Hello, I am trying to launch the standard demo program example with qml6glsink, but I encounter the following error during compilation:
QQmlApplicationEngine failed to load component
qrc:/main.qml:6:1: module "org.freedesktop.gstreamer.Qt6GLVideoItem" is not installed
ASSERT: "!isEmpty()" in file C:\Qt\6.7.2\msvc2019_64\include\QtCore/qlist.h, line 631
I am using GStreamer version 1.24.5 with the plugin for Qt6 (compiling in Qt 6.7.2 MSVS 2019 64b). I checked the existence of the plugin using gst-inspect-1.0 and in the framework folder - it exists. When enabling GST_DEBUG=3, no errors are reported.
Could you please advise on what to do in this case?
There appears to be an issue loading the Qt6GLVIdeoItem contained within the qm6glsink element on a windows environment in some circumstances. I do not have a Windows environment to be able to check and fix the issue there so it requires somebody to delve into why the Qt6GLVIdeoItem is not loaded correctly.
Previously, I tried running the example with GStreamer version 1.22.4 on Qt 6.4, and everything worked correctly (I also tried running GStreamer 1.24.5 with Qt 6.4 but unsuccessfully). I hope this information helps in identifying the problem.
is qml6glsink compiled? Run
gst-inspect-1.0 qml6glsink
to see if it is available. Or check if gstqml6.dll exists under path/gstreamer/lib/gstreamer-1.0.
Normally you need to rebuild gstreamer to get it.
gst-inspect-1.0 says that the plugin exists. I couldn’t find the file you mentioned, but I found the file gstqml6.dll.
I rebuilt GStreamer with the plugin twice, the result is the same.
Try the link from ystreet00. I just tested it on Linux and the example runs with Qt 6.7.2. I think it may be the same case. No issues on Ubuntu 22.04 with gstreamer 1.24.5.
When GST_DEBUG=4 is enabled, GStreamer outputs the following information:
0:00:00.000091900 292 00000181B0577060 INFO GST_INIT gst.c:574:init_pre: Initializing GStreamer Core Library version 1.24.5.1
0:00:00.000176600 292 00000181B0577060 INFO GST_INIT gst.c:575:init_pre: Using library installed in E:\gstreamer\1.0\msvc_x86_64\lib
0:00:00.000445100 292 00000181B0577060 INFO GST_INIT gstmessage.c:129:_priv_gst_message_initialize: init messages
0:00:00.000874700 292 00000181B0577060 INFO GST_INIT gstcontext.c:86:_priv_gst_context_initialize: init contexts
0:00:00.001083000 292 00000181B0577060 INFO GST_PLUGIN_LOADING gstplugin.c:328:_priv_gst_plugin_initialize: registering 0 static plugins
0:00:00.001180700 292 00000181B0577060 INFO GST_PLUGIN_LOADING gstplugin.c:236:gst_plugin_register_static: registered static plugin "staticelements"
0:00:00.001217500 292 00000181B0577060 INFO GST_PLUGIN_LOADING gstplugin.c:238:gst_plugin_register_static: added static plugin "staticelements", result: 1
0:00:00.003680000 292 00000181B0577060 INFO GST_REGISTRY gstregistry.c:1918:ensure_current_registry: reading registry cache: C:\Users\mobut\AppData\Local\Microsoft\Windows\INetCache\gstreamer-1.0\registry.x86_64-msvc.bin
0:00:00.016213600 292 00000181B0577060 INFO GST_REGISTRY gstregistrybinary.c:683:priv_gst_registry_binary_read_cache: loaded C:\Users\mobut\AppData\Local\Microsoft\Windows\INetCache\gstreamer-1.0\registry.x86_64-msvc.bin in 0.012463 seconds
0:00:00.016366200 292 00000181B0577060 INFO GST_REGISTRY gstregistry.c:1785:scan_and_update_registry: Validating plugins from registry cache: C:\Users\mobut\AppData\Local\Microsoft\Windows\INetCache\gstreamer-1.0\registry.x86_64-msvc.bin
0:00:00.195092400 292 00000181B0577060 INFO GST_REGISTRY gstregistry.c:1877:scan_and_update_registry: Registry cache has not changed
0:00:00.195135200 292 00000181B0577060 INFO GST_REGISTRY gstregistry.c:1953:ensure_current_registry: registry reading and updating done
