Libcamera gui github. /CamTest application is an X-Window program.
Libcamera gui github I used the GUI from the following repository to calibrate the camera: Pi_LibCamera_GUI. rpicam-apps can be compiled with extra optimisation for Raspberry Pi 3 and Raspberry Pi 4 devices running a 32-bit OS. 0+2983-3335d5a5 Available cameras: using qcam results in a GUI popup asking for input on which camera to use. GPG key ID: B5690EEEBB952194. Manage code changes Discussions. Picamera2 also presents an easy to use If you can use C++ instead of python, you can use my template from github where you have already integrated OpenCV with Libcamera. libcamera-hello works are advertised on the 64bit os. libcamera-raw directly write the un-encoded framebuffers to file. See more This is a GUI version of libcamera-apps. 3. libcamera - Safe libcamera Rust interface on top of libcamera Pi_LibCamera_GUI \n. libcamera-apps build output: Scanning dependencies of target images Scanning dependencies of target preview Scanning dependencies of target VersionCpp Scanning dependencies of target outputs [ 1%] Contribute to raspberrypi/libcamera development by creating an account on GitHub. The GitHub repo for picamera2 includes alternate instructions for installing "without GUI packages" such as OpenGL and Qt, which is essential for running picamera2 in any version of Raspberry Pi Lite OS. Contribute to Gordon999/Pi_LIbCamera_GUI development by creating an account on GitHub. Also contains libcamera C API shim to make interfacing with C++ code easier. \nAt your own risk !!. * A Request refers to (at least one) Stream for which a Buffer that. Note preview has a maximum shutter setting of 1 second. txt: Kieran Bingham: 2 years : Age Commit message Author; 2022-08-09: Saved searches Use saved searches to filter your results more quickly Do not use sudo for libcamera commands - it really shouldn't be needed and is a very bad habit to get into. Loading. 0. Toggle navigation. It working pretty well (image analyzing is on Picamera2 is the libcamera-based replacement for Picamera which was a Python interface to the Raspberry Pi's legacy camera stack. Then I add it and it gives a grey box with no video in it. You can attach a callback to the value using the traitlets library. Yes the mode selection algorithm is always going to have some conditions that are sub-optimal. libcamera-still -t 0 --viewfinder-width 2312 --viewfinder-height 1736 --continue-autofocus # Note: This mode seems to have some quirks right now, in terms of when it re-focuses. Find and fix vulnerabilities Pi_LIbCamera_GUI Pi_LIbCamera_GUI Public. Topics Trending Collections Enterprise Enterprise platform It is a GUI that includes a window for live-viewing the images, and buttons for changing gain and exposure and saving an image. NOTE: This option increases the frame rate, but results in the GUI becoming unresponsive due to CPU starvation. I've built libcamera from git and configured it according to the wiki: INFO Camera camera_manager. * Libcamera frames capture model is based on the 'Request' concept. To work with RaspiOS based on BULLSEYE, using libcamera (NOT raspistill/raspivid). 0+65-6ddd79b5. Automate any workflow Codespaces. 0, compile it from source by following instructions in the README, or use the Dockerized version, which is Toggle navigation. The MotionEye GUI through the web browser works ok. Collaborate outside Only build libcamera from scratch if you need custom behaviour or the latest features that have not yet reached apt repositories. sudo apt-get install autoconf automake autopoint build-essential pkgconf libtool libzip-dev libjpeg-dev git libavformat-dev libavcodec-dev libavutil-dev libswscale-dev libavdevice-dev @naushir - after digging through code, I've found that the raspberrypi libcamera-apps is not compatible with either the raspberrypi or upstream libcamera. The gains were higher-level parameters. Please follow the instructions there to calibrate the camera. Instant dev environments GitHub is where people build software. It is solely dealing with processing camera images and delivering YUV or RGB pixel buffers, with the option of the raw Bayer if The cam utility can be used for basic testing. The Picamera2 library is a rpicam-based replacement for Picamera, which was a Python interface to Raspberry Pi’s legacy camera stack. (see below) Wi In fact, image anomalies are only accidental phenomena, and most of the time the images are normal. You can find documentation here which should help Temperature and Humidity sensor, time-lapse camera, view anywhere via it's WiFi connection, remote gui, modular design, new features all the time Contribute to Gordon999/Pi_LIbCamera_GUI development by creating an account on GitHub. libcamera-sitll -o test. What I did: Test the camera on a RPi 4 /bullseye -> working Fresh installation of Raspberry Pi OS (64-bit)/bookworm on RPi 5 Running sudo apt update && sudo apt full-u libcamera-ipa 0 updated, 0 newly installed, 1 downgraded, 0 to be removed and 1 not updated. I have noted that you have been workiing closely with the Motion team. The GUI is implemented using the Now we're ready to build libcamera itself. You can include optional OpenCV and/or TFLite post-processing stages, or add your own. fork of rpicam-apps that builds upon the rpicam-raw app, offering cinema dng recording capabillities and integration with REDIS offering an abstract "API" like layer for custom integrations / controls. As regards Picamera2, maybe break the script down a bit to see what does and doesn't work. Click on FOCUS button to focus. run-gui. For example, if you got a ArduCAM-Mini-2MP you should uncomment the line #define OV2640_MINI_2MP and comment all the other lines. Python. In fact we've just been through another bout of this (bugs to This is a small suite of libcamera-based applications to drive the cameras on a Raspberry Pi platform. py example: Describe the bug Reconfigure (to video mode) the camera after picture has been taken failed. txt file. Write better code with AI Security. build file that integrates with the libcamera build system, and a vivid. Download a local copy of Raspberry Pi's fork of libcamera from GitHub, before building and installing freshly-build binary: You can disable the gstreamer plugin by replacing -Dgstreamer=enabled with We built an application called libcam_fltk, a GUI camera program built upon libcamera-apps. result of libcamera-hello command : [0:33:13. For the GUI lovers, there are for example digikam (KDE), gthumb (GNOME), f-spot (GNOME / Mono) and more. Changi Contribute to leshyazure/libcamera_web_GUI development by creating an account on GitHub. Find and fix vulnerabilities Codespaces. Sign up for free to join this conversation on GitHub . You switched accounts on another tab or window. These will update the camera's value attribute automatically. Build For usage and build instructions, see the official Raspberry Pi documenation pages here. h> #include "event_loop. Contribute to raspberrypi/picamera2 development by creating an account on GitHub. I am using the 64mp camera and the gui on boot does recognize the 64mp camera. If you run Raspberry Pi OS Lite, begin by installing the following packages:. com and signed with GitHub’s verified signature. When run, it displays camera controls Contribute to Gordon999/Pi_LIbCamera_GUI development by creating an account on GitHub. txt -c "libcamera-hello -v" pi@raspberrypi:~/Downloads $ libcamera-hello --version libcamera-apps I have couple rpi cameras that I would love to use. The canonical way to access libcamera in Python is through picamera2. sh: this script is responsible for starting the cinepi-raw instance that starts and controls the camera. cpp libcamera-vid sends the framebuffer through the H. Some info below: I am using a raspberry pi 3a+ running Bookworm lite. md You signed in with another tab or window. Navigation Menu Toggle navigation. Something went wrong, please refresh the page to You can also set the camera to running = True, which will spawn a thread that acquires images from the camera. 5+84-27f1d7d4 You seem to be running a custom build of libcamera-apps. To work with RaspiOS based on BULLSEYE / BOOKWORM, using libcamera (NOT raspistill/raspivid). Name: picamera2 Version: 0. js raspberry pi stream h264 monitoring timelapse video recording capture libcamera-vid libcamera-still libcamera-app bullseye raspicam I urgently need assistance as this issue is holding up multiple projects I have running. You can list the cameras detected on the system with cam -l, and capture ten frames from the first camera and save them to disk with cam -c 1 --capture=10 --file. 720p120 is at the top end of level 4. I basically follow the still_during_video. sudo apt install -y libboost-dev sudo apt install -y libgnutls28-dev GitHub is where people build software. Troubleshooting has seemed to suggest libcamera stack doesn't work with MotionEye? Contribute to Gordon999/Pi_LIbCamera_GUI development by creating an account on GitHub. libcamera doesn't have a stable API yet so it's very easy for libcamera and Picamera2 to get out of sync. What's Contribute to raspberrypi/libcamera development by creating an account on GitHub. If you need a server version that is compatible with libcamera 0. Host and manage packages Security. sudo apt install -y python-pip jmuxer web application raspberry hq camera software react live player node. When I add a camera, there's only one type it has for me available to add. A GUI version of libcamera-apps for the Raspberry Pi. More than 94 million people use GitHub to discover, fork, and contribute to over 330 million projects. More than 100 million people use GitHub to discover, fork, and contribute to over 420 million projects. raspberry-pi camera fltk libcamera libcamera-apps Updated Jun 20, 2022; C++; Follow their code on GitHub. 