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
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
|
/* decssasub.c
Copyright (c) 2003-2018 HandBrake Team
This file is part of the HandBrake source code
Homepage: <http://handbrake.fr/>.
It may be used under the terms of the GNU General Public License v2.
For full terms see the file COPYING file or visit http://www.gnu.org/licenses/gpl-2.0.html
*/
/*
* Converts SSA subtitles to either:
* (1) TEXTSUB format: UTF-8 subtitles with limited HTML-style markup (<b>, <i>, <u>), or
* (2) PICTURESUB format, using libass.
*
* SSA format references:
* http://www.matroska.org/technical/specs/subtitles/ssa.html
* http://moodub.free.fr/video/ass-specs.doc
* vlc-1.0.4/modules/codec/subtitles/subsass.c:ParseSSAString
*
* libass references:
* libass-0.9.9/ass.h
* vlc-1.0.4/modules/codec/libass.c
*
* @author David Foster (davidfstr)
*/
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include "hb.h"
#include <ass/ass.h>
#include "decssasub.h"
#include "colormap.h"
struct hb_work_private_s
{
// If decoding to PICTURESUB format:
int readOrder;
hb_job_t *job;
};
#define SSA_VERBOSE_PACKETS 0
static int ssa_update_style(char *ssa, hb_subtitle_style_t *style)
{
int pos, end, index;
if (ssa[0] != '{')
return 0;
pos = 1;
while (ssa[pos] != '}' && ssa[pos] != '\0')
{
index = -1;
// Skip any malformed markup junk
while (strchr("\\}", ssa[pos]) == NULL) pos++;
pos++;
// Check for an index that is in some markup (e.g. font color)
if (isdigit(ssa[pos]))
{
index = ssa[pos++] - 0x30;
}
// Find the end of this markup clause
end = pos;
while (strchr("\\}", ssa[end]) == NULL) end++;
// Handle simple integer valued attributes
if (strchr("ibu", ssa[pos]) != NULL && isdigit(ssa[pos+1]))
{
int val = strtol(ssa + pos + 1, NULL, 0);
switch (ssa[pos])
{
case 'i':
style->flags = (style->flags & ~HB_STYLE_FLAG_ITALIC) |
!!val * HB_STYLE_FLAG_ITALIC;
break;
case 'b':
style->flags = (style->flags & ~HB_STYLE_FLAG_BOLD) |
!!val * HB_STYLE_FLAG_BOLD;
break;
case 'u':
style->flags = (style->flags & ~HB_STYLE_FLAG_UNDERLINE) |
!!val * HB_STYLE_FLAG_UNDERLINE;
break;
}
}
if (ssa[pos] == 'c' && ssa[pos+1] == '&' && ssa[pos+2] == 'H')
{
// Font color markup
char *endptr;
uint32_t bgr;
bgr = strtol(ssa + pos + 3, &endptr, 16);
if (*endptr == '&')
{
switch (index)
{
case -1:
case 1:
style->fg_rgb = HB_BGR_TO_RGB(bgr);
break;
case 2:
style->alt_rgb = HB_BGR_TO_RGB(bgr);
break;
case 3:
style->ol_rgb = HB_BGR_TO_RGB(bgr);
break;
case 4:
style->bg_rgb = HB_BGR_TO_RGB(bgr);
break;
default:
// Unknown color index, ignore
break;
}
}
}
if ((ssa[pos] == 'a' && ssa[pos+1] == '&' && ssa[pos+2] == 'H') ||
(!strcmp(ssa+pos, "alpha") && ssa[pos+5] == '&' && ssa[pos+6] == 'H'))
{
// Font alpha markup
char *endptr;
uint8_t alpha;
int alpha_pos = 3;
if (ssa[1] == 'l')
alpha_pos = 7;
alpha = strtol(ssa + pos + alpha_pos, &endptr, 16);
if (*endptr == '&')
{
// SSA alpha is inverted 0 is opaque
alpha = 255 - alpha;
switch (index)
{
case -1:
case 1:
style->fg_alpha = alpha;
break;
case 2:
style->alt_alpha = alpha;
break;
case 3:
style->ol_alpha = alpha;
break;
case 4:
style->bg_alpha = alpha;
break;
default:
// Unknown alpha index, ignore
break;
}
}
}
pos = end;
}
if (ssa[pos] == '}')
pos++;
return pos;
}
char * hb_ssa_to_text(char *in, int *consumed, hb_subtitle_style_t *style)
{
int markup_len = 0;
int in_pos = 0;
int out_pos = 0;
char *out = malloc(strlen(in) + 1); // out will never be longer than in
for (in_pos = 0; in[in_pos] != '\0'; in_pos++)
{
if ((markup_len = ssa_update_style(in + in_pos, style)))
{
*consumed = in_pos + markup_len;
out[out_pos++] = '\0';
return out;
}
// Check escape codes
if (in[in_pos] == '\\')
{
in_pos++;
switch (in[in_pos])
{
case '\0':
in_pos--;
break;
case 'N':
case 'n':
out[out_pos++] = '\n';
break;
case 'h':
out[out_pos++] = ' ';
break;
default:
out[out_pos++] = in[in_pos];
break;
}
}
else
{
out[out_pos++] = in[in_pos];
}
}
*consumed = in_pos;
out[out_pos++] = '\0';
return out;
}
void hb_ssa_style_init(hb_subtitle_style_t *style)
{
style->flags = 0;
style->fg_rgb = 0x00FFFFFF;
style->alt_rgb = 0x00FFFFFF;
style->ol_rgb = 0x000F0F0F;
style->bg_rgb = 0x000F0F0F;
style->fg_alpha = 0xFF;
style->alt_alpha = 0xFF;
style->ol_alpha = 0xFF;
style->bg_alpha = 0xFF;
}
static int decssaInit( hb_work_object_t * w, hb_job_t * job )
{
hb_work_private_t * pv;
pv = calloc( 1, sizeof( hb_work_private_t ) );
w->private_data = pv;
pv->job = job;
return 0;
}
static int decssaWork( hb_work_object_t * w, hb_buffer_t ** buf_in,
hb_buffer_t ** buf_out )
{
hb_buffer_t * in = *buf_in;
#if SSA_VERBOSE_PACKETS
printf("\nPACKET(%"PRId64",%"PRId64"): %.*s\n", in->s.start/90, in->s.stop/90, in->size, in->data);
#endif
*buf_in = NULL;
*buf_out = in;
if (in->s.flags & HB_BUF_FLAG_EOF)
{
return HB_WORK_DONE;
}
// Not much to do here. ffmpeg already supplies SSA subtitles in the
// requried matroska packet format.
//
// We require string termination of the buffer
hb_buffer_realloc(in, ++in->size);
in->data[in->size - 1] = '\0';
return HB_WORK_OK;
}
static void decssaClose( hb_work_object_t * w )
{
free( w->private_data );
}
hb_work_object_t hb_decssasub =
{
WORK_DECSSASUB,
"SSA Subtitle Decoder",
decssaInit,
decssaWork,
decssaClose
};
|
