3 * Copyright (c) 2008 Michael Niedermayer
5 * This file is part of FFmpeg.
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.
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.
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
22 #include "libavutil/avstring.h"
26 #include "libavutil/opt.h"
28 typedef struct DialogueLine {
31 struct DialogueLine *prev, *next;
34 typedef struct ASSContext{
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;
45 static int write_header(AVFormatContext *s)
47 ASSContext *ass = s->priv_data;
48 AVCodecContext *avctx= s->streams[0]->codec;
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);
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");
71 static void purge_dialogues(AVFormatContext *s, int force)
74 ASSContext *ass = s->priv_data;
75 DialogueLine *dialogue = ass->dialogue_cache;
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;
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_freep(&dialogue->line);
91 dialogue = ass->dialogue_cache = next;
92 ass->expected_readorder++;
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);
101 static void insert_dialogue(ASSContext *ass, DialogueLine *dialogue)
103 DialogueLine *cur, *next = NULL, *prev = NULL;
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)
115 /* from the beginning to the last one added */
117 next = ass->dialogue_cache;
118 for (cur = next; cur != ass->last_added_dialogue; cur = cur->next) {
119 if (cur->readorder > dialogue->readorder)
127 prev->next = dialogue;
128 dialogue->prev = prev;
130 dialogue->prev = ass->dialogue_cache;
131 ass->dialogue_cache = dialogue;
134 next->prev = dialogue;
135 dialogue->next = next;
138 ass->last_added_dialogue = dialogue;
141 static int write_packet(AVFormatContext *s, AVPacket *pkt)
143 ASSContext *ass = s->priv_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));
155 return AVERROR(ENOMEM);
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);
164 if (ass->ssa_mode && !strncmp(p, "Marked=", 7))
167 layer = strtol(p, &p, 10);
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;
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) {
182 return AVERROR(ENOMEM);
184 insert_dialogue(ass, dialogue);
185 purge_dialogues(s, ass->ignore_readorder);
187 avio_write(s->pb, pkt->data, pkt->size);
193 static int write_trailer(AVFormatContext *s)
195 purge_dialogues(s, 1);
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 },
206 static const AVClass ass_class = {
207 .class_name = "ass muxer",
208 .item_name = av_default_item_name,
210 .version = LIBAVUTIL_VERSION_INT,
213 AVOutputFormat ff_ass_muxer = {
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,