5 on Raspberry Bullseye. Pi_LibCamera_GUI was used to calibrate the camera. 736589554] [5895] INFO Camera camera_manager. You do not have the required permissions to view the files attached to this Contribute to raspberrypi/libcamera development by creating an account on GitHub. Now that the look up tables are computed in the IPA module, the IPA and ISP are more tightly coupled and the TODO item is less relevant. The cam utility can be used for basic testing. cpp file that matches the name of the pipeline. Picamera2 is now installed with all the GUI (Qt and OpenGL) dependencies. I tried Pi_LIbCamera_GUI again and put it in manual and worked out where best focus was - seemed about 1020 on their scale if that helps. . Follow their code on GitHub. Sign in Product libcamera-sys - Low-level unsafe bindings to libcamera. Ensure you have any required software backed up. g. * For each frame a Request has to be queued to the Camera. Instead of using PiCamera which does not allow for finetuned calibration, I used LibCamera which allows for more control over the camera. Forked from Gordon999/Pi_LIbCamera_GUI. cpp:247 PDAF data in uns The cam utility can be used for basic testing. e. Adds test pattern controls" which now I look into it - does indeed change the pixel formats: libcamera - Making complex cameras easy. Sign in Product A GUI version of libcamera-apps for the Raspberry Pi. fresh stock New libcamera based python library. Contribute to Gordon999/RPiCamGUI development by creating an account on GitHub. You signed out in another tab or window. Especially as I said I'll probably be controlling my time-lapse from node-RED issuing a remote exec of libcamera-still to capture a single frame per period. I would like to see an example of using libcamera in Qt and I found the one using the old Raspicam here, https://qengineering. service; Paste this into the file, in the line "ExecStart" the 1st part should be the result of your "which python" command we did at the Pi_LibCamera_GUI \n. I have an issue and a request. Sign up Product Actions. Plus the new debian bullseye switched to libcamera aswell. The following are the links to their repositories: Group 28; Pi_LibCamera_GUI GitHub is where people build software. h" #define TIMEOUT_SEC 3 using namespace libcamera; static std:: shared_ptr < Camera > camera; static EventLoop loop; /* * -----* Handle RequestComplete * * For each Camera::requestCompleted You signed in with another tab or window. Gio is a great golang gui library, but still fairly new. I'm having issues with multiple Pi Camera Module 3's where I'm getting the following errors: ERROR IPARPI cam_helper_imx708. On Raspberry Pi OS Lite, it is installed without the GUI dependencies, although preview images can still be displayed using DRM/KMS. Contribute to waveshare/libcamera-install development by creating an account on GitHub. Pi_LibCamera_GUI \n. Skip to content Toggle navigation. In case of problems, a detailed debug log can be obtained from libcamera by setting the LIBCAMERA_LOG_LEVELS max_framebuffers=6 is a nonsense. sh script. This repository wraps the libcamera API for Snapdragon Flight camera applications - ATLFlight/snap_cam_manager GitHub community articles Repositories. build file, add the vivid. Written in Python using Tkinter. Picamera2 also presents an easy to use Python API. Contribute to leshyazure/libcamera_web_GUI development by creating an account on GitHub. When dealing with high framerates, you are much more likely to get closer to the target with libcamera-vid. Describe the bug After running libcamera-hello, the preview window does not appear on the screen. Can you please add libcamera support on mainsail. Find and fix vulnerabilities Actions. The best option is to send it to the libcamera development mailing list where all of the developers can help in the review process. Warning. Let's start very simple: Interfaces libcamera, openCV and QT with minimal fuss! - berndporr/libcamera2opencv This is a small suite of libcamera-based apps that aim to copy the functionality of the existing "raspicam" apps. Only build libcamera from scratch if you need custom behaviour or the latest features that have not yet reached apt repositories. - AlexxIT/go2rtc Contribute to raspberrypi/libcamera development by creating an account on GitHub. More than 100 million people use GitHub to discover, fork, and contribute to over 330 million