#include <gst/gst.h>

int
main (int argc, char *argv[])
{
  GstElement *pipeline;
  GstElement *filesink;
  GstMessage *msg;
  GstBus *bus;
  GError *error = NULL;

  gst_init (&argc, &argv);

  if (argc != 2) {
    g_print ("usage: %s <filename>\n", argv[0]);
    return -1;
  }

  pipeline = gst_parse_launch ("v4l2src device=/dev/video0 num-buffers=1 ! ffmpegcolorspace ! pngenc ! filesink name=myfilesink location=testpng.png", &error);
  if (!pipeline) {
    g_print ("Parse error: %s\n", error->message);
    exit (1);
  }
  
  filesink = gst_bin_get_by_name (GST_BIN (pipeline), "myfilesink");
  g_object_set (filesink, "location", argv[1], NULL);

  gst_element_set_state (pipeline, GST_STATE_PLAYING);

  bus = gst_element_get_bus (pipeline);

  /* wait until we either get an EOS or an ERROR message. Note that in a real
   * program you would probably not use gst_bus_poll(), but rather set up an
   * async signal watch on the bus and run a main loop and connect to the
   * bus's signals to catch certain messages or all messages */
  msg = gst_bus_poll (bus, GST_MESSAGE_EOS | GST_MESSAGE_ERROR, -1);

  switch (GST_MESSAGE_TYPE (msg)) {
    case GST_MESSAGE_EOS: {
      g_print ("EOS\n");
      break;
    }
    case GST_MESSAGE_ERROR: {
      GError *err = NULL; /* error to show to users                 */
      gchar *dbg = NULL;  /* additional debug string for developers */

      gst_message_parse_error (msg, &err, &dbg);
      if (err) {
        g_printerr ("ERROR: %s\n", err->message);
        g_error_free (err);
      }
      if (dbg) {
        g_printerr ("[Debug details: %s]\n", dbg);
        g_free (dbg);
      }
    }
    default:
      g_printerr ("Unexpected message of type %d", GST_MESSAGE_TYPE (msg));
      break;
  }
  gst_message_unref (msg);

  gst_element_set_state (pipeline, GST_STATE_NULL);
  gst_object_unref (pipeline);
  gst_object_unref (bus);

  return 0;
}