qgstreamervideooverlay.cpp

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#include "qgstreamervideooverlay_p.h"

#include <QtGui/qguiapplication.h>
#include "qgstutils_p.h"

#if !GST_CHECK_VERSION(1,0,0)
#include <gst/interfaces/xoverlay.h>
#else
#include <gst/video/videooverlay.h>
#endif

QT_BEGIN_NAMESPACE

struct ElementMap
{
   const char *qtPlatform;
   const char *gstreamerElement;
};

// Ordered by descending priority
static const ElementMap elementMap[] =
{
    { "xcb", "vaapisink" },
    { "xcb", "xvimagesink" },
    { "xcb", "ximagesink" }
};

QGstreamerVideoOverlay::QGstreamerVideoOverlay(QObject *parent, const QByteArray &elementName)
    : QObject(parent)
    , QGstreamerBufferProbe(QGstreamerBufferProbe::ProbeCaps)
    , m_videoSink(0)
    , m_isActive(false)
    , m_hasForceAspectRatio(false)
    , m_hasBrightness(false)
    , m_hasContrast(false)
    , m_hasHue(false)
    , m_hasSaturation(false)
    , m_hasShowPrerollFrame(false)
    , m_windowId(0)
    , m_aspectRatioMode(Qt::KeepAspectRatio)
    , m_brightness(0)
    , m_contrast(0)
    , m_hue(0)
    , m_saturation(0)
{
    if (!elementName.isEmpty())
        m_videoSink = gst_element_factory_make(elementName.constData(), NULL);
    else
        m_videoSink = findBestVideoSink();

    if (m_videoSink) {
        qt_gst_object_ref_sink(GST_OBJECT(m_videoSink)); //Take ownership

        GstPad *pad = gst_element_get_static_pad(m_videoSink, "sink");
        addProbeToPad(pad);
        gst_object_unref(GST_OBJECT(pad));

        m_hasForceAspectRatio = g_object_class_find_property(G_OBJECT_GET_CLASS(m_videoSink), "force-aspect-ratio");
        m_hasBrightness = g_object_class_find_property(G_OBJECT_GET_CLASS(m_videoSink), "brightness");
        m_hasContrast = g_object_class_find_property(G_OBJECT_GET_CLASS(m_videoSink), "contrast");
        m_hasHue = g_object_class_find_property(G_OBJECT_GET_CLASS(m_videoSink), "hue");
        m_hasSaturation = g_object_class_find_property(G_OBJECT_GET_CLASS(m_videoSink), "saturation");
        m_hasShowPrerollFrame = g_object_class_find_property(G_OBJECT_GET_CLASS(m_videoSink), "show-preroll-frame");

        if (m_hasShowPrerollFrame) {
            g_signal_connect(m_videoSink, "notify::show-preroll-frame",
                             G_CALLBACK(showPrerollFrameChanged), this);
        }
    }
}

QGstreamerVideoOverlay::~QGstreamerVideoOverlay()
{
    if (m_videoSink) {
        GstPad *pad = gst_element_get_static_pad(m_videoSink, "sink");
        removeProbeFromPad(pad);
        gst_object_unref(GST_OBJECT(pad));
        gst_object_unref(GST_OBJECT(m_videoSink));
    }
}

static bool qt_gst_element_is_functioning(GstElement *element)
{
    GstStateChangeReturn ret = gst_element_set_state(element, GST_STATE_READY);
    if (ret == GST_STATE_CHANGE_SUCCESS) {
        gst_element_set_state(element, GST_STATE_NULL);
        return true;
    }

    return false;
}

GstElement *QGstreamerVideoOverlay::findBestVideoSink() const
{
    GstElement *choice = 0;
    QString platform = QGuiApplication::platformName();

    // We need a native window ID to use the GstVideoOverlay interface.
    // Bail out if the Qt platform plugin in use cannot provide a sensible WId.
    if (platform != QLatin1String("xcb"))
        return 0;

