gi.repository.GLib.Error: gst_parse_error: no element "Collection" (1)

[vinit13792]

System specs: Ubuntu 20.04 8GB RAM DFK 37BUX178 6.3MP color camera.

I installed from source using all the instructions mentioned here.

When i "Save Image" using tcam-capture, I get the following error:

(tcam-capture:57615): GStreamer-CRITICAL **: 16:38:06.206: gst_element_make_from_uri: assertion 'gst_uri_is_valid (uri)' failed Traceback (most recent call last): File "/home/ubuntu/tiscamera/tools/tcam-capture/tcam-capture", line 420, in save_image_action self.view.save_image(self.settings.get_image_type()) File "/home/ubuntu/tiscamera/tools/tcam-capture/tcam_capture/TcamView.py", line 190, in save_image self.imagesaver.save_image(get_encoder_dict()[image_type]) File "/home/ubuntu/tiscamera/tools/tcam-capture/tcam_capture/MediaSaver.py", line 246, in save_image self._create_pipeline() File "/home/ubuntu/tiscamera/tools/tcam-capture/tcam_capture/MediaSaver.py", line 146, in _create_pipeline self.pipeline = Gst.parse_launch(save_str) gi.repository.GLib.Error: gst_parse_error: no element "Collection" (1)

And no image is saved in the default folder after clicking "Save Image"

[TIS-Stefan]

Hello

Maybe tcam-capture does not find any Gstreamer encoder modules. Which is strange. Please run gst-inspect-1.0 pngenc. It should show the properties of the png encode.

Stefan

[vinit13792]

Hello

Maybe tcam-capture does not find any Gstreamer encoder modules. Which is strange. Please run gst-inspect-1.0 pngenc. It should show the properties of the png encode.

Stefan

Hi Stefan,

I get the following output after running gst-inspect-1.0 pngenc:

Factory Details: Rank primary (256) Long-name PNG image encoder Klass Codec/Encoder/Image Description Encode a video frame to a .png image Author Jeremy SIMON <[email protected]>

Plugin Details: Name png Description PNG plugin library Filename /usr/lib/x86_64-linux-gnu/gstreamer-1.0/libgstpng.so Version 1.16.2 License LGPL Source module gst-plugins-good Source release date 2019-12-03 Binary package GStreamer Good Plugins (Ubuntu) Origin URL https://launchpad.net/distros/ubuntu/+source/gst-plugins-good1.0

GObject +----GInitiallyUnowned +----GstObject +----GstElement +----GstVideoEncoder :

[TIS-Stefan]

Hello

Lets see, whether you get an image at all in your other support case

Stefan

[TIS-Stefan]

If you look into the source code of tcam-capture you find in /MediaSaver.py"

   self.encoder_dict = get_encoder_dict()
  self.image_encoder = self.encoder_dict["png"]

get_encoder_dict() uses:

    if Gst.ElementFactory.find("pngenc") is not None:
        encoder_dict["png"] = Encoder("png", "pngenc", MediaType.image, "png")

I conclude, that tcam-capture can not find pngenc. Therefore, It may is possible, that tcam-capture runs in a different environment, than gst-inspect. In case you use Anaconda or Pythonbox(?), you must add the GStreamer search paths to these environments.

Stefan

[vinit13792]

Hi Stefan,

I actually formatted the system, and re-installed Ubuntu and tiscamera, it started working. I guess there was some issue with the path

[vinit13792]

Hi Stefan,

This is recurring issue, formatting a OS cannot be an option always. Is there any particular reason why this keeps happening?

[TIS-Stefan]

You are nearly the only one with this issue. Therefore, I wonder, what is different on your computers compared to most others.

Do you use Anaconda or Pythonbox? Do you use a Docker container? Did you change the standard path of Gstreamer etc?

Since it worked once, what did you change, so it does not work anymore?

Stefan

[vinit13792]

Do you use Anaconda or Pythonbox?

Hi Stefan,

Do you use Anaconda or Pythonbox? No

Do you use a Docker container? No

Did you change the standard path of Gstreamer etc? How to find the gstreamer path? and how to add it to path?

Since it worked once, what did you change, so it does not work anymore? I uninstalled the tiscamera, and reinstalled, and then this error ocurred.

