| 1 | /* |
| 2 | * SSA/ASS muxer |
| 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 "libavutil/avstring.h" |
| 23 | #include "avformat.h" |
| 24 | #include "internal.h" |
| 25 | |
| 26 | #include "libavutil/opt.h" |
| 27 | |
| 28 | typedef struct DialogueLine { |
| 29 | int readorder; |
| 30 | char *line; |
| 31 | struct DialogueLine *prev, *next; |
| 32 | } DialogueLine; |
| 33 | |
| 34 | typedef struct ASSContext{ |
| 35 | const AVClass *class; |
| 36 | int write_ts; // 0: ssa (timing in payload), 1: ass (matroska like) |
| 37 | int expected_readorder; |
| 38 | DialogueLine *dialogue_cache; |
| 39 | DialogueLine *last_added_dialogue; |
| 40 | int cache_size; |
| 41 | int ssa_mode; |
| 42 | int ignore_readorder; |
| 43 | }ASSContext; |
| 44 | |
| 45 | static int write_header(AVFormatContext *s) |
| 46 | { |
| 47 | ASSContext *ass = s->priv_data; |
| 48 | AVCodecContext *avctx= s->streams[0]->codec; |
| 49 | |
| 50 | if (s->nb_streams != 1 || (avctx->codec_id != AV_CODEC_ID_SSA && |
| 51 | avctx->codec_id != AV_CODEC_ID_ASS)) { |
| 52 | av_log(s, AV_LOG_ERROR, "Exactly one ASS/SSA stream is needed.\n"); |
| 53 | return AVERROR(EINVAL); |
| 54 | } |
| 55 | ass->write_ts = avctx->codec_id == AV_CODEC_ID_ASS; |
| 56 | avpriv_set_pts_info(s->streams[0], 64, 1, 100); |
| 57 | if (avctx->extradata_size > 0) { |
| 58 | avio_write(s->pb, avctx->extradata, avctx->extradata_size); |
| 59 | if (avctx->extradata[avctx->extradata_size - 1] != '\n') |
| 60 | avio_write(s->pb, "\r\n", 2); |
| 61 | ass->ssa_mode = !strstr(avctx->extradata, "\n[V4+ Styles]"); |
| 62 | if (!strstr(avctx->extradata, "\n[Events]")) |
| 63 | avio_printf(s->pb, "[Events]\r\nFormat: %s, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text\r\n", |
| 64 | ass->ssa_mode ? "Marked" : "Layer"); |
| 65 | } |
| 66 | avio_flush(s->pb); |
| 67 | |
| 68 | return 0; |
| 69 | } |
| 70 | |
| 71 | static void purge_dialogues(AVFormatContext *s, int force) |
| 72 | { |
| 73 | int n = 0; |
| 74 | ASSContext *ass = s->priv_data; |
| 75 | DialogueLine *dialogue = ass->dialogue_cache; |
| 76 | |
| 77 | while (dialogue && (dialogue->readorder == ass->expected_readorder || force)) { |
| 78 | DialogueLine *next = dialogue->next; |
| 79 | if (dialogue->readorder != ass->expected_readorder) { |
| 80 | av_log(s, AV_LOG_WARNING, "ReadOrder gap found between %d and %d\n", |
| 81 | ass->expected_readorder, dialogue->readorder); |
| 82 | ass->expected_readorder = dialogue->readorder; |
| 83 | } |
| 84 | avio_printf(s->pb, "Dialogue: %s\r\n", dialogue->line); |
| 85 | if (dialogue == ass->last_added_dialogue) |
| 86 | ass->last_added_dialogue = next; |
| 87 | av_free(dialogue->line); |
| 88 | av_free(dialogue); |
| 89 | if (next) |
| 90 | next->prev = NULL; |
| 91 | dialogue = ass->dialogue_cache = next; |
| 92 | ass->expected_readorder++; |
| 93 | n++; |
| 94 | } |
| 95 | ass->cache_size -= n; |
| 96 | if (n > 1) |
| 97 | av_log(s, AV_LOG_DEBUG, "wrote %d ASS lines, cached dialogues: %d, waiting for event id %d\n", |
| 98 | n, ass->cache_size, ass->expected_readorder); |
| 99 | } |
| 100 | |
| 101 | static void insert_dialogue(ASSContext *ass, DialogueLine *dialogue) |
| 102 | { |
| 103 | DialogueLine *cur, *next = NULL, *prev = NULL; |
| 104 | |
| 105 | /* from the last added to the end of the list */ |
| 106 | if (ass->last_added_dialogue) { |
| 107 | for (cur = ass->last_added_dialogue; cur; cur = cur->next) { |
| 108 | if (cur->readorder > dialogue->readorder) |
| 109 | break; |
| 110 | prev = cur; |
| 111 | next = cur->next; |
| 112 | } |
| 113 | } |
| 114 | |
| 115 | /* from the beginning to the last one added */ |
| 116 | if (!prev) { |
| 117 | next = ass->dialogue_cache; |
| 118 | for (cur = next; cur != ass->last_added_dialogue; cur = cur->next) { |
