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Wednesday, August 6, 2014

Switching the channels/ inputs while capturing

While capturing (with mplayer or any other program) you can change the active input channel with this command in the terminal:

v4l2-ctl -d /dev/video0 -i 1

The -d option of the v4l2-ctl command selects the videodevice, it is not needed if there is only one (/dev/video0) in the system.

The -i option selects/ changes the input channel of your device.

The v4l2-ctl utility is part of the v4l-utils package.

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With the "Qt V4L2 test utility" program (qv4l2) you can test switching the inputs.
In this program there is a drop down menu where you can select the different inputs while capturing.



Wednesday, April 16, 2014

Activate audio for the STK1160 device

The stk1160 module registers a control-only alsa soundcard. This sound card is called 'stk1160-mixer'.
The real sound capture is done through the 'Controlle' soundcard which is also created after plugging in the EasyCAP.
To get a list of the registerd ALSA soundcards, run the following command:
cat /proc/asound/cards
Sample output:
  0 [Intel          ]: HDA-Intel - HDA Intel
                      HDA Intel at 0xf0580000 irq 44
 1 [stk1160mixer   ]: stk1160 - stk1160-mixer
                      stk1160 ac97 codec mixer control
 2 [Controlle      ]: USB-Audio - USB 2.0 Video Capture Controlle
Syntek Semiconductor USB 2.0 Video Capture Controlle at usb-0000:00:1d.7-1.1, h

Activate audio

To enable sound capture you have to open alsamixer when the EasyCAP is plugged in and select the 'Line' item on the capture menu for the stk1160-mixer device:
1. start alsamixer
2. select stk1160-mixer sound card (with F6)
3. select capture controls (with F4)
4. select "Line" output (with space key) 
You can do this on the commandline as well with this line:
amixer -c stk1160mixer sset Line unmute cap 

Note! In the viewing- or capturing program you must then select the 'Controlle' soundcard or its number to hear sound!