libavcodec/subviewerdec.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  * SubViewer subtitle decoder
  24  * @see https://en.wikipedia.org/wiki/SubViewer
  25  */
  26
  27 #include "avcodec.h"
  28 #include "ass.h"
  29 #include "codec_internal.h"
  30 #include "libavutil/bprint.h"
  31
  32 static int subviewer_event_to_ass(AVBPrint *buf, const char *p)
  33 {
  34     while (*p) {
  35         if (!strncmp(p, "[br]", 4)) {
  36             av_bprintf(buf, "\\N");
  37             p += 4;
  38         } else {
  39             if (p[0] == '\n' && p[1])
  40                 av_bprintf(buf, "\\N");
  41             else if (*p != '\n' && *p != '\r')
  42                 av_bprint_chars(buf, *p, 1);
  43             p++;
  44         }
  45     }
  46
  47     return 0;
  48 }
  49
  50 static int subviewer_decode_frame(AVCodecContext *avctx, AVSubtitle *sub,
  51                                   int *got_sub_ptr, const AVPacket *avpkt)
  52 {
  53     int ret = 0;
  54     const char *ptr = avpkt->data;
  55     FFASSDecoderContext *s = avctx->priv_data;
  56     AVBPrint buf;
  57
  58     av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
  59     if (ptr && avpkt->size > 0 && !subviewer_event_to_ass(&buf, ptr))
  60         ret = ff_ass_add_rect(sub, buf.str, s->readorder++, 0, NULL, NULL);
  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 const FFCodec ff_subviewer_decoder = {
  69     .p.name         = "subviewer",
  70     CODEC_LONG_NAME("SubViewer subtitle"),
  71     .p.type         = AVMEDIA_TYPE_SUBTITLE,
  72     .p.id           = AV_CODEC_ID_SUBVIEWER,
  73     FF_CODEC_DECODE_SUB_CB(subviewer_decode_frame),
  74     .init           = ff_ass_subtitle_header_default,
  75     .flush          = ff_ass_decoder_flush,
  76     .priv_data_size = sizeof(FFASSDecoderContext),
  77 };