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#include "qgstreamerv4l2input.h"

#include <QtCore/qdebug.h>

#include <QtCore/qfile.h>

#include <linux/types.h>

#include <sys/time.h>

#include <sys/ioctl.h>

#include <sys/poll.h>

#include <unistd.h>

#include <fcntl.h>

#include <errno.h>

#include <string.h>

#include <stdlib.h>

#include <sys/mman.h>

#include <linux/videodev2.h>

QT_BEGIN_NAMESPACE

static inline uint qHash(const QSize& key) { return uint(key.width()*256+key.height()); }

static bool operator<(const QSize &s1, const QSize s2)

{

    return s1.width()*s1.height() < s2.width()*s2.height();

}

QT_END_NAMESPACE

QGstreamerV4L2Input::QGstreamerV4L2Input(QObject *parent)

    :QObject(parent)

{

}

QGstreamerV4L2Input::~QGstreamerV4L2Input()

{

}

GstElement *QGstreamerV4L2Input::buildElement()

{

#ifndef Q_WS_MAEMO_5

    GstElement *camera = gst_element_factory_make("v4l2src", "camera_source");

#else

    GstElement *camera = gst_element_factory_make("v4l2camsrc", "camera_source");

#endif

    if (camera && !m_device.isEmpty() )

        g_object_set(G_OBJECT(camera), "device", m_device.constData(), NULL);

    return camera;

}

void QGstreamerV4L2Input::setDevice(const QByteArray &newDevice)

{

    if (m_device != newDevice) {

        m_device = newDevice;

        updateSupportedResolutions(newDevice);

    }

}

void QGstreamerV4L2Input::setDevice(const QString &device)

{

    setDevice(QFile::encodeName(device));

}

void QGstreamerV4L2Input::updateSupportedResolutions(const QByteArray &device)

{

    m_frameRates.clear();

    m_resolutions.clear();

    m_ratesByResolution.clear();

    QSet<QSize> allResolutions;

    QSet<int> allFrameRates;

    QFile f(device);

    if (!f.open(QFile::ReadOnly))

        return;

    int fd = f.handle();

    //get the list of formats:

    QList<quint32> supportedFormats;

    {

        v4l2_fmtdesc fmt;

        memset(&fmt, 0, sizeof(v4l2_fmtdesc));

        fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

        int sanity = 0;

        for (fmt.index = 0;; fmt.index++) {

            if (sanity++ > 8)

                break;

            if(  ::ioctl(fd, VIDIOC_ENUM_FMT, &fmt) == -1) {

                if(errno == EINVAL)

                    break;

            }

            supportedFormats.append(fmt.pixelformat);

        }

    }

    QList<QSize> commonSizes;

    commonSizes << QSize(128, 96)

            <<QSize(160,120)

            <<QSize(176, 144)

            <<QSize(320, 240)

            <<QSize(352, 288)

            <<QSize(640, 480)

            <<QSize(1024, 768)

            <<QSize(1280, 1024)

            <<QSize(1600, 1200)

            <<QSize(1920, 1200)

            <<QSize(2048, 1536)

            <<QSize(2560, 1600)

            <<QSize(2580, 1936);

    QList<int> commonRates;

    commonRates << 05*1000 << 75*1000  << 10*1000 << 15*1000 << 20*1000

            << 24*1000 << 25*1000 << 30*1000 << 50*1000 << 60*1000;

    //get the list of resolutions:

    foreach (quint32 format, supportedFormats) {

        struct v4l2_frmsizeenum formatSize;

        memset(&formatSize, 0, sizeof(formatSize));

        formatSize.pixel_format = format;

        QList<QSize> sizeList;

        if (0) {

            char formatStr[5];

            memcpy(formatStr, &format, 4);

            formatStr[4] = 0;

            //qDebug() << "trying format" << formatStr;

        }

        for (int i=0;;i++) {

            formatSize.index = i;

            if (ioctl (fd, VIDIOC_ENUM_FRAMESIZES, &formatSize) < 0)

                break;

            if (formatSize.type == V4L2_FRMSIZE_TYPE_DISCRETE) {

                sizeList.append(QSize(formatSize.discrete.width, formatSize.discrete.height));

