Quickstart

Quickstart information 

How to get analogue TV capture devices (v4l2 devices), like the EasyCAP DC60 or any TV-card, Webcam ... (NOT DVB devices !!!) to work quickly on Linux.

When you do not know if your EasyCAP labeled device is supported under Linux read my
Easycap article on the linuxtv.org wiki before!

It is assumed for this guide that you know how to start and use the terminal and the software/ packagemanager on a Linux desktop. 

What is v4l2 ?
"Video4Linux second version or V4L2 is a video capture application programming interface for Linux. Many USB webcams, TV tuners, and other devices are supported." (Wikipedia)

V4l2 is part of almost all Linux distributions. For capturing video an appropriate v4l2 driver for every capture device (especially for the chip inside the device) is needed. The drivers for all Linux supported devices are in the Linux kernel.

For some new or exotic devices Linux drivers may not exist.

Some drivers (e.g. stk11xx, somagic-easycap) are not yet in the kernel because they are experimental or not fulfilling all requirements for Linux kernel modules. If you have a device which is supported by such a driver, you need to install it by yourself following the instructions of the developer. 

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• GUI programs for testing
  Plug in your device. When your device is supported under Linux (if there is a driver for it in the Linux kernel or if you have installed the driver by yourself) you can test your device with the following programs:
  
  • The first program I recommend for testing is qv4l2 (V4L2 Test Bench)

• If you have more than one /dev/videoN on your system, start the program from the commandline: e.g.
  qv4l2 /dev/video1

• Not so experienced Linux users should try guvcview first.
  Guvcview "provides a GTK interface for capturing and viewing video from devices supported by the linux UVC driver, although it should also work with any v4l2 compatible device." (http://guvcview.sourceforge.net/)
  
  
  
  

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• Hardware flash test on the commandline
  
  Do not plug in the capture device until the system has booted.
  
  First part:
  To find out how many (if any) /dev/videoN and sound devices (OSS and ALSA) are present without attached capture device, type in the following commands in the terminal:
  
  1.  ls /dev/video*      Lists all present videodevices
  

  (You'll have one if there is a builtin webcam, you'll have none if no analogue video device is attached to your system.)

  2.  cat /proc/asound/cards       Lists all present ALSA soundcards
  
   
  3.  ls /dev/dsp      Check if the OSS soundsystem is supported on your system

  On Ubuntu (since 10.10) and some other newer distros  there is no /dev/dsp anymore because OSS support is entirely disabled.

  Sample output before plugging in the device:

  # ls /dev/video*
  ls: Zugriff auf /dev/video* nicht möglich: Datei oder Verzeichnis nicht gefunden

  # cat /proc/asound/cards
   0 [Intel          ]: HDA-Intel - HDA Intel
                        HDA Intel at 0xf0580000 irq 42

  # ls /dev/dsp
  ls: Zugriff auf /dev/dsp nicht möglich: Datei oder Verzeichnis nicht gefunden

  Second part:
  After plugging in the capture device, repeat the first and second command.
  If after ~10 seconds a new /dev/videoN and an additional ALSA soundcard (if the capture device supports sound capturing) is present, your card should work under Linux.
  

  Sample output after plugging in the device:

  #  ls /dev/video*
  /dev/video0

  # cat /proc/asound/cards
   0 [Intel          ]: HDA-Intel - HDA Intel
                        HDA Intel at 0xf0580000 irq 42
   1 [Controlle      ]: USB-Audio - USB 2.0 Video Capture Controlle
                        Syntek Semiconductor USB 2.0 Video Capture Controlle at usb-0000:00:1d.7-2, hig
   2 [stk1160mixer   ]: stk1160 - stk1160-mixer
                        stk1160 ac97 codec mixer control

  
  If the new /dev/videoN is not accessible by a normal user, type in the following command in the terminal as root (with sudo):
  chmod a+rw /dev/videoN (N must be changed to the actual number of your device)
  
  If you want to find out more about the driver of your capture device, run the command
  dmesg in the terminal.
  
  
• Device nodes and input numbers
  Normally the linux kernel module creates only one /dev/videoN for each analogue capture device (e.g. TV-card, Webcam, ...).
  If there are several inputs on the capture device (e.g. Antenna, Composite, S-Video ...), they are numbered: 0, 1, 2 ... and must be specified as 'input' in the viewing/ capturing program in combination with the /dev/videoN realated to the card
  Example for mplayer (without sound, alter the highlighted parts according to your device and source):
  mplayer tv:// -tv driver=v4l2:width=720:height=576:outfmt=uyvy:norm=PAL:device=/dev/video0:input=1:fps=25 -vo sdl -nosound
   
• Sounddevice
  If the capture device is capable of capturing sound and video at once, the sound either comes from /dev/dsp (OSS - now obsolete on some Linux distros like Ubuntu), or from an additional ALSA soundcard which is created by the driver (see the sample ALSA soundcard list above).
  In the capture programs the ALSA soundcard must be specified by its number or ALSA name.
  Notation of the second ALSA soundcard from the listing above:
• in Mplayer/ mencoder: hw.1 or hw.Controlle
• in Vlc: hw:1 or hw:Controlle
• in Avconv: hw:1 or hw:Controlle
  
• Setting up the viewing/ capturing program
  In general, the videodevice, the input number, the TV norm and the sounddevice must be specified in the program.
  So, you "simply" have to find out, how to do this in your favourite program.
  
  Continue reading on the Command Line TV and GUI TV pages.
  
  
• Programs for viewing and capturing
  
• Tvtime
  Read more on the GUI TV page.
• Mtvcgui
• MPlayer/ MEncoder
  Read more on the Command Line TV  page.
  
• VLC
  Read more on the GUI TV page.
• tvcap-script
  Read more on the tvcap page.
• Zoneminder
  Read more on the Practice page.
• Gstreamer
• SoX