blob: 34f0f0d5e66d4b2626ea8d03742be84d423a8f7e
1 | /* |
2 | * SubRip subtitle encoder |
3 | * Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.org> |
4 | * |
5 | * This file is part of FFmpeg. |
6 | * |
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. |
11 | * |
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. |
16 | * |
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 |
20 | */ |
21 | |
22 | #include <stdarg.h> |
23 | #include "avcodec.h" |
24 | #include "libavutil/avstring.h" |
25 | #include "libavutil/bprint.h" |
26 | #include "ass_split.h" |
27 | #include "ass.h" |
28 | |
29 | |
30 | #define SRT_STACK_SIZE 64 |
31 | |
32 | typedef struct { |
33 | AVCodecContext *avctx; |
34 | ASSSplitContext *ass_ctx; |
35 | AVBPrint buffer; |
36 | char stack[SRT_STACK_SIZE]; |
37 | int stack_ptr; |
38 | int alignment_applied; |
39 | } SRTContext; |
40 | |
41 | |
42 | #ifdef __GNUC__ |
43 | __attribute__ ((__format__ (__printf__, 2, 3))) |
44 | #endif |
45 | static void srt_print(SRTContext *s, const char *str, ...) |
46 | { |
47 | va_list vargs; |
48 | va_start(vargs, str); |
49 | av_vbprintf(&s->buffer, str, vargs); |
50 | va_end(vargs); |
51 | } |
52 | |
53 | static int srt_stack_push(SRTContext *s, const char c) |
54 | { |
55 | if (s->stack_ptr >= SRT_STACK_SIZE) |
56 | return -1; |
57 | s->stack[s->stack_ptr++] = c; |
58 | return 0; |
59 | } |
60 | |
61 | static char srt_stack_pop(SRTContext *s) |
62 | { |
63 | if (s->stack_ptr <= 0) |
64 | return 0; |
65 | return s->stack[--s->stack_ptr]; |
66 | } |
67 | |
68 | static int srt_stack_find(SRTContext *s, const char c) |
69 | { |
70 | int i; |
71 | for (i = s->stack_ptr-1; i >= 0; i--) |
72 | if (s->stack[i] == c) |
73 | break; |
74 | return i; |
75 | } |
76 | |
77 | static void srt_close_tag(SRTContext *s, char tag) |
78 | { |
79 | srt_print(s, "</%c%s>", tag, tag == 'f' ? "ont" : ""); |
80 | } |
81 | |
82 | static void srt_stack_push_pop(SRTContext *s, const char c, int close) |
83 | { |
84 | if (close) { |
85 | int i = c ? srt_stack_find(s, c) : 0; |
86 | if (i < 0) |
87 | return; |
88 | while (s->stack_ptr != i) |
89 | srt_close_tag(s, srt_stack_pop(s)); |
90 | } else if (srt_stack_push(s, c) < 0) |
91 | av_log(s->avctx, AV_LOG_ERROR, "tag stack overflow\n"); |
92 | } |
93 | |
94 | static void srt_style_apply(SRTContext *s, const char *style) |
95 | { |
96 | ASSStyle *st = ff_ass_style_get(s->ass_ctx, style); |
97 | if (st) { |
98 | int c = st->primary_color & 0xFFFFFF; |
99 | if (st->font_name && strcmp(st->font_name, ASS_DEFAULT_FONT) || |
100 | st->font_size != ASS_DEFAULT_FONT_SIZE || |
101 | c != ASS_DEFAULT_COLOR) { |
102 | srt_print(s, "<font"); |
103 | if (st->font_name && strcmp(st->font_name, ASS_DEFAULT_FONT)) |
104 | srt_print(s, " face=\"%s\"", st->font_name); |
105 | if (st->font_size != ASS_DEFAULT_FONT_SIZE) |
106 | srt_print(s, " size=\"%d\"", st->font_size); |
107 | if (c != ASS_DEFAULT_COLOR) |
108 | srt_print(s, " color=\"#%06x\"", |
109 | (c & 0xFF0000) >> 16 | c & 0xFF00 | (c & 0xFF) << 16); |
110 | srt_print(s, ">"); |
111 | srt_stack_push(s, 'f'); |
112 | } |
113 | if (st->bold != ASS_DEFAULT_BOLD) { |
114 | srt_print(s, "<b>"); |
115 | srt_stack_push(s, 'b'); |
116 | } |
117 | if (st->italic != ASS_DEFAULT_ITALIC) { |
118 | srt_print(s, "<i>"); |
119 | srt_stack_push(s, 'i'); |
120 | } |
121 | if (st->underline != ASS_DEFAULT_UNDERLINE) { |
122 | srt_print(s, "<u>"); |
123 | srt_stack_push(s, 'u'); |
124 | } |
