| 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 | |
| 30 | typedef struct ASSContext { |
| 31 | FFDemuxSubtitlesQueue q; |
| 32 | } ASSContext; |
| 33 | |
| 34 | static int ass_probe(AVProbeData *p) |
| 35 | { |
| 36 | char buf[13]; |
| 37 | FFTextReader tr; |
| 38 | ff_text_init_buf(&tr, p->buf, p->buf_size); |
| 39 | |
| 40 | ff_text_read(&tr, buf, sizeof(buf)); |
| 41 | |
| 42 | if (!memcmp(buf, "[Script Info]", 13)) |
| 43 | return AVPROBE_SCORE_MAX; |
| 44 | |
| 45 | return 0; |
| 46 | } |
| 47 | |
| 48 | static int ass_read_close(AVFormatContext *s) |
| 49 | { |
| 50 | ASSContext *ass = s->priv_data; |
| 51 | ff_subtitles_queue_clean(&ass->q); |
| 52 | return 0; |
| 53 | } |
| 54 | |
| 55 | static int read_ts(const uint8_t *p, int64_t *start, int *duration) |
| 56 | { |
| 57 | int64_t end; |
| 58 | int hh1, mm1, ss1, ms1; |
| 59 | int hh2, mm2, ss2, ms2; |
| 60 | |
| 61 | if (sscanf(p, "%*[^,],%d:%d:%d%*c%d,%d:%d:%d%*c%d", |
| 62 | &hh1, &mm1, &ss1, &ms1, |
| 63 | &hh2, &mm2, &ss2, &ms2) == 8) { |
| 64 | end = (hh2*3600LL + mm2*60LL + ss2) * 100LL + ms2; |
| 65 | *start = (hh1*3600LL + mm1*60LL + ss1) * 100LL + ms1; |
| 66 | *duration = end - *start; |
| 67 | return 0; |
| 68 | } |
| 69 | return -1; |
| 70 | } |
| 71 | |
| 72 | static int64_t get_line(AVBPrint *buf, FFTextReader *tr) |
| 73 | { |
| 74 | int64_t pos = ff_text_pos(tr); |
| 75 | |
| 76 | av_bprint_clear(buf); |
| 77 | for (;;) { |
| 78 | char c = ff_text_r8(tr); |
| 79 | if (!c) |
| 80 | break; |
| 81 | av_bprint_chars(buf, c, 1); |
| 82 | if (c == '\n') |
| 83 | break; |
| 84 | } |
| 85 | return pos; |
| 86 | } |
| 87 | |
| 88 | static int ass_read_header(AVFormatContext *s) |
| 89 | { |
| 90 | ASSContext *ass = s->priv_data; |
| 91 | AVBPrint header, line; |
| 92 | int header_remaining, res = 0; |
| 93 | AVStream *st; |
| 94 | FFTextReader tr; |
| 95 | ff_text_init_avio(&tr, s->pb); |
| 96 | |
| 97 | st = avformat_new_stream(s, NULL); |
| 98 | if (!st) |
| 99 | return AVERROR(ENOMEM); |
| 100 | avpriv_set_pts_info(st, 64, 1, 100); |
| 101 | st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE; |
| 102 | st->codec->codec_id = AV_CODEC_ID_SSA; |
| 103 | |
| 104 | header_remaining = INT_MAX; |
| 105 | |
| 106 | av_bprint_init(&header, 0, AV_BPRINT_SIZE_UNLIMITED); |
| 107 | av_bprint_init(&line, 0, AV_BPRINT_SIZE_UNLIMITED); |
| 108 | |
| 109 | for (;;) { |
| 110 | int64_t pos = get_line(&line, &tr); |
| 111 | |
| 112 | if (!line.str[0]) // EOF |
| 113 | break; |
| 114 | |
| 115 | if (!memcmp(line.str, "[Events]", 8)) |
| 116 | header_remaining = 2; |
| 117 | else if (line.str[0] == '[') |
| 118 | header_remaining = INT_MAX; |
| 119 | |
| 120 | if (header_remaining) { |
| 121 | av_bprintf(&header, "%s", line.str); |
| 122 | header_remaining--; |
| 123 | } else { |
| 124 | int64_t ts_start = AV_NOPTS_VALUE; |
| 125 | int duration = -1; |
| 126 | AVPacket *sub; |
| 127 | |
| 128 | if (read_ts(line.str, &ts_start, &duration) < 0) |
| 129 | continue; |
| 130 | sub = ff_subtitles_queue_insert(&ass->q, line.str, line.len, 0); |
| 131 | if (!sub) { |
| 132 | res = AVERROR(ENOMEM); |
| 133 | goto end; |
| 134 | } |
| 135 | sub->pos = pos; |
| 136 | sub->pts = ts_start; |
| 137 | sub->duration = duration; |
| 138 | } |
| 139 | } |
| 140 | |
| 141 | av_bprint_finalize(&line, NULL); |
| 142 | |
| 143 | res = avpriv_bprint_to_extradata(st->codec, &header); |
| 144 | if (res < 0) |
| 145 | goto end; |
| 146 | |
| 147 | ff_subtitles_queue_finalize(&ass->q); |
| 148 | |
| 149 | end: |
| 150 | return res; |
| 151 | } |
| 152 | |
| 153 | static int ass_read_packet(AVFormatContext *s, AVPacket *pkt) |
| 154 | { |
| 155 | ASSContext *ass = s->priv_data; |
| 156 | return ff_subtitles_queue_read_packet(&ass->q, pkt); |
| 157 | } |
| 158 | |
| 159 | static int ass_read_seek(AVFormatContext *s, int stream_index, |
| 160 | int64_t min_ts, int64_t ts, int64_t max_ts, int flags) |
| 161 | { |
| 162 | ASSContext *ass = s->priv_data; |
| 163 | return ff_subtitles_queue_seek(&ass->q, s, stream_index, |
| 164 | min_ts, ts, max_ts, flags); |
| 165 | } |
| 166 | |
| 167 | AVInputFormat ff_ass_demuxer = { |
| 168 | .name = "ass", |
| 169 | .long_name = NULL_IF_CONFIG_SMALL("SSA (SubStation Alpha) subtitle"), |
| 170 | .priv_data_size = sizeof(ASSContext), |
| 171 | .read_probe = ass_probe, |
| 172 | .read_header = ass_read_header, |
| 173 | .read_packet = ass_read_packet, |
| 174 | .read_close = ass_read_close, |
| 175 | .read_seek2 = ass_read_seek, |
| 176 | }; |