.value(codec);

        QMapIterator<QString,QVariant> it(options);

        while (it.hasNext()) {

            it.next();

            QString option = it.key();

            QVariant value = it.value();

            switch (value.type()) {

            case QVariant::Int:

                g_object_set(G_OBJECT(encoderElement), option.toAscii(), value.toInt(), NULL);

                break;

            case QVariant::Bool:

                g_object_set(G_OBJECT(encoderElement), option.toAscii(), value.toBool(), NULL);

                break;

            case QVariant::Double:

                g_object_set(G_OBJECT(encoderElement), option.toAscii(), value.toDouble(), NULL);

                break;

            case QVariant::String:

                g_object_set(G_OBJECT(encoderElement), option.toAscii(), value.toString().toUtf8().constData(), NULL);

                break;

            default:

                qWarning() << "unsupported option type:" << option << value;

                break;

            }

        }

    }

    if (!m_videoSettings.resolution().isEmpty() || m_videoSettings.frameRate() > 0.001) {

        GstCaps *caps = gst_caps_new_empty();

        QStringList structureTypes;

        structureTypes << "video/x-raw-yuv" << "video/x-raw-rgb";

        foreach(const QString &structureType, structureTypes) {

            GstStructure *structure = gst_structure_new(structureType.toAscii().constData(), NULL);

            if (!m_videoSettings.resolution().isEmpty()) {

                gst_structure_set(structure, "width", G_TYPE_INT, m_videoSettings.resolution().width(), NULL);

                gst_structure_set(structure, "height", G_TYPE_INT, m_videoSettings.resolution().height(), NULL);

            }

            if (m_videoSettings.frameRate() > 0.001) {

                QPair<int,int> rate = rateAsRational();

                //qDebug() << "frame rate:" << num << denum;

                gst_structure_set(structure, "framerate", GST_TYPE_FRACTION, rate.first, rate.second, NULL);

            }

            gst_caps_append_structure(caps,structure);

        }

        //qDebug() << "set video caps filter:" << gst_caps_to_string(caps);

        g_object_set(G_OBJECT(capsFilter), "caps", caps, NULL);

    }

    return GST_ELEMENT(encoderBin);

}

QPair<int,int> QGstreamerVideoEncode::rateAsRational() const

{

    qreal frameRate = m_videoSettings.frameRate();

    if (frameRate > 0.001) {

        //convert to rational number

        QList<int> denumCandidates;

        denumCandidates << 1 << 2 << 3 << 5 << 10 << 1001 << 1000;

        qreal error = 1.0;

        int num = 1;

        int denum = 1;

        foreach (int curDenum, denumCandidates) {

            int curNum = qRound(frameRate*curDenum);

            qreal curError = qAbs(qreal(curNum)/curDenum - frameRate);

            if (curError < error) {

                error = curError;

                num = curNum;

                denum = curDenum;

            }

            if (curError < 1e-8)

                break;

        }

        return QPair<int,int>(num,denum);

    }

    return QPair<int,int>();

}

QSet<QString> QGstreamerVideoEncode::supportedStreamTypes(const QString &codecName) const

{

    return m_streamTypes.value(codecName);

}