Fwd: Error Releasing VideoCapture in OpenCV Using GStreamer Pipeline
Naushir Patuck
naush at raspberrypi.com
Fri Nov 15 09:28:27 CET 2024
On Fri, 15 Nov 2024 at 00:25, Laurent Pinchart
<laurent.pinchart at ideasonboard.com> wrote:
>
> Hi Gaspar,
>
> On Thu, Nov 14, 2024 at 12:28:14PM +0100, Gaspar Ramôa wrote:
> > Hello Laurent,
> >
> > Sorry for the double reply, but I was already able to solve the problem
> > I sent you in the previous email.
>
> That's good news, I won't complain that I didn't have to help you :-)
>
> > Here's the solution, (I might create another issue on GitHub and close
> > it with the solution to help others):
> >
> > I am still quite not sure, but basically gstreamer does not support the
> > same *frame sizes* has the ones from the *sensor format*.
> >
> > When I do the command: *rpicam-vid --list-cameras: *I get the following
> > sensor format: 1640x1232 - 41 FPS
> > Available cameras
> > -----------------
> > 0 : imx219 [3280x2464 10-bit RGGB] (/base/soc/i2c0mux/i2c at 1/imx219 at 10)
> > Modes: 'SRGGB10_CSI2P' : 640x480 [103.33 fps - (1000, 752)/1280x960 crop]
> > *1640x1232* [41.85 fps - (0, 0)/3280x2464 crop]
> > 1920x1080 [47.57 fps - (680, 692)/1920x1080 crop]
> > 3280x2464 [21.19 fps - (0, 0)/3280x2464 crop]
> > 'SRGGB8' : 640x480 [103.33 fps - (1000, 752)/1280x960 crop]
> > *1640x1232* [41.85 fps - (0, 0)/3280x2464 crop]
> > 1920x1080 [47.57 fps - (680, 692)/1920x1080 crop]
> > 3280x2464 [21.19 fps - (0, 0)/3280x2464 crop]
> >
> > In the gstreamer pipeline I was using this format size, and although I
> > was getting 41 fps, my frames had this *striping *effect.
> >
> > * libcamerasrc camera-name=/base/soc/i2c0mux/i2c at 1/imx219 at 10 !
> > video/x-raw,*width=1640,height=1232*,format=RGBx,framerate=41/1 !
> > videoconvert ! appsink
>
> As Nicolas replied separately, there's a patch that was submitted very
> recently to fix this. It's under review, I hope to merge it soon once
> all reviews comments are addressed.
>
> > After looking up, I installed gstreamer1.0-plugins-base-apps and use the
> > command *gst-device-monitor-1.0 Video *to check which gstreamer video
> > streaming formats were available for my camera. And I checked that there
> > was no 1640x1232 option, but a similar one 1600x1200 (same ratio as
> > 640x480). I then tried with this frame size format and it is now working
> > at 41fps with no striping effect:
> >
> > * libcamerasrc camera-name=/base/soc/i2c0mux/i2c at 1/imx219 at 10 !
> > video/x-raw,*width=1600,height=1200*,format=RGBx,framerate=41/1 !
> > videoconvert ! appsink
>
> I'm not sure what logic rpicam-vid uses to determine the formats it
> lists as supported. We may be using a different logic in libcamerasrc.
> That's something we should look at. If it bothers you, could you please
> file a bug on bugs.libcamera.org to track the issue ? I can't promise to
> look at it very quickly though, but it will then be on our list.
I think this is probably related to
https://bugs.libcamera.org/show_bug.cgi?id=169
since (I assume) gstreamer expected a 32-byte aligned stride. A width
of 1640 is not a multiple of 32, but 1600 is.
Naush
>
> > I just have another short question. Now that gstreamer works properly
> > and I can release the capture without that warning/error. I want to know
> > if I can use libcamerasrc without having to activate this environment
> > under /libcamera/build/ with *meson devenv -C build. *If I don't do
> > this, I cannot use gstreamer with libcamerasrc, the libcamerasrc is not
> > recognize for some reason.
> >
> > Isn't it possible to just install libcamera where *libcamerasrc *is
> > available without this virtual environment?
>
> GStreamer looks for plugins in the $GST_PLUGIN_PATH and
> $GST_PLUGIN_SYSTEM_PATH directories. The directory containing
> libgstlibcamera.so in your build directory is not known to GStreamer, so
> it won't find the element. You can either install libcamera to the
> system, which will copy the libgstlibcamera.so file to the GStreamer
> system pluings directory, or set GST_PLUGIN_PATH to point to the
> src/gstreamer/ directory in your build tree. This is what "meson devenv"
> does, see src/gstreamer/meson.build:
>
> --------
> # Make the plugin visible to GStreamer inside meson devenv.
> fs = import('fs')
> gst_plugin_path = fs.parent(libcamera_gst.full_path())
>
> gst_env = environment()
> gst_env.prepend('GST_PLUGIN_PATH', gst_plugin_path)
>
> # Avoid polluting the system registry.
