ffmpeg/libavformat/aqtitledec.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  * AQTitle subtitles format demuxer
  24  *
  25  * @see http://web.archive.org/web/20070210095721/http://www.volny.cz/aberka/czech/aqt.html
  26  * @see https://trac.annodex.net/wiki/AQTitle
  27  */
  28
  29 #include "avformat.h"
  30 #include "internal.h"
  31 #include "subtitles.h"
  32 #include "libavutil/opt.h"
  33
  34 typedef struct {
  35     const AVClass *class;
  36     FFDemuxSubtitlesQueue q;
  37     AVRational frame_rate;
  38 } AQTitleContext;
  39
  40 static int aqt_probe(AVProbeData *p)
  41 {
  42     int frame;
  43     const char *ptr = p->buf;
  44
  45     if (sscanf(ptr, "-->> %d", &frame) == 1)
  46         return AVPROBE_SCORE_EXTENSION;
  47     return 0;
  48 }
  49
  50 static int aqt_read_header(AVFormatContext *s)
  51 {
  52     AQTitleContext *aqt = s->priv_data;
  53     AVStream *st = avformat_new_stream(s, NULL);
  54     int new_event = 1;
  55     int64_t pos = 0, frame = AV_NOPTS_VALUE;
  56     AVPacket *sub = NULL;
  57
  58     if (!st)
  59         return AVERROR(ENOMEM);
  60     avpriv_set_pts_info(st, 64, aqt->frame_rate.den, aqt->frame_rate.num);
  61     st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
  62     st->codec->codec_id   = AV_CODEC_ID_TEXT;
  63
  64     while (!avio_feof(s->pb)) {
  65         char line[4096];
  66         int len = ff_get_line(s->pb, line, sizeof(line));
  67
  68         if (!len)
  69             break;
  70
  71         line[strcspn(line, "\r\n")] = 0;
  72
  73         if (sscanf(line, "-->> %"SCNd64, &frame) == 1) {
  74             new_event = 1;
  75             pos = avio_tell(s->pb);
  76             if (sub) {
  77                 sub->duration = frame - sub->pts;
  78                 sub = NULL;
  79             }
  80         } else if (*line) {
  81             if (!new_event) {
  82                 sub = ff_subtitles_queue_insert(&aqt->q, "\n", 1, 1);
  83                 if (!sub)
  84                     return AVERROR(ENOMEM);
  85             }
  86             sub = ff_subtitles_queue_insert(&aqt->q, line, strlen(line), !new_event);
  87             if (!sub)
  88                 return AVERROR(ENOMEM);
  89             if (new_event) {
  90                 sub->pts = frame;
  91                 sub->duration = -1;
  92                 sub->pos = pos;
  93             }
  94             new_event = 0;
  95         }
  96     }
  97
  98     ff_subtitles_queue_finalize(&aqt->q);
  99     return 0;
 100 }
 101
 102 static int aqt_read_packet(AVFormatContext *s, AVPacket *pkt)
 103 {
 104     AQTitleContext *aqt = s->priv_data;
 105     return ff_subtitles_queue_read_packet(&aqt->q, pkt);
 106 }
 107
 108 static int aqt_read_seek(AVFormatContext *s, int stream_index,
 109                          int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
 110 {
 111     AQTitleContext *aqt = s->priv_data;
 112     return ff_subtitles_queue_seek(&aqt->q, s, stream_index,
 113                                    min_ts, ts, max_ts, flags);
 114 }
 115
 116 static int aqt_read_close(AVFormatContext *s)
 117 {
 118     AQTitleContext *aqt = s->priv_data;
 119     ff_subtitles_queue_clean(&aqt->q);
 120     return 0;
 121 }
 122
 123 #define OFFSET(x) offsetof(AQTitleContext, x)
 124 #define SD AV_OPT_FLAG_SUBTITLE_PARAM|AV_OPT_FLAG_DECODING_PARAM
 125 static const AVOption aqt_options[] = {
 126     { "subfps", "set the movie frame rate", OFFSET(frame_rate), AV_OPT_TYPE_RATIONAL, {.dbl=25}, 0, INT_MAX, SD },
 127     { NULL }
 128 };
 129
 130 static const AVClass aqt_class = {
 131     .class_name = "aqtdec",
 132     .item_name  = av_default_item_name,
 133     .option     = aqt_options,
 134     .version    = LIBAVUTIL_VERSION_INT,
 135 };
 136
 137 AVInputFormat ff_aqtitle_demuxer = {
 138     .name           = "aqtitle",
 139     .long_name      = NULL_IF_CONFIG_SMALL("AQTitle subtitles"),
 140     .priv_data_size = sizeof(AQTitleContext),
 141     .read_probe     = aqt_probe,
 142     .read_header    = aqt_read_header,
 143     .read_packet    = aqt_read_packet,
 144     .read_seek2     = aqt_read_seek,
 145     .read_close     = aqt_read_close,
 146     .extensions     = "aqt",
 147     .priv_class     = &aqt_class,
 148 };