0:00:00.195157700 292 00000181B0577060 INFO GST_INIT gst.c:808:init_post: GLib runtime version: 2.74.4
0:00:00.195204300 292 00000181B0577060 INFO GST_INIT gst.c:810:init_post: GLib headers version: 2.74.4
0:00:00.195225600 292 00000181B0577060 INFO GST_INIT gst.c:811:init_post: initialized GStreamer successfully
0:00:00.218424800 292 00000181B0577060 INFO GST_ELEMENT_FACTORY gstelementfactory.c:489:gst_element_factory_create_with_properties: creating element "pipeline"
0:00:00.220522400 292 00000181B0577060 INFO GST_PLUGIN_LOADING gstplugin.c:995:_priv_gst_plugin_load_file_for_registry: plugin "E:\gstreamer\1.0\msvc_x86_64\lib\gstreamer-1.0\gstvideotestsrc.dll" loaded
0:00:00.220559200 292 00000181B0577060 INFO GST_ELEMENT_FACTORY gstelementfactory.c:489:gst_element_factory_create_with_properties: creating element "videotestsrc"
0:00:00.220743300 292 00000181B0577060 INFO GST_ELEMENT_PADS gstelement.c:759:gst_element_add_pad:<GstBaseSrc@00000181B299CE60> adding pad 'src'
0:00:00.221274100 292 00000181B0577060 INFO GST_PLUGIN_LOADING gstplugin.c:995:_priv_gst_plugin_load_file_for_registry: plugin "E:\gstreamer\1.0\msvc_x86_64\lib\gstreamer-1.0\gstcoreelements.dll" loaded
0:00:00.221307000 292 00000181B0577060 INFO GST_ELEMENT_FACTORY gstelementfactory.c:489:gst_element_factory_create_with_properties: creating element "capsfilter"
0:00:00.221363700 292 00000181B0577060 INFO GST_ELEMENT_PADS gstelement.c:759:gst_element_add_pad:<GstBaseTransform@00000181B2994A40> adding pad 'sink'
0:00:00.221393500 292 00000181B0577060 INFO GST_ELEMENT_PADS gstelement.c:759:gst_element_add_pad:<GstBaseTransform@00000181B2994A40> adding pad 'src'
0:00:00.221429500 292 00000181B0577060 INFO GST_EVENT gstevent.c:1687:gst_event_new_reconfigure: creating reconfigure event
0:00:00.224507000 292 00000181B0577060 INFO GST_PLUGIN_LOADING gstplugin.c:995:_priv_gst_plugin_load_file_for_registry: plugin "E:\gstreamer\1.0\msvc_x86_64\lib\gstreamer-1.0\gstopengl.dll" loaded
0:00:00.224543200 292 00000181B0577060 INFO GST_ELEMENT_FACTORY gstelementfactory.c:489:gst_element_factory_create_with_properties: creating element "glupload"
0:00:00.224736200 292 00000181B0577060 INFO GST_ELEMENT_PADS gstelement.c:759:gst_element_add_pad:<GstBaseTransform@00000181B29EA280> adding pad 'sink'
0:00:00.224769000 292 00000181B0577060 INFO GST_ELEMENT_PADS gstelement.c:759:gst_element_add_pad:<GstBaseTransform@00000181B29EA280> adding pad 'src'
0:00:00.228604500 292 00000181B0577060 INFO GST_PLUGIN_LOADING gstplugin.c:995:_priv_gst_plugin_load_file_for_registry: plugin "E:\gstreamer\1.0\msvc_x86_64\lib\gstreamer-1.0\gstqml6.dll" loaded
0:00:00.228648700 292 00000181B0577060 INFO GST_ELEMENT_FACTORY gstelementfactory.c:489:gst_element_factory_create_with_properties: creating element "qml6glsink"
0:00:00.228747900 292 00000181B0577060 INFO GST_ELEMENT_PADS gstelement.c:759:gst_element_add_pad:<GstBaseSink@00000181B2A07510> adding pad 'sink'
0:00:00.228820900 292 00000181B0577060 INFO GST_ELEMENT_PADS gstutils.c:1821:gst_element_link_pads_full: trying to link element videotestsrc0:(any) to element capsfilter0:(any)
0:00:00.228851800 292 00000181B0577060 INFO GST_PADS gstutils.c:1081:gst_pad_check_link: trying to link videotestsrc0:src and capsfilter0:sink
0:00:00.228914500 292 00000181B0577060 INFO GST_PADS gstpad.c:4398:gst_pad_peer_query:<capsfilter0:src> pad has no peer
0:00:00.228953800 292 00000181B0577060 INFO GST_PADS gstutils.c:1635:prepare_link_maybe_ghosting: videotestsrc0 and capsfilter0 in same bin, no need for ghost pads
0:00:00.228985200 292 00000181B0577060 INFO GST_PADS gstpad.c:2441:gst_pad_link_prepare: trying to link videotestsrc0:src and capsfilter0:sink
