gstreamer/sys/v4l/v4l-overlay_calls.c

/* G-Streamer generic V4L element - generic V4L overlay handling
 * Copyright (C) 2001-2002 Ronald Bultje <rbultje@ronald.bitfreak.net>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <string.h>
#include <errno.h>
#include "v4l_calls.h"

#define DEBUG(format, args...) \
	GST_DEBUG_OBJECT (\
		GST_ELEMENT(v4lelement), \
		"V4L-overlay: " format, ##args)


/******************************************************
 * gst_v4l_set_overlay():
 *   calls v4l-conf
 * return value: TRUE on success, FALSE on error
 ******************************************************/

gboolean
gst_v4l_set_overlay (GstV4lElement * v4lelement)
{
  gchar *buff;

  if (v4lelement->display)
    g_free (v4lelement->display);
  v4lelement->display = g_strdup (g_getenv ("DISPLAY"));

  DEBUG ("setting display to '%s'", v4lelement->display);
  GST_V4L_CHECK_NOT_OPEN (v4lelement);

  if (!v4lelement->display || v4lelement->display[0] != ':')
    return FALSE;

  /* start v4l-conf */
  buff = g_strdup_printf ("v4l-conf -q -c %s -d %s",
      v4lelement->videodev, v4lelement->display);

  switch (system (buff)) {
    case -1:
      GST_ELEMENT_ERROR (v4lelement, RESOURCE, FAILED,
          (_("Could not start v4l-conf.")), GST_ERROR_SYSTEM);
      g_free (buff);
      return FALSE;
    case 0:
      break;
    default:
      GST_ELEMENT_ERROR (v4lelement, RESOURCE, FAILED,
          (_("Executing v4l-conf failed.")), GST_ERROR_SYSTEM);
      g_free (buff);
      return FALSE;
  }

  g_free (buff);
  return TRUE;
}


/******************************************************
 * gst_v4l_set_window():
 *   sets the window where to display the video overlay
 * return value: TRUE on success, FALSE on error
 ******************************************************/

gboolean
gst_v4l_set_window (GstElement * element,
    gint x, gint y, gint w, gint h, struct video_clip * clips, gint num_clips)
{
  GstV4lElement *v4lelement = GST_V4LELEMENT (element);
  struct video_window vwin;

  DEBUG ("setting video window to position (x,y/wxh) = %d,%d/%dx%d",
      x, y, w, h);
  GST_V4L_CHECK_OPEN (v4lelement);
  GST_V4L_CHECK_OVERLAY (v4lelement);

  vwin.x = x;
  vwin.y = y;
  vwin.width = w;
  vwin.height = h;
  vwin.flags = 0;

  if (clips && !(v4lelement->vcap.type & VID_TYPE_CLIPPING)) {
    DEBUG ("Device \'%s\' doesn't do clipping",
        v4lelement->videodev ? v4lelement->videodev : "/dev/video");
    vwin.clips = 0;
  } else {
    vwin.clips = clips;
    vwin.clipcount = num_clips;
  }

  if (ioctl (v4lelement->video_fd, VIDIOCSWIN, &vwin) < 0) {
    GST_ELEMENT_ERROR (v4lelement, RESOURCE, TOO_LAZY, (NULL),
        ("Failed to set the video window: %s", g_strerror (errno)));
    return FALSE;
  }

  return TRUE;
}


/******************************************************
 * gst_v4l_enable_overlay():
 *   enables/disables actual video overlay display
 * return value: TRUE on success, FALSE on error
 ******************************************************/

gboolean
gst_v4l_enable_overlay (GstV4lElement * v4lelement, gboolean enable)
{
  gint doit = enable ? 1 : 0;

  DEBUG ("%s overlay", enable ? "enabling" : "disabling");
  GST_V4L_CHECK_OPEN (v4lelement);
  GST_V4L_CHECK_OVERLAY (v4lelement);

  if (ioctl (v4lelement->video_fd, VIDIOCCAPTURE, &doit) < 0) {
    GST_ELEMENT_ERROR (v4lelement, RESOURCE, TOO_LAZY, (NULL),
        ("Failed to %s overlay display: %s",
            enable ? "enable" : "disable", g_strerror (errno)));
    return FALSE;
  }

  return TRUE;
}