[Interest] Quick2 OpenGL inefficiency?

[Jani Tykka]

I'm creating the image from buffer which is unsigned char buffer containing
video frame data
QImage( buffer, width, height, QImage::Format_RGB32 );


On Mon, Mar 7, 2016 at 10:05 PM, Filip Piechocki <fpiechocki at gmail.com>
wrote:
>
> How are you generating those images? What do they represent?
>
> On Mar 7, 2016 20:55, "Jani Tykka" <jtykka at broadsoft.com> wrote:
>>
>> Images are passed from another thread in rate 15-30 fps. Is there an
example available how to achieve Image to OpenGL texture and use it in
scene graph?
>>
>> On Mon, Mar 7, 2016 at 5:11 PM, Filip Piechocki <fpiechocki at gmail.com>
wrote:
>>>
>>> And where it comes from? How frequent it happens? Probably the best
thing here would be to generate this image as an OpenGL texture and then
use in the Qt's scene graph.
>>>
>>> On Mon, Mar 7, 2016 at 4:04 PM, Jani Tykka <jtykka at broadsoft.com> wrote:
>>>>
>>>> Yes, the image is always changed when the update is invoked.
>>>>
>>>> On Mon, Mar 7, 2016 at 4:43 PM, Filip Piechocki <fpiechocki at gmail.com>
wrote:
>>>>>
>>>>> Hi,
>>>>>
>>>>> Why are you re-creating the texture on every node update? Does the
m_Renderer->getImage() really changes? My first guess would be that the
texture creation from image is the most costly part here (uploading the
texture to GPU?) and I would do this only if necessary (the image really
changes).
>>>>>
>>>>> BR,
>>>>> Filip
>>>>>
>>>>> On Mon, Mar 7, 2016 at 3:04 PM, Jani Tykka <jtykka at broadsoft.com>
wrote:
>>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> We are rendering QImages on QQuickItem as following:
>>>>>>
>>>>>> QSGNode * DisplayItem::updatePaintNode( QSGNode * node,
UpdatePaintNodeData * /*data*/ )
>>>>>>
>>>>>> {
>>>>>>
>>>>>> QSGSimpleTextureNode * n = static_cast< QSGSimpleTextureNode* >(
node );
>>>>>>
>>>>>> if ( !n )
>>>>>>
>>>>>> n = new QSGSimpleTextureNode;
>>>>>>
>>>>>>
>>>>>> n->setRect( 0, 0, width(), height() );
>>>>>>
>>>>>>
>>>>>> delete m_Texture;
>>>>>>
>>>>>>
>>>>>> m_Texture = window()->createTextureFromImage( m_Renderer->getImage()
);
>>>>>>
>>>>>> n->setTexture( m_Texture );
>>>>>>
>>>>>>
>>>>>> return n;
>>>>>>
>>>>>> }
>>>>>>
>>>>>>
>>>>>>
>>>>>> It seems that computers with separate GPU there is a decent amount
of CPU utilised. We are running into problems if the machine lacks GPU,
then with large images the CPU usage grows drastically. Any suggestions how
to improve large image painting on QQuickItem? With Quick1 and painting
directly on HWND/CocoaWindow we didn't experience this high CPU usage.
>>>>>>
>>>>>>
>>>>>>
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>>>>>>
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>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Jani Tykkä
>>>> Development Manager | BroadSoft, Inc. | +358 44 596 0587 |
jtykka at broadsoft.com
>>>>
>>>>
>>>> This email is intended solely for the person or entity to which it is
addressed and may contain confidential and/or privileged information. If
you are not the intended recipient and have received this email in error,
please notify BroadSoft, Inc. immediately by replying to this message, and
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>>>
>>>
>>
>>
>>
>> --
>> Jani Tykkä
>> Development Manager | BroadSoft, Inc. | +358 44 596 0587 |
jtykka at broadsoft.com
>>
>>
>> This email is intended solely for the person or entity to which it is
addressed and may contain confidential and/or privileged information. If
you are not the intended recipient and have received this email in error,
please notify BroadSoft, Inc. immediately by replying to this message, and
destroy all copies of this message, along with any attachment, prior to
reading, distributing or copying it.




--
Jani Tykkä
Development Manager | BroadSoft, Inc. | +358 44 596 0587 |
jtykka at broadsoft.com

-- 


This email is intended solely for the person or entity to which it is 
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