            } else {

                foreach (const QSize& candidate, commonSizes) {

                    if (candidate.width() <= (int)formatSize.stepwise.max_width &&

                        candidate.height() >= (int)formatSize.stepwise.min_width &&

                        candidate.width() % formatSize.stepwise.step_width == 0 &&

                        candidate.height() <= (int)formatSize.stepwise.max_height &&

                        candidate.height() >= (int)formatSize.stepwise.min_height &&

                        candidate.height() % formatSize.stepwise.step_height == 0) {

                        sizeList.append(candidate);

                    }

                }

                if (!sizeList.contains(QSize(formatSize.stepwise.min_width, formatSize.stepwise.min_height)))

                    sizeList.prepend(QSize(formatSize.stepwise.min_width, formatSize.stepwise.min_height));

                if (!sizeList.contains(QSize(formatSize.stepwise.max_width, formatSize.stepwise.max_height)))

                    sizeList.append(QSize(formatSize.stepwise.max_width, formatSize.stepwise.max_height));

                break; //stepwise values are returned only for index 0

            }

        }

        //and frameRates for each resolution.

        foreach (const QSize &s, sizeList) {

            allResolutions.insert(s);

            struct v4l2_frmivalenum formatInterval;

            memset(&formatInterval, 0, sizeof(formatInterval));

            formatInterval.pixel_format = format;

            formatInterval.width = s.width();

            formatInterval.height = s.height();

            QList<int> frameRates; //in 1/1000 of fps

            for (int i=0; ; i++) {

                formatInterval.index = i;

                if (ioctl(fd, VIDIOC_ENUM_FRAMEINTERVALS, &formatInterval) < 0)

                    break;

                if (formatInterval.type == V4L2_FRMIVAL_TYPE_DISCRETE) {

                    //converts seconds to fps*1000

                    if (formatInterval.discrete.numerator)

                        frameRates.append(qRound(formatInterval.discrete.denominator*1000.0 / formatInterval.discrete.numerator));

                } else {

                    if (formatInterval.stepwise.min.numerator == 0 ||

                        formatInterval.stepwise.max.numerator == 0) {

                        qWarning() << "received invalid frame interval";

                        break;

                    }

                    int minRate = qRound(formatInterval.stepwise.min.denominator*1000.0 /

                                         formatInterval.stepwise.min.numerator);

                    int maxRate = qRound(formatInterval.stepwise.max.denominator*1000.0 /

                                         formatInterval.stepwise.max.numerator);

                    foreach (int candidate, commonRates) {

                        if (candidate >= minRate && candidate <= maxRate)

                            frameRates.append(candidate);

                    }

                    if (!frameRates.contains(minRate))

                        frameRates.prepend(minRate);

                    if (!frameRates.contains(maxRate))

                        frameRates.append(maxRate);

                    break; //stepwise values are returned only for index 0

                }

            }

            allFrameRates.unite(frameRates.toSet());

            m_ratesByResolution[s].unite(frameRates.toSet());

        }

    }

    f.close();

    foreach(int rate, allFrameRates) {

        m_frameRates.append(rate/1000.0);

    }

    qSort(m_frameRates);

    m_resolutions = allResolutions.toList();

    qSort(m_resolutions);

    //qDebug() << "frame rates:" << m_frameRates;

    //qDebug() << "resolutions:" << m_resolutions;

}

QList<qreal> QGstreamerV4L2Input::supportedFrameRates(const QSize &frameSize) const

{

    if (frameSize.isEmpty())

        return m_frameRates;

    else {

        QList<qreal> res;

        foreach(int rate, m_ratesByResolution[frameSize]) {

            res.append(rate/1000.0);

        }

        return res;

    }

}

QList<QSize> QGstreamerV4L2Input::supportedResolutions(qreal frameRate) const

{

    Q_UNUSED(frameRate);

    return m_resolutions;

}