> gst_env.set('GST_REGISTRY', gst_plugin_path / 'registry.data')
>
> meson.add_devenv(gst_env)
> --------
>
> > On 13/11/2024 19:00, Gaspar Ramôa wrote:
> > >
> > > Hello Laurent Pinchart,
> > >
> > >
> > > Thank you for the quick reply!
> > >
> > > As I created the issue 3 months ago and got no reply from you I
> > > thought that you were no longer active or working in this project, and
> > > that is why I said it was difficult to get you! But I am glad I was
> > > able to reach you! :-)
> > >
> > > I spent the entire afternoon following your suggestion.
> > >
> > > So I was successfully able to install the latest version of libcamera
> > > and the latest version of the rpicam-apps:
> > >
> > > /rpicam-apps build: v1.5.3 50958df98d3c 13-11-2024 (16:55:55)
> > > rpicam-apps capabilites: egl:1 qt:1 drm:1 libav:1
> > > libcamera build: v0.3.2+98-75fe515a/
> > >
> > > However when trying to run *gst-inspect-1.0 libcamerasrc *the system
> > > could not find the libcamerasrc. I had to activate some environment
> > > under /libcamera/build/ with *meson devenv -C build*
> > >
> > > After this I was able to start the capture and release it *without any
> > > errors or warnings*. This is really a great positive step for me!
> > >
> > > The frame saved is still weird but I think you probably know what is
> > > missing here. I know that I still have to use some tunnig-files but
> > > the horizontal strips I have no idea what they are. I am using *format
> > > *= BGR and x-raw video on the gstreamer pipeline. Do you have any idea
> > > on how to convert these to the normal RGB. Like using the
> > > *rpicam-still *-o test.png gives me this:
> > >
> > > And I able getting something like this from the gstreamer pipeline:
> > >
> > > Any ideas? Where can I find the documentation of *libcamerasrc *so I
> > > can have an idea on what I can change/do.
> > >
> > >
> > > My end goal is to just be able to use the benefits of libcamera
> > > (changing analog gain, exposure, etc) in JAVA.
> > >
> > >
> > > Best Regards,
> > >
> > > Gaspar Ramôa
> > >
> > >
> > > On 13/11/2024 14:35, Laurent Pinchart wrote:
> > >> Hello Gaspar,
> > >>
> > >> On Wed, Nov 13, 2024 at 12:51:11PM +0100, Gaspar Ramôa wrote:
> > >>> Dear libcamera community,
> > >>>
> > >>> Thank you for developing such a helpful library.
> > >> I'm glad you find it helpful.
> > >>
> > >>> I am trying to get frames using opencv. I am actually able to get frames via
> > >>> cv2.VideoCapture through GStreamer.
> > >>>
> > >>> However, when I try to release the capture (for ending the program or maybe
> > >>> adjusting raw image size): cap.release()
> > >>> I get the following error:
> > >>>
> > >>> [1:39:52.854669803] [1885] ERROR DeviceEnumerator device_enumerator.cpp:172
> > >>> Removing media device /dev/media4 while still in use
> > >>> [1:39:52.854709759] [1885] ERROR DeviceEnumerator device_enumerator.cpp:172
> > >>> Removing media device /dev/media3 while still in use
> > >>>
> > >>> I've already published an issue on the raspberry Pi libcamera GitHub repo where
> > >>> you can get more detail on my problem:https://github.com/raspberrypi/libcamera
> > >>> /issues/163
> > >>>
> > >>> I found the following commit which apparently did to solve the problem I am
> > >>> having now:https://github.com/raspberrypi/libcamera/commit/
> > >>> fa63d428aef62bacf0a6ad1622a7965b3ff2ba2f
> > >> That commit has been merged a long time ago, before v0.0.1, so I expect
> > >> it is included in the libcamera version you are using. Your problem may
> > >> have the same symptoms but a different root cause.
> > >>
> > >> You mentioned in your bug report that you tried both libcamera v0.0.5
> > >> and v0.3.0+65-6ddd79b5. v0.0.5 is fairly old. v0.3.0 is better, but I
> > >> would still recommend trying the latest master branch to see if the
> > >> issue has been fixed already.
> > >>
> > >> If the issue is still present, can you try running the same GStreamer
> > >> pipeline (likely replacing appsink with some sort of display sink, or
> > >> even fakesink) from gst-launch, and see if the problem exists there too
> > >> ?
> > >>
> > >>> This commit was done by the userhttps://github.com/pinchartl. But I have no
> > >>> way of contacting him to help me fix the problem.
> > >> I'm slightly puzzled by why you had trouble contacting me, given that my
> > >> e-mail address is listed in the commit you mentioned above. Regardless,
> > >> it looks like you found a way :-)
> > >>
> > >>> Any suggestions? Thanks in advance!
>
> --
> Regards,
>
> Laurent Pinchart
More information about the libcamera-devel
mailing list