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;
40 static int write_header(AVFormatContext *s)
42 ASSContext *ass = s->priv_data;
43 AVCodecContext *avctx= s->streams[0]->codec;
45 if (s->nb_streams != 1 || (avctx->codec_id != AV_CODEC_ID_SSA &&
46 avctx->codec_id != AV_CODEC_ID_ASS)) {
47 av_log(s, AV_LOG_ERROR, "Exactly one ASS/SSA stream is needed.\n");
48 return AVERROR(EINVAL);
50 ass->write_ts = avctx->codec_id == AV_CODEC_ID_ASS;
51 avpriv_set_pts_info(s->streams[0], 64, 1, 100);
52 if (avctx->extradata_size > 0) {
53 avio_write(s->pb, avctx->extradata, avctx->extradata_size);
54 if (avctx->extradata[avctx->extradata_size - 1] != '\n')
55 avio_write(s->pb, "\r\n", 2);
57 if (!strstr(avctx->extradata, "\n[Events]"))
58 avio_printf(s->pb, "[Events]\r\nFormat: Layer, Start, End, Style, Actor, MarginL, MarginR, MarginV, Effect, Text\r\n");
64 static void purge_dialogues(AVFormatContext *s, int force)
67 ASSContext *ass = s->priv_data;
68 DialogueLine *dialogue = ass->dialogue_cache;
70 while (dialogue && (dialogue->readorder == ass->expected_readorder || force)) {
71 DialogueLine *next = dialogue->next;
72 if (dialogue->readorder != ass->expected_readorder) {
73 av_log(s, AV_LOG_WARNING, "ReadOrder gap found between %d and %d\n",
74 ass->expected_readorder, dialogue->readorder);
75 ass->expected_readorder = dialogue->readorder;
77 avio_printf(s->pb, "Dialogue: %s\r\n", dialogue->line);
78 if (dialogue == ass->last_added_dialogue)
79 ass->last_added_dialogue = next;
80 av_free(dialogue->line);
84 dialogue = ass->dialogue_cache = next;
85 ass->expected_readorder++;
90 av_log(s, AV_LOG_DEBUG, "wrote %d ASS lines, cached dialogues: %d, waiting for event id %d\n",
91 n, ass->cache_size, ass->expected_readorder);
94 static void insert_dialogue(ASSContext *ass, DialogueLine *dialogue)
96 DialogueLine *cur, *next = NULL, *prev = NULL;
98 /* from the last added to the end of the list */
99 if (ass->last_added_dialogue) {
100 for (cur = ass->last_added_dialogue; cur; cur = cur->next) {
101 if (cur->readorder > dialogue->readorder)
108 /* from the beginning to the last one added */
110 next = ass->dialogue_cache;
111 for (cur = next; cur != ass->last_added_dialogue; cur = cur->next) {
112 if (cur->readorder > dialogue->readorder)
120 prev->next = dialogue;
121 dialogue->prev = prev;
123 dialogue->prev = ass->dialogue_cache;
124 ass->dialogue_cache = dialogue;
127 next->prev = dialogue;
128 dialogue->next = next;
131 ass->last_added_dialogue = dialogue;
134 static int write_packet(AVFormatContext *s, AVPacket *pkt)
136 ASSContext *ass = s->priv_data;
141 int64_t start = pkt->pts;
142 int64_t end = start + pkt->duration;
143 int hh1, mm1, ss1, ms1;
144 int hh2, mm2, ss2, ms2;
145 DialogueLine *dialogue = av_mallocz(sizeof(*dialogue));
148 return AVERROR(ENOMEM);
150 dialogue->readorder = strtol(p, &p, 10);
151 if (dialogue->readorder < ass->expected_readorder)
152 av_log(s, AV_LOG_WARNING, "Unexpected ReadOrder %d\n",
153 dialogue->readorder);
157 layer = strtol(p, &p, 10);
160 hh1 = (int)(start / 360000); mm1 = (int)(start / 6000) % 60;
161 hh2 = (int)(end / 360000); mm2 = (int)(end / 6000) % 60;
162 ss1 = (int)(start / 100) % 60; ms1 = (int)(start % 100);
163 ss2 = (int)(end / 100) % 60; ms2 = (int)(end % 100);
164 if (hh1 > 9) hh1 = 9, mm1 = 59, ss1 = 59, ms1 = 99;
165 if (hh2 > 9) hh2 = 9, mm2 = 59, ss2 = 59, ms2 = 99;
167 dialogue->line = av_asprintf("%ld,%d:%02d:%02d.%02d,%d:%02d:%02d.%02d,%s",
168 layer, hh1, mm1, ss1, ms1, hh2, mm2, ss2, ms2, p);
169 if (!dialogue->line) {
171 return AVERROR(ENOMEM);
173 insert_dialogue(ass, dialogue);
174 purge_dialogues(s, 0);
176 avio_write(s->pb, pkt->data, pkt->size);
182 static int write_trailer(AVFormatContext *s)
184 purge_dialogues(s, 1);
188 AVOutputFormat ff_ass_muxer = {
190 .long_name = NULL_IF_CONFIG_SMALL("SSA (SubStation Alpha) subtitle"),
191 .mime_type = "text/x-ssa",
192 .extensions = "ass,ssa",
193 .priv_data_size = sizeof(ASSContext),
194 .subtitle_codec = AV_CODEC_ID_SSA,
195 .write_header = write_header,
196 .write_packet = write_packet,
197 .write_trailer = write_trailer,
198 .flags = AVFMT_GLOBALHEADER | AVFMT_NOTIMESTAMPS | AVFMT_TS_NONSTRICT,