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 * MPlayer subtitles format demuxer 24 */ 25 26#include "avformat.h" 27#include "internal.h" 28#include "subtitles.h" 29 30#define TSBASE 10000000 31 32typedef struct { 33 FFDemuxSubtitlesQueue q; 34} MPSubContext; 35 36static int mpsub_probe(const AVProbeData *p) 37{ 38 const char *ptr = p->buf; 39 const char *ptr_end = p->buf + p->buf_size; 40 41 while (ptr < ptr_end) { 42 int inc; 43 44 if (!memcmp(ptr, "FORMAT=TIME", 11)) 45 return AVPROBE_SCORE_EXTENSION; 46 if (!memcmp(ptr, "FORMAT=", 7)) 47 return AVPROBE_SCORE_EXTENSION / 3; 48 inc = ff_subtitles_next_line(ptr); 49 if (!inc) 50 break; 51 ptr += inc; 52 } 53 return 0; 54} 55 56static int parse_line(const char *line, int64_t *value, int64_t *value2) 57{ 58 int vi, p1, p2; 59 60 for (vi = 0; vi < 2; vi++) { 61 long long intval, fracval; 62 int n = av_sscanf(line, "%lld%n.%lld%n", &intval, &p1, &fracval, &p2); 63 if (n <= 0 || intval < INT64_MIN / TSBASE || intval > INT64_MAX / TSBASE) 64 return AVERROR_INVALIDDATA; 65 66 intval *= TSBASE; 67 68 if (n == 2) { 69 if (fracval < 0) 70 return AVERROR_INVALIDDATA; 71 for (;p2 - p1 < 7 + 1; p1--) 72 fracval *= 10; 73 for (;p2 - p1 > 7 + 1; p1++) 74 fracval /= 10; 75 if (intval > 0) intval = av_sat_add64(intval, fracval); 76 else intval = av_sat_sub64(intval, fracval); 77 line += p2; 78 } else 79 line += p1; 80 81 *value = intval; 82 83 value = value2; 84 } 85 86 return 0; 87} 88 89static int mpsub_read_header(AVFormatContext *s) 90{ 91 MPSubContext *mpsub = s->priv_data; 92 AVStream *st; 93 AVBPrint buf; 94 AVRational pts_info = (AVRational){ TSBASE, 1 }; // ts based by default 95 int res = 0; 96 int64_t current_pts = 0; 97 int i; 98 int common_factor = 0; 99 100 av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED); 101 102 while (!avio_feof(s->pb)) { 103 char line[1024]; 104 int64_t start, duration; 105 int fps, len = ff_get_line(s->pb, line, sizeof(line)); 106 107 if (!len) 108 break; 109 110 line[strcspn(line, "\r\n")] = 0; 111 112 if (sscanf(line, "FORMAT=%d", &fps) == 1 && fps > 3 && fps < 100) { 113 /* frame based timing */ 114 pts_info = (AVRational){ TSBASE * fps, 1 }; 115 } else if (parse_line(line, &start, &duration) >= 0) { 116 AVPacket *sub; 117 const int64_t pos = avio_tell(s->pb); 118 119 ff_subtitles_read_chunk(s->pb, &buf); 120 if (buf.len) { 121 sub = ff_subtitles_queue_insert(&mpsub->q, buf.str, buf.len, 0); 122 if (!sub) { 123 res = AVERROR(ENOMEM); 124 goto end; 125 } 126 if ( current_pts < 0 && start < INT64_MIN - current_pts 127 || current_pts > 0 && start > INT64_MAX - current_pts) { 128 res = AVERROR_INVALIDDATA; 129 goto end; 130 } 131 sub->pts = current_pts + start; 132 if (duration < 0 || sub->pts > INT64_MAX - duration) { 133 res = AVERROR_INVALIDDATA; 134 goto end; 135 } 136 sub->duration = duration; 137 138 common_factor = av_gcd(duration, common_factor); 139 common_factor = av_gcd(sub->pts, common_factor); 140 141 current_pts = sub->pts + duration; 142 sub->pos = pos; 143 } 144 } 145 } 146 147 if (common_factor > 1) { 148 common_factor = av_gcd(pts_info.num, common_factor); 149 for (i = 0; i < mpsub->q.nb_subs; i++) { 150 mpsub->q.subs[i]->pts /= common_factor; 151 mpsub->q.subs[i]->duration /= common_factor; 152 } 153 pts_info.num /= common_factor; 154 } 155 156 st = avformat_new_stream(s, NULL); 157 if (!st) { 158 res = AVERROR(ENOMEM); 159 goto end; 160 } 161 avpriv_set_pts_info(st, 64, pts_info.den, pts_info.num); 162 st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE; 163 st->codecpar->codec_id = AV_CODEC_ID_TEXT; 164 165 ff_subtitles_queue_finalize(s, &mpsub->q); 166 167end: 168 av_bprint_finalize(&buf, NULL); 169 return res; 170} 171 172const AVInputFormat ff_mpsub_demuxer = { 173 .name = "mpsub", 174 .long_name = NULL_IF_CONFIG_SMALL("MPlayer subtitles"), 175 .priv_data_size = sizeof(MPSubContext), 176 .flags_internal = FF_FMT_INIT_CLEANUP, 177 .read_probe = mpsub_probe, 178 .read_header = mpsub_read_header, 179 .extensions = "sub", 180 .read_packet = ff_subtitles_read_packet, 181 .read_seek2 = ff_subtitles_read_seek, 182 .read_close = ff_subtitles_read_close, 183}; 184