125 | if (st->alignment != ASS_DEFAULT_ALIGNMENT) { |
126 | srt_print(s, "{\\an%d}", st->alignment); |
127 | s->alignment_applied = 1; |
128 | } |
129 | } |
130 | } |
131 | |
132 | |
133 | static av_cold int srt_encode_init(AVCodecContext *avctx) |
134 | { |
135 | SRTContext *s = avctx->priv_data; |
136 | s->avctx = avctx; |
137 | s->ass_ctx = ff_ass_split(avctx->subtitle_header); |
138 | av_bprint_init(&s->buffer, 0, AV_BPRINT_SIZE_UNLIMITED); |
139 | return s->ass_ctx ? 0 : AVERROR_INVALIDDATA; |
140 | } |
141 | |
142 | static void srt_text_cb(void *priv, const char *text, int len) |
143 | { |
144 | SRTContext *s = priv; |
145 | av_bprint_append_data(&s->buffer, text, len); |
146 | } |
147 | |
148 | static void srt_new_line_cb(void *priv, int forced) |
149 | { |
150 | srt_print(priv, "\r\n"); |
151 | } |
152 | |
153 | static void srt_style_cb(void *priv, char style, int close) |
154 | { |
155 | srt_stack_push_pop(priv, style, close); |
156 | if (!close) |
157 | srt_print(priv, "<%c>", style); |
158 | } |
159 | |
160 | static void srt_color_cb(void *priv, unsigned int color, unsigned int color_id) |
161 | { |
162 | if (color_id > 1) |
163 | return; |
164 | srt_stack_push_pop(priv, 'f', color == 0xFFFFFFFF); |
165 | if (color != 0xFFFFFFFF) |
166 | srt_print(priv, "<font color=\"#%06x\">", |
167 | (color & 0xFF0000) >> 16 | color & 0xFF00 | (color & 0xFF) << 16); |
168 | } |
169 | |
170 | static void srt_font_name_cb(void *priv, const char *name) |
171 | { |
172 | srt_stack_push_pop(priv, 'f', !name); |
173 | if (name) |
174 | srt_print(priv, "<font face=\"%s\">", name); |
175 | } |
176 | |
177 | static void srt_font_size_cb(void *priv, int size) |
178 | { |
179 | srt_stack_push_pop(priv, 'f', size < 0); |
180 | if (size >= 0) |
181 | srt_print(priv, "<font size=\"%d\">", size); |
182 | } |
183 | |
184 | static void srt_alignment_cb(void *priv, int alignment) |
185 | { |
186 | SRTContext *s = priv; |
187 | if (!s->alignment_applied && alignment >= 0) { |
188 | srt_print(s, "{\\an%d}", alignment); |
189 | s->alignment_applied = 1; |
190 | } |
191 | } |
192 | |
193 | static void srt_cancel_overrides_cb(void *priv, const char *style) |
194 | { |
195 | srt_stack_push_pop(priv, 0, 1); |
196 | srt_style_apply(priv, style); |
197 | } |
198 | |
199 | static void srt_move_cb(void *priv, int x1, int y1, int x2, int y2, |
200 | int t1, int t2) |
201 | { |
202 | // TODO: add a AV_PKT_DATA_SUBTITLE_POSITION side data when a new subtitles |
203 | // encoding API passing the AVPacket is available. |
204 | } |
205 | |
206 | static void srt_end_cb(void *priv) |
207 | { |
208 | srt_stack_push_pop(priv, 0, 1); |
209 | } |
210 | |
211 | static const ASSCodesCallbacks srt_callbacks = { |
212 | .text = srt_text_cb, |
213 | .new_line = srt_new_line_cb, |
214 | .style = srt_style_cb, |
215 | .color = srt_color_cb, |
216 | .font_name = srt_font_name_cb, |
217 | .font_size = srt_font_size_cb, |
218 | .alignment = srt_alignment_cb, |
219 | .cancel_overrides = srt_cancel_overrides_cb, |
220 | .move = srt_move_cb, |
221 | .end = srt_end_cb, |
222 | }; |
223 | |
224 | static const ASSCodesCallbacks text_callbacks = { |
225 | .text = srt_text_cb, |
226 | .new_line = srt_new_line_cb, |
227 | }; |
228 | |
229 | static int encode_frame(AVCodecContext *avctx, |
230 | unsigned char *buf, int bufsize, const AVSubtitle *sub, |
231 | const ASSCodesCallbacks *cb) |
232 | { |
233 | SRTContext *s = avctx->priv_data; |
234 | ASSDialog *dialog; |
235 | int i; |
236 | |
237 | av_bprint_clear(&s->buffer); |
