/* GStreamer

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

 * Copyright (C) <2005> Tim-Philipp Müller <tim@centricular.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.

 */

/**

 * SECTION:element-timeoverlay

 * @see_also: #GstTextOverlay, #GstClockOverlay

 *

 * <refsect2>

 * <para>

 * This element overlays the buffer time stamps of a video stream on

 * top of itself. You can position the text and configure the font details

 * using the properties of the #GstTextOverlay class. By default, the

 * time stamp is displayed in the top left corner of the picture, with some

 * padding to the left and to the top.

 * </para>

 * <para>

 * Here is a simple pipeline that displays the time stamps in the top left

 * corner of the video picture:

 * <programlisting>

 * gst-launch -v videotestsrc ! timeoverlay ! xvimagesink

 * </programlisting>

 * </para>

 * <para>

 * Here is another pipeline that displays the time stamps with some leading

 * text in the bottom right corner of the video picture, with the background

 * of the text being shaded in order to make it more legible on top of a

 * bright video background:

 * <programlisting>

 * gst-launch -v videotestsrc ! timeoverlay halign=right valign=bottom text="Stream time:" shaded-background=true ! xvimagesink

 * </programlisting>

 * </para>

 * </refsect2>

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include <gst/video/video.h>

#include <gsttimeoverlay.h>

static const GstElementDetails time_overlay_details =

GST_ELEMENT_DETAILS ("Time overlay",

    "Filter/Editor/Video",

    "Overlays buffer time stamps on a video stream",

    "Tim-Philipp Müller <tim@centricular.net>");

GST_BOILERPLATE (GstTimeOverlay, gst_time_overlay, GstTextOverlay,

    GST_TYPE_TEXT_OVERLAY)

     static void gst_time_overlay_base_init (gpointer g_class)

{

  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);

  gst_element_class_set_details (element_class, &time_overlay_details);

}

static gchar *

gst_time_overlay_render_time (GstTimeOverlay * overlay, GstClockTime time)

{

  guint hours, mins, secs, msecs;

  if (!GST_CLOCK_TIME_IS_VALID (time))

    return g_strdup ("");

  hours = (guint) (time / (GST_SECOND * 60 * 60));

  mins = (guint) ((time / (GST_SECOND * 60)) % 60);

  secs = (guint) ((time / GST_SECOND) % 60);

  msecs = (guint) ((time % GST_SECOND) / (1000 * 1000));

  return g_strdup_printf ("%u:%02u:%02u.%03u", hours, mins, secs, msecs);

}

/* Called with lock held */

static gchar *

gst_time_overlay_get_text (GstTextOverlay * overlay, GstBuffer * video_frame)

{

  GstClockTime time = GST_BUFFER_TIMESTAMP (video_frame);

  gchar *time_str, *txt, *ret;

  overlay->need_render = TRUE;

  if (!GST_CLOCK_TIME_IS_VALID (time)) {

    GST_DEBUG ("buffer without valid timestamp");

    return g_strdup ("");

  }

  GST_DEBUG ("buffer with timestamp %" GST_TIME_FORMAT, GST_TIME_ARGS (time));

  txt = g_strdup (overlay->default_text);

  time_str = gst_time_overlay_render_time (GST_TIME_OVERLAY (overlay), time);

  if (txt != NULL && *txt != '\0') {

    ret = g_strdup_printf ("%s %s", txt, time_str);

  } else {

    ret = time_str;

    time_str = NULL;

  }

  g_free (txt);

  g_free (time_str);

  return ret;

}

static void

gst_time_overlay_class_init (GstTimeOverlayClass * klass)

{

  GstTextOverlayClass *gsttextoverlay_class;

  gsttextoverlay_class = (GstTextOverlayClass *) klass;

  gsttextoverlay_class->get_text = gst_time_overlay_get_text;

}

static void

gst_time_overlay_init (GstTimeOverlay * overlay, GstTimeOverlayClass * klass)

{

  PangoFontDescription *font_description;

  GstTextOverlay *textoverlay;

  PangoContext *context;

  textoverlay = GST_TEXT_OVERLAY (overlay);

  context = GST_TEXT_OVERLAY_CLASS (klass)->pango_context;

  pango_context_set_language (context, pango_language_from_string ("en_US"));

  pango_context_set_base_dir (context, PANGO_DIRECTION_LTR);

  font_description = pango_font_description_new ();

  pango_font_description_set_family_static (font_description, "Monospace");

  pango_font_description_set_style (font_description, PANGO_STYLE_NORMAL);

  pango_font_description_set_variant (font_description, PANGO_VARIANT_NORMAL);

  pango_font_description_set_weight (font_description, PANGO_WEIGHT_NORMAL);

  pango_font_description_set_stretch (font_description, PANGO_STRETCH_NORMAL);

  pango_font_description_set_size (font_description, 18 * PANGO_SCALE);

  pango_context_set_font_description (context, font_description);

  pango_font_description_free (font_description);

  textoverlay->valign = GST_TEXT_OVERLAY_VALIGN_TOP;

  textoverlay->halign = GST_TEXT_OVERLAY_HALIGN_LEFT;

}