How does a V4L2 video capture driver knows where the stream is coming from

1
votes

I need to write a driver that receives 24-bit RGB input and put it on the display (either by 3rd party app as mplayer, or by dumping it to the fame buffer, it is not important at the moment)

The setup is 2.3.39 kernel on a OMAP3 platform, with a video capture chip connected to it.

I know which GPIOs receive the data from the video capture chip (including clk, hsync and vsync).

I tried to review several drivers to understand how they define to stream the CPU GPIO input to the device, but could find no clue on how it connects. I currently have a camera working on those exact GPIOs, which uses omap3isp. I am trying to replace it with other video input.

Can some please shed some light on the matter, any help will be appreciated.

Best, Jonathan.

1
video-capturev4l2omap

1 Answers

0
votes

In Ubuntu, you can check for video capture devices by entering following command in a terminal:

ls /dev/video*

Consequently, v4l2 also uses these same devices. If you have a device at /dev/video0 or /dev/video1, you can use VLC/FFmpeg/MPlayer/MEncoder to capture these streams. From https://help.ubuntu.com/community/Webcam#VLC, a simple test to make sure you can see a webcam stream would be to type the following command into a terminal.

vlc v4l2:///dev/video0