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 typedef struct DialogueLine {
29 struct DialogueLine *prev, *next;
32 typedef struct ASSContext{
33 int write_ts; // 0: ssa (timing in payload), 1: ass (matroska like)
34 int expected_readorder;
35 DialogueLine *dialogue_cache;
36 DialogueLine *last_added_dialogue;
41 static int write_header(AVFormatContext *s)
43 ASSContext *ass = s->priv_data;
44 AVCodecContext *avctx= s->streams[0]->codec;
46 if (s->nb_streams != 1 || (avctx->codec_id != AV_CODEC_ID_SSA &&
47 avctx->codec_id != AV_CODEC_ID_ASS)) {
48 av_log(s, AV_LOG_ERROR, "Exactly one ASS/SSA stream is needed.\n");
49 return AVERROR(EINVAL);
51 ass->write_ts = avctx->codec_id == AV_CODEC_ID_ASS;
52 avpriv_set_pts_info(s->streams[0], 64, 1, 100);
53 if (avctx->extradata_size > 0) {
54 avio_write(s->pb, avctx->extradata, avctx->extradata_size);
55 if (avctx->extradata[avctx->extradata_size - 1] != '\n')
56 avio_write(s->pb, "\r\n", 2);
57 ass->ssa_mode = !strstr(avctx->extradata, "\n[V4+ Styles]");
58 if (!strstr(avctx->extradata, "\n[Events]"))
59 avio_printf(s->pb, "[Events]\r\nFormat: %s, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text\r\n",
60 ass->ssa_mode ? "Marked" : "Layer");
67 static void purge_dialogues(AVFormatContext *s, int force)
70 ASSContext *ass = s->priv_data;
71 DialogueLine *dialogue = ass->dialogue_cache;
73 while (dialogue && (dialogue->readorder == ass->expected_readorder || force)) {
74 DialogueLine *next = dialogue->next;
75 if (dialogue->readorder != ass->expected_readorder) {
76 av_log(s, AV_LOG_WARNING, "ReadOrder gap found between %d and %d\n",
77 ass->expected_readorder, dialogue->readorder);
78 ass->expected_readorder = dialogue->readorder;
80 avio_printf(s->pb, "Dialogue: %s\r\n", dialogue->line);
81 if (dialogue == ass->last_added_dialogue)
82 ass->last_added_dialogue = next;
83 av_free(dialogue->line);
87 dialogue = ass->dialogue_cache = next;
88 ass->expected_readorder++;
93 av_log(s, AV_LOG_DEBUG, "wrote %d ASS lines, cached dialogues: %d, waiting for event id %d\n",
94 n, ass->cache_size, ass->expected_readorder);
97 static void insert_dialogue(ASSContext *ass, DialogueLine *dialogue)
99 DialogueLine *cur, *next = NULL, *prev = NULL;
101 /* from the last added to the end of the list */
102 if (ass->last_added_dialogue) {
103 for (cur = ass->last_added_dialogue; cur; cur = cur->next) {
104 if (cur->readorder > dialogue->readorder)
111 /* from the beginning to the last one added */
113 next = ass->dialogue_cache;
114 for (cur = next; cur != ass->last_added_dialogue; cur = cur->next) {
115 if (cur->readorder > dialogue->readorder)
123 prev->next = dialogue;
124 dialogue->prev = prev;
126 dialogue->prev = ass->dialogue_cache;
127 ass->dialogue_cache = dialogue;
130 next->prev = dialogue;
131 dialogue->next = next;
134 ass->last_added_dialogue = dialogue;
137 static int write_packet(AVFormatContext *s, AVPacket *pkt)
139 ASSContext *ass = s->priv_data;
144 int64_t start = pkt->pts;
145 int64_t end = start + pkt->duration;
146 int hh1, mm1, ss1, ms1;
147 int hh2, mm2, ss2, ms2;
148 DialogueLine *dialogue = av_mallocz(sizeof(*dialogue));
151 return AVERROR(ENOMEM);
153 dialogue->readorder = strtol(p, &p, 10);
154 if (dialogue->readorder < ass->expected_readorder)
155 av_log(s, AV_LOG_WARNING, "Unexpected ReadOrder %d\n",
156 dialogue->readorder);
160 if (ass->ssa_mode && !strncmp(p, "Marked=", 7))
163 layer = strtol(p, &p, 10);
166 hh1 = (int)(start / 360000); mm1 = (int)(start / 6000) % 60;
167 hh2 = (int)(end / 360000); mm2 = (int)(end / 6000) % 60;
168 ss1 = (int)(start / 100) % 60; ms1 = (int)(start % 100);
169 ss2 = (int)(end / 100) % 60; ms2 = (int)(end % 100);
170 if (hh1 > 9) hh1 = 9, mm1 = 59, ss1 = 59, ms1 = 99;
171 if (hh2 > 9) hh2 = 9, mm2 = 59, ss2 = 59, ms2 = 99;
173 dialogue->line = av_asprintf("%s%ld,%d:%02d:%02d.%02d,%d:%02d:%02d.%02d,%s",
174 ass->ssa_mode ? "Marked=" : "",
175 layer, hh1, mm1, ss1, ms1, hh2, mm2, ss2, ms2, p);
176 if (!dialogue->line) {
178 return AVERROR(ENOMEM);
180 insert_dialogue(ass, dialogue);
181 purge_dialogues(s, 0);
183 avio_write(s->pb, pkt->data, pkt->size);
189 static int write_trailer(AVFormatContext *s)
191 purge_dialogues(s, 1);
195 AVOutputFormat ff_ass_muxer = {
197 .long_name = NULL_IF_CONFIG_SMALL("SSA (SubStation Alpha) subtitle"),
198 .mime_type = "text/x-ssa",
199 .extensions = "ass,ssa",
200 .priv_data_size = sizeof(ASSContext),
201 .subtitle_codec = AV_CODEC_ID_SSA,
202 .write_header = write_header,
203 .write_packet = write_packet,
204 .write_trailer = write_trailer,
205 .flags = AVFMT_GLOBALHEADER | AVFMT_NOTIMESTAMPS | AVFMT_TS_NONSTRICT,