Linux test web camera

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Introduction

This document describes how to choose, setup and use a webcam in Ubuntu. If you are reading this page, you are probably in either/both of the following situations:

1. Looking for information on which webcam to buy.
2. Trying to setup and use your existing webcam.

Please note that this document is intended for the current release: Ubuntu 10.10 (Maverick Meerkat).

1. Choosing a Webcam

Webcam support in Linux is mainly provided by the Linux UVC Project’s UVC driver. This aims to provide a universal driver in the same way that a generic driver handles USB storage devices (memory sticks, hard drives etc). However, other drivers also exist that may allow more devices to be used. When looking to purchase a webcam for use with Ubuntu, you should look for a UVC compatible camera. The Linux-UVC project has a good list of UVC compatible webcams.

2. Testing Your Webcam Using Cheese

Ubuntu aims to provide ‘out-of-the-box’ or ‘just-works’ functionality for webcams. This means that you should be able to plug-in your webcam and use it straight away: no driver disks or installation. To test whether or not your webcam works in this way, install Cheese, a GNOME program for capturing video and stills from a webcam. It can also apply some special effects. Cheese is included in the Main repositories since Ubuntu 8.04 LTS (Hardy Heron). It uses the gstreamer library, which utlilizes the video4linux2 API.

Download and install Cheese using the following steps:

1. Open a terminal window.
2. Type in the following command:
3. Run Cheese. Cheese should automatically detect your webcam and display live video stream.

To record video or take a snapshot, click either on photo or video and select Take a Photo or Start recording.

If Cheese doesn’t display the output from your webcam, test that the problem is not with Cheese before trying anything else by using one of the programs in the next section.

If Cheese displays a garbled picture or one with poor colour/brightness/contrast, go to the Ubuntu wiki Webcam Troubleshooting page for steps to resolve this.

3. Webcam Software

This is a list of software that allows you to do a simple ‘plug-in-and-go’ test with your webcam. You should try one of these programs if Cheese didn’t display anything at all to make sure that Cheese is not causing the problem.

Empathy has been the default VoIP/Video Chat application since Ubuntu 9.10 (Karmic Koala), and can be used to establish whether or not your webcam is working.

3.1. Configuring Webcam Software

In some cases your media player (VLC, mplayer, amongst others) will need to know the video and audio device files for your webcam. Before you plug in your webcam, try the following two commands at a console:

Make a note of the devices appearing. Now plug in your webcam, allow the system a few seconds to register the device, and run the two commands again. The new appearances should belong to your webcam (for instance, /dev/video0 and /dev/audio2). If nothing new appears, you may need to switch your webcam on. For a built-in webcam, you may have a function key to do so.

3.2. VLC

3.2.1. Using the GUI

In VLC, choose ‘Open capture device’ from the file menu and enter the video and audio device files (see above) in video device name and audio device name, respectively. If you just want a ‘mirror’ (to see what the webcam is showing), click ‘OK’ and you’re done. If you wish to record, tick off ‘Stream/save’ in the ‘Advanced options’ section. Click the settings button right next to it. Tick ‘File’ off under ‘Outputs’ and enter a filename. Encapsulation method can be left at the default (MPEG TS). Under ‘Transcoding options’, tick ‘Audio codec’ and ‘Video codec’. These can also safely be left the defaults (obviously greater compression results in lower file sizes, so experiment). Click ‘OK’ in the Settings screen and once again in the main webcam screen (Video4linux). If you want to have more control, you can access several settings, including resolution, by clicking the Advanced options button.

3.2.2. Using the Command Line

A simple test of just the video from your webcam can be done as follows. This assumes the webcam is installed as ‘/dev/video0’.

If you wish to be able to quickly start a video session with your webcam, the resulting vlc command is printed in the Customize line at the bottom. You simply need to prepend ‘vlc’, e.g.

The recording instructions will similarly need to be appended. Copy the contents of the ‘Stream Output MRL’ box under ‘Settings’ and change «:sout=» to «—sout » and append it to your vlc command:, e.g.

To simple take a few snapshots, open the webcam without recording and choose ‘Snapshot’ under the ‘Video’ menu.

