[libcamera-devel] raspberrypi pipeline gstreamer bug

[Kieran Bingham]

Hi Xishan, (Adding Naush)

On 10/06/2020 10:57, Xishan Sun wrote:
> 
> Trying to use gstreamer plugin on raspberrypi platform. 
> 
> 
> For very simple test started with 
> 
> gst-launch-1.0 libcamerasrc ! fakesink
> 
> will get error:
> 
> Setting pipeline to PAUSED ...
> [5:14:54.902707301] [6325]  INFO Camera camera_manager.cpp:277 libcamera
> v0.0.0+1423-78150899-dirty
> Pipeline is live and does not need PREROLL ...
> Setting pipeline to PLAYING ...
> ERROR: from element
> /GstPipeline:pipeline0/GstLibcameraSrc:libcamerasrc0: Internal data
> stream error.
> Additional debug info:
> ../src/gstreamer/gstlibcamerasrc.cpp(461): gst_libcamera_src_task_enter
> (): /GstPipeline:pipeline0/GstLibcameraSrc:libcamerasrc0:
> streaming stopped, reason not-negotiated (-4)
> Execution ended after 0:00:00.000989404
> Setting pipeline to PAUSED ...
> Setting pipeline to READY ...
> Setting pipeline to NULL ...
> Freeing pipeline ...
> 
> debug tracking all the way down to
> file src/gstreamer/gstlibcamerasrc.cpp line 377, the function 
> 
> g_autoptr(GstCaps) filter =
> gst_libcamera_stream_formats_to_caps(stream_cfg.formats());
> 
> will always return empty filter list, since stream_cfg.formats() return
> empty. 
> 
> further down to the source:
> src/libcamera/pipeline/raspberrypi/raspberrypi.cpp line 515, in the
> function 
> 
> CameraConfiguration *PipelineHandlerRPi::generateConfiguration(Camera
> *camera, const StreamRoles &roles)
> 
> there is no configuration for the output format sets. In order to
> generate the format sets, I copied the code from uvc pipeline. add it
> into line 522
> 
> ....
>         if (roles.empty())
>                  return config;
>  
>         std::map<V4L2PixelFormat, std::vector<SizeRange>> v4l2Formats =
>                  data->isp_[Isp::Output0].dev()->formats();
>         std::map<PixelFormat, std::vector<SizeRange>> deviceFormats;
>         std::transform(v4l2Formats.begin(), v4l2Formats.end(),
>                         std::inserter(deviceFormats, deviceFormats.begin()),
>                         [&](const decltype(v4l2Formats)::value_type
> &format) {
>                                 return decltype(deviceFormats)::value_type{
>                                         format.first.toPixelFormat(),
>                                         format.second
>                                 };
>                          });

I wish all that code was friendlier to read (from the original) ... But
I think that's going to be cleaned up by Jacopo's ImageFormats anyway?

>          StreamFormats formats(deviceFormats);
>  
>          for (const StreamRole role : roles) {
>                  //StreamConfiguration cfg{};
>                  StreamConfiguration cfg(formats);
> ....
> 
> it can solve the issue but obviously it is not the best way to do it.
> Could you please revise the code here and advice me a better solution?

Actually it might be quite close to being the right solution,

The raspberrypi StreamConfiguration isn't currently being populated with
the 'capabilities' of the stream, - only a single option based on the
role given, so applications have no way to know what they 'could' ask
for other than the specific choice given by the requested role.


Preloading the StreamConfiguration with the formats supported by the ISP
is probably the right thing to do indeed, as long as it only exposes
things which are supported by the stream.

There may be cases (depending on capabilities of the hardware) where
this list might have to be filtered depending on the number (or type) of
streams requested, but at least initially - populating the
StreamConfiguration with the output capabilities of the ISP should get
things going again.

Naush - Is this something you can look at please?

--
Regards

Kieran


> 
> Thanks
> 
> -- 
> Xishan Sun
> 
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> libcamera-devel at lists.libcamera.org
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> 

-- 
Regards
--
Kieran