gstreamer/gst-libs/gst/video/video.c

/* GStreamer
 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
 * Library       <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.
 */

#include "video.h"

#define NUM_UNITS 1000000000

/* This is simply a convenience function, nothing more or less */

gdouble
gst_video_frame_rate (GstPad *pad)
{
  GstFormat dest_format = GST_FORMAT_UNITS;
  gint64 dest_value = 0;
  gdouble fps;

  /* do a convert request on the source pad */
  if (!gst_pad_convert(pad,
                       GST_FORMAT_TIME, GST_SECOND * NUM_UNITS,
                       &dest_format, &dest_value))
  {
    g_warning("gstvideo: pad %s:%s failed to convert time to unit!\n",
              GST_ELEMENT_NAME(gst_pad_get_parent (pad)), GST_PAD_NAME(pad));
    return 0.;
  }

  fps = ((gdouble) dest_value) / NUM_UNITS;

  GST_DEBUG(GST_CAT_ELEMENT_PADS, "Framerate request on pad %s:%s - %f fps",
            GST_ELEMENT_NAME(gst_pad_get_parent (pad)), GST_PAD_NAME(pad), fps);

  return fps;
}

gboolean
gst_video_get_size (GstPad *pad,
                    gint   *width,
                    gint   *height)
{
  GstCaps *caps;

  g_return_val_if_fail(pad != NULL, FALSE);

  caps = GST_PAD_CAPS(pad);
  if (!caps) {
    g_warning("gstvideo: failed to get caps of pad %s:%s",
              GST_ELEMENT_NAME(gst_pad_get_parent (pad)), GST_PAD_NAME(pad));
    return FALSE;
  }
  if (!gst_caps_has_property(caps, "width") ||
      !gst_caps_has_property(caps, "height")) {
    g_warning("gstvideo: resulting caps doesn't have width/height properties");
    return FALSE;
  }

  if (width)
    gst_caps_get_int(caps, "width", width);
  if (height)
    gst_caps_get_int(caps, "height", height);

  GST_DEBUG(GST_CAT_ELEMENT_PADS, "size request on pad %s:%s: %dx%d",
	    GST_ELEMENT_NAME(gst_pad_get_parent (pad)), GST_PAD_NAME(pad),
            width?*width:0, height?*height:0);

  return TRUE;
}

static gboolean
plugin_init (GModule *module, GstPlugin *plugin)
{
  gst_plugin_set_longname (plugin, "Convenience routines for video plugins");
  return TRUE;
}

GstPluginDesc plugin_desc = {
  GST_VERSION_MAJOR,
  GST_VERSION_MINOR,
  "gstvideo",
  plugin_init
};