libavcodec/ass.c

   1 /*
   2  * SSA/ASS common funtions
   3  * Copyright (c) 2010  Aurelien Jacobs <aurel@gnuage.org>
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * Libav is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with Libav; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "avcodec.h"
  23 #include "ass.h"
  24 #include "libavutil/avstring.h"
  25 #include "libavutil/common.h"
  26
  27 /**
  28  * Generate a suitable AVCodecContext.subtitle_header for SUBTITLE_ASS.
  29  *
  30  * @param avctx pointer to the AVCodecContext
  31  * @param font name of the default font face to use
  32  * @param font_size default font size to use
  33  * @param color default text color to use (ABGR)
  34  * @param back_color default background color to use (ABGR)
  35  * @param bold 1 for bold text, 0 for normal text
  36  * @param italic 1 for italic text, 0 for normal text
  37  * @param underline 1 for underline text, 0 for normal text
  38  * @param alignment position of the text (left, center, top...), defined after
  39  *                  the layout of the numpad (1-3 sub, 4-6 mid, 7-9 top)
  40  * @return >= 0 on success otherwise an error code <0
  41  */
  42 static int ff_ass_subtitle_header(AVCodecContext *avctx,
  43                                   const char *font, int font_size,
  44                                   int color, int back_color,
  45                                   int bold, int italic, int underline,
  46                                   int alignment)
  47 {
  48     char header[512];
  49
  50     snprintf(header, sizeof(header),
  51              "[Script Info]\r\n"
  52              "ScriptType: v4.00+\r\n"
  53              "\r\n"
  54              "[V4+ Styles]\r\n"
  55              "Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, AlphaLevel, Encoding\r\n"
  56              "Style: Default,%s,%d,&H%x,&H%x,&H%x,&H%x,%d,%d,%d,1,1,0,%d,10,10,10,0,0\r\n"
  57              "\r\n"
  58              "[Events]\r\n"
  59              "Format: Layer, Start, End, Text\r\n",
  60              font, font_size, color, color, back_color, back_color,
  61              -bold, -italic, -underline, alignment);
  62
  63     avctx->subtitle_header = av_strdup(header);
  64     if (!avctx->subtitle_header)
  65         return AVERROR(ENOMEM);
  66     avctx->subtitle_header_size = strlen(avctx->subtitle_header);
  67     return 0;
  68 }
  69
  70 int ff_ass_subtitle_header_default(AVCodecContext *avctx)
  71 {
  72     return ff_ass_subtitle_header(avctx, ASS_DEFAULT_FONT,
  73                                          ASS_DEFAULT_FONT_SIZE,
  74                                          ASS_DEFAULT_COLOR,
  75                                          ASS_DEFAULT_BACK_COLOR,
  76                                          ASS_DEFAULT_BOLD,
  77                                          ASS_DEFAULT_ITALIC,
  78                                          ASS_DEFAULT_UNDERLINE,
  79                                          ASS_DEFAULT_ALIGNMENT);
  80 }
  81
  82 void ff_ass_init(AVSubtitle *sub)
  83 {
  84     memset(sub, 0, sizeof(*sub));
  85 }
  86
  87 static int ts_to_string(char *str, int strlen, int ts)
  88 {
  89     int h, m, s;
  90     h = ts/360000;  ts -= 360000*h;
  91     m = ts/  6000;  ts -=   6000*m;
  92     s = ts/   100;  ts -=    100*s;
  93     return snprintf(str, strlen, "%d:%02d:%02d.%02d", h, m, s, ts);
  94 }
  95
  96 int ff_ass_add_rect(AVSubtitle *sub, const char *dialog,
  97                     int ts_start, int ts_end, int raw)
  98 {
  99     int len = 0, dlen, duration = ts_end - ts_start;
 100     char s_start[16], s_end[16], header[48] = {0};
 101     AVSubtitleRect **rects;
 102
 103     if (!raw) {
 104         ts_to_string(s_start, sizeof(s_start), ts_start);
 105         ts_to_string(s_end,   sizeof(s_end),   ts_end  );
 106         len = snprintf(header, sizeof(header), "Dialogue: 0,%s,%s,",
 107                        s_start, s_end);
 108     }
 109
 110     dlen = strcspn(dialog, "\n");
 111     dlen += dialog[dlen] == '\n';
 112
 113     rects = av_realloc(sub->rects, (sub->num_rects+1) * sizeof(*sub->rects));
 114     if (!rects)
 115         return AVERROR(ENOMEM);
 116     sub->rects = rects;
 117     sub->end_display_time = FFMAX(sub->end_display_time, 10 * duration);
 118     rects[sub->num_rects]       = av_mallocz(sizeof(*rects[0]));
 119     rects[sub->num_rects]->type = SUBTITLE_ASS;
 120     rects[sub->num_rects]->ass  = av_malloc(len + dlen + 1);
 121     strcpy (rects[sub->num_rects]->ass      , header);
 122     av_strlcpy(rects[sub->num_rects]->ass + len, dialog, dlen + 1);
 123     sub->num_rects++;
 124     return dlen;
 125 }