Yocto OpenCV w/ GStreamer installation issues - c++

Question

I have a simple GStreamer pipeline that I instantiate through OpenCV VideoWriter
LOG_INFO("Opening VP8 GStreamer writer object at "
<< host << ":" << port << " with " << horizontal_resolution
<< "x" << vertical_resolution << "p#" << fps << "fps"
<< "(color=" << is_color << ")");
const std::string filename{
" appsrc is-live=true ! videoconvert ! "
" vp8enc cpu-used=2 threads=2 min_quantizer=5 max_quantizer=5 deadline=100000 ! "
" rtpvp8pay ! application/x-rtp,media=video,encoding-name=VP8,payload=96 ! "
" udpsink host= " + host + " port= " + port
};
writer.open(
filename,
cv::CAP_GSTREAMER,
fps,
cv::Size{horizontal_resolution, vertical_resolution},
is_color
);
On my host machine it runs smoothly but when I cross-compile and run on the target I get the following:
Opening VP8 GStreamer writer object at 127.0.0.1:8004 with 160x120p#30fps(color=true)
0:00:00.003785000 3484 0xe7e0ac0 WARN GST_ELEMENT_FACTORY gstelementfactory.c:456:gst_element_factory_make: no such element factory "appsrc"!
0:00:00.003901750 3484 0xe7e0ac0 ERROR GST_PIPELINE grammar.y:816:priv_gst_parse_yyparse: no element "appsrc"
0:00:00.003951125 3484 0xe7e0ac0 WARN GST_ELEMENT_FACTORY gstelementfactory.c:456:gst_element_factory_make: no such element factory "videoconvert"!
0:00:00.003972875 3484 0xe7e0ac0 ERROR GST_PIPELINE grammar.y:816:priv_gst_parse_yyparse: no element "videoconvert"
0:00:00.003998375 3484 0xe7e0ac0 ERROR GST_PIPELINE grammar.y:901:priv_gst_parse_yyparse: link has no source [sink=#(nil)]
0:00:00.004042250 3484 0xe7e0ac0 WARN GST_ELEMENT_FACTORY gstelementfactory.c:456:gst_element_factory_make: no such element factory "vp8enc"!
0:00:00.004070875 3484 0xe7e0ac0 ERROR GST_PIPELINE grammar.y:816:priv_gst_parse_yyparse: no element "vp8enc"
0:00:00.004105500 3484 0xe7e0ac0 ERROR GST_PIPELINE grammar.y:901:priv_gst_parse_yyparse: link has no source [sink=#(nil)]
0:00:00.004135750 3484 0xe7e0ac0 WARN GST_ELEMENT_FACTORY gstelementfactory.c:456:gst_element_factory_make: no such element factory "rtpvp8pay"!
0:00:00.004160250 3484 0xe7e0ac0 ERROR GST_PIPELINE grammar.y:816:priv_gst_parse_yyparse: no element "rtpvp8pay"
0:00:00.004186875 3484 0xe7e0ac0 ERROR GST_PIPELINE grammar.y:901:priv_gst_parse_yyparse: link has no source [sink=#(nil)]
0:00:00.004309875 3484 0xe7e0ac0 WARN GST_ELEMENT_FACTORY gstelementfactory.c:456:gst_element_factory_make: no such element factory "udpsink"!
0:00:00.004336375 3484 0xe7e0ac0 ERROR GST_PIPELINE grammar.y:816:priv_gst_parse_yyparse: no element "udpsink"
0:00:00.004364125 3484 0xe7e0ac0 ERROR GST_PIPELINE grammar.y:901:priv_gst_parse_yyparse: link has no source [sink=#(nil)]
(EXE:3484): GStreamer-CRITICAL **: gst_debug_log_valist: assertion 'category != NULL' failed
** (EXE:3484): CRITICAL **: gst_app_src_end_of_stream: assertion 'GST_IS_APP_SRC (appsrc)' failed
My Yocto configuration file is the following, target platform is a i.MX8M Mini.
require conf/distro/include/yocto-uninative.inc
MACHINE ??= "e0219"
UBOOT_CONFIG ??= "sd"
UBOOT_CONFIG[sd] ??= "e0219_config"
#MACHINE ??= 'imx8mmevk'
DISTRO ?= 'fsl-imx-xwayland'
PACKAGE_CLASSES ?= "package_rpm"
EXTRA_IMAGE_FEATURES ?= "debug-tweaks"
USER_CLASSES ?= "buildstats image-mklibs image-prelink"
PATCHRESOLVE = "noop"
BB_DISKMON_DIRS ??= "\
STOPTASKS,${TMPDIR},1G,100K \
STOPTASKS,${DL_DIR},1G,100K \
STOPTASKS,${SSTATE_DIR},1G,100K \
STOPTASKS,/tmp,100M,100K \
ABORT,${TMPDIR},100M,1K \
ABORT,${DL_DIR},100M,1K \
ABORT,${SSTATE_DIR},100M,1K \
ABORT,/tmp,10M,1K"
PACKAGECONFIG_append_pn-qemu-native = " sdl"
PACKAGECONFIG_append_pn-nativesdk-qemu = " sdl"
CONF_VERSION = "1"
DL_DIR ?= "${BSPDIR}/downloads/"
CORE_IMAGE_EXTRA_INSTALL += " net-tools iputils dhcpcd"
CORE_IMAGE_EXTRA_INSTALL += " openssh nano python3 ethtool i2c-tools strace spitools"
CORE_IMAGE_EXTRA_INSTALL += " tcpdump socat opencv libmicrohttpd libsrtp curl boost"
CORE_IMAGE_EXTRA_INSTALL += " nmap python-djangorestframework net-snmp"
CORE_IMAGE_EXTRA_INSTALL += " openmp llvm"
ACCEPT_FSL_EULA = "1"
If I understand this correctly the opencv recipe should require gstreamer and some of its plugins but it seems to me that, after the build, GStreamer can't find the needed plugins to run the pipeline. Here's the output of gst-inspect:
$ gst-inspect-1.0
coreelements: capsfilter: CapsFilter
coreelements: concat: Concat
coreelements: dataurisrc: data: URI source element
coreelements: downloadbuffer: DownloadBuffer
coreelements: fakesrc: Fake Source
coreelements: fakesink: Fake Sink
coreelements: fdsrc: Filedescriptor Source
coreelements: fdsink: Filedescriptor Sink
coreelements: filesrc: File Source
coreelements: funnel: Funnel pipe fitting
coreelements: identity: Identity
coreelements: input-selector: Input selector
coreelements: output-selector: Output selector
coreelements: queue: Queue
coreelements: queue2: Queue 2
coreelements: filesink: File Sink
coreelements: tee: Tee pipe fitting
coreelements: typefind: TypeFind
coreelements: multiqueue: MultiQueue
coreelements: valve: Valve element
coreelements: streamiddemux: Streamid Demux
staticelements: bin: Generic bin
staticelements: pipeline: Pipeline object
Total count: 2 plugins, 23 features
How can I solve this?
Update 2 using #Subrata suggestion
I added the packages suggested by #Subrata to my local.conf like so:
CORE_IMAGE_EXTRA_INSTALL += " gstreamer1.0 gstreamer1.0-plugins-base gstreamer1.0-plugins-good gstreamer1.0-plugins-bad gstreamer1.0-plugins-ugly gstreamer1.0-libav"
And now can see 179 plugins through gst-inspect.
Launching my application I'm still missing an element, but it's a step in the right direction.
Opening VP8 GStreamer writer object at 127.0.0.1:8004 with 160x120p#30fps(color=true)
0:00:00.053317750 3520 0x16290b00 WARN GST_ELEMENT_FACTORY gstelementfactory.c:456:gst_element_factory_make: no such element factory "vp8enc"!
0:00:00.053537875 3520 0x16290b00 ERROR GST_PIPELINE grammar.y:816:priv_gst_parse_yyparse: no element "vp8enc"
0:00:00.053606125 3520 0x16290b00 ERROR GST_PIPELINE grammar.y:901:priv_gst_parse_yyparse: link has no sink [source=#0x16293290]
0:00:00.057937500 3520 0x16290b00 ERROR GST_PIPELINE grammar.y:901:priv_gst_parse_yyparse: link has no source [sink=#0x162a0250]
0:00:00.081852625 3520 0x1629f720 FIXME default gstutils.c:3981:gst_pad_create_stream_id_internal:<appsrc0:src> Creating random stream-id, consider implementing a deterministic way of creating a stream-id