3.3. FFmpeg

FFmpeg is a cross-platform audio/video recording, conversion and streaming application.

3.3.1. Recording Video

1. To record both video and audio using FFmpeg, first make sure it is installed:
2. Run ffmpeg with arguments such as these:

With recent versions of Ubuntu (>= 12.10) you should use avconv instead of ffmpeg command:

3.4. MPlayer

MPlayer is capable of displaying a webcam video stream,

3.4.1. Recording Video

To record video from the command line:

Open a terminal window and type the following:

This example assumes that your webcam device is at /dev/video0

The resolution (width=. & height=. ) should be chosen to match the output of your device.

3.5. MEncoder

The companion to MPlayer, MEncoder can record from a webcam to video files.

3.5.1. Recording Video

1. Recording AVI, without audio:
2. Recording AVI, with audio:
   • Type ‘man mencoder’ for more info on the audio options.

/dev/dsp1 refers to the webcam USB Audio device.

/dev/dsp refers to the sound card.

You may need to install these programs with

Camera Monitor from chaos infinito shows a tray icon that lets you know when your webcam is on. It has been in the Universe repository since Ubuntu 10.10 (Maverick Meerkat) and is released under the GPL.

luvcview is a good program you can use to test that the camera is working. It has been in the Universe repository since Ubuntu 8.04 LTS (Hardy Heron). If it doesn’t work, you may need to update the UVC driver (see Manual install instructions below).

guvcview is based on luvcview and has a graphical user interface. It has been in the Universe repositories since Ubuntu 9.10 (Karmic Koala).

Camorama (not updated since 2007), xawtv, aMSN, and Kopete can all be used to test and use your webcam. They have been in the Universe repositories since Ubuntu 6.06 LTS (Dapper Drake) apart from Kopete, which is in the main repositories.

3.6. Skype

See the dedicated Skype and SkypeWebCams pages.

3.7. streamer

The streamer package provides a very simple command line interface for taking pictures:

The package can be installed as follows:

4. Identifying Your Webcam

Although webcams may look quite different from one another, they often share similar or identical major components. This means that drivers may work for many different makes and models with little or no modification.

To definitively identify your webcam, the following information will be of use:

Make and Model Name/Number.

Any version or revision information. This is often printed on the device or its packaging and will read something similar to REV 01 or VER. 2.2. This information can be particularly useful.

The output of the lsusb. Type lsusb -v into a terminal window.

• This program prints information about the devices connected to the USB bus. If you scroll through it, you should find some information about your webcam.

Type lsusb -n into a terminal window. This version of the command lists the device’s USB ID; a number that is unique to every device.

5. Driver installation

Linux Webcam drivers are provided by several different projects. Although the Linux UVC project covers many devices, support for others is provided elsewhere. This section aims to help you install your webcam’s drivers if they have not been automatically installed by Ubuntu.

If the drivers for your webcam haven’t been loaded automatically by Ubuntu, you may have to install them manually.

ov51x — The Ubuntu wiki page is here.

ov51x-jpeg — This is a hacked driver by http://www.rastageeks.org/ and more info is available here.

Suported Hardware — A list of webcams supported by the rastageeks driver.

6. See Also

UVC — The Ubuntu wiki page for the Universal Video Class.

7. External Links

The Linux TV Project Homepage — This is the project responsible for the video4linux drivers for webcams and tv capture/tuner devices.

The linuxtv.org V4L-DVB Wiki Webcam Page — This page contains lots of information about webcam support in Linux.

The UVC Homepage — The home of the Universal Video Class for Linux project. This project aims to provide a universal driver for Linux webcams.

FFmpeg — This project develops the cross-platform recording, conversion and streaming solution for audio and video.

Webcam (последним исправлял пользователь ckimes 2017-08-23 23:00:23)

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9 Best Free Linux Webcam Tools (Updated 2020)

A webcam is a video capture device that is either connected to a computer directly (typically by USB) or over a computer network. Many modern netbooks and laptops have a built-in webcam.

