src/video_output/video_text.c

   1 /*****************************************************************************
   2  * video_text.c : OSD text manipulation functions
   3  *****************************************************************************
   4  * Copyright (C) 1999-2010 VLC authors and VideoLAN
   5  * $Id$
   6  *
   7  * Author: Sigmund Augdal Helberg <dnumgis@videolan.org>
   8  *         Laurent Aimar <fenrir _AT_ videolan _DOT_ org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU Lesser General Public License as published by
  12  * the Free Software Foundation; either version 2.1 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License
  21  * along with this program; if not, write to the Free Software Foundation,
  22  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 #ifdef HAVE_CONFIG_H
  26 # include "config.h"
  27 #endif
  28 #include <assert.h>
  29
  30 #include <vlc_common.h>
  31 #include <vlc_vout.h>
  32 #include <vlc_vout_osd.h>
  33
  34 struct subpicture_updater_sys_t {
  35     int  position;
  36     char *text;
  37 };
  38
  39 static int OSDTextValidate(subpicture_t *subpic,
  40                            bool has_src_changed, const video_format_t *fmt_src,
  41                            bool has_dst_changed, const video_format_t *fmt_dst,
  42                            mtime_t ts)
  43 {
  44     VLC_UNUSED(subpic); VLC_UNUSED(ts);
  45     VLC_UNUSED(fmt_src); VLC_UNUSED(has_src_changed);
  46     VLC_UNUSED(fmt_dst);
  47
  48     if( !has_dst_changed )
  49         return VLC_SUCCESS;
  50     return VLC_EGENERIC;
  51 }
  52
  53 static void OSDTextUpdate(subpicture_t *subpic,
  54                           const video_format_t *fmt_src,
  55                           const video_format_t *fmt_dst,
  56                           mtime_t ts)
  57 {
  58     subpicture_updater_sys_t *sys = subpic->updater.p_sys;
  59     VLC_UNUSED(fmt_src); VLC_UNUSED(ts);
  60
  61     if( fmt_dst->i_sar_num <= 0 || fmt_dst->i_sar_den <= 0 )
  62         return;
  63
  64     subpic->b_absolute = false;
  65     subpic->i_original_picture_width  = fmt_dst->i_visible_width * fmt_dst->i_sar_num / fmt_dst->i_sar_den;
  66     subpic->i_original_picture_height = fmt_dst->i_visible_height;
  67
  68     video_format_t fmt;
  69     video_format_Init( &fmt, VLC_CODEC_TEXT);
  70     fmt.i_sar_num = 1;
  71     fmt.i_sar_den = 1;
  72
  73     subpicture_region_t *r = subpic->p_region = subpicture_region_New(&fmt);
  74     if (!r)
  75         return;
  76
  77     r->p_text = text_segment_New( sys->text );
  78
  79     const float margin_ratio = 0.04;
  80     const int   margin_h     = margin_ratio * fmt_dst->i_visible_width;
  81     const int   margin_v     = margin_ratio * fmt_dst->i_visible_height;
  82
  83     r->i_text_align = sys->position;
  84     r->i_align = sys->position;
  85     r->i_x = 0;
  86     if (r->i_align & SUBPICTURE_ALIGN_LEFT)
  87         r->i_x += margin_h + fmt_dst->i_x_offset;
  88     else if (r->i_align & SUBPICTURE_ALIGN_RIGHT)
  89         r->i_x += margin_h - fmt_dst->i_x_offset;
  90
  91     r->i_y = 0;
  92     if (r->i_align & SUBPICTURE_ALIGN_TOP )
  93         r->i_y += margin_v + fmt_dst->i_y_offset;
  94     else if (r->i_align & SUBPICTURE_ALIGN_BOTTOM )
  95         r->i_y += margin_v - fmt_dst->i_y_offset;
  96 }
  97
  98 static void OSDTextDestroy(subpicture_t *subpic)
  99 {
 100     subpicture_updater_sys_t *sys = subpic->updater.p_sys;
 101
 102     free(sys->text);
 103     free(sys);
 104 }
 105
 106 void vout_OSDText(vout_thread_t *vout, int channel,
 107                    int position, mtime_t duration, const char *text)
 108 {
 109     assert( (position & ~SUBPICTURE_ALIGN_MASK) == 0);
 110     if (!var_InheritBool(vout, "osd") || duration <= 0)
 111         return;
 112
 113     subpicture_updater_sys_t *sys = malloc(sizeof(*sys));
 114     if (!sys)
 115         return;
 116     sys->position = position;
 117     sys->text     = strdup(text);
 118
 119     subpicture_updater_t updater = {
 120         .pf_validate = OSDTextValidate,
 121         .pf_update   = OSDTextUpdate,
 122         .pf_destroy  = OSDTextDestroy,
 123         .p_sys       = sys,
 124     };
 125     subpicture_t *subpic = subpicture_New(&updater);
 126     if (!subpic) {
 127         free(sys->text);
 128         free(sys);
 129         return;
 130     }
 131
 132     subpic->i_channel  = channel;
 133     subpic->i_start    = mdate();
 134     subpic->i_stop     = subpic->i_start + duration;
 135     subpic->b_ephemer  = true;
 136     subpic->b_absolute = false;
 137     subpic->b_fade     = true;
 138
 139     vout_PutSubpicture(vout, subpic);
 140 }
 141
 142 void vout_OSDMessage(vout_thread_t *vout, int channel, const char *format, ...)
 143 {
 144     va_list args;
 145     va_start(args, format);
 146
 147     char *string;
 148     if (vasprintf(&string, format, args) != -1) {
 149         vout_OSDText(vout, channel,
 150                      SUBPICTURE_ALIGN_TOP|SUBPICTURE_ALIGN_RIGHT, 1000000,
 151                      string);
 152         free(string);
 153     }
 154     va_end(args);
 155 }
 156