ffmpeg/libavcodec/textdec.c

   1 /*
   2  * Copyright (c) 2012 Clément Bœsch
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with FFmpeg; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 /**
  22  * @file
  23  * Raw subtitles decoder
  24  */
  25
  26 #include "avcodec.h"
  27 #include "ass.h"
  28 #include "libavutil/bprint.h"
  29 #include "libavutil/opt.h"
  30
  31 typedef struct {
  32     AVClass *class;
  33     const char *linebreaks;
  34     int keep_ass_markup;
  35 } TextContext;
  36
  37 #define OFFSET(x) offsetof(TextContext, x)
  38 #define SD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM
  39 static const AVOption options[] = {
  40     { "keep_ass_markup", "Set if ASS tags must be escaped", OFFSET(keep_ass_markup), AV_OPT_TYPE_INT,    {.i64=0}, 0, 1, .flags=SD },
  41     { NULL }
  42 };
  43
  44 static int text_decode_frame(AVCodecContext *avctx, void *data,
  45                              int *got_sub_ptr, AVPacket *avpkt)
  46 {
  47     int ret = 0;
  48     AVBPrint buf;
  49     AVSubtitle *sub = data;
  50     const char *ptr = avpkt->data;
  51     const TextContext *text = avctx->priv_data;
  52     const int ts_start     = av_rescale_q(avpkt->pts,      avctx->time_base, (AVRational){1,100});
  53     const int ts_duration  = avpkt->duration != -1 ?
  54                              av_rescale_q(avpkt->duration, avctx->time_base, (AVRational){1,100}) : -1;
  55
  56     av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
  57     if (ptr && avpkt->size > 0 && *ptr) {
  58         ff_ass_bprint_text_event(&buf, ptr, avpkt->size, text->linebreaks, text->keep_ass_markup);
  59         ret = ff_ass_add_rect_bprint(sub, &buf, ts_start, ts_duration);
  60     }
  61     av_bprint_finalize(&buf, NULL);
  62     if (ret < 0)
  63         return ret;
  64     *got_sub_ptr = sub->num_rects > 0;
  65     return avpkt->size;
  66 }
  67
  68 #define DECLARE_CLASS(decname) static const AVClass decname ## _decoder_class = {   \
  69     .class_name = #decname " decoder",      \
  70     .item_name  = av_default_item_name,     \
  71     .option     = decname ## _options,      \
  72     .version    = LIBAVUTIL_VERSION_INT,    \
  73 }
  74
  75 #if CONFIG_TEXT_DECODER
  76 #define text_options options
  77 DECLARE_CLASS(text);
  78
  79 AVCodec ff_text_decoder = {
  80     .name           = "text",
  81     .long_name      = NULL_IF_CONFIG_SMALL("Raw text subtitle"),
  82     .priv_data_size = sizeof(TextContext),
  83     .type           = AVMEDIA_TYPE_SUBTITLE,
  84     .id             = AV_CODEC_ID_TEXT,
  85     .decode         = text_decode_frame,
  86     .init           = ff_ass_subtitle_header_default,
  87     .priv_class     = &text_decoder_class,
  88 };
  89 #endif
  90
  91 #if CONFIG_VPLAYER_DECODER || CONFIG_PJS_DECODER || CONFIG_SUBVIEWER1_DECODER || CONFIG_STL_DECODER
  92
  93 static int linebreak_init(AVCodecContext *avctx)
  94 {
  95     TextContext *text = avctx->priv_data;
  96     text->linebreaks = "|";
  97     return ff_ass_subtitle_header_default(avctx);
  98 }
  99
 100 #if CONFIG_VPLAYER_DECODER
 101 #define vplayer_options options
 102 DECLARE_CLASS(vplayer);
 103
 104 AVCodec ff_vplayer_decoder = {
 105     .name           = "vplayer",
 106     .long_name      = NULL_IF_CONFIG_SMALL("VPlayer subtitle"),
 107     .priv_data_size = sizeof(TextContext),
 108     .type           = AVMEDIA_TYPE_SUBTITLE,
 109     .id             = AV_CODEC_ID_VPLAYER,
 110     .decode         = text_decode_frame,
 111     .init           = linebreak_init,
 112     .priv_class     = &vplayer_decoder_class,
 113 };
 114 #endif
 115
 116 #if CONFIG_STL_DECODER
 117 #define stl_options options
 118 DECLARE_CLASS(stl);
 119
 120 AVCodec ff_stl_decoder = {
 121     .name           = "stl",
 122     .long_name      = NULL_IF_CONFIG_SMALL("Spruce subtitle format"),
 123     .priv_data_size = sizeof(TextContext),
 124     .type           = AVMEDIA_TYPE_SUBTITLE,
 125     .id             = AV_CODEC_ID_STL,
 126     .decode         = text_decode_frame,
 127     .init           = linebreak_init,
 128     .priv_class     = &stl_decoder_class,
 129 };
 130 #endif
 131
 132 #if CONFIG_PJS_DECODER
 133 #define pjs_options options
 134 DECLARE_CLASS(pjs);
 135
 136 AVCodec ff_pjs_decoder = {
 137     .name           = "pjs",
 138     .long_name      = NULL_IF_CONFIG_SMALL("PJS subtitle"),
 139     .priv_data_size = sizeof(TextContext),
 140     .type           = AVMEDIA_TYPE_SUBTITLE,
 141     .id             = AV_CODEC_ID_PJS,
 142     .decode         = text_decode_frame,
 143     .init           = linebreak_init,
 144     .priv_class     = &pjs_decoder_class,
 145 };
 146 #endif
 147
 148 #if CONFIG_SUBVIEWER1_DECODER
 149 #define subviewer1_options options
 150 DECLARE_CLASS(subviewer1);
 151
 152 AVCodec ff_subviewer1_decoder = {
 153     .name           = "subviewer1",
 154     .long_name      = NULL_IF_CONFIG_SMALL("SubViewer1 subtitle"),
 155     .priv_data_size = sizeof(TextContext),
 156     .type           = AVMEDIA_TYPE_SUBTITLE,
 157     .id             = AV_CODEC_ID_SUBVIEWER1,
 158     .decode         = text_decode_frame,
 159     .init           = linebreak_init,
 160     .priv_class     = &subviewer1_decoder_class,
 161 };
 162 #endif
 163
 164 #endif /* text subtitles with '|' line break */