    // First, try some known video sinks, depending on the Qt platform plugin in use.
    for (quint32 i = 0; i < (sizeof(elementMap) / sizeof(ElementMap)); ++i) {
        if (platform == QLatin1String(elementMap[i].qtPlatform)
                && (choice = gst_element_factory_make(elementMap[i].gstreamerElement, NULL))) {

            if (qt_gst_element_is_functioning(choice))
                return choice;

            gst_object_unref(choice);
            choice = 0;
        }
    }

    // If none of the known video sinks are available, try to find one that implements the
    // GstVideoOverlay interface and has autoplugging rank.
    GList *list = qt_gst_video_sinks();
    for (GList *item = list; item != NULL; item = item->next) {
        GstElementFactory *f = GST_ELEMENT_FACTORY(item->data);

        if (!gst_element_factory_has_interface(f, QT_GSTREAMER_VIDEOOVERLAY_INTERFACE_NAME))
            continue;

        if (GstElement *el = gst_element_factory_create(f, NULL)) {
            if (qt_gst_element_is_functioning(el)) {
                choice = el;
                break;
            }

            gst_object_unref(el);
        }
    }

    gst_plugin_feature_list_free(list);

    return choice;
}

GstElement *QGstreamerVideoOverlay::videoSink() const
{
    return m_videoSink;
}

QSize QGstreamerVideoOverlay::nativeVideoSize() const
{
    return m_nativeVideoSize;
}

void QGstreamerVideoOverlay::setWindowHandle(WId id)
{
    m_windowId = id;

    if (isActive())
        setWindowHandle_helper(id);
}

void QGstreamerVideoOverlay::setWindowHandle_helper(WId id)
{
#if GST_CHECK_VERSION(1,0,0)
    if (m_videoSink && GST_IS_VIDEO_OVERLAY(m_videoSink)) {
        gst_video_overlay_set_window_handle(GST_VIDEO_OVERLAY(m_videoSink), id);
#else
    if (m_videoSink && GST_IS_X_OVERLAY(m_videoSink)) {
# if GST_CHECK_VERSION(0,10,31)
        gst_x_overlay_set_window_handle(GST_X_OVERLAY(m_videoSink), id);
# else
        gst_x_overlay_set_xwindow_id(GST_X_OVERLAY(m_videoSink), id);
# endif
#endif

        // Properties need to be reset when changing the winId.
        setAspectRatioMode(m_aspectRatioMode);
        setBrightness(m_brightness);
        setContrast(m_contrast);
        setHue(m_hue);
        setSaturation(m_saturation);
    }
}

void QGstreamerVideoOverlay::expose()
{
    if (!isActive())
        return;

#if !GST_CHECK_VERSION(1,0,0)
    if (m_videoSink && GST_IS_X_OVERLAY(m_videoSink))
        gst_x_overlay_expose(GST_X_OVERLAY(m_videoSink));
#else
    if (m_videoSink && GST_IS_VIDEO_OVERLAY(m_videoSink)) {
        gst_video_overlay_expose(GST_VIDEO_OVERLAY(m_videoSink));
    }
#endif
}

void QGstreamerVideoOverlay::setRenderRectangle(const QRect &rect)
{
    int x = -1;
    int y = -1;
    int w = -1;
    int h = -1;

    if (!rect.isEmpty()) {
        x = rect.x();
        y = rect.y();
        w = rect.width();
        h = rect.height();
    }

#if GST_CHECK_VERSION(1,0,0)
    if (m_videoSink && GST_IS_VIDEO_OVERLAY(m_videoSink))
        gst_video_overlay_set_render_rectangle(GST_VIDEO_OVERLAY(m_videoSink), x, y, w, h);
#elif GST_CHECK_VERSION(0, 10, 29)
    if (m_videoSink && GST_IS_X_OVERLAY(m_videoSink))
        gst_x_overlay_set_render_rectangle(GST_X_OVERLAY(m_videoSink), x, y , w , h);
#else
    Q_UNUSED(x)
    Q_UNUSED(y)
    Q_UNUSED(w)
    Q_UNUSED(h)
#endif
}

bool QGstreamerVideoOverlay::processSyncMessage(const QGstreamerMessage &message)
{
    GstMessage* gm = message.rawMessage();

