1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
|
/*
* TTML subtitle encoder
* Copyright (c) 2020 24i
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* TTML subtitle encoder
* @see https://www.w3.org/TR/ttml1/
* @see https://www.w3.org/TR/ttml2/
* @see https://www.w3.org/TR/ttml-imsc/rec
*/
#include "avcodec.h"
#include "internal.h"
#include "libavutil/avstring.h"
#include "libavutil/bprint.h"
#include "libavutil/internal.h"
#include "ass_split.h"
#include "ass.h"
#include "ttmlenc.h"
typedef struct {
AVCodecContext *avctx;
ASSSplitContext *ass_ctx;
AVBPrint buffer;
} TTMLContext;
static void ttml_text_cb(void *priv, const char *text, int len)
{
TTMLContext *s = priv;
AVBPrint cur_line = { 0 };
AVBPrint *buffer = &s->buffer;
av_bprint_init(&cur_line, len, AV_BPRINT_SIZE_UNLIMITED);
av_bprint_append_data(&cur_line, text, len);
if (!av_bprint_is_complete(&cur_line)) {
av_log(s->avctx, AV_LOG_ERROR,
"Failed to move the current subtitle dialog to AVBPrint!\n");
av_bprint_finalize(&cur_line, NULL);
return;
}
av_bprint_escape(buffer, cur_line.str, NULL, AV_ESCAPE_MODE_XML,
0);
av_bprint_finalize(&cur_line, NULL);
}
static void ttml_new_line_cb(void *priv, int forced)
{
TTMLContext *s = priv;
av_bprintf(&s->buffer, "<br/>");
}
static const ASSCodesCallbacks ttml_callbacks = {
.text = ttml_text_cb,
.new_line = ttml_new_line_cb,
};
static int ttml_encode_frame(AVCodecContext *avctx, uint8_t *buf,
int bufsize, const AVSubtitle *sub)
{
TTMLContext *s = avctx->priv_data;
ASSDialog *dialog;
int i;
av_bprint_clear(&s->buffer);
for (i=0; i<sub->num_rects; i++) {
const char *ass = sub->rects[i]->ass;
if (sub->rects[i]->type != SUBTITLE_ASS) {
av_log(avctx, AV_LOG_ERROR, "Only SUBTITLE_ASS type supported.\n");
return AVERROR(EINVAL);
}
#if FF_API_ASS_TIMING
if (!strncmp(ass, "Dialogue: ", 10)) {
int num;
dialog = ff_ass_split_dialog(s->ass_ctx, ass, 0, &num);
for (; dialog && num--; dialog++) {
int ret = ff_ass_split_override_codes(&ttml_callbacks, s,
dialog->text);
int log_level = (ret != AVERROR_INVALIDDATA ||
avctx->err_recognition & AV_EF_EXPLODE) ?
AV_LOG_ERROR : AV_LOG_WARNING;
if (ret < 0) {
av_log(avctx, log_level,
"Splitting received ASS dialog failed: %s\n",
av_err2str(ret));
if (log_level == AV_LOG_ERROR)
return ret;
}
}
} else {
#endif
dialog = ff_ass_split_dialog2(s->ass_ctx, ass);
if (!dialog)
return AVERROR(ENOMEM);
{
int ret = ff_ass_split_override_codes(&ttml_callbacks, s,
dialog->text);
int log_level = (ret != AVERROR_INVALIDDATA ||
avctx->err_recognition & AV_EF_EXPLODE) ?
AV_LOG_ERROR : AV_LOG_WARNING;
if (ret < 0) {
av_log(avctx, log_level,
"Splitting received ASS dialog text %s failed: %s\n",
dialog->text,
av_err2str(ret));
if (log_level == AV_LOG_ERROR) {
ff_ass_free_dialog(&dialog);
return ret;
}
}
ff_ass_free_dialog(&dialog);
}
#if FF_API_ASS_TIMING
}
#endif
}
if (!av_bprint_is_complete(&s->buffer))
return AVERROR(ENOMEM);
if (!s->buffer.len)
return 0;
// force null-termination, so in case our destination buffer is
// too small, the return value is larger than bufsize minus null.
if (av_strlcpy(buf, s->buffer.str, bufsize) > bufsize - 1) {
av_log(avctx, AV_LOG_ERROR, "Buffer too small for TTML event.\n");
return AVERROR_BUFFER_TOO_SMALL;
}
return s->buffer.len;
}
static av_cold int ttml_encode_close(AVCodecContext *avctx)
{
TTMLContext *s = avctx->priv_data;
ff_ass_split_free(s->ass_ctx);
av_bprint_finalize(&s->buffer, NULL);
return 0;
}
static av_cold int ttml_encode_init(AVCodecContext *avctx)
{
TTMLContext *s = avctx->priv_data;
s->avctx = avctx;
if (!(s->ass_ctx = ff_ass_split(avctx->subtitle_header))) {
return AVERROR_INVALIDDATA;
}
if (!(avctx->extradata = av_mallocz(TTMLENC_EXTRADATA_SIGNATURE_SIZE +
1 + AV_INPUT_BUFFER_PADDING_SIZE))) {
return AVERROR(ENOMEM);
}
avctx->extradata_size = TTMLENC_EXTRADATA_SIGNATURE_SIZE;
memcpy(avctx->extradata, TTMLENC_EXTRADATA_SIGNATURE,
TTMLENC_EXTRADATA_SIGNATURE_SIZE);
av_bprint_init(&s->buffer, 0, AV_BPRINT_SIZE_UNLIMITED);
return 0;
}
AVCodec ff_ttml_encoder = {
.name = "ttml",
.long_name = NULL_IF_CONFIG_SMALL("TTML subtitle"),
.type = AVMEDIA_TYPE_SUBTITLE,
.id = AV_CODEC_ID_TTML,
.priv_data_size = sizeof(TTMLContext),
.init = ttml_encode_init,
.encode_sub = ttml_encode_frame,
.close = ttml_encode_close,
.capabilities = FF_CODEC_CAP_INIT_CLEANUP,
};
|
