| 1 | /* |
| 2 | * SSA/ASS demuxer |
| 3 | * Copyright (c) 2008 Michael Niedermayer |
| 4 | * Copyright (c) 2014 Clément Bœsch |
| 5 | * |
| 6 | * This file is part of FFmpeg. |
| 7 | * |
| 8 | * FFmpeg is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU Lesser General Public |
| 10 | * License as published by the Free Software Foundation; either |
| 11 | * version 2.1 of the License, or (at your option) any later version. |
| 12 | * |
| 13 | * FFmpeg is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 16 | * Lesser General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU Lesser General Public |
| 19 | * License along with FFmpeg; if not, write to the Free Software |
| 20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 21 | */ |
| 22 | |
| 23 | #include <stdint.h> |
| 24 | |
| 25 | #include "avformat.h" |
| 26 | #include "internal.h" |
| 27 | #include "subtitles.h" |
| 28 | #include "libavcodec/internal.h" |
| 29 | #include "libavutil/bprint.h" |
| 30 | |
| 31 | typedef struct ASSContext { |
| 32 | FFDemuxSubtitlesQueue q; |
| 33 | unsigned readorder; |
| 34 | } ASSContext; |
| 35 | |
| 36 | static int ass_probe(AVProbeData *p) |
| 37 | { |
| 38 | char buf[13]; |
| 39 | FFTextReader tr; |
| 40 | ff_text_init_buf(&tr, p->buf, p->buf_size); |
| 41 | |
| 42 | ff_text_read(&tr, buf, sizeof(buf)); |
| 43 | |
| 44 | if (!memcmp(buf, "[Script Info]", 13)) |
| 45 | return AVPROBE_SCORE_MAX; |
| 46 | |
| 47 | return 0; |
| 48 | } |
| 49 | |
| 50 | static int ass_read_close(AVFormatContext *s) |
| 51 | { |
| 52 | ASSContext *ass = s->priv_data; |
| 53 | ff_subtitles_queue_clean(&ass->q); |
| 54 | return 0; |
| 55 | } |
| 56 | |
| 57 | static int read_dialogue(ASSContext *ass, AVBPrint *dst, const uint8_t *p, |
| 58 | int64_t *start, int *duration) |
| 59 | { |
| 60 | int pos = 0; |
| 61 | int64_t end; |
| 62 | int hh1, mm1, ss1, ms1; |
| 63 | int hh2, mm2, ss2, ms2; |
| 64 | |
| 65 | if (sscanf(p, "Dialogue: %*[^,],%d:%d:%d%*c%d,%d:%d:%d%*c%d,%n", |
| 66 | &hh1, &mm1, &ss1, &ms1, |
| 67 | &hh2, &mm2, &ss2, &ms2, &pos) >= 8 && pos > 0) { |
| 68 | |
| 69 | /* This is not part of the sscanf itself in order to handle an actual |
| 70 | * number (which would be the Layer) or the form "Marked=N" (which is |
| 71 | * the old SSA field, now replaced by Layer, and will lead to Layer |
| 72 | * being 0 here). */ |
| 73 | const int layer = atoi(p + 10); |
| 74 | |
| 75 | end = (hh2*3600LL + mm2*60LL + ss2) * 100LL + ms2; |
| 76 | *start = (hh1*3600LL + mm1*60LL + ss1) * 100LL + ms1; |
| 77 | *duration = end - *start; |
| 78 | |
| 79 | av_bprint_clear(dst); |
| 80 | av_bprintf(dst, "%u,%d,%s", ass->readorder++, layer, p + pos); |
| 81 | |
| 82 | /* right strip the buffer */ |
| 83 | while (dst->len > 0 && |
| 84 | dst->str[dst->len - 1] == '\r' || |
| 85 | dst->str[dst->len - 1] == '\n') |
| 86 | dst->str[--dst->len] = 0; |
| 87 | return 0; |
| 88 | } |
| 89 | return -1; |
| 90 | } |
| 91 | |
| 92 | static int64_t get_line(AVBPrint *buf, FFTextReader *tr) |
| 93 | { |