I am using ubuntu 20.04, followed tiscamera install guide on github There was no environment of anaconda involved here. This error occurred and i re-installed the tiscamera after uninstalling it from build directory

[TIS-Stefan]

I am using ubuntu 20.04, followed tiscamera install guide on github There was no environment of anaconda involved here. This error occurred and i re-installed the tiscamera after uninstalling it from build directory

Did that work?

Stefan

[vinit13792]

I am using ubuntu 20.04, followed tiscamera install guide on github There was no environment of anaconda involved here. This error occurred and i re-installed the tiscamera after uninstalling it from build directory

Did that work?

Stefan

Hi Stefan,

It didnt work.

[TIS-Stefan]

But you wrote, it worked once at https://github.com/vinit13792. Therefore, what changed since then?

Stefan

[vinit13792]

But you wrote, it worked once at https://github.com/vinit13792. Therefore, what changed since then?

Stefan

So to make aravis work, i tried uninstalling, and then re-installed tiscamera again. And since then this error shows up everytime i try to click an image.

[TIS-Stefan]

Please show me your cmake line. It should be cmake -DBUILD_ARAVIS=ON -DTCAM_ARAVIS_USB_VISION=ON .. Then rebuild and run sudo make install.

(Source : https://www.theimagingsource.com/documentation/tiscamera/building.html)

Stefan

[vinit13792]

Please show me your cmake line. It should be cmake -DBUILD_ARAVIS=ON -DTCAM_ARAVIS_USB_VISION=ON .. Then rebuild and run sudo make install.

(Source : https://www.theimagingsource.com/documentation/tiscamera/building.html)

Stefan

Hi Stefan,

I actually did a fresh ubuntu install, and then installed tiscamera using the tutorial mentioned here and it worked now.

I won't be using aravis as it is not helping and i think it needs to be looked into from the TIS team. The tcam-capture should not hang if one is using aravis.

Please look into this issue, as color correction is important as well, if its a feature that we are paying for, we should be able to utilize it in the software.

[vinit13792]

Please show me your cmake line. It should be cmake -DBUILD_ARAVIS=ON -DTCAM_ARAVIS_USB_VISION=ON .. Then rebuild and run sudo make install.

(Source : https://www.theimagingsource.com/documentation/tiscamera/building.html)

Stefan

Hi Stefan,

I just rebooted my computer, and i got the same error. gi.repository.GLib.Error: gst_parse_error: no element "Collection" (1)

So i followed the cmake line as you suggested, and i got the following:

There were two errors at the end.