#if !GST_CHECK_VERSION(1,0,0)
    if (gm && (GST_MESSAGE_TYPE(gm) == GST_MESSAGE_ELEMENT) &&
            gst_structure_has_name(gm->structure, "prepare-xwindow-id")) {
#else
      if (gm && (GST_MESSAGE_TYPE(gm) == GST_MESSAGE_ELEMENT) &&
              gst_structure_has_name(gst_message_get_structure(gm), "prepare-window-handle")) {
#endif
        setWindowHandle_helper(m_windowId);
        return true;
    }

    return false;
}

bool QGstreamerVideoOverlay::processBusMessage(const QGstreamerMessage &message)
{
    GstMessage* gm = message.rawMessage();

    if (GST_MESSAGE_TYPE(gm) == GST_MESSAGE_STATE_CHANGED &&
            GST_MESSAGE_SRC(gm) == GST_OBJECT_CAST(m_videoSink)) {

        updateIsActive();
    }

    return false;
}

void QGstreamerVideoOverlay::probeCaps(GstCaps *caps)
{
    QSize size = QGstUtils::capsCorrectedResolution(caps);
    if (size != m_nativeVideoSize) {
        m_nativeVideoSize = size;
        emit nativeVideoSizeChanged();
    }
}

bool QGstreamerVideoOverlay::isActive() const
{
    return m_isActive;
}

void QGstreamerVideoOverlay::updateIsActive()
{
    if (!m_videoSink)
        return;

    GstState state = GST_STATE(m_videoSink);
    gboolean showPreroll = true;

    if (m_hasShowPrerollFrame)
        g_object_get(G_OBJECT(m_videoSink), "show-preroll-frame", &showPreroll, NULL);

    bool newIsActive = (state == GST_STATE_PLAYING || (state == GST_STATE_PAUSED && showPreroll));

    if (newIsActive != m_isActive) {
        m_isActive = newIsActive;
        emit activeChanged();
    }
}

void QGstreamerVideoOverlay::showPrerollFrameChanged(GObject *, GParamSpec *, QGstreamerVideoOverlay *overlay)
{
    overlay->updateIsActive();
}

Qt::AspectRatioMode QGstreamerVideoOverlay::aspectRatioMode() const
{
    Qt::AspectRatioMode mode = Qt::KeepAspectRatio;

    if (m_hasForceAspectRatio) {
        gboolean forceAR = false;
        g_object_get(G_OBJECT(m_videoSink), "force-aspect-ratio", &forceAR, NULL);
        if (!forceAR)
            mode = Qt::IgnoreAspectRatio;
    }

    return mode;
}

void QGstreamerVideoOverlay::setAspectRatioMode(Qt::AspectRatioMode mode)
{
    if (m_hasForceAspectRatio) {
        g_object_set(G_OBJECT(m_videoSink),
                     "force-aspect-ratio",
                     (mode == Qt::KeepAspectRatio),
                     (const char*)NULL);
    }

    m_aspectRatioMode = mode;
}

int QGstreamerVideoOverlay::brightness() const
{
    int brightness = 0;

    if (m_hasBrightness)
        g_object_get(G_OBJECT(m_videoSink), "brightness", &brightness, NULL);

    return brightness / 10;
}

void QGstreamerVideoOverlay::setBrightness(int brightness)
{
    if (m_hasBrightness) {
        g_object_set(G_OBJECT(m_videoSink), "brightness", brightness * 10, NULL);
        emit brightnessChanged(brightness);
    }

    m_brightness = brightness;
}

int QGstreamerVideoOverlay::contrast() const
{
    int contrast = 0;

    if (m_hasContrast)
        g_object_get(G_OBJECT(m_videoSink), "contrast", &contrast, NULL);

    return contrast / 10;
}

void QGstreamerVideoOverlay::setContrast(int contrast)
{
    if (m_hasContrast) {
        g_object_set(G_OBJECT(m_videoSink), "contrast", contrast * 10, NULL);
        emit contrastChanged(contrast);
    }

    m_contrast = contrast;
}

int QGstreamerVideoOverlay::hue() const
{
    int hue = 0;

    if (m_hasHue)
        g_object_get(G_OBJECT(m_videoSink), "hue", &hue, NULL);

    return hue / 10;
}

void QGstreamerVideoOverlay::setHue(int hue)
{
    if (m_hasHue) {
        g_object_set(G_OBJECT(m_videoSink), "hue", hue * 10, NULL);
        emit hueChanged(hue);
    }

    m_hue = hue;
}

int QGstreamerVideoOverlay::saturation() const
{
    int saturation = 0;

    if (m_hasSaturation)
        g_object_get(G_OBJECT(m_videoSink), "saturation", &saturation, NULL);

    return saturation / 10;
}

void QGstreamerVideoOverlay::setSaturation(int saturation)
{
    if (m_hasSaturation) {
        g_object_set(G_OBJECT(m_videoSink), "saturation", saturation * 10, NULL);
        emit saturationChanged(saturation);
    }

    m_saturation = saturation;
}

QT_END_NAMESPACE