| 94 | int64_t pos = ff_text_pos(tr); |
| 95 | |
| 96 | av_bprint_clear(buf); |
| 97 | for (;;) { |
| 98 | char c = ff_text_r8(tr); |
| 99 | if (!c) |
| 100 | break; |
| 101 | av_bprint_chars(buf, c, 1); |
| 102 | if (c == '\n') |
| 103 | break; |
| 104 | } |
| 105 | return pos; |
| 106 | } |
| 107 | |
| 108 | static int ass_read_header(AVFormatContext *s) |
| 109 | { |
| 110 | ASSContext *ass = s->priv_data; |
| 111 | AVBPrint header, line, rline; |
| 112 | int res = 0; |
| 113 | AVStream *st; |
| 114 | FFTextReader tr; |
| 115 | ff_text_init_avio(s, &tr, s->pb); |
| 116 | |
| 117 | st = avformat_new_stream(s, NULL); |
| 118 | if (!st) |
| 119 | return AVERROR(ENOMEM); |
| 120 | avpriv_set_pts_info(st, 64, 1, 100); |
| 121 | st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE; |
| 122 | st->codec->codec_id = AV_CODEC_ID_ASS; |
| 123 | |
| 124 | av_bprint_init(&header, 0, AV_BPRINT_SIZE_UNLIMITED); |
| 125 | av_bprint_init(&line, 0, AV_BPRINT_SIZE_UNLIMITED); |
| 126 | av_bprint_init(&rline, 0, AV_BPRINT_SIZE_UNLIMITED); |
| 127 | |
| 128 | for (;;) { |
| 129 | int64_t pos = get_line(&line, &tr); |
| 130 | int64_t ts_start = AV_NOPTS_VALUE; |
| 131 | int duration = -1; |
| 132 | AVPacket *sub; |
| 133 | |
| 134 | if (!line.str[0]) // EOF |
| 135 | break; |
| 136 | |
| 137 | if (read_dialogue(ass, &rline, line.str, &ts_start, &duration) < 0) { |
| 138 | av_bprintf(&header, "%s", line.str); |
| 139 | continue; |
| 140 | } |
| 141 | sub = ff_subtitles_queue_insert(&ass->q, rline.str, rline.len, 0); |
| 142 | if (!sub) { |
| 143 | res = AVERROR(ENOMEM); |
| 144 | goto end; |
| 145 | } |
| 146 | sub->pos = pos; |
| 147 | sub->pts = ts_start; |
| 148 | sub->duration = duration; |
| 149 | } |
| 150 | |
| 151 | res = avpriv_bprint_to_extradata(st->codec, &header); |
| 152 | if (res < 0) |
| 153 | goto end; |
| 154 | |
| 155 | ff_subtitles_queue_finalize(&ass->q); |
| 156 | |
| 157 | end: |
| 158 | av_bprint_finalize(&header, NULL); |
| 159 | av_bprint_finalize(&line, NULL); |
| 160 | av_bprint_finalize(&rline, NULL); |
| 161 | return res; |
| 162 | } |
| 163 | |
| 164 | static int ass_read_packet(AVFormatContext *s, AVPacket *pkt) |
| 165 | { |
| 166 | ASSContext *ass = s->priv_data; |
| 167 | return ff_subtitles_queue_read_packet(&ass->q, pkt); |
| 168 | } |
| 169 | |
| 170 | static int ass_read_seek(AVFormatContext *s, int stream_index, |
| 171 | int64_t min_ts, int64_t ts, int64_t max_ts, int flags) |
| 172 | { |
| 173 | ASSContext *ass = s->priv_data; |
| 174 | return ff_subtitles_queue_seek(&ass->q, s, stream_index, |
| 175 | min_ts, ts, max_ts, flags); |
| 176 | } |
| 177 | |
| 178 | AVInputFormat ff_ass_demuxer = { |
| 179 | .name = "ass", |
| 180 | .long_name = NULL_IF_CONFIG_SMALL("SSA (SubStation Alpha) subtitle"), |
| 181 | .priv_data_size = sizeof(ASSContext), |
| 182 | .read_probe = ass_probe, |
| 183 | .read_header = ass_read_header, |
| 184 | .read_packet = ass_read_packet, |
| 185 | .read_close = ass_read_close, |
| 186 | .read_seek2 = ass_read_seek, |
| 187 | }; |