Answer 1

Try reinstalling the gstreamer packages like gstreamer1.0-plugins-good, gstreamer1.0-plugins-bad, gstreamer1.0-plugins-ugly and gstreamer1.0-libav.
Following packages will provide: gstreamer1.0-audiosink, gstreamer1.0-audiosource, gstreamer1.0-videosink, gstreamer1.0-videosource, gstreamer1.0-visualization
libav have elements for encoding 40+ formats (MPEG, DivX, MPEG4, AC3, DV, ...), decoding elements for decoding 90+ formats (AVI, MPEG, OGG, Matroska, ASF, ...).

Answer 2

To complete the answer of #Subrata:
You need to install the package corresponding to the elements requiered by gstreamer.
I don't know which Yocto version you are using but you can see which gstreamer elements are installed by default on gstreamer. In the meta/recipes-multimedia/gstreamer/gstreamer1.0-plugins-good.inc file:
PACKAGECONFIG ??= " \
${GSTREAMER_ORC} \
${#bb.utils.filter('DISTRO_FEATURES', 'pulseaudio x11', d)} \
cairo flac gdk-pixbuf gudev jpeg libpng soup speex taglib v4l2 \
"
[...]
PACKAGECONFIG[vpx] = "--enable-vpx,--disable-vpx,libvpx"
Now you are required vp8enc, included in vpx library, but, as you can see, the PACKAGECONFIG variable does not contains this option.
You need to add a .bbappend file with this option added to use this plugin, in your meta :your-meta/repices-multimedia/gstreamer/gstreamer1.0-plugins-good_%.bbappend
PACKAGECONFIG_append=" vpx"
If you plan to write a recipe which needs this vpx element, you can add it in the RDEPENDS:
DEPENDS=" gstreamer1.0 gstreamer1.0-plugins-good"
RDEPENDS_${PN}=" gstreamer1.0 \
gstreamer1.0-plugins-good-vpx "