| 119 | if (cur->readorder > dialogue->readorder) |
| 120 | break; |
| 121 | prev = cur; |
| 122 | next = cur->next; |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | if (prev) { |
| 127 | prev->next = dialogue; |
| 128 | dialogue->prev = prev; |
| 129 | } else { |
| 130 | dialogue->prev = ass->dialogue_cache; |
| 131 | ass->dialogue_cache = dialogue; |
| 132 | } |
| 133 | if (next) { |
| 134 | next->prev = dialogue; |
| 135 | dialogue->next = next; |
| 136 | } |
| 137 | ass->cache_size++; |
| 138 | ass->last_added_dialogue = dialogue; |
| 139 | } |
| 140 | |
| 141 | static int write_packet(AVFormatContext *s, AVPacket *pkt) |
| 142 | { |
| 143 | ASSContext *ass = s->priv_data; |
| 144 | |
| 145 | if (ass->write_ts) { |
| 146 | long int layer; |
| 147 | char *p = pkt->data; |
| 148 | int64_t start = pkt->pts; |
| 149 | int64_t end = start + pkt->duration; |
| 150 | int hh1, mm1, ss1, ms1; |
| 151 | int hh2, mm2, ss2, ms2; |
| 152 | DialogueLine *dialogue = av_mallocz(sizeof(*dialogue)); |
| 153 | |
| 154 | if (!dialogue) |
| 155 | return AVERROR(ENOMEM); |
| 156 | |
| 157 | dialogue->readorder = strtol(p, &p, 10); |
| 158 | if (dialogue->readorder < ass->expected_readorder) |
| 159 | av_log(s, AV_LOG_WARNING, "Unexpected ReadOrder %d\n", |
| 160 | dialogue->readorder); |
| 161 | if (*p == ',') |
| 162 | p++; |
| 163 | |
| 164 | if (ass->ssa_mode && !strncmp(p, "Marked=", 7)) |
| 165 | p += 7; |
| 166 | |
| 167 | layer = strtol(p, &p, 10); |
| 168 | if (*p == ',') |
| 169 | p++; |
| 170 | hh1 = (int)(start / 360000); mm1 = (int)(start / 6000) % 60; |
| 171 | hh2 = (int)(end / 360000); mm2 = (int)(end / 6000) % 60; |
| 172 | ss1 = (int)(start / 100) % 60; ms1 = (int)(start % 100); |
| 173 | ss2 = (int)(end / 100) % 60; ms2 = (int)(end % 100); |
| 174 | if (hh1 > 9) hh1 = 9, mm1 = 59, ss1 = 59, ms1 = 99; |
| 175 | if (hh2 > 9) hh2 = 9, mm2 = 59, ss2 = 59, ms2 = 99; |
| 176 | |
| 177 | dialogue->line = av_asprintf("%s%ld,%d:%02d:%02d.%02d,%d:%02d:%02d.%02d,%s", |
| 178 | ass->ssa_mode ? "Marked=" : "", |
| 179 | layer, hh1, mm1, ss1, ms1, hh2, mm2, ss2, ms2, p); |
| 180 | if (!dialogue->line) { |
| 181 | av_free(dialogue); |
| 182 | return AVERROR(ENOMEM); |
| 183 | } |
| 184 | insert_dialogue(ass, dialogue); |
| 185 | purge_dialogues(s, ass->ignore_readorder); |
| 186 | } else { |
| 187 | avio_write(s->pb, pkt->data, pkt->size); |
| 188 | } |
| 189 | |
| 190 | return 0; |
| 191 | } |
| 192 | |
| 193 | static int write_trailer(AVFormatContext *s) |
| 194 | { |
| 195 | purge_dialogues(s, 1); |
| 196 | return 0; |
| 197 | } |
| 198 | |
| 199 | #define OFFSET(x) offsetof(ASSContext, x) |
| 200 | #define E AV_OPT_FLAG_ENCODING_PARAM |
| 201 | static const AVOption options[] = { |
| 202 | { "ignore_readorder", "write events immediately, even if they're out-of-order", OFFSET(ignore_readorder), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, E }, |
| 203 | { NULL }, |
| 204 | }; |
| 205 | |
| 206 | static const AVClass ass_class = { |
| 207 | .class_name = "ass muxer", |
| 208 | .item_name = av_default_item_name, |
| 209 | .option = options, |
| 210 | .version = LIBAVUTIL_VERSION_INT, |
| 211 | }; |
| 212 | |
| 213 | AVOutputFormat ff_ass_muxer = { |
| 214 | .name = "ass", |
| 215 | .long_name = NULL_IF_CONFIG_SMALL("SSA (SubStation Alpha) subtitle"), |
| 216 | .mime_type = "text/x-ssa", |
| 217 | .extensions = "ass,ssa", |
| 218 | .priv_data_size = sizeof(ASSContext), |
| 219 | .subtitle_codec = AV_CODEC_ID_SSA, |
| 220 | .write_header = write_header, |
| 221 | .write_packet = write_packet, |
| 222 | .write_trailer = write_trailer, |
| 223 | .flags = AVFMT_GLOBALHEADER | AVFMT_NOTIMESTAMPS | AVFMT_TS_NONSTRICT, |
| 224 | .priv_class = &ass_class, |
| 225 | }; |