Webcams spice up online communication by offering real-time video chat and webcasting. These tiny cameras enable users to chat in realtime with friends and family, send video email around the world, to videoconference with co-workers and clients, and even to broadcast a TV-like channel over the net. Other people use a webcam as part of a security system, making use of motion detection to receive image and video intrusion alerts, both interior and exterior, of a building or home.

To use a webcam in Linux requires dedicated webcam software. In this article, we have chosen our favorite tools which enable webcams to capture images and video, and to act as a video surveillance device. Here’s our ratings.

To provide an insight into the quality of software available for Linux, we have compiled a list of 9 useful webcam tools. Hopefully, there will be something of interest here for anyone interested in using the versatile webcam.

Now, let’s explore the 9 webcam tools tools at hand. For each title we have compiled its own portal page, a full description with an in-depth analysis of its features, screenshots (where appropriate), together with links to relevant resources.

Webcam Tools
Webcamoid	Full featured and multi-platform webcam suite with a simple interface
ZoneMinder	All-in-one security camera solution
Motion	V4L capture program supporting motion detection
Kerberos.io	Video surveillance solution
Clight	Webcam becomes light sensor
Cheese	Take pictures and videos from your webcam
Ekiga	VoIP and video conferencing application
Kamoso	Qt-based webcam utility
HasciiCam	ASCII cam streaming

We have not included Skype in the list above. While millions of people use Skype for voice chat, instant messaging, file transfer, and video conferencing, the no-charge application is not available under a freely distributable license. Nevertheless, Skype is worthy of a special mention.

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Работа с usb видеокамерой в Linux. Часть 1

По популярности видеокамера, сегодня, стоит в одном ряду с микрофоном и наушниками. Она используется в различных направлениях, таких как распознавание объектов, дополненная реальность, видеоконференции и множество других. Но что же скрыто под капотом этих сложнейших программ? Как мы получаем картинку с видеокамеры? Этот цикл статей позволит взглянуть на простоту работы с видеокамерой на низком уровне, обработку полученного изображения.

Для начала, немного информации о работе с устройствами в системе Linux. Устройства в nix системах представляют собой файл. С некоторыми файлами-устройств мы можем работать как с обычными файлами. Например:

эта команда выведет на экран весь диск sda.

Есть устройства с которыми нельзя работать напрямую, к ним относится видеокамера.При попытке это сделать мы получим такую реакцию системы:

*Где /dev/video0 это файл-устройство найшей видеокамеры.

Для работы с ней нам понадобится системная функция ioctl детальнее о ней можно ознакомится [1]. Попробуем это применить. Вот код позволяющий считать информации с устройства (альтернатива команде cat для видеоустройств):

В первых строках кода считываются параметры с которой запущено приложение. Если параметров нету то device_name принимает стандартоне значение «/dev/video0».

В блоке «Open Device» происходит открытие устройства системной функцией open (нужно подключить header fcntl.h). Обязательный параметр O_RDWR отвечает за открытие устройства считывания/записи. Если при подключении возникла ошибка, то функция open вернет -1.

Блок «Read Params From Device» — это сердце нашей маленькой программы. Для его использования надо подключить билиотеку возможно прийдется её установить, у каждого дистрибутива свой пакет под эту библиотеку
Системная функция ioctl имеет три параметра:
file_device — дескриптор нашего устройства
VIDIOC_QUERYCAP — функция ядра, которую применяем для нашего устройства.
device_params — область памяти куда будет сброшен результат функции «VIDIOC_QUERYCAP».

device_params это структура состоящая из таких полей:

если возникла ошибка ioctl вернет -1

Блок «Close Device» закрывает дескриптор устройства.

Посмотрим программу в действии.

устройство не определилось ядром либо не подключено уборщица опять ненужные провода дергала.
Подключаем и заново запуск. Получаем такую информацию:

поле capabilities и device capabilities можно расшифровать благодаря константам из файла videodev2.h:

На этом вводная статья заканчивается. В следующих обзорах будут затронуты, такие темы как memory-mapping, виодеформаты изображения, настройка камеры, вывод изображения в текстуру, работа с несколькими камерами.

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