[ 0%] Performing configure step for 'aravis' autoreconf: Entering directory .' autoreconf: configure.ac: not using Gettext autoreconf: running: aclocal --force -I m4 autoreconf: configure.ac: tracing autoreconf: running: libtoolize --copy --force libtoolize: putting auxiliary files in '.'. libtoolize: copying file './ltmain.sh' libtoolize: putting macros in AC_CONFIG_MACRO_DIRS, 'm4'. libtoolize: copying file 'm4/libtool.m4' libtoolize: copying file 'm4/ltoptions.m4' libtoolize: copying file 'm4/ltsugar.m4' libtoolize: copying file 'm4/ltversion.m4' libtoolize: copying file 'm4/lt~obsolete.m4' autoreconf: running: /usr/bin/autoconf --force autoreconf: running: /usr/bin/autoheader --force autoreconf: running: automake --add-missing --copy --force-missing configure.ac:31: installing './compile' configure.ac:10: installing './missing' gst-0.10/Makefile.am: installing './depcomp' autoreconf: Leaving directory .' checking for a BSD-compatible install... /usr/bin/install -c checking whether build environment is sane... yes checking for a thread-safe mkdir -p... /usr/bin/mkdir -p checking for gawk... no checking for mawk... mawk checking whether make sets $(MAKE)... yes checking whether make supports nested variables... yes checking whether to enable maintainer-specific portions of Makefiles... no checking whether make supports nested variables... (cached) yes checking whether make supports the include directive... yes (GNU style) checking for gcc... gcc checking whether the C compiler works... yes checking for C compiler default output file name... a.out checking for suffix of executables... checking whether we are cross compiling... no checking for suffix of object files... o checking whether we are using the GNU C compiler... yes checking whether gcc accepts -g... yes checking for gcc option to accept ISO C89... none needed checking whether gcc understands -c and -o together... yes checking dependency style of gcc... none checking for library containing strerror... none required checking for gcc... (cached) gcc checking whether we are using the GNU C compiler... (cached) yes checking whether gcc accepts -g... (cached) yes checking for gcc option to accept ISO C89... (cached) none needed checking whether gcc understands -c and -o together... (cached) yes checking dependency style of gcc... (cached) none checking for g++... g++ checking whether we are using the GNU C++ compiler... yes checking whether g++ accepts -g... yes checking dependency style of g++... none checking how to run the C preprocessor... gcc -E checking for grep that handles long lines and -e... /usr/bin/grep checking for egrep... /usr/bin/grep -E checking for ANSI C header files... yes checking for sys/types.h... yes checking for sys/stat.h... yes checking for stdlib.h... yes checking for string.h... yes checking for memory.h... yes checking for strings.h... yes checking for inttypes.h... yes checking for stdint.h... yes checking for unistd.h... yes checking locale.h usability... yes checking locale.h presence... yes checking for locale.h... yes checking for LC_MESSAGES... yes checking for CFPreferencesCopyAppValue... no checking for CFLocaleCopyCurrent... no checking libintl.h usability... yes checking libintl.h presence... yes checking for libintl.h... yes checking for ngettext in libc... yes checking for dgettext in libc... yes checking for bind_textdomain_codeset... yes checking for msgfmt... /usr/bin/msgfmt checking for dcgettext... yes checking if msgfmt accepts -c... yes checking for gmsgfmt... /usr/bin/msgfmt checking for xgettext... /usr/bin/xgettext checking whether NLS is requested... yes checking for intltool >= 0.31.2... 0.51.0 found checking for intltool-update... /usr/bin/intltool-update checking for intltool-merge... /usr/bin/intltool-merge checking for intltool-extract... /usr/bin/intltool-extract checking for xgettext... (cached) /usr/bin/xgettext checking for msgmerge... /usr/bin/msgmerge checking for msgfmt... (cached) /usr/bin/msgfmt checking for gmsgfmt... (cached) /usr/bin/msgfmt checking for perl... /usr/bin/perl checking for perl >= 5.8.1... 5.30.0 checking for XML::Parser... ok checking build system type... x86_64-pc-linux-gnu checking host system type... x86_64-pc-linux-gnu checking how to print strings... printf checking for a sed that does not truncate output... /usr/bin/sed checking for fgrep... /usr/bin/grep -F checking for ld used by gcc... /usr/bin/ld checking if the linker (/usr/bin/ld) is GNU ld... yes checking for BSD- or MS-compatible name lister (nm)... /usr/bin/nm -B checking the name lister (/usr/bin/nm -B) interface... BSD nm checking whether ln -s works... yes checking the maximum length of command line arguments... 