[libcamera-devel] using libcamerasrc gst element

[Martin Kepplinger]

Am Donnerstag, dem 02.09.2021 um 17:48 +0300 schrieb Laurent Pinchart:
> Hi Martin,
> 
> On Thu, Sep 02, 2021 at 10:56:41AM +0200, Martin Kepplinger wrote:
> > hi all,
> > 
> > I'm starting to use libcamera with the hi846 camera on imx8mq. (The
> > following all works on my laptop btw, where there's only 1 camera.)
> > 
> > I test using the "libaperture" gstreamer app with the libcamera gst
> > src
> > element
> > (https://gitlab.gnome.org/jwestman/libaperture/-/issues/14 ).
> > But it doesn't work on imx8mq where I have 2 cameras (and 1 is
> > working
> > with libcamera currently, but that shouldn't matter I think).
> > 
> > Here's the end of the logs. earlier logs seem to be the same as the
> > successful case with qcam, see below.
> > 
> > 
> > [1:57:12.541751844] [3187] DEBUG Camera camera_manager.cpp:150
> > Found registered pipeline handler 'PipelineHandlerUVC'
> > [1:57:12.541817127] [3187] DEBUG Camera camera_manager.cpp:150
> > Found registered pipeline handler 'PipelineHandlerVimc'
> > [1:57:12.542646484] [3180] DEBUG Camera camera.cpp:878 streams
> > configuration: (0) 1632x1224-SGBRG16
> > [1:57:12.543146546] [3187] DEBUG V4L2 v4l2_videodevice.cpp:1423
> > /dev/video0[32:cap]: Releasing buffers
> > [1:57:12.543212069] [3187] DEBUG V4L2 v4l2_videodevice.cpp:1160
> > /dev/video0[32:cap]: 0 buffers requested.

[snip]

> > 
> > what does libcamerasrc do wrong? Why isn't it configuring the
> > stream?
> > What config options do I have for the gstreamer element to play
> > with?
> 
> Have you tried using libcamerasrc with a simple gst-launch pipeline
> first ? That could give us additional feedback from GStreamer itself.
> 

thanks. first, verified that the gstreamer test src works:

LANG=C LIBCAMERA_LOG_FILE=/home/purism/lc.log LIBCAMERA_LOG_LEVELS=0
GST_PLUGIN_PATH=/usr/local/lib/aarch64-linux-gnu/gstreamer-1.0/ gst-
launch-1.0 videotestsrc ! glimagesink

one appearent problem: gstreamer and libcamerasrc don't know about the
SGBRG16 format I'm receiving. Tried to workaround that like so (?):

--- a/src/gstreamer/gstlibcamera-utils.cpp
+++ b/src/gstreamer/gstlibcamera-utils.cpp
@@ -30,6 +30,8 @@ static struct {
        { GST_VIDEO_FORMAT_YUY2, formats::YUYV },
        { GST_VIDEO_FORMAT_YVYU, formats::YVYU },
        /* \todo NV42 is used in libcamera but is not mapped in
GStreamer yet. */
+       { GST_VIDEO_FORMAT_GRAY16_BE, formats::SGBRG16 },
+       /* 16bit bayer not supported by gstreamer yet (?) */
 };
 

but that results in:

purism at pureos:~$ GST_DEBUG=3 LANG=C
LIBCAMERA_LOG_FILE=/home/purism/lc.log LIBCAMERA_LOG_LEVELS=0
GST_PLUGIN_PATH=/usr/local/lib/aarch64-linux-gnu/gstreamer-1.0/ gst-
launch-1.0 libcamerasrc ! videoconvert ! glimagesink
Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
0:00:01.793370564  3386 0xaaaaddf97760 FIXME                default
gstutils.c:4025:gst_pad_create_stream_id_internal:<libcamerasrc0:src>
Creating random stream-id, consider implementing a deterministic way of
creating a stream-id
Got context from element 'sink': gst.gl.GLDisplay=context,
gst.gl.GLDisplay=(GstGLDisplay)"\(GstGLDisplayWayland\)\
gldisplaywayland0";
Pipeline is PREROLLED ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock

(gst-launch-1.0:3386): GStreamer-CRITICAL **: 09:20:50.114:
gst_value_set_int_range_step: assertion 'start < end' failed

(gst-launch-1.0:3386): GStreamer-CRITICAL **: 09:20:50.116:
gst_value_set_int_range_step: assertion 'start < end' failed
^Chandling interrupt.
Interrupt: Stopping pipeline ...
Execution ended after 0:00:05.128408250
Setting pipeline to NULL ...
Freeing pipeline ...


the clock is *not* running. it just shows how long it ran after killing
it.

not sure what my specific question is but in case you've seen this
before and have an idea, just say so :)

thanks,
                               martin