0:00:00.229010700 292 00000181B0577060 INFO GST_PADS gstpad.c:4398:gst_pad_peer_query:<capsfilter0:src> pad has no peer
0:00:00.229038800 292 00000181B0577060 INFO GST_PADS gstpad.c:2622:gst_pad_link_full: linked videotestsrc0:src and capsfilter0:sink, successful
0:00:00.229060400 292 00000181B0577060 INFO GST_EVENT gstevent.c:1687:gst_event_new_reconfigure: creating reconfigure event
0:00:00.229081700 292 00000181B0577060 INFO GST_EVENT gstpad.c:6018:gst_pad_send_event_unchecked:<videotestsrc0:src> Received event on flushing pad. Discarding
0:00:00.229106400 292 00000181B0577060 INFO GST_ELEMENT_PADS gstutils.c:1821:gst_element_link_pads_full: trying to link element capsfilter0:(any) to element gluploadelement0:(any)
0:00:00.229131000 292 00000181B0577060 INFO GST_PADS gstutils.c:1081:gst_pad_check_link: trying to link capsfilter0:src and gluploadelement0:sink
0:00:00.229161400 292 00000181B0577060 INFO GST_PADS gstpad.c:4398:gst_pad_peer_query:<gluploadelement0:src> pad has no peer
0:00:00.229357000 292 00000181B0577060 INFO GST_PADS gstutils.c:1635:prepare_link_maybe_ghosting: capsfilter0 and gluploadelement0 in same bin, no need for ghost pads
0:00:00.229399600 292 00000181B0577060 INFO GST_PADS gstpad.c:2441:gst_pad_link_prepare: trying to link capsfilter0:src and gluploadelement0:sink
0:00:00.229445100 292 00000181B0577060 INFO GST_PADS gstpad.c:4398:gst_pad_peer_query:<gluploadelement0:src> pad has no peer
0:00:00.229611600 292 00000181B0577060 INFO GST_PADS gstpad.c:2622:gst_pad_link_full: linked capsfilter0:src and gluploadelement0:sink, successful
0:00:00.229647200 292 00000181B0577060 INFO GST_EVENT gstevent.c:1687:gst_event_new_reconfigure: creating reconfigure event
0:00:00.229688600 292 00000181B0577060 INFO GST_EVENT gstpad.c:6018:gst_pad_send_event_unchecked:<capsfilter0:src> Received event on flushing pad. Discarding
0:00:00.229726800 292 00000181B0577060 INFO GST_ELEMENT_PADS gstutils.c:1821:gst_element_link_pads_full: trying to link element gluploadelement0:(any) to element qml6glsink0:(any)
0:00:00.229753300 292 00000181B0577060 INFO GST_PADS gstutils.c:1081:gst_pad_check_link: trying to link gluploadelement0:src and qml6glsink0:sink
0:00:00.229832500 292 00000181B0577060 INFO GST_PADS gstutils.c:1635:prepare_link_maybe_ghosting: gluploadelement0 and qml6glsink0 in same bin, no need for ghost pads
0:00:00.229859700 292 00000181B0577060 INFO GST_PADS gstpad.c:2441:gst_pad_link_prepare: trying to link gluploadelement0:src and qml6glsink0:sink
0:00:00.229928700 292 00000181B0577060 INFO GST_PADS gstpad.c:2622:gst_pad_link_full: linked gluploadelement0:src and qml6glsink0:sink, successful
0:00:00.229953000 292 00000181B0577060 INFO GST_EVENT gstevent.c:1687:gst_event_new_reconfigure: creating reconfigure event
0:00:00.229973900 292 00000181B0577060 INFO GST_EVENT gstpad.c:6018:gst_pad_send_event_unchecked:<gluploadelement0:src> Received event on flushing pad. Discarding
It seems I have partially identified the problem. For some reason, the framework works correctly with Qt only in release build mode, and since the .pro file specifies running in debug mode, the program example does not work. After I changed the mode to release, everything worked, but now it is unclear how to make the framework work in debug mode.
Ah, interesting. I think in order to work in debug mode, the cerbero command also has to build against debug QT binaries which I am not sure if that is supported or possible at the moment. This might require pointing to a diffferent qmake binary or Qt installation.
There is a strange situation on Windows, however
I dug up information that such a situation with the debug mode has been happening on windows since the time of qt 5.
