libv4l | thin abstraction layer on top of video4linux2 devices

by philips C Version: Current License: LGPL-2.1

X-Ray Key Features Code Snippets Community Discussions(10)Vulnerabilities Install Support

kandi X-RAY | libv4l Summary

libv4l is a C library. libv4l has no bugs, it has no vulnerabilities, it has a Weak Copyleft License and it has low support. You can download it from GitHub.

libv4l is a collection of libraries which adds a thin abstraction layer on top of video4linux2 devices. The purpose of this (thin) layer is to make it easy for application writers to support a wide variety of devices without having to write seperate code for different devices in the same class. All libv4l components are licensed under the GNU Lesser General Public License version 2 or (at your option) any later version.

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Quality

Security

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Support

libv4l has a low active ecosystem.

It has 34 star(s) with 20 fork(s). There are 12 watchers for this library.

It had no major release in the last 6 months.

There are 2 open issues and 0 have been closed. There are no pull requests.

It has a neutral sentiment in the developer community.

The latest version of libv4l is current.

Quality

libv4l has no bugs reported.

Security

libv4l has no vulnerabilities reported, and its dependent libraries have no vulnerabilities reported.

License

libv4l is licensed under the LGPL-2.1 License. This license is Weak Copyleft.

Weak Copyleft licenses have some restrictions, but you can use them in commercial projects.

Reuse

libv4l releases are not available. You will need to build from source code and install.

Installation instructions are available. Examples and code snippets are not available.

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libv4l Key Features

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libv4l Examples and Code Snippets

No Code Snippets are available at this moment for libv4l.

Community Discussions

Trending Discussions on libv4l

Display /dev/videoX feed in a GUI on Linux-ARM64

OpenCV Docker multistage build - cannot install prebuilt source

Calling Opencv's Video Capture on a Video-URL does not work on Heroku

Can apt-get autoremove remove system files?

opencv - cmake error : No such file or directory on Ubuntu

snapcraft gives 'ascii' codec can't decode byte 0xd0 in position 0: ordinal not in range(128)

docker: building opencv with cuda image size too big (22.4 GB)

Install gstreamer support for opencv python package

Setting camera resolution in OpenCV - pre-built vs. custom build

Compiling error using make install to install OpenCV 4 in Raspbian Raspberry Pi 3+

QUESTION

Display /dev/videoX feed in a GUI on Linux-ARM64

Asked 2021-Apr-12 at 16:56

I've got a device running Ubuntu 18.04LTS on a 64-bit ARM processor. I'd like to develop a GUI that will let me access the camera feed of potentially multiple attached devices (/dev/video0, /dev/video1). Ideally this will be possible with a .NET stack (.NET Core and AvaloniaUI are what I'm looking at). I'm aware of using P/Invoke, but only have a rough understanding of using it. I'm also aware of the libv4l2 library, however I'm not sure where to go from there.

If I have to phrase this as a more direct question for SO: How can I display the /dev/videoX feed on an Ubuntu-ARM64 device in a GUI app built with NET Core (ideally with AvaloniaUI)?

...

ANSWER

Answered 2021-Apr-12 at 16:56

Install https://www.nuget.org/packages/LibVLCSharp.Avalonia/
MainWindow.axaml

Source https://stackoverflow.com/questions/67059022

QUESTION

OpenCV Docker multistage build - cannot install prebuilt source

Asked 2020-Sep-15 at 06:48

I'm trying to build a Docker image including a very particular configuration of OpenCV with CUDA and GPU support.

The build succeeds, and if I make install it from the same context that built the image, it works with no problems.

The problem happens when I try to use a multi stage build, to avoid keeping all the dependencies needed to build OpenCV. Before you continue reading, what follows might actually be an XY problem, if you have a better solution on how to copy OpenCV build artifacts (including Python bindings!) in a Docker multistage build, that is my actual intent.

Now for my attempted solution and the struggle I have:

I run COPY --from=requirements /opencv /opencv and it works and it apparently copies everything in the right path (I checked the filesystem). But, when I run from the build folder make install, I get this CMake error:

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ANSWER

Answered 2020-Sep-15 at 06:48

It is simpler to run cmake & make and make install in the same stage and then copy the install folders. It will allow to not have any build tools like cmake or build-essential in the final docker image.

We will use a custom CMAKE_INSTALL_PREFIX so that OpenCV binaries are installed to a directory and we can copy it straight to the next stage. Using a custom prefix will avoid having to copy CUDA installation or development libraries no longer required. Then we will run ldconfig on that directory to link the libraries as usual.

Modify the build script to use a custom CMAKE_INSTALL_PREFIX:

Source https://stackoverflow.com/questions/63592138

QUESTION

Calling Opencv's Video Capture on a Video-URL does not work on Heroku

Asked 2020-Aug-16 at 08:09

I'm trying to open a videoURL using cv2.VideoCapture on Heroku, and it consistently fails to open. I've called the same code on my local machine (Windows 10) and it ran with no problems. Does anyone have recommendations/buildpacks/alternatives to resolve this?

OpenCV Version: 3.4.2.16

Python: 3.7

Current Buildpacks:

Open Cv Build info (Video) from the Heroku Dyno

...

