libavformat/pjsdec.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  * PJS (Phoenix Japanimation Society) subtitles format demuxer
  24  *
  25  * @see http://subs.com.ru/page.php?al=pjs
  26  */
  27
  28 #include "avformat.h"
  29 #include "demux.h"
  30 #include "internal.h"
  31 #include "subtitles.h"
  32
  33 typedef struct {
  34     FFDemuxSubtitlesQueue q;
  35 } PJSContext;
  36
  37 static int pjs_probe(const AVProbeData *p)
  38 {
  39     char c;
  40     int64_t start, end;
  41     const unsigned char *ptr = p->buf;
  42
  43     if (sscanf(ptr, "%"SCNd64",%"SCNd64",%c", &start, &end, &c) == 3) {
  44         size_t q1pos = strcspn(ptr, "\"");
  45         size_t q2pos = q1pos + strcspn(ptr + q1pos + 1, "\"") + 1;
  46         if (strcspn(ptr, "\r\n") > q2pos)
  47             return AVPROBE_SCORE_MAX;
  48     }
  49     return 0;
  50 }
  51
  52 static int64_t read_ts(char **line, int *duration)
  53 {
  54     int64_t start, end;
  55
  56     if (sscanf(*line, "%"SCNd64",%"SCNd64, &start, &end) == 2) {
  57         *line += strcspn(*line, "\"");
  58         *line += !!**line;
  59         if (end < start || end - (uint64_t)start > INT_MAX)
  60             return AV_NOPTS_VALUE;
  61         *duration = end - start;
  62         return start;
  63     }
  64     return AV_NOPTS_VALUE;
  65 }
  66
  67 static int pjs_read_header(AVFormatContext *s)
  68 {
  69     PJSContext *pjs = s->priv_data;
  70     AVStream *st = avformat_new_stream(s, NULL);
  71
  72     if (!st)
  73         return AVERROR(ENOMEM);
  74     avpriv_set_pts_info(st, 64, 1, 10);
  75     st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
  76     st->codecpar->codec_id   = AV_CODEC_ID_PJS;
  77
  78     while (!avio_feof(s->pb)) {
  79         char line[4096];
  80         char *p = line;
  81         const int64_t pos = avio_tell(s->pb);
  82         int len = ff_get_line(s->pb, line, sizeof(line));
  83         int64_t pts_start;
  84         int duration;
  85
  86         if (!len)
  87             break;
  88
  89         line[strcspn(line, "\r\n")] = 0;
  90
  91         pts_start = read_ts(&p, &duration);
  92         if (pts_start != AV_NOPTS_VALUE) {
  93             AVPacket *sub;
  94
  95             p[strcspn(p, "\"")] = 0;
  96             sub = ff_subtitles_queue_insert(&pjs->q, p, strlen(p), 0);
  97             if (!sub)
  98                 return AVERROR(ENOMEM);
  99             sub->pos = pos;
 100             sub->pts = pts_start;
 101             sub->duration = duration;
 102         }
 103     }
 104
 105     ff_subtitles_queue_finalize(s, &pjs->q);
 106     return 0;
 107 }
 108
 109 const FFInputFormat ff_pjs_demuxer = {
 110     .p.name         = "pjs",
 111     .p.long_name    = NULL_IF_CONFIG_SMALL("PJS (Phoenix Japanimation Society) subtitles"),
 112     .p.extensions   = "pjs",
 113     .priv_data_size = sizeof(PJSContext),
 114     .flags_internal = FF_INFMT_FLAG_INIT_CLEANUP,
 115     .read_probe     = pjs_probe,
 116     .read_header    = pjs_read_header,
 117     .read_packet    = ff_subtitles_read_packet,
 118     .read_seek2     = ff_subtitles_read_seek,
 119     .read_close     = ff_subtitles_read_close,
 120 };