QtQuick VideoItem qtgstreamer preview color problem

RiteshPanchal

I am using Qt 5.2.1 on nVidia jetson TX1 embedded board.
I want to use qtgstreamer pipeline in qt.

For testing i want to preview videotestsrc on surface of VideoItem defined in qtquick 2.0

VideoItem {
id: video
width: 1920
height: 1080
surface: videoSurface1
}

// Create gstreamer elements
m_pipeline      = QGst::Pipeline::create();
QGst::ElementPtr m_source        = QGst::ElementFactory::make("videotestsrc", "videotestsrc");

m_pipeline->setProperty("video-sink", m_videoSink);

// Add elements to pipeline
m_pipeline->add(m_source);
m_pipeline->add(m_videoSink);

// Link elements
m_source->link(m_videoSink);

This work great. and preview appear with proper color.
But if i add caps to pipeline for 1920x1080 resolution

// Create gstreamer elements
m_pipeline      = QGst::Pipeline::create("Video Player + Snapshots pipelin");
QGst::ElementPtr m_source        = QGst::ElementFactory::make("videotestsrc", "videotestsrc");
QGst::ElementPtr m_filter        = QGst::ElementFactory::make("capsfilter",	"capsfilter");

m_filter->setProperty("caps", QGst::Caps::fromString("video/x-raw, width=1920, height=1080, format=I420, framerate=30/1"));

m_pipeline->setProperty("video-sink", m_videoSink);

if (!m_pipeline || !m_source || !m_videoSink) {
    return;
}

// Add elements to pipeline
m_pipeline->add(m_source);
m_pipeline->add(m_filter);
m_pipeline->add(m_videoSink);

// Link elements
m_source->link(m_filter);
m_filter->link(m_videoSink);

The preview appear but its reddish. I think the problem is with format(I420). if i use RGB format color appears ok. but with RGB its slow.
But with the same pipeline if i use another gstreamer sink element like "autovideosink" or "filesink" the preview appear with normal color.

So how to preview in videosurface with proper color?

SGaist

Hi,

~~Looking for the QtLocation module ?~~

[edit: wrong window... SGaist]

RiteshPanchal

Hello SGaist,

Thanks for the Reply. But i am confused by your reply. How QtLocation is related to VideoItem gstreamer I420 color preview problem?

SGaist

Absolutely completely unrelated. Typical two windows wrong answer situation. Sorry for that.

Can you use the YUV422 format ?

RiteshPanchal

When you want me to use YUV422 format?
In pileline caps?

m_filter->setProperty("caps", QGst::Caps::fromString("video/x-raw, width=1920, height=1080, format=I420, framerate=30/1"));

Available format in videotestsrc

Capabilities:
      video/x-raw
                 format: { I420, YV12, YUY2, UYVY, AYUV, RGBx, BGRx, xRGB, xBGR, RGBA, BGRA, ARGB, ABGR, RGB, BGR, Y41B, Y42B, YVYU, Y444, v210, v216, NV12, NV21, NV16, NV24, GRAY8, GRAY16_BE, GRAY16_LE, v308, RGB16, BGR16, RGB15, BGR15, UYVP, A420, RGB8P, YUV9, YVU9, IYU1, ARGB64, AYUV64, r210, I420_10LE, I420_10BE, I422_10LE, I422_10BE, Y444_10LE, Y444_10BE, GBR, GBR_10LE, GBR_10BE }
                  width: [ 1, 2147483647 ]
                 height: [ 1, 2147483647 ]
              framerate: [ 0/1, 2147483647/1 ]
      video/x-bayer
                 format: { bggr, rggb, grbg, gbrg }
                  width: [ 1, 2147483647 ]
                 height: [ 1, 2147483647 ]
              framerate: [ 0/1, 2147483647/1 ]

I have tried I422_10LE and I422_10BE but result in "Internal data flow error.".

SGaist

Either UYVY or YUYV is YUV422.

By the way which version of Qt are you using ?

Support for YUV422 has been added for QML in 5.8 IIRC.

RiteshPanchal

I am using QT 5.2.1.
I think in QT 5.8, direct YUV422 capture supported by QtMutlimedia package. But qt gstreamer supports YUV422 for previous versions also.

In this case, i am just using videotestsrc plugin as camera source. And that is not UYVY or YUYV.
If i add caps to pipeline the color conversion issue occur.

I think, the problem is that video surface shows a wrong color conversion as it considers video frame in BGR not in RGB.
Any idea or suggestions about how to fix?

RiteshPanchal

http://gstreamer-devel.966125.n4.nabble.com/QGst-Quick-VideoSurface-Green-Hue-td4664931.html
other person having same problem but his getting green instead of red.
But i am unable to find any solution.
Perhaps you can help.

SGaist

What is your image source ?

RiteshPanchal

gstreamer "videotestsrc" is image source

SGaist

I meant the one that is not working correctly. Also the test source ?

RiteshPanchal

Ya videotestsrc is also not working with I420 format. giving Red hue preview on Videosurface.

m_filter->setProperty("caps", QGst::Caps::fromString("video/x-raw, width=1920, height=1080, format=I420, framerate=30/1"));

But if i changed I420 with RGB its showing proper color.

But if i use RGB for my camera (UYVY) input with videoconvert. I got proper color but its too slow.
But with I420 preview renders smoothly but Reddish preview.

In my AMD64 linux pc i tried same with qt 5.5 the preview is with Green Hue.

SGaist

Can you create a small sample application that shows that behavior ?

RiteshPanchal

Please find sample app in below link
https://drive.google.com/open?id=0B8d7zQv-G71oM1JONzlpR2t1OWc

There are 4 different cases for videosourece as videotestsrc. For my camera i just replace videotestsrc by v4l2src. But the behavior are same for both sources.

I am using QT 5.2.1 with qtgstreamer 1.2.0 and gstreamer 1.2.4.

Please suggest some solution of videosurface color conversion issue or any other videosink element that i can use in qml.

RiteshPanchal

can you get any clue whats wrong in my code?