1/* 2 * SubRip subtitle demuxer 3 * Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.org> 4 * 5 * This file is part of Libav. 6 * 7 * Libav is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * Libav is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with Libav; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22#include "avformat.h" 23#include "internal.h" 24#include "libavutil/intreadwrite.h" 25 26static int srt_probe(AVProbeData *p) 27{ 28 unsigned char *ptr = p->buf; 29 int i, v, num = 0; 30 31 if (AV_RB24(ptr) == 0xEFBBBF) 32 ptr += 3; /* skip UTF-8 BOM */ 33 34 for (i=0; i<2; i++) { 35 if (num == i && sscanf(ptr, "%*d:%*2d:%*2d%*1[,.]%*3d --> %*d:%*2d:%*2d%*1[,.]%3d", &v) == 1) 36 return AVPROBE_SCORE_MAX; 37 num = atoi(ptr); 38 ptr += strcspn(ptr, "\n") + 1; 39 } 40 return 0; 41} 42 43static int srt_read_header(AVFormatContext *s, AVFormatParameters *ap) 44{ 45 AVStream *st = avformat_new_stream(s, NULL); 46 if (!st) 47 return -1; 48 avpriv_set_pts_info(st, 64, 1, 1000); 49 st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE; 50 st->codec->codec_id = CODEC_ID_SRT; 51 return 0; 52} 53 54static int64_t get_pts(const char *buf) 55{ 56 int i, v, hour, min, sec, hsec; 57 58 for (i=0; i<2; i++) { 59 if (sscanf(buf, "%d:%2d:%2d%*1[,.]%3d --> %*d:%*2d:%*2d%*1[,.]%3d", 60 &hour, &min, &sec, &hsec, &v) == 5) { 61 min += 60*hour; 62 sec += 60*min; 63 return sec*1000+hsec; 64 } 65 buf += strcspn(buf, "\n") + 1; 66 } 67 return AV_NOPTS_VALUE; 68} 69 70static inline int is_eol(char c) 71{ 72 return c == '\r' || c == '\n'; 73} 74 75static int srt_read_packet(AVFormatContext *s, AVPacket *pkt) 76{ 77 char buffer[2048], *ptr = buffer, *ptr2; 78 int64_t pos = avio_tell(s->pb); 79 int res = AVERROR_EOF; 80 81 do { 82 ptr2 = ptr; 83 ptr += ff_get_line(s->pb, ptr, sizeof(buffer)+buffer-ptr); 84 } while (!is_eol(*ptr2) && !s->pb->eof_reached && ptr-buffer<sizeof(buffer)-1); 85 86 if (buffer[0] && !(res = av_new_packet(pkt, ptr-buffer))) { 87 memcpy(pkt->data, buffer, pkt->size); 88 pkt->flags |= AV_PKT_FLAG_KEY; 89 pkt->pos = pos; 90 pkt->pts = pkt->dts = get_pts(pkt->data); 91 } 92 return res; 93} 94 95AVInputFormat ff_srt_demuxer = { 96 .name = "srt", 97 .long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle format"), 98 .read_probe = srt_probe, 99 .read_header = srt_read_header, 100 .read_packet = srt_read_packet, 101 .flags = AVFMT_GENERIC_INDEX, 102}; 103