ANSWER

Answered 2020-Aug-16 at 08:09

My apologies for the delay. I am assuming you are using pip to install OpenCV. The answer to your question is that for OpenCV 3.x, Mac OS and Linux (and ultimately the environment that Heroku is run under) do not link with FFMPEG which means that video support is not enabled for those platforms. However, it is enabled with Windows. This is the reason why there is an inconsistency between the platforms: What is the deal with `pip install opencv-python` is it a full opencv?

The solution is you will either need to build OpenCV 3.x from source, or use OpenCV 4 which now bundles FFMPEG with it. I would highly recommend you use OpenCV 4 unless there is something blocking you from using it. However to install OpenCV 4, use either pip install --upgrade opencv-python or pip install --upgrade opencv-contrib-python. I'm not sure which flavour you are using, but either one should work.

Source https://stackoverflow.com/questions/63319628

QUESTION

Can apt-get autoremove remove system files?

Asked 2020-May-12 at 08:57

I tried to install Python 3 on my Ubuntu 16.04.4 LTS and while using apt i found this:

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ANSWER

Answered 2018-Aug-16 at 14:47

No. apt-get autoremove will only remove files which are not in use by any installed package. Since all the packages you need to run your system have been installed apt-get autoremove will not remove any important system file.

If you require one of the package listed in the apt-get autoremove, you can always install it manually using:

Source https://stackoverflow.com/questions/51861505

QUESTION

opencv - cmake error : No such file or directory on Ubuntu

Asked 2020-Feb-24 at 05:35

I have been trying to install opencv from source rather than pip since I could not read a VideoCapture successfully.

Installing opencv-3.2.0 on Ubuntu 16.04.3 LTS. Followed the details mentioned here.

I get the following errors in ".../opencv-3.2.0/build/CMakeFiles/CMakeError.log":

...

ANSWER

Answered 2017-Aug-09 at 07:06

For your problem, you have to run following command

Source https://stackoverflow.com/questions/45582565

QUESTION

snapcraft gives 'ascii' codec can't decode byte 0xd0 in position 0: ordinal not in range(128)

Asked 2019-Nov-28 at 11:55

I try to compile Qt 5.13 in a snap package, but I get the following error when priming it:

...

ANSWER

Answered 2019-Nov-28 at 11:55

In the traceback, a get_string function is raising a UnicodeDecodeError because it can't decode some text from ASCII.

In the current source for elftools, this line has been replaced by

Source https://stackoverflow.com/questions/59085407

QUESTION

docker: building opencv with cuda image size too big (22.4 GB)

Asked 2019-Nov-27 at 08:36

After countless errors i have been able to build an image of opencv with cuda for python. But image size is way too big. I have tried to reduce the size by following some articles but failed to do so. Here's one that i followed: https://medium.com/@saiprasanth2007/how-did-i-slim-down-the-docker-image-by-70-of-its-original-size-3099458ed7aa

My Dockerfile below:

...

ANSWER

Answered 2019-Nov-27 at 08:36

I tackled the problem by merging all the RUN command into one with a lot of '&& \'. This helped me get the image size down to 5.2 GB.

Source https://stackoverflow.com/questions/59025568

QUESTION

Install gstreamer support for opencv python package

Asked 2019-May-08 at 11:11

I have built my own opencv python package from source.

...

ANSWER

Answered 2019-Feb-22 at 14:42

For those who are struggling with the same problem on Windows... I had to set following CMake Options:

only set "WITH_GSTREAMER" option to True, "WITH_GSTREAMER_0_10" MUST BE FALSE
add new entry "GSTREAMER_DIR"=(path to gstreamer) for me it was "C:/gstreamer/1.0/x86_64" I found this solution here

My OpenCV version: 3.4.3

Source https://stackoverflow.com/questions/54095699

QUESTION

Setting camera resolution in OpenCV - pre-built vs. custom build

Asked 2019-Apr-25 at 11:47

Using OpenCV we are able to get the camera resolution from a USB webcam if supported by

...

ANSWER

Answered 2019-Apr-25 at 11:47

So I found out that the final issue had to do with OpenCV not using the MJPEG format rather than defaulting to YUYV. Changing this using:

Source https://stackoverflow.com/questions/55823952

QUESTION

Compiling error using make install to install OpenCV 4 in Raspbian Raspberry Pi 3+

Asked 2019-Apr-15 at 17:24

`Hello, I have installed OpenCV on the Raspberry a couple of times. However, since everything is constantly evolving (OS, libraries, etc...). This time I am getting the following error:

...

ANSWER

Answered 2019-Apr-09 at 22:47

I have also been running into this error and was able to solve it using the following steps:

navigate to your OpenCV directory (running cd .. from your build directory).
run the following command:

Source https://stackoverflow.com/questions/55520742

Community Discussions, Code Snippets contain sources that include Stack Exchange Network

Vulnerabilities

No vulnerabilities reported

Install libv4l

Simple type the following commands from the libv4l-x.y.z directory (adjusting PREFIX as desired): make make install PREFIX=/usr/local. Note: make install also supports the DESTDIR=... parameter for installation into chroots.

Support

For any new features, suggestions and bugs create an issue on GitHub. If you have any questions check and ask questions on community page Stack Overflow .

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