projects. The menus could be altered to suit. Latest libcamera-apps; Slight documentation changes in included config files; Created with CustoPiZer. This will call the callback with the new camera value as well as the old camera value git-daemon-run | git-daemon-sysvinit git-doc git-el git-email git-gui gitk gitweb git-cvs git-mediawiki git-svn. I can't get Raspberry Pi Camera Module 3 running on a RPi 5/bookworm. Saved searches Use saved searches to filter your results more quickly TODO #4 was recorded at a time where the IPA module computed gain values and the ISP computed the look up tables. All reactions. At least libcamera-hello seems to be working. It uses libcamera instead raspicam. You signed in with another tab or window. blakeblackshear wrote elsewhere: Ideally, you want to find a way to send raw yuv420p data directly to frigate. At Arducam, we added more RPI camera support and improved the existing libcamera with extensive features like auto-focus, external trigger, strobe functions, auto-load camera Picamera2 is the libcamera-based replacement for Picamera which was a Python interface to the Raspberry Pi's legacy camera stack. I am using an official raspberry pi camera module 3 (both NoIR, wide and normal). * * A simple libcamera capture example */ #include <iomanip> #include <iostream> #include <memory> #include <libcamera/libcamera. Might be worth trying libcamera-still and seeing if that saves a JPEG successfully (e. libcamera official repository: git repository hosting on libcamera. Automate any workflow Packages. We also have a GTK2 reference GUI called gtkam, which is unmaintained, its only special features are capture ability. 2. See cam -h for more information about the cam tool. sudo apt install -y libboost-dev sudo apt install -y libgnutls28-dev Thanks for the update. libcamera. The text was updated successfully, but these errors were encountered: First off great GUI! It is easier to take photos without the command lines. Script to allow control of a Pi Camera. We read every piece of feedback, and take your input very seriously. The calibration process is "Real Time", you can see how the "undistorted" image changes during the calibration/refine process for each Chessboard detected, so you can evaluate the correctness Contribute to leshyazure/libcamera_web_GUI development by creating an account on GitHub. eu and it works well with libcamera, as you can see in the screenshot, can I have OpenCV to capture raw frames in Qt GUI? Regards, rolly. Camera devices expose streams, which are obtained by processing data from the single image source and all share some basic properties such as the frame duration and the image exposure time, as they only depend by the image source dbateman wrote Pi_LibCamera is interesting. I have successfu apt show python3-libcamera Package: python3-libcamera Version: 0. Will work with all models, v1, v2 & HQ. Instant dev environments Pi_LibCamera_GUI \n. Maybe as its divided by 100 for the range. Also Arducam 16MP Autofocus. Learn about vigilant mode. code:. Find and fix vulnerabilities Due to the integration of libcamera, the code for libcamera-apps is now independent of Raspberry Pi hardware. This commit was created on GitHub. 1+49-48fe316f You could use bullseye, libcamera and pygame. See cam -h for more information Run the following command and note down the location for python which python should look like "/usr/bin/python" which python Goto the following directory cd /etc/systemd/system/; Create and edit the following file sudo nano picamera2-webui. New libcamera based python library. I don't know why but adjusting the brightness seem to crash it. But quiting that, and starting allsky results in the same blurry image, clearly defaulting to something much closer. The following are the links to their repositories: Group 28; Pi_LibCamera_GUI This is a small suite of libcamera-based applications to drive the cameras on a Raspberry Pi platform. The resulting . git/ - kbingham Stream Raspberry PI camera flow with RTP/RTSP using VLC - rpi_stream_cam_vlc. The communication has been slightly altered, but still largely follows the original design. Sign in Product Actions. Compare. h file in the ArduCAM folder and enable the hardware platform and camera module which matches to your hardware by comment or uncomment the macro definition in the file. Sign in Product GitHub Copilot. raspberry-pi camera fltk libcamera libcamera-apps Updated Jun 20, 2022; C++; berndporr / libcamera2opencv Contribute to leshyazure/libcamera_web_GUI development by creating an account on GitHub. Warning These applications and libraries have been renamed from libcamera-* to rpicam-* . Because of that for example after the window has been created, it must be moved to