1572864 checking how to convert x86_64-pc-linux-gnu file names to x86_64-pc-linux-gnu format... func_convert_file_noop checking how to convert x86_64-pc-linux-gnu file names to toolchain format... func_convert_file_noop checking for /usr/bin/ld option to reload object files... -r checking for objdump... objdump checking how to recognize dependent libraries... pass_all checking for dlltool... no checking how to associate runtime and link libraries... printf %s\n checking for ar... ar checking for archiver @FILE support... @ checking for strip... strip checking for ranlib... ranlib checking command to parse /usr/bin/nm -B output from gcc object... ok checking for sysroot... no checking for a working dd... /usr/bin/dd checking how to truncate binary pipes... /usr/bin/dd bs=4096 count=1 checking for mt... mt checking if mt is a manifest tool... no checking for dlfcn.h... yes checking for objdir... .libs checking if gcc supports -fno-rtti -fno-exceptions... no checking for gcc option to produce PIC... -fPIC -DPIC checking if gcc PIC flag -fPIC -DPIC works... yes checking if gcc static flag -static works... yes checking if gcc supports -c -o file.o... yes checking if gcc supports -c -o file.o... (cached) yes checking whether the gcc linker (/usr/bin/ld -m elf_x86_64) supports shared libraries... yes checking whether -lc should be explicitly linked in... no checking dynamic linker characteristics... GNU/Linux ld.so checking how to hardcode library paths into programs... immediate checking whether stripping libraries is possible... yes checking if libtool supports shared libraries... yes checking whether to build shared libraries... yes checking whether to build static libraries... yes checking how to run the C++ preprocessor... g++ -E checking for ld used by g++... /usr/bin/ld -m elf_x86_64 checking if the linker (/usr/bin/ld -m elf_x86_64) is GNU ld... yes checking whether the g++ linker (/usr/bin/ld -m elf_x86_64) supports shared libraries... yes checking for g++ option to produce PIC... -fPIC -DPIC checking if g++ PIC flag -fPIC -DPIC works... yes checking if g++ static flag -static works... yes checking if g++ supports -c -o file.o... yes checking if g++ supports -c -o file.o... (cached) yes checking whether the g++ linker (/usr/bin/ld -m elf_x86_64) supports shared libraries... yes checking dynamic linker characteristics... (cached) GNU/Linux ld.so checking how to hardcode library paths into programs... immediate checking for valgrind... no checking whether to build with code coverage support... no checking for pkg-config... /usr/bin/pkg-config checking pkg-config is at least version 0.14... yes checking for ARAVIS_USB... yes checking for ARAVIS... yes checking for asan flags... no checking for glib-mkenums... /usr/bin/glib-mkenums checking for gobject-introspection... yes checking for gtk-doc... yes checking for gtkdoc-check... gtkdoc-check.test checking for gtkdoc-check... /usr/bin/gtkdoc-check checking for gtkdoc-rebase... /usr/bin/gtkdoc-rebase checking for gtkdoc-mkpdf... /usr/bin/gtkdoc-mkpdf checking whether to build gtk-doc documentation... no checking for GTKDOC_DEPS... yes checking for appstream-util... no checking that generated files are newer than configure... done configure: creating ./config.status config.status: creating Makefile config.status: creating src/Makefile config.status: creating src/arvfeatures.h config.status: creating src/arvversion.h config.status: creating viewer/Makefile config.status: creating viewer/data/Makefile config.status: creating viewer/data/arv-viewer.desktop.in config.status: creating viewer/data/arv-viewer.appdata.xml config.status: creating gst/Makefile config.status: creating gst-0.10/Makefile config.status: creating tests/Makefile config.status: creating po/Makefile.in config.status: creating man/Makefile config.status: creating docs/Makefile config.status: creating docs/reference/Makefile config.status: creating docs/reference/aravis/Makefile config.status: creating aravis.pc config.status: creating src/arvconfig.h config.status: executing depfiles commands config.status: executing default-1 commands config.status: executing libtool commands config.status: executing po/stamp-it commands

