1/* 2 * SSA/ASS demuxer 3 * Copyright (c) 2008 Michael Niedermayer 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg 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 * FFmpeg 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 FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22#include <stdint.h> 23 24#include "avformat.h" 25#include "internal.h" 26#include "subtitles.h" 27#include "libavcodec/internal.h" 28#include "libavutil/bprint.h" 29 30typedef struct ASSContext { 31 FFDemuxSubtitlesQueue q; 32} ASSContext; 33 34static int ass_probe(AVProbeData *p) 35{ 36 const char *header = "[Script Info]"; 37 38 if (!memcmp(p->buf, header, strlen(header)) || 39 !memcmp(p->buf + 3, header, strlen(header))) 40 return AVPROBE_SCORE_MAX; 41 42 return 0; 43} 44 45static int ass_read_close(AVFormatContext *s) 46{ 47 ASSContext *ass = s->priv_data; 48 ff_subtitles_queue_clean(&ass->q); 49 return 0; 50} 51 52static int read_ts(const uint8_t *p, int64_t *start, int *duration) 53{ 54 int64_t end; 55 int hh1, mm1, ss1, ms1; 56 int hh2, mm2, ss2, ms2; 57 58 if (sscanf(p, "%*[^,],%d:%d:%d%*c%d,%d:%d:%d%*c%d", 59 &hh1, &mm1, &ss1, &ms1, 60 &hh2, &mm2, &ss2, &ms2) == 8) { 61 end = (hh2*3600LL + mm2*60LL + ss2) * 100LL + ms2; 62 *start = (hh1*3600LL + mm1*60LL + ss1) * 100LL + ms1; 63 *duration = end - *start; 64 return 0; 65 } 66 return -1; 67} 68 69static int64_t get_line(AVBPrint *buf, AVIOContext *pb) 70{ 71 int64_t pos = avio_tell(pb); 72 73 av_bprint_clear(buf); 74 for (;;) { 75 char c = avio_r8(pb); 76 if (!c) 77 break; 78 av_bprint_chars(buf, c, 1); 79 if (c == '\n') 80 break; 81 } 82 return pos; 83} 84 85static int ass_read_header(AVFormatContext *s) 86{ 87 ASSContext *ass = s->priv_data; 88 AVBPrint header, line; 89 int header_remaining, res = 0; 90 AVStream *st; 91 92 st = avformat_new_stream(s, NULL); 93 if (!st) 94 return AVERROR(ENOMEM); 95 avpriv_set_pts_info(st, 64, 1, 100); 96 st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE; 97 st->codec->codec_id = AV_CODEC_ID_SSA; 98 99 header_remaining = INT_MAX; 100 101 av_bprint_init(&header, 0, AV_BPRINT_SIZE_UNLIMITED); 102 av_bprint_init(&line, 0, AV_BPRINT_SIZE_UNLIMITED); 103 104 for (;;) { 105 int64_t pos = get_line(&line, s->pb); 106 107 if (!line.str[0]) // EOF 108 break; 109 110 if (!memcmp(line.str, "[Events]", 8)) 111 header_remaining = 2; 112 else if (line.str[0] == '[') 113 header_remaining = INT_MAX; 114 115 if (header_remaining) { 116 av_bprintf(&header, "%s", line.str); 117 header_remaining--; 118 } else { 119 int64_t ts_start = AV_NOPTS_VALUE; 120 int duration = -1; 121 AVPacket *sub; 122 123 if (read_ts(line.str, &ts_start, &duration) < 0) 124 continue; 125 sub = ff_subtitles_queue_insert(&ass->q, line.str, line.len, 0); 126 if (!sub) { 127 res = AVERROR(ENOMEM); 128 goto end; 129 } 130 sub->pos = pos; 131 sub->pts = ts_start; 132 sub->duration = duration; 133 } 134 } 135 136 av_bprint_finalize(&line, NULL); 137 138 res = avpriv_bprint_to_extradata(st->codec, &header); 139 if (res < 0) 140 goto end; 141 142 ff_subtitles_queue_finalize(&ass->q); 143 144end: 145 return res; 146} 147 148static int ass_read_packet(AVFormatContext *s, AVPacket *pkt) 149{ 150 ASSContext *ass = s->priv_data; 151 return ff_subtitles_queue_read_packet(&ass->q, pkt); 152} 153 154static int ass_read_seek(AVFormatContext *s, int stream_index, 155 int64_t min_ts, int64_t ts, int64_t max_ts, int flags) 156{ 157 ASSContext *ass = s->priv_data; 158 return ff_subtitles_queue_seek(&ass->q, s, stream_index, 159 min_ts, ts, max_ts, flags); 160} 161 162AVInputFormat ff_ass_demuxer = { 163 .name = "ass", 164 .long_name = NULL_IF_CONFIG_SMALL("SSA (SubStation Alpha) subtitle"), 165 .priv_data_size = sizeof(ASSContext), 166 .read_probe = ass_probe, 167 .read_header = ass_read_header, 168 .read_packet = ass_read_packet, 169 .read_close = ass_read_close, 170 .read_seek2 = ass_read_seek, 171}; 172