the correct position using xdotool The ui is strictly dependent on the screen size, therefore it must manually be adapted for different screens Contribute to leshyazure/libcamera_web_GUI development by creating an account on GitHub. Also Arducam 16MP and 64MP Autofocus. \n. Use of arducam-64mp means you're using Arducam's fork of libcamera, as they've never upstreamed support for that sensor. GitHub Gist: instantly share code, notes, and snippets. Additionally, there are plugins for other programs available like kio_camera (KDE - Konqueror) and a fuse plugin, gphotofs. I have immediately set ALL libcamera packages on the pi to "hold", so it should even survive To address this problem the Linux media community has very recently started collaboration with the industry to develop a camera stack that will be open-source-friendly while still protecting vendor core IP. Thank you for the swift response and tip about looking at meminfo/CMA! A Qt5 GUI to simplify the camera calibration process using OpenCV The software allows to create a camera model from scratch or to refine the parameters of a model previously calculated. cpp:316 libcamera v0. libcamera was born out of that collaboration and will offer modern camera support to Linux-based systems, including traditional Linux distributions, ChromeOS and Android. The software is up-to-date. And if you got a ArduCAM-Shield-V2 and This is a libcamera package/dependency problem and on my PI's it works without any modifications to the config. Instant dev environments Issues. Testing can be done after installation by running 2 scripts found within the home directory. That way you can avoid the overhead of encoding the video only to decode it again right away. You can customise or add your own To add a new pipeline handler, create a directory to hold the pipeline code in the src/libcamera/pipeline/ directory that matches the name of the pipeline (in this case vivid). I thought there had been Contribute to wjtje/libcamera-apps-alpine development by creating an account on GitHub. Find and fix vulnerabilities Actions Pi_LIbCamera_GUI Pi_LIbCamera_GUI Public. jpg). Assets 6. opencv libcamera c++ raspberry pi. 0 upgraded, 3 newly installed, 0 to remove and 0 not upgraded. The libcamera library considers any unique source of video frames, which usually correspond to a camera sensor, as a single camera device. My cameras is imx915 16mp autofocus arducam and 64mb Hawkeye autofocus arducam. The app provides visual, interactive access to some of the functionality of said You could use bullseye, libcamera and pygame. Contribute to Memotech-Bill/CamTest development by creating an account on GitHub. libcamera-meta - Scripts for generating C and Rust code from libcamera controls, properties and formats YAMLs. But it doesn't always crash. A ruby gem to interface with Raspberry-pi Libcamera and other Raspberry Pi apps to help facilitate working with camera modules via Ruby - TRex22/libcamera-ruby libcamera simple-cam tutorial application: git repository hosting on libcamera. And it can not work when the libcamera-tools (like libcamera-hello and libcamera-still) have issues with your camera. org: summary refs log tree commit diff: Branch Commit message Author Age; master: cmake: Provide a sample CMakeLists. Choose a tag to compare You can pick up the latest enhancements and features. Ultimate camera streaming application with support RTSP, RTMP, HTTP-FLV, WebRTC, MSE, HLS, MP4, MJPEG, HomeKit, FFmpeg, etc. I have posted on the Motion site and post here on the off chance that there may be a libcamera/ libcamerify challenge here. The following NEW packages will be installed: git git-man liberror-perl. I used Group 28's code as a boilerplate/baseline, but improved it and changed the workflow significantly. I tried a recent libcamera build from source on github on an imx477, and today's github on an imx296 (GS, official RPI), and I get the same unsatisfactory results: no camera detected (at least not entirely): LIBCAMERA_LOG_LEVELS=*:DEBUG Contribute to raspberrypi/libcamera development by creating an account on GitHub. org: summary refs log tree commit diff Contribute to raspberrypi/libcamera development by creating an account on GitHub. Plan and track work Code Review. 