[gst-devel] Problem Trying To Use v4l2src

Kulecz, Walter (JSC-SK)[WYLE LABORATORIES] walter.kulecz-1 at nasa.gov
Wed Aug 19 00:30:16 CEST 2009

I'm evaluating the possibility of using gstreamer for the next version of my real time image processing application.  It seems I need to write a gstreamer plugin to get access to the actual data being passed through the gstreamer pipeline.

I've succeed in using the gst-template to compile a simple filter plugin, but before I put much more effort into learning gstreamer I need to solve a problem with the v4l2src plugin.

My question is how do I initialize the plugin?  I need to set NTSC mode (some of our cards default to PAL on powerup), image size to 640x480 (although it seems I could use one of the resize or cropping plugins),  select the composite or S-Video input (most cards seem to default to tuner), and maybe set 8-bit grayscale video mode (our cameras are monochrome).  

If I run an application like TVtime first, the card then works with v4l2src in a simple gst-launch pipeline to test my plugin.  But it seems pretty fragile with respect to video errors often requiring another run of TVtime to reset the card so v4l2src will work.

I've searched the gestreamer-devel archive and only found some discussion of a similar issue on Win32 with directshow tuners.

More information about the gstreamer-devel mailing list