QT Mobility Camera Example on QWS

kostya111

I tried to execute Camera example from qt Mobility on arm-based platform with qt-embedded. I use QWS as window system. But when I run program, there appears message "not compatible codecs and container format", then another message "Failed to build media capture pipeline" and also there is text on stderr:
"
(<unknown>:7557): GStreamer-WARNING **: Element video-preview-bin is not in bin media-capture-pipeline

(<unknown>:7557): GStreamer-WARNING **: Element video-preview-queue is not in bin media-capture-pipeline

(<unknown>:7557): GStreamer-WARNING **: Element video-preview-tee is not in bin media-capture-pipeline".
Example works fine on my Desktop computer.
I use Qt 4.7.3 and the latest snapshot of Qt Mobility from "official gitorious source tree":http://qt.gitorious.org/qt-mobility/.
The camera is found by the kernel. There's dmesg log:
"[ 1616.393951] usb 2-2.3: new high speed USB device using ehci-omap and address 7
[ 1616.550567] usb 2-2.3: New USB device found, idVendor=0c45, idProduct=62e0
[ 1616.557647] usb 2-2.3: New USB device strings: Mfr=2, Product=1, SerialNumber=0
[ 1616.565093] usb 2-2.3: Product: USB 2.0 Camera
[ 1616.569641] usb 2-2.3: Manufacturer: Sonix Technology Co., Ltd.
[ 1616.578735] uvcvideo: Found UVC 1.00 device USB 2.0 Camera (0c45:62e0)
[ 1616.591430] input: USB 2.0 Camera as /devices/platform/ehci-omap.0/usb2/2-2/2-2.3/2-2.3:1.0/input/input6"

brents1

Did you solve this? I have the same problem. Thanks!

kostya111

You have to install gstreamer libraries and mediaservice plugins for Qt. But qt Mobility very slow. I use instead QtGStreamer and build gstreamer pipeline manually.

brents1

Can you explain a little more on how you build gstreamer pipeline manually? Did you build the mediaservice plugins, or were they installed with opkg/apt-get?

I ended up copying some of the mediaservice plugins from my OE build, but I still get the following errors:

GStreamer-WARNING **: Element 'video-preview-bin' is not in bin 'media-capture-pipeline'

GStreamer-WARNING **: Element 'video-preview-queue' is not in bin 'media-capture-pipeline'

GStreamer-WARNING **: Element 'video-preview-tee' is not in bin 'media-capture-pipeline'

kostya111

bq. I ended up copying some of the mediaservice plugins from my OE build, but I still get the following errors

Do you install gstreamer libraries?

bq. Can you explain a little more on how you build gstreamer pipeline manually?

There's my code to build gstreamer pipeline with QtGStreamer:
@bool makeTestPipeline(QGraphicsView *view)
{
m_surface = new QGst::Ui::GraphicsVideoSurface(view);
if (!m_surface)
{
qCritical() << func << "Can't create surface.";
return false;
}

m_pipeline = QGst::Pipeline::create();

m_src = QGst::ElementFactory::make("videotestsrc");

// m_testSrc->setProperty("pattern", 1);

// m_src = QGst::ElementFactory::make("v4l2src");
// m_src->setProperty("device", "/dev/video0");

m_convcolor = QGst::ElementFactory::make("ffmpegcolorspace");

m_videoSink = m_surface->videoSink();

if (m_pipeline && m_src && m_convcolor && m_videoSink)
{
    m_pipeline->add(m_src, m_convcolor, m_videoSink);
    m_src->link(m_convcolor);
    m_convcolor->link(m_videoSink,
                QGst::Caps::fromString("video/x-raw-rgb,"
                                       "framerate=(fraction)20/1,"
                                       "width=320,height=240"));

    return true; // successfully initiated
}
else
    return false; // something wrong

}@

@http://gstreamer.freedesktop.org/data/doc/gstreamer/head/qt-gstreamer/html/index.html@ - QtGStreamer API Reference