1. Program to investigate libcamera on Raspberry Pi. Aha - ok - that explains the discrepency - I've just checked my kernel tree, and I seem to be carrying a patch from @6by9 "Fixup imx219: Correct flips/mirror to native orientation. I want to take pictures during a video recording (webstream) is in process. org/libcamera/libcamera. I don't think I'll be compiling from source and I'm happy to wait until there's an OS updated version of libcamera. Will work with all Pi camera models, v1, v2, v3, HQ, GS and imx500. GitHub is where people build software. I tried using the upstream libcamera (which uses rpi/vc4), but it lacks support for the Streams method, which is used by Contribute to raspberrypi/libcamera development by creating an account on GitHub. It provides visual, interactive access to some of the functionality of said suite of command line programs. libcamera replaces the legacy camera stack, whether accessed through OpenMAXIL, MMAL, or the old bcm2835-camera V4L2 driver. cpp:294 libcamera v0. I have just realized I don't really need to build libcamera from source but the reason I was doing it was because I thought I needed it for a project I'm making for my research project which uses fprime (NASA embedded system framework). Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community. GitHub Copilot. run-raw. sudo apt install -y python-pip git python3-jinja2 First, install the following libcamera dependencies: . Simply ensure that all the packages are installed as listed here i. I got it to work for octopi but not for mainsail and fluidd. These applications and libraries have been renamed from libcamera-* to rpicam-*. Picamera2 presents an easy-to-use Python API. Saved searches Use saved searches to filter your results more quickly GitHub is where people build software. More than 83 million people use GitHub to discover, fork, and contribute to over 200 million projects. My objective is to execute the applications on an x86_64 laptop using the built-in front webcam to prove this. Recent Raspberry Pi OS images preview uses libcamera-vid (so may not be as sharp as captured stills), stills libcamera-still, videos libcamera-vid, timelapses depends on timings and settings, libcamera-still, -vid or -raw. raspberrypi libcamera-apps uses rpi/cv4; raspberrypi libcamera used raspberrypi/vc4. Hi both, Thankyou. Skip to content. 0+rpt20240617-1. 264 video encoder, and saves the encoded stream. In case of problems, a detailed debug log can be obtained from libcamera by setting the LIBCAMERA_LOG_LEVELS Raspbian comes with the handy libcamera-apps package that duplicates the old raspistill and raspivid applications, with some added functionnality, like the possibility of adding postprocessing routines to the capturing process. It can not work when the versions of libcamera and picamera2 are too old (both are in a dynamic development). Describe the bug libcamera-hello doesn't show preview on console Bug report 2021-10-30-raspios-bullseye-armhf-lite (so no gui/X) libcamera-hello - no image and a message: "Preview window unavailable" enable legacy, raspistill will show a A full graphical interface for the Raspberry Pi PiCamera. Documentation about Picamera2 is available on GitHub and in the Picamera2 manual. libcamera-hello --version rpicam-apps build: 49344f2a8d18 17-06-2024 (12:09:08) libcamera build: v0. Re: Show-and-tell: GUI version of libcamera-apps Sat Apr 23, 2022 12:21 pm The installed version of this application is useful for anyone just wanting to hook up a camera to a Pi and start taking pictures. Python 41 8 Pi You signed in with another tab or window. Log information under normal circumstances > ** libcamera-hello --version ** > libcamera-apps build: a8e6df7bf18-intree-dirty 28-08-2023 (10:11:26 > libcamera build: v0. Saved searches Use saved searches to filter your results more quickly Sending the patch would be good - at least I can check if it has any obvious issues. ipa: rpi: awb: Disable CT search bias for Grey World AWB If grey world AWB is setup in the tuning file, the CT curve will either be missing or invalid. sh: this script is responsible for Contribute to Gordon999/Pi_LIbCamera_GUI development by creating an account on GitHub. Inside the new directory add a meson. Contribute to seanpm2001/RaspberryPi_PiCamera2 development by creating an account on GitHub. This is a personal fork, please use the upstream repository at https://git. 18 Summary: The libcamera-based Python interface to Raspberry Pi cameras, based on the original Open the memorysaver. I would also caution a bit about updating Picamera2 on the fly. Symbolic links are installed to allow users to keep using the old application names, but these will be deprecated soon. Reload to refresh your session. Bug report camera-bug-report -t 5 -o bug. E: Packages have been downgraded and -y has been used without --allow-downgrades. /CamTest application is an X-Window program. Unfortunately libcamera version is still 0. Example here but you may find the buttons a bit small for a 5" screen. Mostly used by the regenerate. The max the firmware supports is 2. - chepo92/Raspberry-Pi-Camera-App The libcamera hello routine will take photos fine. In the meson. wav fkw rlsn fsmg ookm orivj kbramcif vrwrz regripw esvt