Configuration:

Compiler: gcc Compiler flags: -pthread -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/libxml2 -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/libusb-1.0 Linker flags: -lm -lgio-2.0 -lgobject-2.0 -lxml2 -lgthread-2.0 -pthread -lglib-2.0 -lz -lusb-1.0

Build USB support: yes Build packet socket support: no Build viewer: no Build gstreamer plugin: no Build gstreamer-0.10 plugin: no Build with fast heartbeat: yes Build with address sanitizer: no

[ 1%] Performing build step for 'aravis' Making all in src CC arvuvinterface.lo CC arvuvdevice.lo CC arvuvstream.lo CC arvuvcp.lo /home/ubuntu/tiscamera/external/aravis/src/arvuvcp.c: In function ‘arv_uvcp_packet_type_to_string’: /home/ubuntu/tiscamera/external/aravis/src/arvuvcp.c:127:29: error: ‘ARV_TYPE_UVCP_PACKET_TYPE’ undeclared (first use in this function); did you mean ‘ARV_TYPE_GVCP_PACKET_TYPE’? 127 | return arv_enum_to_string (ARV_TYPE_UVCP_PACKET_TYPE, value); /home/ubuntu/tiscamera/external/aravis/src/arvuvcp.c:127:29: note: each undeclared identifier is reported only once for each function it appears in /home/ubuntu/tiscamera/external/aravis/src/arvuvcp.c: In function ‘arv_uvcp_command_to_string’: /home/ubuntu/tiscamera/external/aravis/src/arvuvcp.c:133:29: error: ‘ARV_TYPE_UVCP_COMMAND’ undeclared (first use in this function); did you mean ‘ARV_TYPE_GVCP_COMMAND’? 133 | return arv_enum_to_string (ARV_TYPE_UVCP_COMMAND, value); /home/ubuntu/tiscamera/external/aravis/src/arvuvcp.c: In function ‘arv_uvcp_packet_type_to_string’: /home/ubuntu/tiscamera/external/aravis/src/arvuvcp.c:128:1: warning: control reaches end of non-void function [-Wreturn-type] 128 | } /home/ubuntu/tiscamera/external/aravis/src/arvuvcp.c: In function ‘arv_uvcp_command_to_string’: /home/ubuntu/tiscamera/external/aravis/src/arvuvcp.c:134:1: warning: control reaches end of non-void function [-Wreturn-type] 134 | } make[5]: *** [Makefile:952: arvuvcp.lo] Error 1 make[5]: *** Waiting for unfinished jobs.... /home/ubuntu/tiscamera/external/aravis/src/arvuvinterface.c: In function ‘arv_uv_interface_init’: /home/ubuntu/tiscamera/external/aravis/src/arvuvinterface.c:369:13: warning: Deprecated pre-processor symbol, replace with 369 | uv_interface->priv = G_TYPE_INSTANCE_GET_PRIVATE (uv_interface, ARV_TYPE_UV_INTERFACE, ArvUvInterfacePrivate); /home/ubuntu/tiscamera/external/aravis/src/arvuvdevice.c: In function ‘arv_uv_device_init’: /home/ubuntu/tiscamera/external/aravis/src/arvuvdevice.c:748:13: warning: Deprecated pre-processor symbol, replace with 748 | uv_device->priv = G_TYPE_INSTANCE_GET_PRIVATE (uv_device, ARV_TYPE_UV_DEVICE, ArvUvDevicePrivate); /home/ubuntu/tiscamera/external/aravis/src/arvuvstream.c: In function ‘arv_uv_stream_init’: /home/ubuntu/tiscamera/external/aravis/src/arvuvstream.c:418:13: warning: Deprecated pre-processor symbol, replace with 418 | uv_stream->priv = G_TYPE_INSTANCE_GET_PRIVATE (uv_stream, ARV_TYPE_UV_STREAM, ArvUvStreamPrivate); make[4]: *** [Makefile:702: all] Error 2 make[3]: *** [Makefile:583: all-recursive] Error 1 make[2]: *** [external/CMakeFiles/aravis.dir/build.make:113: external/aravis-prefix/src/aravis-stamp/aravis-build] Error 2 make[1]: *** [CMakeFiles/Makefile2:638: external/CMakeFiles/aravis.dir/all] Error 2 make: *** [Makefile:152: all] Error 2

[TIS-Stefan]

Hello

I give up.

I do not know, what happens, but it is something totally weird. The very same works on nearly all other computers, only on your is all after reboot destroyed. You seem to delete set search paths. I am sure, you are not even aware of what is happening.

Regarding color correction matrix: Will be done at some day.

Stefan

[TIS-Stefan]

Hello

what happens here:

/home/ubuntu/tiscamera/external/aravis/src/arvuvcp.c:133:29: error: ‘ARV_TYPE_UVCP_COMMAND’ undeclared (first use in this function); did you mean ‘ARV_TYPE_GVCP_COMMAND’?

Why is there an error, we do not get`? what is the cmake command line you use?

[vinit13792]

I give up.

I did a reset on Ubuntu system, updated my system. And then installed tiscamera. It worked well on day 1. Next day when I fired up my system, and clicked an image, it gave the same error. I do not understand why is this happening just over a reboot.

[TIS-Stefan]

Hello

If a reboot destroys all, then the first question is, how did you install tiscamera? How do you execute tcam-capture? From terminal or desktop? what happens if open a terminal and enter

cd tiscamera/build
. ./env.sh
tcam-capture

You may ask yourself, what happens on reboot on your system, that does no happen on all other computers? Do you have kind of reset program? Do you run in a virtual machine?

Stefan

[vinit13792]

Hello

If a reboot destroys all, then the first question is, how did you install tiscamera? How do you execute tcam-capture? From terminal or desktop? what happens if open a terminal and enter

cd tiscamera/build
. ./env.sh
tcam-capture

You may ask yourself, what happens on reboot on your system, that does no happen on all other computers? Do you have kind of reset program? Do you run in a virtual machine?

Stefan

how did you install tiscamera? with the help of instructions mentioned on Tiscamera github

How do you execute tcam-capture? using terminal

what happens if open a terminal and enter cd tiscamera/build . ./env.sh tcam-capture ? tcam-capture opens.

