qtmultimedia/src/plugins/gstreamer/camerabin/camerabinvideoencoder.cpp

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#include "camerabinvideoencoder.h"
#include "camerabinsession.h"
#include "camerabincontainer.h"

#include <QtCore/qdebug.h>

QT_BEGIN_NAMESPACE

CameraBinVideoEncoder::CameraBinVideoEncoder(CameraBinSession *session)
    :QVideoEncoderSettingsControl(session),
     m_session(session),
     m_codecs(QGstCodecsInfo::VideoEncoder)
{
}

CameraBinVideoEncoder::~CameraBinVideoEncoder()
{
}

QList<QSize> CameraBinVideoEncoder::supportedResolutions(const QVideoEncoderSettings &settings, bool *continuous) const
{
    if (continuous)
        *continuous = false;

    QPair<int,int> rate = rateAsRational(settings.frameRate());

    //select the closest supported rational rate to settings.frameRate()

    return m_session->supportedResolutions(rate, continuous, QCamera::CaptureVideo);
}

QList< qreal > CameraBinVideoEncoder::supportedFrameRates(const QVideoEncoderSettings &settings, bool *continuous) const
{
    if (continuous)
        *continuous = false;

    QList< qreal > res;
    QPair<int,int> rate;

    foreach(rate, m_session->supportedFrameRates(settings.resolution(), continuous)) {
        if (rate.second > 0)
            res << qreal(rate.first)/rate.second;
    }

    return res;
}

QStringList CameraBinVideoEncoder::supportedVideoCodecs() const
{
    return m_codecs.supportedCodecs();
}

QString CameraBinVideoEncoder::videoCodecDescription(const QString &codecName) const
{
    return m_codecs.codecDescription(codecName);
}

QVideoEncoderSettings CameraBinVideoEncoder::videoSettings() const
{
    return m_videoSettings;
}

void CameraBinVideoEncoder::setVideoSettings(const QVideoEncoderSettings &settings)
{
    if (m_videoSettings != settings) {
        m_actualVideoSettings = settings;
        m_videoSettings = settings;
        emit settingsChanged();
    }
}

QVideoEncoderSettings CameraBinVideoEncoder::actualVideoSettings() const
{
    return m_actualVideoSettings;
}

void CameraBinVideoEncoder::setActualVideoSettings(const QVideoEncoderSettings &settings)
{
    m_actualVideoSettings = settings;
}

void CameraBinVideoEncoder::resetActualSettings()
{
    m_actualVideoSettings = m_videoSettings;
}


QPair<int,int> CameraBinVideoEncoder::rateAsRational(qreal frameRate) const
{
    if (frameRate > 0.001) {
        //convert to rational number
        QList<int> denumCandidates;
        denumCandidates << 1 << 2 << 3 << 5 << 10 << 25 << 30 << 50 << 100 << 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>();
}

GstEncodingProfile *CameraBinVideoEncoder::createProfile()
{
    QString codec = m_actualVideoSettings.codec();
    GstCaps *caps;

    if (codec.isEmpty())
        caps = gst_caps_new_any();
    else
        caps = gst_caps_from_string(codec.toLatin1());

    return (GstEncodingProfile *)gst_encoding_video_profile_new(
                caps,
                NULL, //preset
                NULL, //restriction
                0); //presence
}

QT_END_NAMESPACE