[bug PyQt 5.15.2] segmentation fault using QVideoFilterRunnable

[Adrian Fiergolski]

On 11.02.2021 at 10:48, Phil Thompson wrote:
> On 11/02/2021 09:19, Adrian Fiergolski wrote:
>> On 10.02.2021 at 23:09, Phil Thompson wrote:
>>> On 10/02/2021 17:53, Adrian Fiergolski wrote:
>>>> On 10.02.2021 18:35, Phil Thompson wrote:
>>>>> On 10/02/2021 16:30, Adrian Fiergolski wrote:
>>>>>> Hi,
>>>>>>
>>>>>> I am getting segmentation fault using QVideoFilterRunnable. I try to
>>>>>> follow the example from the documentation.
>>>>>>
>>>>>> I am enclosing the testcase and the log from the debugger (gdb).
>>>>>>
>>>>>> My setup: yocto (with meta-qt5 gatesgarth, PyQt 5.15.2) running on
>>>>>> Cortex A-53, kernel 5.4).
>>>>>>
>>>>>> I got the same issue with PyQt 5.13.2 on my embedded platform. The
>>>>>> problem is reproducible on a PC (running Ubuntu 20.04 with installed
>>>>>> qt5-default and pyqt5-dev).
>>>>>>
>>>>>> Once the filter is commented out (case.qml:17), everything runs
>>>>>> smoothly.
>>>>>>
>>>>>> Do you know any workaround for that? I need to process data from a
>>>>>> camera in OpenCV (I wanted to do it the QVideoFilterRunnable:run)
>>>>>> and
>>>>>> paint the resulting processed frame.
>>>>>
>>>>> I suspect that this needs hard-coded support for QVideoFilterRunnable
>>>>> in the same way that PyQt supports QValidator in QML.
>>>>>
>>>>> There is no workaround that I'm aware of.
>>>>
>>>> Hi Phil,
>>>>
>>>> Thank you for your reply. I am new to Qt. Could you elaborate on your
>>>> answer?
>>>
>>> I'm not sure what you mean - PyQt would need to be enhanced to support
>>> this particular use case.
>>>
>>> Phil
>>
>> So which use case of QVideoFilterRunnable and QAbstractVideoFilter is
>> currently supported in PyQt?
>
> Using them from QML.
>
> Phil

Could you point please to some example? Would it be still possible to
execute python from this QML object which would do manipulations with
the frame (OpenCV) and return a new frame to QML QVideoFilterRunnable?

Adrian