gst_plugins_base/ext/pango/gstclockoverlay.c
branchRCL_3
changeset 30 7e817e7e631c
parent 0 0e761a78d257
equal deleted inserted replaced
29:567bb019e3e3 30:7e817e7e631c
       
     1 /* GStreamer
       
     2  * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
       
     3  * Copyright (C) <2005> Tim-Philipp Müller <tim@centricular.net>
       
     4  *
       
     5  * This library is free software; you can redistribute it and/or
       
     6  * modify it under the terms of the GNU Library General Public
       
     7  * License as published by the Free Software Foundation; either
       
     8  * version 2 of the License, or (at your option) any later version.
       
     9  *
       
    10  * This library is distributed in the hope that it will be useful,
       
    11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
       
    12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
       
    13  * Library General Public License for more details.
       
    14  *
       
    15  * You should have received a copy of the GNU Library General Public
       
    16  * License along with this library; if not, write to the
       
    17  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
       
    18  * Boston, MA 02111-1307, USA.
       
    19  */
       
    20 
       
    21 /**
       
    22  * SECTION:element-clockoverlay
       
    23  * @see_also: #GstTextOverlay, #GstTimeOverlay
       
    24  *
       
    25  * <refsect2>
       
    26  * <para>
       
    27  * This element overlays the current clock time on top of a video
       
    28  * stream. You can position the text and configure the font details
       
    29  * using the properties of the #GstTextOverlay class. By default, the
       
    30  * time is displayed in the top left corner of the picture, with some
       
    31  * padding to the left and to the top.
       
    32  * </para>
       
    33  * <para>
       
    34  * Here is a simple pipeline that displays the current time in the top left
       
    35  * corner of the video picture:
       
    36  * <programlisting>
       
    37  * gst-launch -v videotestsrc ! clockoverlay ! xvimagesink
       
    38  * </programlisting>
       
    39  * </para>
       
    40  * <para>
       
    41  * Here is another pipeline that displays the current time with some leading
       
    42  * text in the bottom right corner of the video picture, with the background
       
    43  * of the text being shaded in order to make it more legible on top of a
       
    44  * bright video background:
       
    45  * <programlisting>
       
    46  * gst-launch -v videotestsrc ! clockoverlay halign=right valign=bottom text="Edge City" shaded-background=true ! ffmpegcolorspace ! ximagesink
       
    47  * </programlisting>
       
    48  * </para>
       
    49  * </refsect2>
       
    50  */
       
    51 
       
    52 #ifdef HAVE_CONFIG_H
       
    53 #include "config.h"
       
    54 #endif
       
    55 
       
    56 #include <gstclockoverlay.h>
       
    57 #include <gst/video/video.h>
       
    58 #include <time.h>
       
    59 
       
    60 static const GstElementDetails clock_overlay_details =
       
    61 GST_ELEMENT_DETAILS ("Clock overlay",
       
    62     "Filter/Editor/Video",
       
    63     "Overlays the current clock time on a video stream",
       
    64     "Tim-Philipp Müller <tim@centricular.net>");
       
    65 
       
    66 GST_BOILERPLATE (GstClockOverlay, gst_clock_overlay, GstTextOverlay,
       
    67     GST_TYPE_TEXT_OVERLAY)
       
    68 
       
    69      static void gst_clock_overlay_base_init (gpointer g_class)
       
    70 {
       
    71   GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
       
    72 
       
    73   gst_element_class_set_details (element_class, &clock_overlay_details);
       
    74 }
       
    75 
       
    76 static gchar *
       
    77 gst_clock_overlay_render_time (GstClockOverlay * overlay)
       
    78 {
       
    79   struct tm *t;
       
    80   time_t now;
       
    81 
       
    82 #ifdef HAVE_LOCALTIME_R
       
    83   struct tm dummy;
       
    84 #endif
       
    85 
       
    86   now = time (NULL);
       
    87 
       
    88 #ifdef HAVE_LOCALTIME_R
       
    89   t = localtime_r (&now, &dummy);
       
    90 #else
       
    91   /* on win32 this apparently returns a per-thread struct which would be fine */
       
    92   t = localtime (&now);
       
    93 #endif
       
    94 
       
    95   if (t == NULL)
       
    96     return g_strdup ("--:--:--");
       
    97 
       
    98   return g_strdup_printf ("%02u:%02u:%02u", t->tm_hour, t->tm_min, t->tm_sec);
       
    99 }
       
   100 
       
   101 /* Called with lock held */
       
   102 static gchar *
       
   103 gst_clock_overlay_get_text (GstTextOverlay * overlay, GstBuffer * video_frame)
       
   104 {
       
   105   gchar *time_str, *txt, *ret;
       
   106 
       
   107   overlay->need_render = TRUE;
       
   108 
       
   109   txt = g_strdup (overlay->default_text);
       
   110 
       
   111   time_str = gst_clock_overlay_render_time (GST_CLOCK_OVERLAY (overlay));
       
   112   if (txt != NULL && *txt != '\0') {
       
   113     ret = g_strdup_printf ("%s %s", txt, time_str);
       
   114   } else {
       
   115     ret = time_str;
       
   116     time_str = NULL;
       
   117   }
       
   118 
       
   119   g_free (txt);
       
   120   g_free (time_str);
       
   121 
       
   122   return ret;
       
   123 }
       
   124 
       
   125 static void
       
   126 gst_clock_overlay_class_init (GstClockOverlayClass * klass)
       
   127 {
       
   128   GstTextOverlayClass *gsttextoverlay_class;
       
   129 
       
   130   gsttextoverlay_class = (GstTextOverlayClass *) klass;
       
   131 
       
   132   gsttextoverlay_class->get_text = gst_clock_overlay_get_text;
       
   133 }
       
   134 
       
   135 static void
       
   136 gst_clock_overlay_init (GstClockOverlay * overlay, GstClockOverlayClass * klass)
       
   137 {
       
   138   PangoFontDescription *font_description;
       
   139   GstTextOverlay *textoverlay;
       
   140   PangoContext *context;
       
   141 
       
   142   textoverlay = GST_TEXT_OVERLAY (overlay);
       
   143 
       
   144   context = GST_TEXT_OVERLAY_CLASS (klass)->pango_context;
       
   145 
       
   146   pango_context_set_language (context, pango_language_from_string ("en_US"));
       
   147   pango_context_set_base_dir (context, PANGO_DIRECTION_LTR);
       
   148 
       
   149   font_description = pango_font_description_new ();
       
   150   pango_font_description_set_family_static (font_description, "Monospace");
       
   151   pango_font_description_set_style (font_description, PANGO_STYLE_NORMAL);
       
   152   pango_font_description_set_variant (font_description, PANGO_VARIANT_NORMAL);
       
   153   pango_font_description_set_weight (font_description, PANGO_WEIGHT_NORMAL);
       
   154   pango_font_description_set_stretch (font_description, PANGO_STRETCH_NORMAL);
       
   155   pango_font_description_set_size (font_description, 18 * PANGO_SCALE);
       
   156   pango_context_set_font_description (context, font_description);
       
   157   pango_font_description_free (font_description);
       
   158 
       
   159   textoverlay->valign = GST_TEXT_OVERLAY_VALIGN_TOP;
       
   160   textoverlay->halign = GST_TEXT_OVERLAY_HALIGN_LEFT;
       
   161 }