238 | |
239 | for (i=0; i<sub->num_rects; i++) { |
240 | const char *ass = sub->rects[i]->ass; |
241 | |
242 | if (sub->rects[i]->type != SUBTITLE_ASS) { |
243 | av_log(avctx, AV_LOG_ERROR, "Only SUBTITLE_ASS type supported.\n"); |
244 | return AVERROR(ENOSYS); |
245 | } |
246 | |
247 | #if FF_API_ASS_TIMING |
248 | if (!strncmp(ass, "Dialogue: ", 10)) { |
249 | int num; |
250 | dialog = ff_ass_split_dialog(s->ass_ctx, ass, 0, &num); |
251 | for (; dialog && num--; dialog++) { |
252 | s->alignment_applied = 0; |
253 | if (avctx->codec_id == AV_CODEC_ID_SUBRIP) |
254 | srt_style_apply(s, dialog->style); |
255 | ff_ass_split_override_codes(cb, s, dialog->text); |
256 | } |
257 | } else { |
258 | #endif |
259 | dialog = ff_ass_split_dialog2(s->ass_ctx, ass); |
260 | if (!dialog) |
261 | return AVERROR(ENOMEM); |
262 | s->alignment_applied = 0; |
263 | if (avctx->codec_id == AV_CODEC_ID_SUBRIP) |
264 | srt_style_apply(s, dialog->style); |
265 | ff_ass_split_override_codes(cb, s, dialog->text); |
266 | ff_ass_free_dialog(&dialog); |
267 | #if FF_API_ASS_TIMING |
268 | } |
269 | #endif |
270 | } |
271 | |
272 | if (!av_bprint_is_complete(&s->buffer)) |
273 | return AVERROR(ENOMEM); |
274 | if (!s->buffer.len) |
275 | return 0; |
276 | |
277 | if (s->buffer.len > bufsize) { |
278 | av_log(avctx, AV_LOG_ERROR, "Buffer too small for ASS event.\n"); |
279 | return -1; |
280 | } |
281 | memcpy(buf, s->buffer.str, s->buffer.len); |
282 | |
283 | return s->buffer.len; |
284 | } |
285 | |
286 | static int srt_encode_frame(AVCodecContext *avctx, |
287 | unsigned char *buf, int bufsize, const AVSubtitle *sub) |
288 | { |
289 | return encode_frame(avctx, buf, bufsize, sub, &srt_callbacks); |
290 | } |
291 | |
292 | static int text_encode_frame(AVCodecContext *avctx, |
293 | unsigned char *buf, int bufsize, const AVSubtitle *sub) |
294 | { |
295 | return encode_frame(avctx, buf, bufsize, sub, &text_callbacks); |
296 | } |
297 | |
298 | static int srt_encode_close(AVCodecContext *avctx) |
299 | { |
300 | SRTContext *s = avctx->priv_data; |
301 | ff_ass_split_free(s->ass_ctx); |
302 | av_bprint_finalize(&s->buffer, NULL); |
303 | return 0; |
304 | } |
305 | |
306 | #if CONFIG_SRT_ENCODER |
307 | /* deprecated encoder */ |
308 | AVCodec ff_srt_encoder = { |
309 | .name = "srt", |
310 | .long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"), |
311 | .type = AVMEDIA_TYPE_SUBTITLE, |
312 | .id = AV_CODEC_ID_SUBRIP, |
313 | .priv_data_size = sizeof(SRTContext), |
314 | .init = srt_encode_init, |
315 | .encode_sub = srt_encode_frame, |
316 | .close = srt_encode_close, |
317 | }; |
318 | #endif |
319 | |
320 | #if CONFIG_SUBRIP_ENCODER |
321 | AVCodec ff_subrip_encoder = { |
322 | .name = "subrip", |
323 | .long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"), |
324 | .type = AVMEDIA_TYPE_SUBTITLE, |
325 | .id = AV_CODEC_ID_SUBRIP, |
326 | .priv_data_size = sizeof(SRTContext), |
327 | .init = srt_encode_init, |
328 | .encode_sub = srt_encode_frame, |
329 | .close = srt_encode_close, |
330 | }; |
331 | #endif |
332 | |
333 | #if CONFIG_TEXT_ENCODER |
334 | AVCodec ff_text_encoder = { |
335 | .name = "text", |
336 | .long_name = NULL_IF_CONFIG_SMALL("Raw text subtitle"), |
337 | .type = AVMEDIA_TYPE_SUBTITLE, |
338 | .id = AV_CODEC_ID_TEXT, |
339 | .priv_data_size = sizeof(SRTContext), |
340 | .init = srt_encode_init, |
341 | .encode_sub = text_encode_frame, |
342 | .close = srt_encode_close, |
343 | }; |
344 | #endif |
345 |