Do you have kind of reset program? No I do not.

Do you run in a virtual machine? No, its an old HP 7th gen 8gb laptop.

You may ask yourself, what happens on reboot on your system? I think there might be some disk errors. because before installing Ubuntu, the setup checks for disk errors, and there were some 6 errors found in disk checks. I think those disk checks has something to do withthis problem which is causing some important files to corrupt

[vinit13792]

If you look into the source code of tcam-capture you find in /MediaSaver.py"

   self.encoder_dict = get_encoder_dict()
  self.image_encoder = self.encoder_dict["png"]

get_encoder_dict() uses:

    if Gst.ElementFactory.find("pngenc") is not None:
        encoder_dict["png"] = Encoder("png", "pngenc", MediaType.image, "png")

I conclude, that tcam-capture can not find pngenc. Therefore, It may is possible, that tcam-capture runs in a different environment, than gst-inspect. In case you use Anaconda or Pythonbox(?), you must add the GStreamer search paths to these environments.

Stefan

you must add the GStreamer search paths to these environments... How to add Gstreamer search paths to environment?

[TIS-Stefan]

Hi

what happens if open a terminal and enter cd tiscamera/build . ./env.sh tcam-capture ? tcam-capture opens.

Do you get a live stream and are you able to save images? the ". ./env.sh" sets include paths for the tiscamera files to your current build directory.

I think there might be some disk errors. because before installing Ubuntu, the setup checks for disk errors, and there were some 6 errors found in disk checks. I think those disk checks has something to do with this problem which is causing some important files to corrupt

I do not think, this could be an issue, but who knows? That could be possible.

How to add Gstreamer search paths to environment?

Use the GST_PLUGIN_PATH environment variable to point at the directory you want. Please see https://stackoverflow.com/questions/2120444/gstreamer-plugin-search-path and https://gstreamer.freedesktop.org/documentation/gstreamer/gstregistry.html?gi-language=c

Stefan

[vinit13792]

Hi Stefan,

I dont know the logic behind using gst plugin path and how that would make a difference since i am not installing anything else apart from tiscamera. The building from source does exactly the same thing. So I am not sure how this would make a difference.

[vinit13792]

Also, I tried tcam-capture --reset, and the error disappeared and it started saving the image in the given folder.

[TIS-Stefan]

Hi

I dont know the logic behind using gst plugin path and how that would make a difference since i am not installing anything else apart from tiscamera.

Welcome to Linux. It is also about installing additional packages. However, I am guessing.

Also, I tried tcam-capture --reset, and the error disappeared and it started saving the image in the given folder.

Where to go from here? I have no more ideas.

Stefan

[vinit13792]

Hi

I dont know the logic behind using gst plugin path and how that would make a difference since i am not installing anything else apart from tiscamera.

Welcome to Linux. It is also about installing additional packages. However, I am guessing.

Also, I tried tcam-capture --reset, and the error disappeared and it started saving the image in the given folder.

Where to go from here? I have no more ideas.

Stefan

Welcome to Linux. It is also about installing additional packages. However, I am guessing. I agree I am new to Linux, but i thought gstreamer was being installed as a dependency with tiscamera.

Where to go from here? I have no more ideas. Well i think anyone who gets this similar error can run tcam-capture --reset in their terminal and check it out themselves if it works for them or not. We can close this issue for now.

[TIS-Stefan]

Until now, you are the only one with this error. That makes it so hard to narrow down.

Therefore, lets keep the issue open.

Stefan

[vinit13792]

Hi Stefan,

Yeah i guess you are right, because I searched for the same issue and i couldn't find anything anywhere. So I think its better if its open.

Vinit

[TIS-Stefan]

Hi Vinit

ok.

What do you want to do with the camera? Maybe programs like "qv4l2" are sufficient for you.

Stefan

[vinit13792]

Hi Stefan,

I am working on a instance segmentation problem. I need the camera to click and save a color accurate image and save it in a folder. I want to take it a step further by automating this process soon by sending software triggers. But for software triggers i read in your documentation that all the automatics need to be Turned OFF. Hence i may have to just stream the video with all the automatics enabled and snap an image from the video stream.

Could you please elaborate on the qv4l2 part? i do not know about it. Vinit